Effect of WRN helicase on the development and maturation of goat oocytes

WRN helicase is a member of the RecQ family and has both DNA helicase and exonuclease activity. It plays key roles in keeping genomic stability, maintaining telomere integrity, and helping repair double-strand breaks. This study aimed to investigate the effects of WRN helicase inhibitor on organelles and the expression of related functional genes in goat oocytes using an in vitro maturation system. A control group (NC) and a WRN inhibitor treated group (IN-WRN) were established. We looked at where WRN localizes at the GV, GVBD, MI, and MII stages, and asked how inhibiting WRN affects oocyte maturation, organelle function, and DNA repair pathways. Immunolocalization confirmed that WRN is expressed in oocytes at all stages we examined. Dose-response experiments showed that 20 μM of the inhibitor significantly lowered first polar body (PB1) extrusion and stopped oocyte maturation. Functional analyses revealed that WRN deficiency caused abnormal mitochondrial distribution and higher ROS levels. It also disrupted ER structure, accompanied by increased expression of ER-related genes, a clear rise in lysosomal fluorescence signals, and disrupted Golgi distribution. DNA damage assessment showed higher γH2AX levels, pointing to an accumulation of double-strand breaks. Transcriptomic analysis further showed that, after WRN inhibition, reproduction-related genes in goat oocytes formed tightly linked expression patterns. Taken together, these findings offer new insights into how WRN helicase helps regulate oocyte quality.