Stress granules are mRNA-protein assemblies formed from nontranslating mRNAs. 
Stress granules are important in the stress response and may contribute to some 
degenerative diseases. Here, we describe the stress granule transcriptome 
of yeast and mammalian cells through RNA-sequencing (RNA-seq) analysis of 
purified stress granule cores and single-molecule fluorescence in situ 
hybridization (smFISH) validation. While essentially every mRNA, and some 
noncoding RNAs (ncRNAs), can be targeted to stress granules, the targeting 
efficiency varies from <1% to >95%. mRNA accumulation in stress granules 
correlates with longer coding and UTR regions and poor translatability. 
Quantifying the RNA-seq analysis by smFISH reveals that only 10% of bulk mRNA 
molecules accumulate in mammalian stress granules and that only 185 genes have 
more than 50% of their mRNA molecules in stress granules. These results suggest 
that stress granules may not represent a specific biological program of 
messenger ribonucleoprotein (mRNP) assembly, but instead form by condensation of 
nontranslating mRNPs in proportion to their length and lack of association with 
ribosomes.