sta-1 is repressed by mir-58 family in Caenorhabditis elegans

The miR-58 family comprises 6 microRNAs with largely shared functions, and with an overall high expression, because one of its members, miR-58, is the most abundant microRNA in Caenorhabditis elegans. We recently found that 2 TGF-β signaling pathways, Sma/Mab and Dauer, responsible for body size and dauer formation respectively, among other phenotypes, are downregulated by the miR-58 family. Here, we further explore this family by showing that it also acts through the sta-1 3'UTR. sta-1 encodes a transcription factor, homologous to mammalian STATs, that inhibits dauer formation in association with the TGF-β Dauer pathway. We also observe that mutants with a constitutively active TGF-β Dauer pathway express higher levels of sta-1 mRNA. Our results reinforce the view of the miR-58 family and STA-1 as regulators of dauer formation in coordination with the TGF-β Dauer pathway.