livescience--2020-10-15--What if all humans on Earth had albinism?

The series `` Imaginary Earths '' speculates what the world might be like if one key aspect of life changed , be it related to the planet or with humanity itself .
What might Earth be like if it had rings , or if everyone could photosynthesize like plants ?
Albinism , from the Latin `` albus , '' meaning `` white , '' is a group of hereditary conditions with striking results — a dearth and often complete absence of pigment in the eyes , and hair .
In the United States , about 1 in every 18,000 to @ @ @ @ @ @ @ the National Organization for Albinism and Hypopigmentation ( NOAH ) .
Meanwhile , in parts of Africa such as areas within Zimbabwe , as many as 1 in 1,000 have albinism , according to the United Nations .
What might the world be like if everyone on Earth had albinism , from prehistoric times until now ?
The most common form of albinism in the United States is oculocutaneous albinism , which interferes with the production of the dark pigment melanin in both the eyes and skin , according to NOAH .
To @ @ @ @ @ @ @ of this kind of albinism , which doctors have named OCA1 to OCA7 , NOAH noted .
Depending on the subtype , people may have white , blond or brown hair .
`` I have OCA1 , the most severe type of oculocutaneous albinism — I have no pigment in my hair , skin and eyes , '' Kelsey Thompson , a rehabilitation counselor in the Chicago area , told Live Science .
She previously served for 10 years on the board of directors of NOAH , including as its chair .
Related @ @ @ @ @ @ @ human body A common myth is that people with albinism have red eyes .
Although lighting conditions can make the blood vessels at the back of the eye visible , which can result in the eyes looking red or violet , most people with albinism have blue eyes , and some have hazel or brown eyes , NOAH noted .
Thompson 's eyes are light blue .
One key concern for people with albinism is the delicacy of fair skin .
Melanin , a pigment found in hair and skin , protects skin @ @ @ @ @ @ @ have to be wary of sunburns and skin cancer .
`` When I was younger , I was a little cocky about sun exposure , and got severe sunburns , '' Thompson said .
`` Throughout my life , I 've gotten in the habit of being more cautious and mindful about the sun , using sunscreen and seeking out shade as often as I can . ''
So if everyone had albinism , what would happen ?
One scientist interviewed for this story thought this factor alone made it extremely unlikely that @ @ @ @ @ @ @ .
`` That 's disappointing , but not surprising , '' Thompson said .
`` I think a lot of people who do n't have the experience of living with albinism see it as they would any disability — what a horrible fate to have , how it would be so awful to not do even daily tasks without struggle .
But it 's not a death sentence . ''
If everyone had albinism , people around the world might adopt long garments to protect their skin , like desert peoples in , @ @ @ @ @ @ @ protect their heads and faces .
They might also rely on protective coatings on their skin to serve as sunscreens .
The women of the Himba people in Namibia regularly wear an orange or red paste known as otjize that is made of butterfat and ochre , and often perfumed with the aromatic resin of the omuzumba shrub .
Although Himba women use otjize for aesthetic reasons , I can imagine a population with albinism could conceivably create a similar paste to serve as sunscreen .
In addition , `` I can imagine @ @ @ @ @ @ @ activities outside the peak hours of sunlight — more in the early morning and late afternoon , '' Thompson said .
Those with albinism might prefer to make their homes in shady environments and less sunny latitudes — think Norway , not Arizona .
`` I still enjoy going out to the beach with my family , '' Thompson said .
But `` I do think there are parts of the world that would just be inhospitably sunny for people to even consider living there if everyone had albinism , like certain parts @ @ @ @ @ @ @ .
Still , I do know people with albinism living in Southern California and loving it . ''
People with albinism have vision problems because structures within rely on melanin as they develop in the womb .
`` My best visual acuity is 20/200 , making me legally blind , '' Thompson said .
`` I have full color vision , but the details I can see are poor .
It 's not that things look blurry , but it 's like the difference between a high-definition TV and a TV from the @ @ @ @ @ @ @ have photophobia , or be more sensitive to glare from light . ''
Related : What if humans had visual acuity ?
These vision problems might lead one to expect that preindustrial societies in a hypothetical past where everyone had albinism would have extraordinary difficulty surviving .
`` However , there 's a lot of variation in vision in albinism , in what you can do , '' Thompson said .
`` I have to use certain accommodations for my vision every day , but I can function pretty independently .
With albinism @ @ @ @ @ @ @ we have n't lost anything with vision — this is all we 've ever known .
To me , this is normal . ''
For instance , `` I know people with albinism who are skilled hunters , '' Thompson said .
`` I 've been involved with albinism organizations my whole life , and every time I think there 's a task or job that there 's no way a person with albinism can do it , sure enough , there 's someone doing it . ''
So , if the entire @ @ @ @ @ @ @ use canes , seeing-eye animals and perhaps even to help navigate the world .
Still , there are people with albinism with enough functional vision to drive , Thompson noted .
`` My younger brother has the same type of albinism as me , and when we sit in the optometrist 's office , his vision tests pretty similarly , '' Thompson said .
`` But he adapted to it .
He was even a hockey goalie .
He did n't watch for the puck , but looked at the players to tell @ @ @ @ @ @ @ . ''
People with albinism with low vision may rely on magnifying glasses and handheld telescopes to help read , `` or just hold newsprint closer to the face , '' Thompson said .
`` But a lot of the times , we use these aids to accommodate to the sighted world .
If a world evolved only with people with albinism , I 'd imagine all print would be large print . ''
Thompson does think preindustrial societies with albinism would likely rely more on agriculture than on hunting .
Other possibilities @ @ @ @ @ @ @ or net , activities that do n't require keen eyesight .
People with albinism often face stigmatization worldwide because of how they look .
They are often villains in stories — for instance , the evil monk Silas in `` The Da Vinci Code , '' ( Doubleday , 2003 ) .
Dozens of people with albinism have even been murdered for their body parts in Tanzania , according to The New York Times and other sources .
`` Some people with albinism grow up in a very supportive environment and did n't @ @ @ @ @ @ @ others are pretty traumatized , '' Thompson said .
`` My experience was middle of the road — not too terrible , but I did experience a lot of bullying as a kid .
As an adult , it 's more of a little annoyance .
I get rude and invasive questions , and people wanting to touch my hair .
It 's really inappropriate behavior , and people normally would n't dream of crossing those boundaries with a total stranger , but when you have a visible difference like albinism , it @ @ @ @ @ @ @ course , in a world where everyone has albinism , there would almost certainly be no stigma attached to it .
Instead , albinism might be viewed as a feature that sets humanity apart and above the rest of nature , along with language and tool use .
`` It would be interesting to think about how perception of race might change if everyone had albinism , '' Thompson said .
`` A friend of mine from India has the same type of albinism I do , and she and I look more @ @ @ @ @ @ @ even though we come from two very different ethnic backgrounds. ''
.
All in all , she suggests that if everyone had albinism , “ that might really change what judgments we make about each other in terms of appearance.
” Albinism might influence societies other ways .
`` When I 'm talking with a group of people who all have albinism , we do things a little differently than when functioning in the regular world , '' Thompson said .
`` When we see someone you know , I introduce myself almost @ @ @ @ @ @ @ 'Hey , Matt , it 's Kelsey ' — because we know the other person does n't see so well .
And maybe we stand a little bit closer to each other because of our poor eyesight . ''
Such greetings and adjustments to people 's personal bubble of space might become standard features of society in a world where everyone had albinism , Thompson said .
In addition , `` there 's a lot of nonverbal communication that people with low vision have to be taught , like making eye contact , @ @ @ @ @ @ @ nystagmus , so my eyes shake a little bit , and I have trouble seeing a person 's eyes , so I was taught how to make eye contact , and think about things like not staring non-stop .
Those are the kinds of things I 've learned to assimilate to the sighted world . ''
So , if albinism was the default , the norm of making eye contact might not be a norm anymore .
`` This is a really unusual mental experiment , '' Thompson said .
`` It 's @ @ @ @ @ @ @ , and how that would change how that would think about the world and about myself . ''
Follow Charles Q. Choi on Twitter @ cqchoi .
Follow us on Twitter @ LiveScience and on Facebook .

