Research Data for 'Causes and consequences of sex-chromosome turnovers in Diptera' Layana Franco, Lorena Alexandra ; https://orcid.org/0000-0002-1253-6297 Toups, Melissa A ; https://orcid.org/0000-0002-9752-7380 Vicoso, Beatriz ; https://orcid.org/0000-0002-4579-8306 Schizophora sex chromosomes sex-chromosome turnover Diptera genomic features out-of-X movement. Sex-chromosome systems are highly variable across animals, but how they transition from one to another is not well understood. Diptera have undergone multiple sex-chromosome turnovers and expansions while maintaining their general chromosomal content, which makes them an ideal clade to study such transitions. We analysed more than 100 dipteran whole-genome assemblies and identified 4 new lineages that underwent sex-chromosome turnover (in addition to the 5 previously reported). We find the majority of turnovers happened in the group Schizophora, which tend to have fewer genes on the F element (the chromosome homologous to the ancestral insect X chromosome) than lower dipterans, a factor previously hypothesized to facilitate turnover. Most derived X chromosomes have higher GC content than autosomes, consistent with a high prevalence of male-achiasmy in Diptera. In addition, an excess of gene movement out of the X is detected for most of these new X chromosomes, and many of these moved genes have high testis expression in Drosophila, suggesting that out-of-X gene movement contributes to the long-term demasculinization of X chromosomes. Institute of Science and Technology Austria 2026 info:eu-repo/semantics/other doc-type:ResearchData text http://purl.org/coar/resource_type/63NG-B465 https://research-explorer.ista.ac.at/record/20833 https://research-explorer.ista.ac.at/download/20833/20834 https://research-explorer.ista.ac.at/download/20833/20835 https://research-explorer.ista.ac.at/download/20833/20837 https://research-explorer.ista.ac.at/download/20833/20959 Layana Franco LA, Toups MA, Vicoso B. Research Data for “Causes and consequences of sex-chromosome turnovers in Diptera.” 2026. doi:<a href="https://doi.org/10.15479/AT-ISTA-20833">10.15479/AT-ISTA-20833</a> info:eu-repo/semantics/altIdentifier/doi/10.15479/AT-ISTA-20833 info:eu-repo/semantics/openAccess