A stress-dependent postembryonic role for the core CPA factor CFIM-1 in germline integrity

Post-transcriptional processing of pre-mRNAs by alternative polyadenylation (APA) generates a diversity of transcript isoforms at the 3' untranslated region (3'UTR) that can affect their function and stability. The differential enrichment of transcript isoforms has been implicated in diseases ranging from cancer to neurodevelopmental disorders. However, the post-embryonic developmental roles of the core ensemble of cleavage and polyadenylation (CPA) factors that mediate these post-transcriptional changes remain poorly characterized. Here, we report a stress-dependent role for the core CPA factor CFIM-1 in Caenorhabditis elegans germline integrity. Total loss-of-function of cfim-1 elicits a temperature-sensitive sterility phenotype in hermaphrodites but CFIM-1 protein levels do not change with temperature. Sterility is accompanied by sperm, oocyte and germline morphology defects. Surveying the transcriptome of cfim-1(lf) worms revealed changes in transcript isoform abundance for dozens of genes with functions related to the development and maintenance of these structures. Collectively, our findings define a post-embryonic role for a core CPA factor in tissue-specific development.