The series "Imaginary Earths" speculates what the world might be like if one key aspect of life changed, be it related to the planet or with humanity itself. What might Earth be like if it had rings, or if everyone could photosynthesize like plants?
Albinism, from the Latin "albus," meaning "white," is a group of hereditary conditions with striking results — a dearth and often complete absence of pigment in the eyes, skin and hair.
In the United States, about 1 in every 18,000 to 20,000 people have albinism, according to the National Organization for Albinism and Hypopigmentation (NOAH) . Meanwhile, in parts of Africa such as areas within Zimbabwe, as many as 1 in 1,000 have albinism, according to the United Nations .
What might the world be like if everyone on Earth had albinism, from prehistoric times until now?
A range of appearances
The most common form of albinism in the United States is oculocutaneous albinism, which interferes with the production of the dark pigment melanin in both the eyes and skin, according to NOAH. To date, there are seven known subtypes of this kind of albinism, which doctors have named OCA1 to OCA7, NOAH noted. Depending on the subtype, people may have white, blond or brown hair.
"I have OCA1, the most severe type of oculocutaneous albinism — I have no pigment in my hair, skin and eyes," Kelsey Thompson, a rehabilitation counselor in the Chicago area, told Live Science. She previously served for 10 years on the board of directors of NOAH, including as its chair.
Related: The 7 biggest mysteries of the human body
A common myth is that people with albinism have red eyes. Although lighting conditions can make the blood vessels at the back of the eye visible, which can result in the eyes looking red or violet, most people with albinism have blue eyes, and some have hazel or brown eyes, NOAH noted. Thompson's eyes are light blue.
Fair skin
One key concern for people with albinism is the delicacy of fair skin. Melanin, a pigment found in hair and skin, protects skin against ultraviolet light, and people with albinism have to be wary of sunburns and skin cancer.
"When I was younger, I was a little cocky about sun exposure, and got severe sunburns," Thompson said. "Throughout my life, I've gotten in the habit of being more cautious and mindful about the sun, using sunscreen and seeking out shade as often as I can."
Related: 5 facts about skin cancer
It would be interesting to think about how perception of race might change if everyone had albinism. Kelsey Thompson
So if everyone had albinism, what would happen? One scientist interviewed for this story thought this factor alone made it extremely unlikely that populations with albinism would survive over time.
"That's disappointing, but not surprising," Thompson said. "I think a lot of people who don't have the experience of living with albinism see it as they would any disability — what a horrible fate to have, how it would be so awful to not do even daily tasks without struggle. But it's not a death sentence."
If everyone had albinism, people around the world might adopt long garments to protect their skin, like desert peoples in the Sahara , and hats, scarves or veils to protect their heads and faces. They might also rely on protective coatings on their skin to serve as sunscreens. The women of the Himba people in Namibia regularly wear an orange or red paste known as otjize that is made of butterfat and ochre, and often perfumed with the aromatic resin of the omuzumba shrub. Although Himba women use otjize for aesthetic reasons, I can imagine a population with albinism could conceivably create a similar paste to serve as sunscreen.
In addition, "I can imagine cultures probably evolving to do more daily activities outside the peak hours of sunlight — more in the early morning and late afternoon," Thompson said.
Those with albinism might prefer to make their homes in shady environments and less sunny latitudes — think Norway, not Arizona. "I still enjoy going out to the beach with my family," Thompson said. But "I do think there are parts of the world that would just be inhospitably sunny for people to even consider living there if everyone had albinism, like certain parts of the Middle East and American Southwest. Still, I do know people with albinism living in Southern California and loving it."
(Image credit: Drazen_ via Getty Images)
Vision problems
People with albinism have vision problems because structures within the eye rely on melanin as they develop in the womb. "My best visual acuity is 20/200, making me legally blind," Thompson said. "I have full color vision, but the details I can see are poor. It's not that things look blurry, but it's like the difference between a high-definition TV and a TV from the '80s. People with albinism can also have photophobia, or be more sensitive to glare from light."
Related: What if humans had visual acuity?
These vision problems might lead one to expect that preindustrial societies in a hypothetical past where everyone had albinism would have extraordinary difficulty surviving. "However, there's a lot of variation in vision in albinism, in what you can do," Thompson said. "I have to use certain accommodations for my vision every day, but I can function pretty independently. With albinism, an advantage we have is that we haven't lost anything with vision — this is all we've ever known. To me, this is normal."
For instance, "I know people with albinism who are skilled hunters," Thompson said. "I've been involved with albinism organizations my whole life, and every time I think there's a task or job that there's no way a person with albinism can do it, sure enough, there's someone doing it."
So, if the entire human population had albinism, we might use canes, seeing-eye animals and perhaps even echolocation to help navigate the world. Still, there are people with albinism with enough functional vision to drive, Thompson noted.
"My younger brother has the same type of albinism as me, and when we sit in the optometrist's office, his vision tests pretty similarly," Thompson said. "But he adapted to it. He was even a hockey goalie. He didn't watch for the puck, but looked at the players to tell when the puck was coming toward him."
People with albinism with low vision may rely on magnifying glasses and handheld telescopes to help read, "or just hold newsprint closer to the face," Thompson said. "But a lot of the times, we use these aids to accommodate to the sighted world. If a world evolved only with people with albinism, I'd imagine all print would be large print."
Thompson does think preindustrial societies with albinism would likely rely more on agriculture than on hunting. Other possibilities include trapping and fishing with a pole or net, activities that don't require keen eyesight.
Social impact
People with albinism often face stigmatization worldwide because of how they look. They are often villains in stories — for instance, the evil monk Silas in "The Da Vinci Code," (Doubleday, 2003). Dozens of people with albinism have even been murdered for their body parts in Tanzania, according to The New York Times and other sources.
"Some people with albinism grow up in a very supportive environment and didn't face a lot of negativity, whereas others are pretty traumatized," Thompson said. "My experience was middle of the road — not too terrible, but I did experience a lot of bullying as a kid. As an adult, it's more of a little annoyance. I get rude and invasive questions, and people wanting to touch my hair. It's really inappropriate behavior, and people normally wouldn't dream of crossing those boundaries with a total stranger, but when you have a visible difference like albinism, it comes with the territory."
Of course, in a world where everyone has albinism, there would almost certainly be no stigma attached to it. Instead, albinism might be viewed as a feature that sets humanity apart and above the rest of nature, along with language and tool use.
Related: The top 10 stigmatized health disorders
"It would be interesting to think about how perception of race might change if everyone had albinism," Thompson said. "A friend of mine from India has the same type of albinism I do, and she and I look more alike than my brother and I, even though we come from two very different ethnic backgrounds.". All in all, she suggests that if everyone had albinism, “that might really change what judgments we make about each other in terms of appearance.”
Albinism might influence societies other ways. "When I'm talking with a group of people who all have albinism, we do things a little differently than when functioning in the regular world," Thompson said. "When we see someone you know, I introduce myself almost like I'm on the telephone — 'Hey, Matt, it's Kelsey' — because we know the other person doesn't see so well. And maybe we stand a little bit closer to each other because of our poor eyesight."
Such greetings and adjustments to people's personal bubble of space might become standard features of society in a world where everyone had albinism, Thompson said.
In addition, "there's a lot of nonverbal communication that people with low vision have to be taught, like making eye contact," Thompson said. "I have nystagmus, so my eyes shake a little bit, and I have trouble seeing a person's eyes, so I was taught how to make eye contact, and think about things like not staring non-stop. Those are the kinds of things I've learned to assimilate to the sighted world."
So, if albinism was the default, the norm of making eye contact might not be a norm anymore.
"This is a really unusual mental experiment," Thompson said. "It's challenging thinking about albinism as a norm, and how that would change how that would think about the world and about myself."
Follow Charles Q. Choi on Twitter @cqchoi. Follow us on Twitter @LiveScience and on Facebook.


livescience--2020-10-15--2 big pieces of space junk could collide tonight

Earth orbit could get a lot more crowded , and a lot more dangerous , on tonight ( Oct. 15 ) .
Two big pieces of are zooming toward a close approach that will occur Thursday at 8:56 p.m. EDT ( 0056 GMT on Oct. 16 ) , according to California-based tracking company LeoLabs .
The encounter will take place 616 miles ( 991 kilometers ) above the South Atlantic Ocean , just off the coast of Antarctica .
LeoLabs ' latest calculations peg the probability of a collision at — a scarily high number , considering that the combined @ @ @ @ @ @ @ lbs .
( 2,800 kilograms ) and they 'll be barreling toward each other at a relatively velocity of 32,900 mph ( 52,950 km/h ) .
`` This event continues to be very high risk and will likely stay this way through the time of closest approach , '' ( Oct. 14 ) .
Also on Twitter , Jonathan McDowell , an astronomer and satellite tracker based at the Harvard-Smithsonian Center for Astrophysics , as a defunct Soviet navigation satellite called Parus ( or Kosmos 2004 ) and a Chinese rocket stage .
@ @ @ @ @ @ @ shortly after the close approach should reveal if a collision did in fact occur , LeoLabs said in another tweet .
And we should all keep our fingers crossed for a near miss ; a smashup would likely result in a `` significant ( 10 to 20 percent ) increase in the LEO debris environment , '' McDowell said in .
( `` LEO '' stands for `` low Earth orbit . ''
) Such a debris superspreader event would not be unprecedented .
In February 2009 , for example , the operational @ @ @ @ @ @ @ defunct Russian military satellite Kosmos 2251 .
The smashup generated by the following October , as well as many others too small to detect .
Humanity has also twice spawned big debris clouds on purpose — during anti-satellite tests in 2007 and 2019 conducted by and , respectively .
Such events , and Thursday night 's potential collision , highlight the growing threat that orbital debris poses to spaceflight and exploration .
The International Space Station has had to maneuver itself away from potential collisions three times in 2020 alone , for example @ @ @ @ @ @ @ and satellite development both continue to fall , Earth orbit will get more and more crowded , often with craft operated by relative neophytes .
The spaceflight community therefore needs to come up with debris-minimizing guidelines , and soon , .
Such guidelines could include a requirement that spent rocket bodies be deorbited shortly after launch , so they ca n't be involved in close encounters like the one that will occur Thursday night over the South Atlantic .
Mike Wall is the author of `` Out There '' ( Grand Central Publishing @ @ @ @ @ @ @ ) , a book about the search for alien life .
Follow him on Twitter @ michaeldwall .
Follow us on Twitter @ Spacedotcom or Facebook .

Still from a LeoLabs animation modeling a close approach between two big pieces of space junk on Thursday night (Oct. 15). The chance of a collision is higher than 10%, LeoLabs has calculated.
Earth orbit could get a lot more crowded, and a lot more dangerous, on tonight (Oct. 15).
Two big pieces of space junk are zooming toward a close approach that will occur Thursday at 8:56 p.m. EDT (0056 GMT on Oct. 16), according to California-based tracking company LeoLabs.
The encounter will take place 616 miles (991 kilometers) above the South Atlantic Ocean, just off the coast of Antarctica. LeoLabs' latest calculations peg the probability of a collision at more than 10% — a scarily high number, considering that the combined mass of the objects is about 6,170 lbs. (2,800 kilograms) and they'll be barreling toward each other at a relatively velocity of 32,900 mph (52,950 km/h).
Related: Space junk explained: The orbital debris threat (infographic)
2/ Current risk metrics from our most recent CDMs:Miss distance: 12 meters (+18/-12 meters)Probability of Collision: >10%, scaled to account for large object sizesRelative velocity: 14.7 km/s pic.twitter.com/y44QXyhHJKOctober 14, 2020 See more
"This event continues to be very high risk and will likely stay this way through the time of closest approach," LeoLabs tweeted today (Oct. 14).
Also on Twitter, Jonathan McDowell, an astronomer and satellite tracker based at the Harvard-Smithsonian Center for Astrophysics, identified the two objects as a defunct Soviet navigation satellite called Parus (or Kosmos 2004) and a Chinese rocket stage.
A "search-mode scan" scheduled for shortly after the close approach should reveal if a collision did in fact occur, LeoLabs said in another tweet. And we should all keep our fingers crossed for a near miss; a smashup would likely result in a "significant (10 to 20 percent) increase in the LEO debris environment," McDowell said in another tweet . ("LEO" stands for "low Earth orbit.")
Such a debris superspreader event would not be unprecedented. In February 2009, for example, the operational Iridium 33 communications satellite collided with the defunct Russian military satellite Kosmos 2251. The smashup generated 1,800 pieces of trackable debris by the following October, as well as many others too small to detect.
Humanity has also twice spawned big debris clouds on purpose — during anti-satellite tests in 2007 and 2019 conducted by China and India , respectively.
Such events, and Thursday night's potential collision, highlight the growing threat that orbital debris poses to spaceflight and exploration. The International Space Station has had to maneuver itself away from potential collisions three times in 2020 alone, for example. And as the costs of launch and satellite development both continue to fall, Earth orbit will get more and more crowded, often with craft operated by relative neophytes.
The spaceflight community therefore needs to come up with debris-minimizing guidelines, and soon, many experts say . Such guidelines could include a requirement that spent rocket bodies be deorbited shortly after launch, so they can't be involved in close encounters like the one that will occur Thursday night over the South Atlantic.
Mike Wall is the author of "Out There" (Grand Central Publishing, 2018; illustrated by Karl Tate), a book about the search for alien life. Follow him on Twitter @michaeldwall. Follow us on Twitter @Spacedotcom or Facebook.


