Post-transcriptional regulation is crucial to proper organismal and tissue-specific development. An abundance of work has uncovered the essentiality of the core repertoire of factors and complexes constituting the cleavage and polyadenylation (CPA) machinery in post-embryonic development. Despite these findings, there is a need to define the precise relationship between these factors and tissue-specific development. Here, we demonstrate a novel role for the RNA-binding protein
cfim-1 in germline function.
cfim-1 functions in the CFIm complex, which is associated with preferential utilization of distal cleavage sites of pre-mRNAs bound for maturation by the core CPA machinery. Ablation of
cfim-1 function results in reduced brood sizes. This effect is exacerbated at higher temperatures where a completely penetrant sterility phenotype is observed. We employ a combination of genetic and imaging analysis tools to characterize the organization and morphology of
cfim-1 ablated germlines, demonstrating a precocious organization of meiotic-proliferating cells along the distal-proximal axis of the germline at the sterility-inducing temperature. We further provide genetic evidence to suggest that these effects are specific to the CFIm complex and not a general effect of antagonizing the function of the core CPA machinery. Data mining of worm 3'-sequencing data reveals an enrichment of the UGUA motif that is canonically bound by the CFIm complex upstream of the proximal cleavage sites of genes undergoing preferential transcript isoform utilization in response to ablation of
cfim-1. These data, in conjunction with our previous findings, may suggest a novel model of regulation in the worm whereby recruitment of the CFIm complex to proximal cleavage sites in
cfim-1 regulated genes antagonizes usage of those sites by the core CPA machinery.