Abstract
BACKGROUND: Sex differentiation is a crucial process that determines the sex ratio of a population, impacting reproductive success and ecological dynamics. In parasitoid wasps and other insects, the sex ratios significantly influence ecological adaptability and biological control potential. Particularly in parasitoid wasps, the regulation of sex ratio is closely linked to the shift between gamogenesis and parthenogenesis. However, the molecular mechanisms regulating sex ratios remain largely unresolved. RESULTS: We found that when the female wasp Copidosomopsis nacoleiae (Eady) reproduces through parthenogenesis, the offspring are all male. However, when the wasp reproduces sexually, females accounted for 24.65 ± 3.64%, and males accounted for 75.35 ± 3.64%. Additionally, we identified 123,982 isoforms and predicted 5,675 alternative splicing events through transcriptomics. Interestingly, we found that the squid gene exhibited different splicing patterns in male and female offspring under different reproductive modes, suggesting that it may play a role in sex differentiation in C. nacoleiae. CONCLUSIONS: Overall, the study provides important insights into the reproductive biology of C. nacoleiae and sheds light on the molecular mechanisms underlying sex differentiation in this species.