livescience--2020-10-15--Coronavirus outbreak: Live updates

Coronavirus outbreak: Live updates

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90-year-old woman in the UK receives first dose of Pfizer vaccine, FDA review confirms vaccine is safe and effective A 90-year-old woman (who will turn 91 next week) became the first in the world to be given Pfizer's coronavirus vaccine outside of clinical trials, according to the BBC. Margaret Keenan, who is originally from Northern Ireland, was given the vaccine at the University Hospital in Coventry, England. She received the first of 800,000 doses expected to be administered in the U.K. in the coming weeks, according to the BBC. "I feel so privileged to be the first person vaccinated against Covid-19," Keenan said, according to the BBC."It's the best early birthday present I could wish for because it means I can finally look forward to spending time with my family and friends in the new year after being on my own for most of the year." "My advice to anyone offered the vaccine is to take it. If I can have it at 90, then you can have it too," she added. Up to four million doses of Pfizer's vaccine is expected to be given to people in the U.K. by the end of the month. Meanwhile, a 53-page Food and Drug Administration (FDA) review published Tuesday (Dec. 8) confirmed that Pfizer's vaccine is safe and effective, according to The Washington Post.
Pfizer's COVID-19 vaccine starts to work just 10 days after 1st dose Pfizer's new COVID-19 vaccine starts to protect people from the novel coronavirus just 10 days after the first dose, according to new documents from the U.S. Food and Drug Administration (FDA). The documents were released on Tuesday (Dec. 8), two days before a meeting of the FDA's vaccine advisory panel, which will vote on whether to recommend authorization of the vaccine in the U.S, Live Science reported . The FDA analyzed data from Pfizer's phase 3 clinical trial, which included some 44,000 people in the United States, Brazil, Argentina, Germany and Turkey, about half of whom received the vaccine while the other half received a placebo. Both groups received two shots, 21 days apart. About 10 days after the first dose, there was a noticeable drop-off in new COVID-19 cases in the vaccine group compared with the placebo group, indicating that even one dose provides some protection, the report said. However, scientists don't know how long the protection from a single dose will last, so it will still be important for people to receive two shots, according to The New York Times . Overall, the vaccine was 52% effective after the first dose and 95% effective after the second dose, the report said.
People with significant allergies should avoid Pfizer vaccine, UK warns The U.K.'s Regulatory Agency is advising people with a history of "significant" allergic reactions to avoid Pfizer's coronavirus vaccine, after two National Health Service members developed severe allergic reactions to it on Tuesday (Dec. 8), Live Science reported. "As is common with new vaccines the MHRA (Medicines and Healthcare products Regulatory Agency) have advised on a precautionary basis that people with a significant history of allergic reactions do not receive this vaccination after two people with a history of significant allergic reactions responded adversely yesterday," Stephen Powis, the national medical director for England's National Health Service said in a statement on Wednesday (Dec. 9). Both workers have a history of severe allergies and carry adrenaline auto injectors (such as EpiPens) around with them, according to The Guardian. Shortly after receiving the vaccine, both NHS workers developed anaphylaxis-like symptoms, or severe allergic reactions, but have recovered after receiving treatment. The MHRA will investigate further and Pfizer and BioNTech will support their investigation, according to Reuters. "Allergic reaction occurs with quite a number of vaccines, and perhaps even more frequently with drugs. So it is not unexpected," Stephen Evans, a professor of pharmacoepidemiology at the London School of Hygiene and Tropical Medicine said in remarks to journalists published by Britain's Science Media Center. “What would be wise, as the MHRA have already advised, would be for anyone who has known severe allergic reaction such that they need to carry an EpiPen, to delay having a vaccination until the reason for the allergic reaction has been clarified," he said. For the general population this does not mean that they would need to be anxious about receiving the vaccination, he added. "One has to remember that even things like marmite [a quintessential British food spread] can cause unexpected severe allergic reactions.”
Canada approves Pfizer's COVID-19 vaccine Canada has authorized Pfizer's new COVID-19 vaccine, with the first doses expected to be administered there as early as next week. Health Canada, the country's health regulatory agency, said in a statement on Wednesday (Dec. 9) that it had determined that the vaccine "meets the Department's stringent safety, efficacy and quality requirements for use in Canada," according to CTV News . "We expect vaccines to arrive maybe as early as Monday [Dec. 14]. It takes time to prepare the vaccine," said Maj.-Gen. Dany Fortin, the top military general leading the vaccine rollout for the Public Health Agency of Canada, according to CTV News. The first doses could be administered by the middle of next week, he said. Canada is the third country in the world to authorize the Pfizer vaccine, following the United Kingdom and Bahrain. The country should receive up to 249,000 doses of the vaccine by the end of December, and has purchased 20 million doses total, with the option to purchase more, CTV News reported.
Daily COVID-19 death toll in the U.S. reaches record-high, surpassed 9/11 On Wednesday (Dec. 9), the U.S. recorded 3,124 new COVID-19 deaths, the highest daily death toll to date, according to CNN . In comparison, 2,977 people were killed in the 9/11 attacks. The U.S. has now recorded 280,488 deaths related to the virus, according to The COVID Tracking Project . A forecast from the U.S. Centers for Disease Control and Prevention predicts that the total death toll can increase to between 332,000 and 362,000 by January 2, according to CNN. There are currently 106,671 people hospitalized with the virus in the U.S.; 20,903 of them are currently in the ICU and 7,621 are currently on a ventilator, according to the COVID Tracking Project. On Thursday (Dec. 10), the Vaccines and Related Biological Products Advisory Committee is set to meet to discuss an emergency use authorization for the Pfizer-BioNTech coronavirus vaccine.
FDA panel recommends authorization of Pfizer's COVID-19 vaccine A panel of experts for the Food and Drug Administration (FDA) has recommended that the agency authorize Pfizer's new COVID-19 vaccine in the United States. On Thursday (Dec. 10), the panel voted 17 to 4 to recommend that the vaccine receive emergency use authorization (EUA) for people ages 16 and older, according to The New York Times . The FDA typically follows the advice of its panels, and so today's vote is an important step towards the vaccine's authorization. It is anticipated that the agency will officially authorize the vaccine on Saturday (Dec. 12), the Times reported. Several countries have already authorized Pfizer's vaccine, including Canada, the United Kingdom and Bahrain.
Vaccine approval could come this weekend, as U.S. continues to record high daily death tolls On Thursday (Dec. 10), the U.S. recorded another 2,902 COVID-19 deaths, a day after the country set a record of 3,253 deaths, according to Reuters . “Probably for the next 60 to 90 days, we’re going to have more deaths per day than we had on 9/11 or we had at Pearl Harbor,” Dr. Robert Redfield, the director of the U.S. Centers for Disease Control and Prevention, told the Council on Foreign Relations on Thursday, according to Reuters. "The reality is the vaccine approval this week is not going to really impact that, I think, to any degree for the next 60 days." On Thursday, the Vaccines and Related Biological Products Advisory Committee discussed, voted and recommended that the Food and Drug Administration (FDA) should grant an emergency use authorization for Pfizer's coronavirus vaccine. The Pfizer vaccine has already been approved in the U.K. and in Canada, and FDA approval for use in the U.S. could come this weekend.
Australia abandons local COVID-19 vaccine after it caused false-positive HIV tests An Australian COVID-19 vaccine that had shown promising results in early trials is being abandoned after researchers found that the shot caused false-positive results on HIV tests. On Friday (Dec. 11), Australian officials said they had canceled an order for some 51 million doses of the vaccine, which was being developed by The University of Queensland and CSL Ltd., a local biotech company, according to The New York Times . In an early trial with 216 participants, the vaccine appeared to be safe and to produce a robust immune response against COVID-19, according to a statement from CSL . But some volunteers falsely tested positive for HIV, which officials feared would undermine trust in the vaccine, the Times reported. The vaccine contained small fragments of an HIV protein, which helped stabilize the vaccine. Some of the participants developed antibodies against these fragments, and these antibodies triggered false positive results on some HIV tests. It's important to note that there is no way for the vaccine to cause an HIV infection, because it contains harmless fragments of the virus.
