RNA processing and the control of spermatogenesis.

The testis is a rich source for expression of mechanisms for gene regulation. Germ cell expansion and differentiation require many cellular changes and regulatory steps. In the developing germ cells, the length of mRNA transcripts often vary as the cells mature, reflecting the ongoing regulatory changes. Due to the numerous maturation stages that germ cells must undergo, novel gene regulation strategies have been developed that provide for flexible gene expression and protein function. Some of the methods employed in the testis to alter gene expression and function include the initiation of transcription at alternative start sites, the splicing in or out exons to alter the properties of the resulting protein, changes in the site of polyadenylation to control mRNA stability, and delays in the translation of transcripts to ensure a source of protein late in germ cell development after transcription ceases. Using these varied expression strategies, individual genes are able to perform different functions that can be directed to specific development timepoints.