GSE62797
Roles of small RNAs in the effects of nutrition on apoptosis and spermatogenesis in the adult testis
In this study, we tested whether reduction in spermatozoal quality induced by under-nutrition is associated with an increase in germ cell apoptosis and a reduction in spermatogenesis, and whether these effects are regulated by small RNAs. Groups of 8 male sheep were fed for a 10% increase or 10% decrease in body mass over 65 days. Testicular tissue from underfed males had more apoptotic germ cells (TUNEL assay; P < 0.05) and greater (P < 0.05) levels of expression of apoptosis-related genes than well-fed males. We identified 44 miRNAs and 35 piRNAs that were differentially expressed in well-fed and underfed males (FDR < 0.05) and found that they were predominantly related to development of the reproductive system, apoptosis (miRNAs), or sperm production and quality (piRNAs). Furthermore, experimental validation showed that novel-miR-144, a homologue of miR-98, would target three apoptotic genes (TP53, CASP3, FASL). The proportion of miRNAs as a total of small RNAs was greater in well-fed males than in underfed males (P < 0.05) and was positively correlated with the proportion of piRNAs in well-fed males (r = 0.8, P < 0.05) and underfed males (r = 0.8, P < 0.05). We conclude that the reductions in spermatozoal quality induced by under-nutrition are due, at least partly, to increased germ cell apoptosis and to changes in the expression of miRNAs and piRNAs. Overall design: Two groups of 8 male sheep were fed for a 10% increase or 10% decrease in body mass over 65 days, and the small RNA expression was profiled.