ICU nurse in New York becomes first person in the US to receive a coronavirus vaccine outside of clinical trials New York, the worst-hit state at the start of the pandemic, just became the first to administer a coronavirus vaccine outside of clinical trials, kicking off a long, massive effort to vaccinate the American people, Live Science reported. Around 9 a.m. E.T. on Monday (Dec. 14), the very first dose of Pfizer and BioNTech's coronavirus vaccine was given to Sandra Lindsay, an intensive care nurse in Long Island Jewish Medical Center in Queens, New York, according to The New York Times. This comes as the U.S. continues to battle a massive wave of the virus that has more than 109,000 people currently hospitalized, according to The COVID Tracking Project. Since the start of the pandemic, New York has recorded more than 780,000 cases of COVID-19 and more than 35,100 deaths, according to The Times. "This vaccine is exciting because I believe this is the weapon that will end the war," Gov. Andrew Cuomo said during a live broadcast of the first vaccination. "It's the beginning of the last chapter of the book, but now we just have to do it."
FDA analysis confirms Moderna's vaccine is safe and effective, emergency authorization is likely to come Friday A new briefing document from the Food and Drug Administration (FDA) released on Tuesday (Dec. 15) confirmed that Moderna's COVID-19 vaccine is safe and effective, according to NPR . Moderna's COVID-19 vaccine is 94% effective and has "a favorable safety profile," according to the document. A panel of experts is set to meet on Thursday (Dec. 17) to discuss the effectiveness and safety of the vaccine and vote on whether or not the FDA should grant emergency approval to the vaccine. Last week, the same panel voted that the FDA should grant emergency approval to Pfizer's coronavirus vaccine; the authorization came a day late and the first doses were given on Monday (Dec. 15). The FDA will likely approve Moderna's vaccine for emergency use on Friday (Dec. 18), according to The New York Times .
FDA authorizes first over-the-counter COVID-19 test The U.S. Food and Drug Administration (FDA) has authorized the first over-the-counter COVID-19 test, which can be done at home and does not need a prescription. The test, made by the Australia-based company Ellume, provides results in as little as 20 minutes, according to a statement from the FDA . It is a "lateral flow antigen test," meaning it works in a similar way to a home pregnancy test, by running a "liquid sample along a surface with reactive molecules," the FDA said. The test works in conjunction with a smartphone app. Users take a nasal swab and place their sample in an analyzer, which communicates to the smartphone app via Bluetooth. The results are delivered through the app, and also reported to public health authorities (based on a user's zip code) through a secure cloud connection, the company said . Ellume is ramping up production of its test, and expects to produce three million tests in January 2021, and 20 million within the first half of 2021.
A wild mink tested positive for the coronavirus, it may be the first wild animal to have a confirmed case A wild mink in Utah may be the first "free-ranging, native wild animal" confirmed to be infected with SARS-CoV-2, according to the U.S. Department of Agriculture (USDA), Live Science reported. The mink was found near a mink farm and likely picked up the infection from the farmed mink. There's no evidence that the virus spread to other minks or wild animals; but if the virus does begin circulating in wild animals, it could pick up mutations that COVID-19 vaccines may not protect well against if it spreads back to humans, according to the report. "If it does [establish a reservoir], then we've got a long-term issue here, where this virus has the potential to be with us for millennia," Sarah Olson, associate director of the health program at the Wildlife Conservation Society, told Vox. The U.S. Department of Agriculture's Animal and Plant Health Inspection Service has screened other animal species for the virus near mink farms in Utah, Michigan and Wisconsin, but all of them have tested negative so far, according to a statement.
An FDA advisory panel will meet today to vote on whether to recommend Moderna's coronavirus vaccine for emergency approval On Thursday (Dec. 17), a Food and Drug Administration (FDA) advisory committee will meet to determine whether to recommend that Moderna’s coronavirus vaccine for emergency approval, according to The New York Times . This panel, composed of independent experts, will vote on whether to recommend the vaccine after hearing from the company, FDA scientists and the public, according to The Times. Last week, the same panel of experts met to discuss Pfizer’s coronavirus vaccine and voted to recommend emergency authorization; the authorization came the next day. There have now been more than 16.9 million cases of COVID-19 in the U.S. and more than 307,000 deaths, according to the Johns Hopkins dashboard . There are currently 113,090 people hospitalized across the country with more than 21,900 of them in the ICU and 7,778 on a ventilator, according to The COVID Tracking Project .
California becomes new epicenter of COVID-19 in U.S. California, once praised for its early pandemic response, is now the new U.S. hotspot for COVID-19 infections. The state has reported an alarming surge in cases, breaking previous records for daily cases. On Thursday (Dec. 17), the state reported some 50,000 COVID-19 infections in 24 hours, and nearly 100,000 in 48 hours, according to The Washington Post . That's more than the daily cases reported in many countries, including India, Germany and Britain, the Post reported. The state also set a record for daily deaths on Thursday, with 379 fatalities reported, up from the previous high of 293. Capacity in intensive care units has also dropped dramatically, with hospitals in Southern California reporting zero percent capacity on Thursday. "I want to be very clear: Our hospitals are under siege, and our model shows no end in sight," said Christina Ghaly, director of Los Angeles County's Department of Health Services, the Post reported.
FDA expected to authorize Moderna's vaccine on Friday The U.S. Food and Drug Administration is expected to authorize Moderna's COVID-19 vaccine on Friday (Dec. 18). Once authorized, it will be the second coronavirus vaccine to get the green light from the agency in just a week, with Pfizer's vaccine gaining authorization on Dec. 11. Moderna is expected to begin shipping 5.9 million doses of its vaccine on Sunday (Dec. 20), with the first deliveries arriving Monday (Dec. 21), according to The New York Times . Unlike the Pfizer vaccine, Moderna's vaccine does not require storage in extremely cold temperatures, and states are hoping to distribute the vaccine to rural hospitals and community health centers, the Times reported.
COVID-19 cases continue to surge across the U.S. There have now been more than 17 million cases of COVID-19 in the U.S. and more than 300,000 deaths, according to The COVID Tracking Project . There are currently 114,237 people hospitalized across the country and 21,900 people in the ICU. California is facing a massive surge in cases; the state reported 41,012 new COVID-19 cases and 300 new deaths on Thursday (Dec. 17), according to the state's COVID-19 dashboard . By comparison, at the start of November, California was reporting a seven-day average of 4,183 cases, compared to an average of 38,774 on Thursday, according to CNN . "We're experiencing an explosive and very deadly surge," Dr. Barbara Ferrer, Los Angeles County Public Health Director said, according to CNN. Intensive care unit beds are rapidly filling up across the state; there are only 1,234 ICU beds left available in California, according to the dashboard. Current closures across California are impacting around 98% of the state's population, according to CNN.
London and southeast England are under an emergency lockdown Following concerns of a new version of the coronavirus that might be more transmissible, London and most of southeast England are now under an emergency lockdown, according to The New York Times . Prime Minister Boris Johnson announced the lockdown on Saturday (Dec. 19) citing concerns that the mutated virus — which was detected a couple of weeks ago in southeast England — may be as much as 70% more transmissible than previous versions, according to the Times. The new version of the coronavirus is detected in more than 60% of new infections in London and have also been detected in several other countries, according to the Times. But it's not yet clear if this coronavirus version is any more infectious than the last and thorough analyses will need to be conducted before conclusions are made, scientists cautioned. In South Africa, a similar version of the virus has been found in up to 90% of new cases detected since mid-November, according to The Times . It's common for viruses to mutate, and this particular coronavirus has mutated many times since the start of the pandemic. But experts told The Times that it would take years for the virus to mutate enough such that it would make the current vaccines developed to fight COVID-19 ineffective.
Biden gets Pfizer's COVID-19 vaccine President-elect Joe Biden received a dose of Pfizer's new COVID-19 vaccine on Monday (Dec. 21), according to The New York Times . He received the shot on camera at the Christiana Hospital in Newark, Delaware. "I'm doing this to demonstrate that people should be prepared when it's available to take the vaccine. There's nothing to worry about," Biden said.
Antarctica has its 1st COVID-19 outbreak The first COVID-19 cases have been reported in Antarctica , meaning the disease has now spread to every continent in the world. On Tuesday (Dec. 22), Chilean officials reported an outbreak of 36 COVID-19 cases at the Chilean research base General Bernardo O'Higgins Riquelme on the Antarctic Peninsula, according to the BBC . Of these, 26 cases were military personnel and 10 were maintenance workers, the BBC reported. All of these cases have been evacuated from Antarctica to Punta Arenas, Chile, according to The Guardian . Antarctica had been COVID-19 free up until the current outbreak. The continent has no permanent residents, but about 1,000 people, including scientists and other workers, stayed there this past winter, The Guardian reported.
Live updates will continue in 2021!


