Decoding mAm by simultaneous transcription-start mapping and methylation quantification.

,2'--dimethyladenosine (mAm) is a modified nucleotide located at the first transcribed position in mRNA and snRNA that is essential for diverse physiological processes. mAm mapping methods assume each gene uses a single start nucleotide. However, gene transcription usually involves multiple start sites, generating numerous 5' isoforms.

Dinoflagellate mRNA is pervasively modified with mA.

-methyladenosine (mA) is a very rare RNA modification in mammalian mRNA, which occurs in sequences resembling the T-loop of tRNAs and may not have significant effects on gene expression. A new study in this issue now reports that mA is abundant and dynamic in the 3′UTR of mRNAs of dinoflagellates, and could have an important role in post-transcriptional gene expression regulation in these organisms.