Aller au contenu. | Aller à la navigation

Outils personnels

Navigation
Vous êtes ici : Accueil / Équipes / Comparative and Integrative Genomics of Organ Development - S.Pantalacci/M. Semon / Publications / Molecular analysis of the sex chromosomes of the platyfish Xiphophorus maculatus: Towards the identification of a new type of master sexual regulator in vertebrates.

Molecular analysis of the sex chromosomes of the platyfish Xiphophorus maculatus: Towards the identification of a new type of master sexual regulator in vertebrates.

Astrid Bohne, Christina Schultheis, Delphine Galiana-Arnoux, Alexander Froschauer, Qingchun Zhou, Cornelia Schmidt, Yvonne Selz, Catherine Ozouf-Costaz, Agnes Dettai, Beatrice Segurens, Arnaud Couloux, Sylvie Bernard-Samain, Valerie Barbe, Stefan Chilmonczyk, Frederic Brunet, Amandine Darras, Marta Tomaszkiewicz, Marie Semon, Manfred Schartl, and Jean-Nicolas Volff (2009)

Integr Zool, 4(3):277-84.

In contrast to mammals and birds, fish display an amazing diversity of genetic sex determination systems, with frequent changes during evolution possibly associated with the emergence of new sex chromosomes and sex-determining genes. To better understand the molecular and evolutionary mechanisms driving this diversity, several fish models are studied in parallel. Besides the medaka (Oryzias latipes Temminck and Schlegel, 1846) for which the master sex-determination gene has been identified, one of the most advanced models for studying sex determination is the Southern platyfish (Xiphophorus maculatus, Gunther 1966). Xiphophorus maculatus belongs to the Poeciliids, a family of live-bearing freshwater fish, including platyfish, swordtails and guppies that perfectly illustrates the diversity of genetic sex-determination mechanisms observed in teleosts. For X. maculatus, bacterial artificial chromosome contigs covering the sex-determination region of the X and Y sex chromosomes have been constructed. Initial molecular analysis demonstrated that the sex-determination region is very unstable and frequently undergoes duplications, deletions, inversions and other rearrangements. Eleven gene candidates linked to the mastersex-determining gene have been identified, some of them corresponding to pseudogenes. All putative genes are present on both the X and the Y chromosomes,suggesting a poor degree of differentiation and a young evolutionary age for platyfish sex chromosomes. When compared with other fish and tetrapod genomes, syntenies were detected only with autosomes. This observation supports an independent origin of sex chromosomes, not only in different vertebrate lineagesbut also between different fish species.

 
automatic medline import

Actions sur le document