A programmed wave of uridylation-primed mRNA degradation is essential for meiotic progression and mammalian spermatogenesis.

Several developmental stages of spermatogenesis are transcriptionally quiescent which presents major challenges associated with the regulation of gene expression. Here we identify that the zygotene to pachytene transition is not only associated with the resumption of transcription but also a wave of programmed mRNA degradation that is essential for meiotic progression. We explored whether terminal uridydyl transferase 4- (TUT4-) or TUT7-mediated 3' mRNA uridylation contributes to this wave of mRNA degradation during pachynema.

Genomic analysis of human microRNA transcripts.

MicroRNAs (miRNAs) are important genetic regulators of development, differentiation, growth, and metabolism. The mammalian genome encodes approximately 500 known miRNA genes. Approximately 50% are expressed from non-protein-coding transcripts, whereas the rest are located mostly in the introns of coding genes.