What is RNA?

More than just DNA 's lesser-known cousin , RNA plays a central role in turning genetic information into your body 's proteins .
This remarkable molecule also carries the genetic instructions for many viruses , and it may have helped life get its start .
Together , RNA , short for ribonucleic acid , and , short for deoxyribonucleic acid , make up the nucleic acids , one of the three or four classes of major `` macromolecules '' considered crucial for life .
( The others are and lipids .
Many scientists also place in this group . )
@ @ @ @ @ @ @ consisting of repeating subunits .
RNA and DNA are made up of subunits called nucleotides .
The two nucleic acids team up to create proteins .
The process of creating proteins using the genetic information in nucleic acids is so important to life that biologists call it `` the central dogma '' of molecular biology .
The dogma , which describes the flow of genetic information in an organism , according to , says that DNA 's information gets written out , or `` transcribed , '' as RNA information , and RNA @ @ @ @ @ @ @ `` translated , '' into protein .
`` RNA in a basic way is the biomolecule that connects DNA and proteins , '' Chuan He , a University of Chicago biologist who studies RNA modifications , told Live Science .
The ability of RNA and DNA to store and copy information depends on the molecules ' repeating nucleotide subunits .
The nucleotides are organized in specific sequences , which can be read like letters in a word .
Each nucleotide has three major parts : a sugar molecule , a phosphate group and @ @ @ @ @ @ @ or base .
Sugars from different nucleotide units hook up via phosphate bridges to create the repeating polymer of an RNA or DNA molecule — like a necklace made of sugar beads linked together by phosphate strings .
The nucleobases attached to the sugars constitute the sequence information needed to build proteins , as described by the .
RNA and DNA each have a set of four bases : adenine , guanine , cytosine and thymine for DNA , with uracil swapping in for thymine in RNA .
The four bases make up @ @ @ @ @ @ @ such , are denoted as letters : A for adenine , G for guanine and so forth .
But RNA and DNA can do more than just encode `` letter '' sequences ; they can also copy them .
This works because the bases on one RNA or DNA string can stick to bases on another string , but only in a very specific way .
Bases link up only with : C to G and A to U in RNA ( or A to T in the case of DNA ) .
@ @ @ @ @ @ @ to transcribe an RNA molecule , which mirrors the DNA sequence — encoding a record of it .
A type of RNA called messenger RNA ( mRNA ) uses this copying function to ferry genetic data from DNA to the ribosomes , the protein-producing components of the cell , according to the .
Ribosomes `` read '' mRNA sequences to determine the order in which protein subunits ( amino acids ) should join a growing protein molecule .
Two other RNA species complete the process : Transfer RNA ( tRNA ) brings amino @ @ @ @ @ @ @ , while ribosomal RNA ( rRNA ) , which makes up the bulk of a ribosome , links the amino acids together .
Scientists consider RNA 's central dogma activities central to the molecule 's definition .
But ideas about what RNA is and what it can do have greatly expanded since the 1980s , when biologists Sidney Altman and Thomas R. Cech discovered that RNA can operate like a protein .
( The researchers won the for their discovery . )
Proteins are key components for most chemical reactions in the body @ @ @ @ @ @ @ part to the stunning variety of shapes , or conformations , these molecules can achieve .
( Enzymes are proteins that facilitate and catalyze chemical reactions . )
Unlike DNA , RNA can also shape-shift to an extent , and so can serve as an RNA-based enzyme , or ribozyme .
RNA 's greater flexibility over DNA comes in part from the extra oxygen on RNA 's ribose sugar , which makes the molecule less stable , biologist Merlin Crossley wrote in .
The `` deoxy '' in deoxyribose references DNA 's 1-oxygen @ @ @ @ @ @ @ important RNA-based catalytic activity happens in the ribosome , where rRNA , a ribozyme , mediates amino acid addition to growing proteins .
Other ribozymes include small nuclear RNAs ( snRNAs ) , which splice mRNA into usable forms , and , one of the first known ribozymes , which similarly clips bacterial tRNA .
In the last three decades , the number of known has blossomed , He said , as researchers discovered a menagerie of RNAs that do something completely different : regulate genes .
`` There 's a whole set @ @ @ @ @ @ @ , '' influencing which genes get expressed and at what rates , He said .
`` In recent years , few areas of biology have been transformed as thoroughly as RNA molecular biology , '' in large part due to the discovery of small regulatory RNAs , researchers wrote in a 2017 review published in the .
Most significant are short interfering RNAs ( siRNAs ) , microRNAs ( miRNAs ) , and piwi-interacting RNAs ( piRNAs ) , the authors wrote .
siRNAs and miRNAs `` silence '' genes by attaching to @ @ @ @ @ @ @ RNAs then activate complexes of proteins that can cut up the mRNA or block their translation , as described in a 2010 review published in the journal .
siRNAs target invasive genetic material , like viral DNA , while miRNAs regulate an organism 's own genes , according to a 2009 review published in the journal .
piRNAs perform similar silencing , but operate specifically in sex cells , targeting moveable bits of genetic material called `` transposable '' elements that can mutate genes , according to a 2014 review published in the @ @ @ @ @ @ @ the heftier long noncoding RNAs ( lncRNAs ) , which affect genes by associating with complexes of DNA and protein called chromatin , as described in a 2019 review in the journal .
lncRNA can function to activate or inactivate sections of chromatin , which packages DNA into a compact form in the cell , so that genes in that chromatin get expressed or inhibited .
Enhancer RNAs have the opposite effect to much of the above , increasing the expression of certain genes via not-yet-understood mechanisms , according to a 2020 review @ @ @ @ @ @ @ have popped up in other organisms .
For instance , bacteria host analogues to miRNA and siRNA called small RNA regulators ( sRNAs ) .
Parts of the gene-editing found in bacteria and archaea also rely on RNA , which binds to the so-called CRISPR DNA sequences that identify invaders .
RNA 's versatility in function and form helped inspire the idea known as the .
Organisms rely on an astoundingly complicated system of DNA , RNA and protein to transmit hereditary information , and scientists have long wondered how this system could @ @ @ @ @ @ @ offers a logical answer , He said : This molecule can both store genetic information and catalyze reactions , suggesting that early , simple organisms could have relied solely on RNA .
`` It 's a hybrid , '' He said .
`` So it makes perfect sense as a start . ''
Additionally , He said , RNA 's sugar base , ribose , always appears first in organisms , as it 's easier to make .
Deoxyribose then gets created from ribose .
`` So that implies in life , you @ @ @ @ @ @ @ , and then the DNA comes later , '' He said .
From that simpler RNA start , more-complex life could arise , evolving the stabler DNA to serve as a long-term library and developing protein as a more efficient catalyst .
Why RNA at all ?
In the path from DNA to protein , RNA essentially serves as a middle-man , so why not eliminate the RNA go-between and move directly from DNA to protein ?
Simple life-forms , like DNA viruses , do just that , He said .
Similarly , @ @ @ @ @ @ @ HIV , the common cold virus , influenza and COVID-19 — stash all their genetic info in RNA , with no DNA predecessor .
More-complicated organisms need to do a lot more genetic regulation , however , He said .
So , most of their genomes do n't code for proteins but code for parts of the genome that regulate other sequences .
, for instance , can turn genes on or off .
He said `` you do n't want to convert [ the human genome 's ] 3 billion base pairs @ @ @ @ @ @ @ resources on so many sequences that do n't code for needed human proteins `` would be a huge waste , '' he said .
RNA makes it possible to transcribe just the protein-coding bits of the genetic sequence into the mRNA intermediary .
Additionally , mRNA provides a handy method of fine-tuning a gene 's output .
`` RNA … is the DNA photocopy , '' said the , a nonprofit that facilitates sharing of RNA research .
`` When the cell needs to produce a certain protein , it … produces multiple @ @ @ @ @ @ @ the form of messenger RNA … Thus , RNA expands the quantity of a given protein that can be made at one time . ''
RNA 's amplification ability is , once again , due to the molecule 's flexibility .
Because RNA can fold into various shapes , it can churn out the mRNA and tRNA conformations needed to run that photocopier .
DNA ca n't do that .
Not only does RNA store the genetic info for many viruses , but it could also help scientists combat those same invaders .
@ @ @ @ @ @ @ to tell a person 's body to make antigens , the substances that trigger immune responses , biologist Alexis Hubaud wrote for .
`` That 's one of the most popular ways for developing anti-COVID-19 vaccines these days , '' He told Live Science .
COVID-19 vaccine candidates such as and Pfizer utilize this approach .
Other potential RNA therapeutic applications could use injected mRNA to tell the body to make a functioning protein in a patient who lacks the genes to encode that protein , such as in people with .
`` @ @ @ @ @ @ @ this is crazy — if you have a defect , I 'm just going to give you a healthy messenger RNA , '' He said .
But it 's now one of the most exciting areas of research , he added .
A June 2020 breakthrough also has RNA researchers excited , .
It showed that eliminating an RNA-binding protein could turn other cells into neurons , with major implications for diseases like , He said .
`` That 's also exciting because fundamentally it indicates RNA can have dramatic effects on cell @ @ @ @ @ @ @ Learn about RNA-editing alternatives to CRISPR on .
• Read how some researchers are challenging the RNA world hypothesis in .

