Male gonad-enriched microRNAs function to control sperm production in C. elegans

Abstract

Germ cell development and gamete production in animals require small RNA pathways. While studies indicate that microRNAs (miRNAs) are necessary for normal sperm production and function, the specific roles for individual miRNAs are largely unknown. Here, we use small RNA sequencing of dissected gonads and functional analysis of new loss of function alleles to identify functions for miRNAs in the control of fecundity and sperm production in Caenorhabditis elegans males and hermaphrodites. We describe a set of 29 male gonad-enriched miRNAs and identify a set of 3 individual miRNAs (mir-58.1, mir-83, and mir-235) and a miRNA cluster (mir-4807-4810.1) that are required for optimal sperm production at 20{degrees}C and 5 additional miRNAs (mir-49, mir-57, mir-261, and mir-357/358) that are required for sperm production at 25{degrees}C. We observed defects in meiotic progression in mir-58.1, mir-83, mir-235, and mir-4807-4810.1 mutants that may contribute to the reduced number of sperm. Further, analysis of multiple mutants of these miRNAs suggested complex genetic interactions between these miRNAs for sperm production. This study provides insights on the regulatory roles of miRNAs that promote optimal sperm production and fecundity in males and hermaphrodites. Article SummaryMicroRNAs are small non-coding RNAs that are required for the normal production of sperm but the roles of individual microRNAs in the process of spermatogenesis are not well understood. Here, we use the nematode Caenorhabditis elegans to identify microRNAs that are enriched in the male gonad to identify specific microRNAs that regulate male fertility. We generated new loss of function mutants for functional analysis to identify a set of microRNAs that are necessary for optimal fertility and fecundity in males.