database Lorena Alexandra Layana Franco author 02814589-eb8f-11eb-b029-a70074f3f18f0000-0002-1253-6297 Melissa A Toups author 4E099E4E-F248-11E8-B48F-1D18A9856A870000-0002-9752-7380 Beatriz Vicoso author 49E1C5C6-F248-11E8-B48F-1D18A9856A870000-0002-4579-8306 BeVi department 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. https://research-explorer.ista.ac.at/download/20833/20834/README.txt text/plainno https://research-explorer.ista.ac.at/download/20833/20835/Supplementary_Datasets.zip application/zipno https://research-explorer.ista.ac.at/download/20833/20837/Perl_scripts.zip application/zipno https://research-explorer.ista.ac.at/download/20833/20959/Supplementary_Tables.zip application/zipno https://creativecommons.org/licenses/by/4.0/ Institute of Science and Technology Austria2026 Schizophorasex chromosomessex-chromosome turnoverDipteragenomic featuresout-of-X movement. 10.15479/AT-ISTA-20833 Layana Franco LA, Toups MA, Vicoso B. 2026. Research Data for ‘Causes and consequences of sex-chromosome turnovers in Diptera’, Institute of Science and Technology Austria, <a href="https://doi.org/10.15479/AT-ISTA-20833">10.15479/AT-ISTA-20833</a>. Layana Franco, Lorena Alexandra, Melissa A Toups, and Beatriz Vicoso. “Research Data for ‘Causes and Consequences of Sex-Chromosome Turnovers in Diptera.’” Institute of Science and Technology Austria, 2026. <a href="https://doi.org/10.15479/AT-ISTA-20833">https://doi.org/10.15479/AT-ISTA-20833</a>. L.A. Layana Franco, M.A. Toups, B. Vicoso, (2026). L. A. Layana Franco, M. A. Toups, and B. Vicoso, “Research Data for ‘Causes and consequences of sex-chromosome turnovers in Diptera.’” Institute of Science and Technology Austria, 2026. Layana Franco, L. A., Toups, M. A., &#38; Vicoso, B. (2026). Research Data for “Causes and consequences of sex-chromosome turnovers in Diptera.” Institute of Science and Technology Austria. <a href="https://doi.org/10.15479/AT-ISTA-20833">https://doi.org/10.15479/AT-ISTA-20833</a> 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> Layana Franco, Lorena Alexandra, et al. <i>Research Data for “Causes and Consequences of Sex-Chromosome Turnovers in Diptera.”</i> Institute of Science and Technology Austria, 2026, doi:<a href="https://doi.org/10.15479/AT-ISTA-20833">10.15479/AT-ISTA-20833</a>. 208332025-12-17T10:10:57Z2026-06-10T09:21:49Z