More than just DNA's lesser-known cousin, RNA plays a central role in turning genetic information into your body's proteins. This remarkable molecule also carries the genetic instructions for many viruses, and it may have helped life get its start.
'Central Dogma'
Together, RNA, short for ribonucleic acid, and DNA , short for deoxyribonucleic acid, make up the nucleic acids, one of the three or four classes of major "macromolecules" considered crucial for life. (The others are proteins and lipids. Many scientists also place carbohydrates in this group.) Macromolecules are very large molecules, often consisting of repeating subunits. RNA and DNA are made up of subunits called nucleotides.
The two nucleic acids team up to create proteins. The process of creating proteins using the genetic information in nucleic acids is so important to life that biologists call it "the central dogma" of molecular biology. The dogma, which describes the flow of genetic information in an organism, according to Oregon State University , says that DNA's information gets written out, or "transcribed," as RNA information, and RNA's information gets written out, or "translated," into protein.
"RNA in a basic way is the biomolecule that connects DNA and proteins," Chuan He, a University of Chicago biologist who studies RNA modifications, told Live Science.
RNA alphabet
The ability of RNA and DNA to store and copy information depends on the molecules' repeating nucleotide subunits. The nucleotides are organized in specific sequences, which can be read like letters in a word.
Each nucleotide has three major parts: a sugar molecule, a phosphate group and a cyclic compound called a nucleobase, or base. Sugars from different nucleotide units hook up via phosphate bridges to create the repeating polymer of an RNA or DNA molecule — like a necklace made of sugar beads linked together by phosphate strings.
The nucleobases attached to the sugars constitute the sequence information needed to build proteins, as described by the National Human Genome Research Institute . RNA and DNA each have a set of four bases: adenine, guanine, cytosine and thymine for DNA, with uracil swapping in for thymine in RNA. The four bases make up the molecules' alphabets, and as such, are denoted as letters: A for adenine, G for guanine and so forth.
Related: How to speak genetics: A glossary
But RNA and DNA can do more than just encode "letter" sequences; they can also copy them. This works because the bases on one RNA or DNA string can stick to bases on another string, but only in a very specific way. Bases link up only with "complementary" partners : C to G and A to U in RNA (or A to T in the case of DNA). So, DNA serves as a template to transcribe an RNA molecule, which mirrors the DNA sequence — encoding a record of it.
A type of RNA called messenger RNA (mRNA) uses this copying function to ferry genetic data from DNA to the ribosomes, the protein-producing components of the cell, according to the University of Massachusetts . Ribosomes "read" mRNA sequences to determine the order in which protein subunits (amino acids) should join a growing protein molecule.
Two other RNA species complete the process: Transfer RNA (tRNA) brings amino acids specified by mRNA to the ribosomes, while ribosomal RNA (rRNA), which makes up the bulk of a ribosome, links the amino acids together.
RNA as an enzyme
Scientists consider RNA's central dogma activities central to the molecule's definition. But ideas about what RNA is and what it can do have greatly expanded since the 1980s, when biologists Sidney Altman and Thomas R. Cech discovered that RNA can operate like a protein. (The researchers won the 1989 Nobel Prize in Chemistry for their discovery.)
Proteins are key components for most chemical reactions in the body, serving as enzymes, thanks in part to the stunning variety of shapes, or conformations, these molecules can achieve. (Enzymes are proteins that facilitate and catalyze chemical reactions.) Unlike DNA, RNA can also shape-shift to an extent, and so can serve as an RNA-based enzyme, or ribozyme. RNA's greater flexibility over DNA comes in part from the extra oxygen on RNA's ribose sugar, which makes the molecule less stable, biologist Merlin Crossley wrote in The Conversation . The "deoxy" in deoxyribose references DNA's 1-oxygen deficit.
According to some researchers , the most important RNA-based catalytic activity happens in the ribosome, where rRNA, a ribozyme, mediates amino acid addition to growing proteins. Other ribozymes include small nuclear RNAs (snRNAs), which splice mRNA into usable forms, and M1 RNA , one of the first known ribozymes, which similarly clips bacterial tRNA.
RNA's regulatory zoo
In the last three decades, the number of known RNA varieties has blossomed, He said, as researchers discovered a menagerie of RNAs that do something completely different: regulate genes. "There's a whole set of RNAs that play critical regulatory roles," influencing which genes get expressed and at what rates, He said.
"In recent years, few areas of biology have been transformed as thoroughly as RNA molecular biology," in large part due to the discovery of small regulatory RNAs, researchers wrote in a 2017 review published in the International Journal of Biomedical Science . Most significant are short interfering RNAs (siRNAs), microRNAs (miRNAs), and piwi-interacting RNAs (piRNAs), the authors wrote.
siRNAs and miRNAs "silence" genes by attaching to complementary sequences in mRNAs. The regulatory RNAs then activate complexes of proteins that can cut up the mRNA or block their translation, as described in a 2010 review published in the journal Current Genomics . siRNAs target invasive genetic material, like viral DNA, while miRNAs regulate an organism's own genes, according to a 2009 review published in the journal Cell . piRNAs perform similar silencing, but operate specifically in sex cells, targeting moveable bits of genetic material called "transposable" elements that can mutate genes, according to a 2014 review published in the journal Development .
Related: What is genetic modification?
Other regulatory RNA players include the heftier long noncoding RNAs (lncRNAs), which affect genes by associating with complexes of DNA and protein called chromatin, as described in a 2019 review in the journal Noncoding RNA . lncRNA can function to activate or inactivate sections of chromatin, which packages DNA into a compact form in the cell, so that genes in that chromatin get expressed or inhibited. Enhancer RNAs have the opposite effect to much of the above, increasing the expression of certain genes via not-yet-understood mechanisms, according to a 2020 review in the journal Frontiers in Cell and Developmental Biology .
Additional RNA types have popped up in other organisms. For instance, bacteria host analogues to miRNA and siRNA called small RNA regulators (sRNAs). Parts of the gene-editing CRISPR-Cas9 system found in bacteria and archaea also rely on RNA, which binds to the so-called CRISPR DNA sequences that identify invaders.
'RNA World'
RNA's versatility in function and form helped inspire the idea known as the "RNA world" hypothesis .
Organisms rely on an astoundingly complicated system of DNA, RNA and protein to transmit hereditary information, and scientists have long wondered how this system could have arisen in early life-forms. RNA offers a logical answer, He said: This molecule can both store genetic information and catalyze reactions, suggesting that early, simple organisms could have relied solely on RNA.
"It's a hybrid," He said. "So it makes perfect sense as a start."
Additionally, He said, RNA's sugar base, ribose, always appears first in organisms, as it's easier to make. Deoxyribose then gets created from ribose. "So that implies in life, you have the ribose, the RNA first, and then the DNA comes later," He said.
From that simpler RNA start, more-complex life could arise, evolving the stabler DNA to serve as a long-term library and developing protein as a more efficient catalyst.
Why RNA at all?
In the path from DNA to protein, RNA essentially serves as a middle-man, so why not eliminate the RNA go-between and move directly from DNA to protein? Simple life-forms, like DNA viruses, do just that, He said. Similarly, some of the most infamous viruses — HIV, the common cold virus, influenza and COVID-19 — stash all their genetic info in RNA, with no DNA predecessor.
More-complicated organisms need to do a lot more genetic regulation, however, He said. So, most of their genomes don't code for proteins but code for parts of the genome that regulate other sequences. Promoters , for instance, can turn genes on or off. He said "you don't want to convert [the human genome's] 3 billion base pairs into protein sequence." Expending cellular resources on so many sequences that don't code for needed human proteins "would be a huge waste," he said. RNA makes it possible to transcribe just the protein-coding bits of the genetic sequence into the mRNA intermediary.
Related: Genetics: The study of heredity
Additionally, mRNA provides a handy method of fine-tuning a gene's output. "RNA … is the DNA photocopy," said the RNA Society , a nonprofit that facilitates sharing of RNA research. "When the cell needs to produce a certain protein, it … produces multiple copies of that piece of DNA in the form of messenger RNA … Thus, RNA expands the quantity of a given protein that can be made at one time."
RNA's amplification ability is, once again, due to the molecule's flexibility. Because RNA can fold into various shapes, it can churn out the mRNA and tRNA conformations needed to run that photocopier. DNA can't do that.
Research frontiers
Not only does RNA store the genetic info for many viruses, but it could also help scientists combat those same invaders. Proposed RNA-based vaccines would use injected mRNA to tell a person's body to make antigens, the substances that trigger immune responses, biologist Alexis Hubaud wrote for Harvard University's graduate school blog . "That's one of the most popular ways for developing anti-COVID-19 vaccines these days," He told Live Science. COVID-19 vaccine candidates such as those made by Moderna and Pfizer utilize this approach.
Related: What is a coronavirus?
Other potential RNA therapeutic applications could use injected mRNA to tell the body to make a functioning protein in a patient who lacks the genes to encode that protein, such as in people with hemophilia . "Several years ago, people would say this is crazy — if you have a defect, I'm just going to give you a healthy messenger RNA," He said. But it's now one of the most exciting areas of research, he added.
A June 2020 breakthrough also has RNA researchers excited, The Scientist reported . It showed that eliminating an RNA-binding protein could turn other cells into neurons, with major implications for diseases like Alzheimer's , He said.
"That's also exciting because fundamentally it indicates RNA can have dramatic effects on cell fate," He said.
Additional resources:


livescience--2020-10-15--Drug tricks cancer cells by impersonating a virus

A new cancer drug helps the immune system destroy tumors by impersonating a virus and `` infecting '' cancer cells .
The drug , called BO-112 , is in human trials and mimics the structure of a molecule , a type of genetic material found in some viruses .
inject their RNA into cells during infection , but cells can spot this viral RNA using specific receptors , and call upon the immune system to intervene when viruses strike .
BO-112 takes advantage of this cellular defense mechanism — once injected inside a tumor , the drug helps to alert @ @ @ @ @ @ @ presence .
To hide from the immune system , cancer cells often cloak themselves in disguises , and also stop signals that could alert the body of their location .
But when treated with BO-112 , tumors throw up red flags that the immune system can spot .
The drug , which has been tested in mice and a a few dozen people , could help amplify the effects of existing cancer treatments designed to rally the immune system , study author Dr. Anusha Kalbasi , an assistant professor of radiation oncology at @ @ @ @ @ @ @ and member of the UCLA Jonsson Cancer Center , told Live Science in an email .
In other words , once BO-112 reveals the location of a tumor , other treatments could more easily target it .
`` I do think the power of BO-112 is in its ability to enable other immunotherapies to maximize their benefit , '' Kalbasi said .
In a new study , published Oct. 14 in the journal , Kalbasi and his colleagues tested BO-112 in lab dish experiments and a mouse model of , a kind of @ @ @ @ @ @ @ trial , , 44 human patients took BO-112 with and without additional cancer treatments , so researchers could begin to analyze how safe and effective the is in people .
The early results hint that BO-112 can make tough-to-treat tumors vulnerable to immunotherapy , but the team now needs to confirm that those results hold up in larger groups .
Cancer immunotherapy works by ramping up the body 's immune defense against tumors , but cancer cells use various tricks to resist these attacks .
For instance , an immunotherapy called `` adoptive @ @ @ @ @ @ @ patient 's immune cells , modifying them to better recognize specific tumors and then reintroducing them to the body , according to a .
These detect tumors by scanning for specific molecules on their surfaces , called antigens — but some tumors can slow or stop production of these antigens , or prevent them from being displayed on a cell 's surface , thanks to specific , making them effectively invisible to T cells .
In theory , forcing such tumors to build and present antigens on their surface would make them visible @ @ @ @ @ @ @ colleagues tested this idea in several mouse studies .
They first engineered mouse tumor cells with mutations that would reduce the number of antigens on their surfaces .
In lab dish studies , the mutant tumor cells could not be detected by T cells .
But when the team turned on a called NLRC5 in the engineered tumors , the cells generated antigens in spite of the other mutations they 'd introduced .
Activating this gene made the tumor cells visible to T cells , leaving the cancer open to attack .
The @ @ @ @ @ @ @ from lab dishes to actual lab ; however , for the same approach to work in humans , scientists would need to somehow turn on the NLRC5 gene in a patient 's tumor cells .
To achieve the same result more practically , the team turned to BO-112 .
Similar to NLRC5 , the drug makes cancer cells produce antigens ; rather than switching on a specific gene , the drug instead tricks the tumor into reacting as if it 's being infected by a virus .
Without an injection of BO-112 , @ @ @ @ @ @ @ succumb to adoptive T cell therapy , because the T cells could not detect the tumors in the first place .
However , after the injection , the T cell treatment suddenly worked , Kalbasi said .
`` When we added BO-112 , the tumors either decreased in size or stopped growing for a period of time , '' he said .
However , in mice with large tumors , the cancer eventually began to grow again , Kalbasi noted .
In mice with small tumors , the combinatory treatment was more effective @ @ @ @ @ @ @ in size and sometimes disappeared altogether , he said .
To probe whether B0-112 works in human patients as it does in mice , another group of researchers conducted a small clinical trial , sponsored by the pharmaceutical company Highlight Therapeutics .
Most of the patients handled the treatment well , although three of the 44 participants experienced a severe reaction , including lung inflammation and a significant drop in platelet levels , which are important for blood clotting , according to the report .
Of the 44 patients , 28 patients who @ @ @ @ @ @ @ injections of B0-112 along with existing immunotherapy drugs , called nivolumab and pembrolizumab .
These treatments `` remove the brakes off the body ’ s T cells '' so they can target tumors more effectively , Kalbasi said .
In the clinical trial , BO-112 made tumors more sensitive to these two drugs ; after eight to 12 weeks of treatment , 10 patients with metastatic cancer reached `` stable disease , '' meaning their tumors had stopped growing , while the tumors of three other patients actually began to shrink .
That @ @ @ @ @ @ @ is too low to draw a formal conclusion about the responses because the main objective of this first in-human clinical trial was safety , '' the authors wrote .
However , these early results hint that BO-112 could be an effective strategy to take down tumors that are resistant to immunotherapy , they noted .
`` Every cell type has a different capacity to sense double-stranded RNA , '' the molecule that BO-112 mimics , Kalbasi added .
`` So we will be watching carefully to learn what factors in each patient may @ @ @ @ @ @ @ '' since some cancers might be more sensitive to the treatment than others .
Given that BO-112 is currently administered as a direct injection into tumors , initial trials will likely focus on cancer types with `` superficially accessible '' tumors , such as melanoma , lymphoma , breast cancer and bladder cancer , said Dr. Joshua Brody , director of the Lymphoma Immunotherapy Program at the Icahn School of Medicine at Mount Sinai , who was not involved in the study .
`` The exciting opportunity presented by these two studies , @ @ @ @ @ @ @ , is that we have medicines that can improve antigen presentation and thereby make immunotherapies — which would otherwise fail — become effective in inducing cancer remissions , '' Brody told Live Science in an email .

