Project description:Seasonal photoperiodic changes have strong impact on development in Nasonia vitripennis. Here, Using high-throughput Reduced Representation Bisulfite Sequencing (RRBS) and single-molecule-based sequencing, we generated DNA methylation maps of female wasps maintained in long vs short day. We have identified differential methylated loci that encode the photoperiodic change. analysis of DNA methylation in female wasps maintained in long vs short day, using RRBS followed by Illumina sequencing
Project description:In this study, we present the first proteome-wide analysis of tissue-specific and developmental protein dynamics in Nasonia vitripennis nymphae with a particular focus on testis differentiation. We profiled protein abundance in heads, legs, and testes across four successive pupal stages, identifying more than 2500 proteins. While a large ubiquitous core proteome was detected, distinct signatures of tissue- and stage-specific expression emerged. Among tissues, testes showed the earliest divergence, with clear separation between early and late pupal stages, consistent with the progressive onset of spermatogenesis. Clustering of protein abundance trajectories revealed sequential molecular programs associated with cytoskeletal remodeling, meiotic processes, and terminal spermiogenesis, highlighting both conserved testis-related pathways and lineage-specific features in Nasonia vitripennis. We focused on a set of 175 proteins developmentally regulated in the testis showing at least a two-fold abundance change between stages. Among them, 11 were uncharacterized proteins whose expression was modulated across testicular development. 3D structure predictions and 3D similarity searches suggested that four of these orphan proteins form a novel family of six-bladed β-propeller–like proteins, likely related to exo-α-sialidases. Strikingly, this family appears restricted to Hymenoptera, pointing to possible lineage-specific innovations associated with organ differentiation, tissue remodeling, and possible roles in reproductive biology.
Project description:The extraordinary range in the degree of sexual dimorphism (SD) among animal species is widely perceived to be caused in part by differences in patterns of sexual selection, but sex-specific adaptations and sex chromosome differences also play a role. Studies in insects have discovered a substantial number of sex-biased genes, but little is known about the epigenetic basis of SD. The degree and genome-wide distribution of sex-biased expression become interesting questions in hymenoptera species with haplodiploid sex-determination. To study the genetic and epigenetic architecture of SD and understand the conservation and evolution of sex-biased expression in a haplodiploid system that lacks sex chromosomes, we performed RNA-seq and whole-genome bisulfite sequencing in female and male adult samples of two parasitoid wasp species, Nasonia vitripennis and Nasonia giraulti. More than 75% of the expressed genes displayed significantly sex-biased expression. Both the number and the degree of sex-biased genes are higher than insects like Drosophila melanogaster, which have sex-chromosome mediated sex determination. Females from the two Nasonia species have far more similar expression profiles than does the contrast between the two sexes within either species. Interestingly, the extremely male- and female-biased genes are enriched for totally different functional categories: male-biased genes are highly enriched for key enzymes in sex-pheromone synthesis; female-biased genes are enriched for nuclear-located genes that are responsible for epigenetic regulation of gene expression. Unlike gene expression profiles, DNA methylomes are more similar within species, and no stable differentially methylated genes have been found between the two sexes, suggesting that DNA methylation is not directly responsible for the molecular basis of SD. However, methylation status does influence sex-biased expression: 80% of female-biased genes are methylated, which is more than two-fold higher than the genome average (30%); almost all male-biased and sex-specific genes are non-methylated, which is consistent with the fact that methylated genes have house-keeping functions and a broader expression breadth. Evolutionarily, male-biased genes have greater sequence divergence between the two species, and they are more likely to have a functional paralog in the Nasonia genome. Sex-specific genes have significantly higher non-synonymous substitution rates and dN/dS ratios. In addition, local clusters of sex-biased genes in the genome may have epigenetic properties similar to the sex chromosome. In summary, Nasonia accomplish a striking degree of sex-differential expression through a difference in ploidy along with associated differences in methylations status. Profiling of expression levels in Nasonia vitripennis and Nasonia giraulti adult male and female samples using Illumina RNA-seq