Poly(A) tail elongation after export of an messenger RNA (mRNA) to the cytoplasm 
is called cytoplasmic polyadenylation. It was first discovered in oocytes and 
embryos, where it has roles in meiosis and development. In recent years, 
however, has been implicated in many other processes, including synaptic 
plasticity and mitosis. This review aims to introduce cytoplasmic 
polyadenylation with an emphasis on the factors and elements mediating this 
process for different mRNAs and in different animal species. We will discuss the 
RNA sequence elements mediating cytoplasmic polyadenylation in the 3' 
untranslated regions of mRNAs, including the CPE, MBE, TCS, eCPE, and C-CPE. In 
addition to describing the role of general polyadenylation factors, we discuss 
the specific RNA binding protein families associated with cytoplasmic 
polyadenylation elements, including CPEB (CPEB1, CPEB2, CPEB3, and CPEB4), 
Pumilio (PUM2), Musashi (MSI1, MSI2), zygote arrest (ZAR2), ELAV like proteins 
(ELAVL1, HuR), poly(C) binding proteins (PCBP2, αCP2, hnRNP-E2), and Bicaudal C 
(BICC1). Some emerging themes in cytoplasmic polyadenylation will be 
highlighted. To facilitate understanding for those working in different 
organisms and fields, particularly those who are analyzing high throughput data, 
HUGO gene nomenclature for the human orthologs is used throughout. Where human 
orthologs have not been clearly identified, reference is made to protein 
families identified in man.