A new cancer drug helps the immune system destroy tumors by impersonating a virus and "infecting" cancer cells.
The drug, called BO-112, is in human trials and mimics the structure of a double-stranded RNA molecule, a type of genetic material found in some viruses. Viruses inject their RNA into cells during infection, but cells can spot this viral RNA using specific receptors, and call upon the immune system to intervene when viruses strike.
BO-112 takes advantage of this cellular defense mechanism — once injected inside a tumor, the drug helps to alert the body's immune system to the cancer's presence. To hide from the immune system, cancer cells often cloak themselves in disguises, and also stop signals that could alert the body of their location. But when treated with BO-112, tumors throw up red flags that the immune system can spot.
Related: Medicine's journey through the body: 4 stages
The drug, which has been tested in mice and a a few dozen people, could help amplify the effects of existing cancer treatments designed to rally the immune system, study author Dr. Anusha Kalbasi, an assistant professor of radiation oncology at the University of California, Los Angeles and member of the UCLA Jonsson Cancer Center, told Live Science in an email.
In other words, once BO-112 reveals the location of a tumor, other treatments could more easily target it. "I do think the power of BO-112 is in its ability to enable other immunotherapies to maximize their benefit," Kalbasi said.
In a new study, published Oct. 14 in the journal Science Translational Medicine , Kalbasi and his colleagues tested BO-112 in lab dish experiments and a mouse model of melanoma , a kind of skin cancer. In a separate clinical trial, published the same day , 44 human patients took BO-112 with and without additional cancer treatments, so researchers could begin to analyze how safe and effective the drug is in people. The early results hint that BO-112 can make tough-to-treat tumors vulnerable to immunotherapy, but the team now needs to confirm that those results hold up in larger groups.
Unmasking cancer cells
Cancer immunotherapy works by ramping up the body's immune defense against tumors, but cancer cells use various tricks to resist these attacks.
For instance, an immunotherapy called "adoptive T cell therapy" involves extracting a patient's immune cells, modifying them to better recognize specific tumors and then reintroducing them to the body, according to a statement . These T cells detect tumors by scanning for specific molecules on their surfaces, called antigens — but some tumors can slow or stop production of these antigens, or prevent them from being displayed on a cell's surface, thanks to specific genetic mutations , making them effectively invisible to T cells.
In theory, forcing such tumors to build and present antigens on their surface would make them visible to T cells; Kalbasi and his colleagues tested this idea in several mouse studies.
Related: 12 amazing images in medicine
They first engineered mouse tumor cells with mutations that would reduce the number of antigens on their surfaces. In lab dish studies, the mutant tumor cells could not be detected by T cells.
But when the team turned on a gene called NLRC5 in the engineered tumors, the cells generated antigens in spite of the other mutations they'd introduced. Activating this gene made the tumor cells visible to T cells, leaving the cancer open to attack. The same strategy worked when the team moved from lab dishes to actual lab mice ; however, for the same approach to work in humans, scientists would need to somehow turn on the NLRC5 gene in a patient's tumor cells.
To achieve the same result more practically, the team turned to BO-112. Similar to NLRC5, the drug makes cancer cells produce antigens; rather than switching on a specific gene, the drug instead tricks the tumor into reacting as if it's being infected by a virus.
Without an injection of BO-112, the lab mice's tumors did not succumb to adoptive T cell therapy, because the T cells could not detect the tumors in the first place. However, after the injection, the T cell treatment suddenly worked, Kalbasi said.
"When we added BO-112, the tumors either decreased in size or stopped growing for a period of time," he said.
From mice to humans
However, in mice with large tumors, the cancer eventually began to grow again, Kalbasi noted. In mice with small tumors, the combinatory treatment was more effective, as the tumors shrunk more dramatically in size and sometimes disappeared altogether, he said.
To probe whether B0-112 works in human patients as it does in mice, another group of researchers conducted a small clinical trial, sponsored by the pharmaceutical company Highlight Therapeutics. Most of the patients handled the treatment well, although three of the 44 participants experienced a severe reaction, including lung inflammation and a significant drop in platelet levels, which are important for blood clotting, according to the report.
Related: 11 surprising facts about the immune system
Of the 44 patients, 28 patients who did not experience these side effects received injections of B0-112 along with existing immunotherapy drugs, called nivolumab and pembrolizumab. These treatments "remove the brakes off the body’s T cells" so they can target tumors more effectively, Kalbasi said. In the clinical trial, BO-112 made tumors more sensitive to these two drugs; after eight to 12 weeks of treatment, 10 patients with metastatic cancer reached "stable disease," meaning their tumors had stopped growing, while the tumors of three other patients actually began to shrink.
That said, "the number of patients is too low to draw a formal conclusion about the responses because the main objective of this first in-human clinical trial was safety," the authors wrote. However, these early results hint that BO-112 could be an effective strategy to take down tumors that are resistant to immunotherapy, they noted.
"Every cell type has a different capacity to sense double-stranded RNA," the molecule that BO-112 mimics, Kalbasi added. "So we will be watching carefully to learn what factors in each patient may predict a better response to BO-112," since some cancers might be more sensitive to the treatment than others. Given that BO-112 is currently administered as a direct injection into tumors, initial trials will likely focus on cancer types with "superficially accessible" tumors, such as melanoma, lymphoma, breast cancer and bladder cancer, said Dr. Joshua Brody, director of the Lymphoma Immunotherapy Program at the Icahn School of Medicine at Mount Sinai, who was not involved in the study.
"The exciting opportunity presented by these two studies, both in the lab and in patients, is that we have medicines that can improve antigen presentation and thereby make immunotherapies — which would otherwise fail — become effective in inducing cancer remissions," Brody told Live Science in an email.
Originally published on Live Science.


livescience--2020-10-15--Hockey game turned into COVID-19 superspreader event

A recreational ice hockey game in Florida turned into a `` superspreader '' event when 14 out of 22 players developed COVID-19 after the game , including players on both teams , according to a new report .
The report , published Thursday ( Oct. 15 ) in the Centers for Disease Control and Prevention journal , highlights the particular risk of indoor sporting events for spreading COVID-19 , the authors said .
The game , which was held on June 16 at an ice rink in Tampa Bay , Florida , involved two teams of 11 players each , @ @ @ @ @ @ @ at the Florida Department of Health .
Typically , six players were on the ice and five on the bench at any given time , the report said .
All of the players were male , and ranged in age from 19 to 53 years old .
None of the players wore cloth masks on the ice or in the locker rooms , although some players wore hockey-related face protection such as metal cages or plastic half-shields that covered the eyes and the top part of the nose .
The game lasted 60 @ @ @ @ @ @ @ minutes in the locker room before and after the game , with each team having a separate locker room .
The day after the game ( June 17 ) , one of the players developed a fever , cough , sore throat and headache , and tested positive for COVID-19 .
In the following four days ( from June 18 to June 21 ) , an additional 13 players developed symptoms of COVID-19 — eight players were on the same team as the initial case , and five players were on the opposing @ @ @ @ @ @ @ rink also developed in the days following the game .
Of the 15 overall cases ( including the initial case and the rink staff member ) , 11 were confirmed to have COVID-19 through a positive test , and two were not tested , the report said .
Asymptomatic players were not tested , so there may have been additional .
The players did n't have other common exposures in the week leading up to the game , and the researchers hypothesize that one player spread COVID-19 to the other players during the @ @ @ @ @ @ @ new report is one of the first to document COVID-19 spread at a sporting event or practice , although there have been a number of anecdotal reports .
`` The ice rink provides a venue that is likely well suited to COVID-19 transmission as an indoor environment where deep breathing occurs , and persons are in close proximity to one another , '' the report said .
The cold temperatures of the ice rink may also help the virus spread , as has been suggested by outbreaks in meat processing plants .
Cold @ @ @ @ @ @ @ longer outside the body , including in the air , .
And one study found that the novel coronavirus particles could travel more than 26 feet ( 8 meters ) in the cold , stale air of a slaughterhouse , .
The ice-rink environment creates the potential for a `` superspreader event , especially with ongoing community COVID-19 transmission , '' they concluded .

