The Role of Maternal Haploid in Nasonia Vitripennis Development

Key chromatin remodeling events occur during spermatogenesis and during fertilization and are essential for proper incorporation of the paternal genome. In Drosophila melanogaster, the maternal effect mutation maternal haploid (mh) disrupts this process, leading to paternal genome elimination (PGE) and the development of gynogenetic embryos. In this study, we investigated the role of the mh ortholog in the parasitoid wasp Nasonia vitripennis. We performed RNA interference (RNAi) knockdowns of MH in both females and males. We showed that crosses between mh females and wildtype (WT) males yielded normal sex ratios and embryos with normal nuclei, indicating a functional divergence or an insufficient knockdown. In contrast, sex ratios observed in male knockdown and WT female crosses were half normal and half all-male broods. These results indicate that MH is required for producing functional sperm or that these broods were a product of virgin females. We were also interested in testing whether MH is required for the activity of PSR, a selfish B chromosome that induces PGE, but were unable to carry out these experiments. Future work will include more extensive knockdown validation, immunostaining to determine MH localization in embryos and germlines, and functional experiments involving PSR. Together, these studies aim to clarify the role of MH in N. vitripennis and deepen our understanding of chromatin remodeling and genome elimination.