Vanderlinde T. auteur aut IRD Uno F. auteur aut IRD Goldstein G. auteur aut IRD Sabot François auteur aut IRD Carareto C. M. A. auteur aut IRD Vieira C. auteur aut IRD Markow T. A. auteur aut IRD Carvalho A. B. auteur aut IRD text journalArticle eng text/pdf born digital access Y chromosomes play important roles in sex determination, male fertility, and, in some cases, hybrid male sterility. Nearly 40 years ago, Zouros and co-workers found that Drosophila mojavensis males carrying a Y chromosome from the sibling species D. arizonae are sterile, with fertility restored by chromosome 4 from D. arizonae. While these findings could result from gene interactions, they may also suggest the movement of an essential male fertility gene from the Y to chromosome 4 in the D. arizonae lineage. To test this, we analyzed the Y-linked gene content of D. mojavensis, D. arizonae, and the closely related D. navojoa. We identified 5 previously unreported Y-linked genes, bringing the total to 14. These genes fit the pattern observed in other Drosophila species: they originated from autosomal, testis-specific genes that duplicated onto the Y chromosome. All Y-linked genes are shared between D. arizonae and D. mojavensis, ruling out the movement of a protein-coding gene as the cause of sterility. However, we found a huge difference in the copy number of GI26128, an HP1 gene family member, with similar to 1,400 Y-linked copies in D. arizonae but only 6 in D. mojavensis, making it a candidate to explain the hybrid male sterility. specialized mojavensis cluster Y chromosome gene duplication hybrid sterility Drosophila 020 Early access [13 p.] 2025 0014-3820 https://www.documentation.ird.fr/hor/fdi:010094972 10.1093/evolut/qpaf163 0014-3820 [F B010094972] https://www.documentation.ird.fr/hor/fdi:010094972 https://www.documentation.ird.fr/intranet/publi/2025-10/010094972.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2025-10-29 2025-11-04 fdi:010094972 fre