| How genes are regulated to produce the correct assortment of proteins for every cell type is a fundamental question in biology. For many genes, regulation begins at the DNA level using promoter sequences to control transcription. Regulation can also occur after transcription using sequences in the 3' untranslated region (UTR) of the mRNA to affect mRNA stability and/or translation. Using a transgenic assay, we compared the contribution of promoters and 3' UTRs to gene regulation during germline development. We found that for most genes tested, 3' UTRs are sufficient for regulation. With the exception of promoters activated during spermatogenesis, promoters are permissive for expression in all germ cell types (from germline stem cells to oocytes and sperm). Furthermore, we found that 3' UTRs inhibit the production of meiotic proteins in germline stem cells by post-transcriptional mechanisms involving PUF-domain RNA-binding proteins. Our findings indicate that genes rely primarily on 3' UTRs, not promoters, for regulation during germline development. |