A recreational ice hockey game in Florida turned into a "superspreader" event when 14 out of 22 players developed COVID-19 after the game, including players on both teams, according to a new report.
The report, published Thursday (Oct. 15) in the Centers for Disease Control and Prevention journal Morbidity and Mortality Weekly Report , highlights the particular risk of indoor sporting events for spreading COVID-19, the authors said.
The game, which was held on June 16 at an ice rink in Tampa Bay, Florida, involved two teams of 11 players each, according to the report, from researchers at the Florida Department of Health. Typically, six players were on the ice and five on the bench at any given time, the report said. All of the players were male, and ranged in age from 19 to 53 years old. None of the players wore cloth masks on the ice or in the locker rooms, although some players wore hockey-related face protection such as metal cages or plastic half-shields that covered the eyes and the top part of the nose.
The game lasted 60 minutes, and players spent about 20 minutes in the locker room before and after the game, with each team having a separate locker room.
The day after the game (June 17), one of the players developed a fever, cough, sore throat and headache, and tested positive for COVID-19. In the following four days (from June 18 to June 21), an additional 13 players developed symptoms of COVID-19 — eight players were on the same team as the initial case, and five players were on the opposing team. A staff member at the rink also developed symptoms of COVID-19 in the days following the game.
Related: 14 coronavirus myths busted by science
Of the 15 overall cases (including the initial case and the rink staff member), 11 were confirmed to have COVID-19 through a positive test, and two were not tested, the report said. Asymptomatic players were not tested, so there may have been additional asymptomatic cases .
The players didn't have other common exposures in the week leading up to the game, and the researchers hypothesize that one player spread COVID-19 to the other players during the game while he was presymptomatic.
The new report is one of the first to document COVID-19 spread at a sporting event or practice, although there have been a number of anecdotal reports.
"The ice rink provides a venue that is likely well suited to COVID-19 transmission as an indoor environment where deep breathing occurs, and persons are in close proximity to one another," the report said.
The cold temperatures of the ice rink may also help the virus spread, as has been suggested by outbreaks in meat processing plants. Cold temperatures allow the virus to survive for longer outside the body, including in the air, according to Wired . And one study found that the novel coronavirus particles could travel more than 26 feet (8 meters) in the cold, stale air of a slaughterhouse, according to Bloomberg .
The ice-rink environment creates the potential for a "superspreader event, especially with ongoing community COVID-19 transmission," they concluded.
Originally published on Live Science.


livescience--2020-10-15--Mosquito 'tongue' neurons ignite like fireworks at taste of human blood

What does your blood taste like to a ?
Researchers recently discovered that the delectable flavor of human blood sends sensory neurons igniting like fireworks in a mosquito 's syringe-like `` tongue , '' a piercing mouthpart called a stylet .
Only female mosquitoes feed on blood , and only to nourish their developing eggs — otherwise , they drink flower nectar .
To better understand the mosquitoes ' attraction to human blood , scientists genetically modified Aedes aegypti mosquitoes to make the insects ' taste-related neurons emit fluorescent light during activation .
The researchers then used fluorescent microscopy to @ @ @ @ @ @ @ stylets as the insects fed on real human blood and other liquid meals , according to a study published Oct. 12 in the journal ..
Biologists who study mosquitoes often do so at the cost of their own skin , allowing the insects to bite them to reveal blood feeding behavior in action .
For the new study , the scientist turned to a device called a biteOscope .
Designed by another research team to `` give scientists and their skin a reprieve , '' the biteOscope is a small open platform with @ @ @ @ @ @ @ .
It offers mosquitoes a chance to drink their fill in an environment that mimics a skin-covered host , while also allowing scientists to observe mosquito feeding behavior and collect data without sacrificing their own skin , the biteOscope creators wrote on Sept. 22 in the journal .
The mosquito researchers observed neuron activity in mosquito stylets as their subjects approached nectar , blood , and an artificial `` blood '' mixture made of glucose , sodium chloride and sodium bicarbonate , in concentrations `` within the range of standard blood values for @ @ @ @ @ @ @ study .
The artificial blood also included adenosine triphosphate ( ATP ) , a compound in blood that transports energy to cells and which prior studies have shown to be attractive to mosquitoes , the scientists reported .
`` To understand the properties of blood-sensitive neurons , we needed a stable mixture with a known composition that we could use to reliably activate blood-sensitive neurons in the stylet , '' said lead study author Veronica Jové , a doctoral candidate and a Howard Hughes Medical Institute ( HHMI ) Gilliam Fellow at The @ @ @ @ @ @ @ In the presence of real blood and the lab-made mixture , a subset of the mosquitoes ' stylet neurons — roughly half of the 40 found in a female mosquito 's stylet — flared brightly , but those neurons did n't activate at all at the taste of the sweet nectar , according to the study .
However , deciphering exactly what our blood might taste like to a mosquito — Are we sweet , because blood contains glucose ?
Salty , because of sodium chloride ?
Somewhere in between ?
— is @ @ @ @ @ @ @ , a professor and investigator with HHMI at The Rockefeller University .
`` There is nothing like this in the human experience , '' Vosshall .
That 's because one of the key components that draws mosquitoes to blood is ATP , which does n't have a `` taste '' on the human tongue , Jove told Live Science in an email .
Vosshall confirmed this firsthand by sampling the lab-made ATP-infused mixture herself .
`` It does n't have a taste at all , '' she said in the statement .
`` @ @ @ @ @ @ @ tastes like nothing to humans .
But it 's got to be incredibly exciting and rewarding for the mosquito . ''
Humans experience five basic : sweet , sour , umami , bitter , and salty , Jové said .
While the researchers could n't say for sure exactly which flavors individually tickle mosquitoes ' tastes , we may share an appreciation for saltiness — our perception of salt flavor is triggered by sodium chloride , or NaCl , which was present in both blood and lab-made blood , when the mosquitoes ' @ @ @ @ @ @ @ Pinpointing what makes human blood so delectable to mosquitoes could be a first step toward producing deterrents that make us less delicious , and could thereby reduce our chances of being bitten , the researchers said in the statement .
Identifying these factors could also shed light on diseases such as dengue and Zika , which mosquitoes spread by feeding on infected people , Jové told Live Science .
`` An understanding of how mosquitoes taste blood to initiate blood-feeding behavior is fundamental for understanding how vector-borne diseases are transmitted across the globe @ @ @ @ @

Neurons in a female mosquito's skin-piercing stylet light up as they detect the taste of blood.
What does your blood taste like to a mosquito ? Researchers recently discovered that the delectable flavor of human blood sends sensory neurons igniting like fireworks in a mosquito's syringe-like "tongue," a piercing mouthpart called a stylet.
Only female mosquitoes feed on blood, and only to nourish their developing eggs — otherwise, they drink flower nectar. To better understand the mosquitoes' attraction to human blood, scientists genetically modified Aedes aegypti mosquitoes to make the insects' taste-related neurons emit fluorescent light during activation.
The researchers then used fluorescent microscopy to detect neurons firing in the mosquitoes' stylets as the insects fed on real human blood and other liquid meals, according to a study published Oct. 12 in the journal Neuron .
Related: Why human blood drives mosquitoes wild
Biologists who study mosquitoes often do so at the cost of their own skin, allowing the insects to bite them to reveal blood feeding behavior in action. For the new study, the scientist turned to a device called a biteOscope. Designed by another research team to "give scientists and their skin a reprieve," the biteOscope is a small open platform with a membrane over pockets that hold liquid. It offers mosquitoes a chance to drink their fill in an environment that mimics a skin-covered host, while also allowing scientists to observe mosquito feeding behavior and collect data without sacrificing their own skin, the biteOscope creators wrote on Sept. 22 in the journal eLife .
The mosquito researchers observed neuron activity in mosquito stylets as their subjects approached nectar, blood, and an artificial "blood" mixture made of glucose, sodium chloride and sodium bicarbonate, in concentrations "within the range of standard blood values for vertebrate species," according to the study. The artificial blood also included adenosine triphosphate (ATP), a compound in blood that transports energy to cells and which prior studies have shown to be attractive to mosquitoes, the scientists reported.
"To understand the properties of blood-sensitive neurons, we needed a stable mixture with a known composition that we could use to reliably activate blood-sensitive neurons in the stylet," said lead study author Veronica Jové, a doctoral candidate and a Howard Hughes Medical Institute (HHMI) Gilliam Fellow at The Rockefeller University in New York City.
An imaging apparatus called a BiteOscope enabled scientists to observe and record mosquito feeding behavior. (Image credit: Prakash Lab)
"Special mystery stuff"
In the presence of real blood and the lab-made mixture, a subset of the mosquitoes' stylet neurons — roughly half of the 40 found in a female mosquito's stylet — flared brightly, but those neurons didn't activate at all at the taste of the sweet nectar, according to the study.
However, deciphering exactly what our blood might taste like to a mosquito — Are we sweet, because blood contains glucose? Salty, because of sodium chloride? Somewhere in between? — is tricky, said study co-author Leslie Vosshall, a professor and investigator with HHMI at The Rockefeller University.
"There is nothing like this in the human experience," Vosshall said in a statement . That's because one of the key components that draws mosquitoes to blood is ATP, which doesn't have a "taste" on the human tongue, Jove told Live Science in an email.
Vosshall confirmed this firsthand by sampling the lab-made ATP-infused mixture herself.
"It doesn't have a taste at all," she said in the statement. "ATP is this special mystery stuff that tastes like nothing to humans. But it's got to be incredibly exciting and rewarding for the mosquito."
Female mosquitoes seek blood to nourish their developing eggs. (Image credit: Shutterstock)
Humans experience five basic tastes : sweet, sour, umami, bitter, and salty, Jové said. While the researchers couldn't say for sure exactly which flavors individually tickle mosquitoes' tastes, we may share an appreciation for saltiness — our perception of salt flavor is triggered by sodium chloride, or NaCl, which was present in both blood and lab-made blood, when the mosquitoes' stylet neurons fired, Jové said.
Pinpointing what makes human blood so delectable to mosquitoes could be a first step toward producing deterrents that make us less delicious, and could thereby reduce our chances of being bitten, the researchers said in the statement. Identifying these factors could also shed light on diseases such as dengue and Zika, which mosquitoes spread by feeding on infected people, Jové told Live Science.
"An understanding of how mosquitoes taste blood to initiate blood-feeding behavior is fundamental for understanding how vector-borne diseases are transmitted across the globe," she said.
Originally published on Live Science.