TY - JOUR T1 - An ancient truncated duplication of the anti-Mullerian hormone receptor type 2 gene is a potential conserved master sex determinant in the Pangasiidae catfish family JF - bioRxiv DO - 10.1101/2022.01.14.475871 SP - 2022.01.14.475871 AU - Ming Wen AU - Qiaowei Pan AU - Elodie Jouanno AU - Jerome Montfort AU - Margot Zahm AU - Cédric Cabau AU - Christophe Klopp AU - Carole Iampietro AU - Céline Roques AU - Olivier Bouchez AU - Adrien Castinel AU - Cécile Donnadieu AU - Hugues Parrinello AU - Charles Poncet AU - Elodie Belmonte AU - Véronique Gautier AU - Jean-Christophe Avarre AU - Remi Dugue AU - Rudhy Gustiano AU - Trần Thị Thúy Hà AU - Marc Campet AU - Kednapat Sriphairoj AU - Josiane Ribolli AU - Fernanda L. de Almeida AU - Thomas Desvignes AU - John H. Postlethwait AU - Christabel Floi Bucao AU - Marc Robinson-Rechavi AU - Julien Bobe AU - Amaury Herpin AU - Yann Guiguen Y1 - 2022/01/01 UR - http://biorxiv.org/content/early/2022/01/15/2022.01.14.475871.abstract N2 - The evolution of sex determination (SD) mechanisms in teleost fishes is amazingly dynamic, as reflected by the variety of different master sex-determining genes identified, even sometimes among closely related species. Pangasiids are a group of economically important catfishes in many South-Asian countries, but little is known about their sex determination system. Here, we generated novel genomic resources for 12 Pangasiid species and provided a first characterization of their SD system. Based on an Oxford Nanopore long-read chromosome-scale high quality genome assembly of the striped catfish Pangasianodon hypophthalmus, we identified a duplication of the anti-Müllerian hormone receptor type II gene (amhr2), which was further characterized as being sex-linked in males and expressed only in testicular samples. These first results point to a male-specific duplication on the Y chromosome (amhr2by) of the autosomal amhr2a. Sequence annotation revealed that the P. hypophthalmus Amhr2by is truncated in its N-terminal domain, lacking the cysteine-rich extracellular part of the receptor that is crucial for ligand binding, suggesting a potential route for its neofunctionalization. Short-read genome sequencing and reference-guided assembly of 11 additional Pangasiid species, along with sex-linkage studies, revealed that this truncated amhr2by duplication is also conserved as a male-specific gene in many Pangasiids. Reconstructions of the amhr2 phylogeny suggested that amhr2by arose from an ancient duplication / insertion event at the root of the Siluroidei radiation that is dated around 100 million years ago. Altogether these results bring multiple lines of evidence supporting that amhr2by is an ancient and conserved master sex-determining gene in Pangasiid catfishes, a finding that highlights the recurrent usage of the transforming growth factor β pathway in teleost sex determination and brings another empirical case towards the understanding of the dynamics or stability of sex determination systems.Competing Interest StatementThe authors have declared no competing interest. ER -