Fish diversity Laura 6 Species richness in vertebrates
Fish diversity Laura (6)
Species richness in vertebrates
Genome and biodiversity - Genome duplication and differential rediploidisation - Transposable elements - Sex chromosomes and sex determination
Sex determination systems in vertebrates Ezaz et al. 2006
Diversity of sex determination in fish - Mank et al. 2006 Others: Autosomal influence Polyfactorial With several sex chromosomes With several pairs of sex chromosomes …
Diversity of sex determination in Poeciliids
Sex determination systems in vertebrates: master sex-determining genes SRY dmrt 1 (? ) (Z) DM-W (? ) (W) dmrt 1 b. Y (Y) Ezaz et al. 2006 medaka XY/XX
Dmrt 1 b. Y, a recent master sex-determining gene from the medaka fish Oryzias latipes
Dmrt 1 b. Y, a recent master sex-determining gene from the medaka fish Oryzias latipes Tanaka et al. 2007 Dmrt 1 b. Y is not the universal master sex-determining gene in fish
Sex determination evolves very rapidly in fish Possible association with the formation of new sex-determining genes and new sex chromosomes Possible role in speciation?
“Speciation genes” on sex chromosomes Qvarnström and Bailey 2009
Sex determination evolution and prezygotic reproductive isolation XY WZ
Fish models for the study of genetic sex determination
The genus Xiphophorus www. Xiphophorus. org Livebearing, freshwater fish, first described 1884 by Heckel, Genus contains three groups: Northern and Southern swordtails and platyfish ~23 species described
Melanoma formation in Xiphophorus interspecific hybrids
Xiphophorus maculatus Xiphophorus hellerii X -/- ; R-/R- Xmrk/Xmrk ; R+/R+ X Xmrk/- ; R+/R- Xmrk/- ; R-/R- Xmrk/- ; R+/R- -/- ; R-/R- - / - ; R+/R- - /- ; R-/R-
The sex-determining region of the platyfish X. maculatus Macromelanophore determining locus Melanomainducing oncogene Sex. Red-yellow determining locus Proto-oncogene locus Tel Cen Y Mdl Xmrk RY SD Egfr-b X Mdl Xmrk RY SD Egfr-b P W Melanoma puberty locus WX WY XX P XY YY
Positional cloning strategy X Xmrk. X X-linked egfrb. X Y Xmrk. Y Y-linked egfrb. Y Bacterial artificial clones (BACs)
Homomorphic sex chromosomes in the platyfish XY XX
Neither dmrt nor sox genes in the sex-determining region of the platyfish No synteny with other fish sex chromosomes Independent origin of sex-determining genes and sex chromosomes in different fish species
Comparative sexomics in vertebrates Mammals Fish Origin Master gene Differentiation Degeneration ancient / unique (Sry) yes (Y) recent / multiple (? ) restricted Suppres. recombination Sex-specific gonad genes Gene duplications Transposable elements yes (Y) yes yes yes
Since 2007 Equipe “Génomique Evolutive des Vertébrés“ Institut de Génomique Fonctionnelle de Lyon CNRS/INRA/UCBL/ENSL Astrid Böhne Frédéric Brunet Delphine Galiana-Arnoux Christina Schultheis Amandine Darras Karim Madani Emilie Deleva Laurie Nave Domittile Chalopin Vincent Martin Jean-Nicolas Volff Until 2006 Bio. Future Research Group “Evolutionary Fish Genomics” Biozentrum, University of Würzburg, Germany Christina Schultheis Cornelia Schmidt Anne-Marie Veith Yvonne Selz Sabine Matschl Astrid Böhne Marc Rathmann Ingo Braasch Mariam Naciri Qingchun Zhou Agnès Dettai Alexander Froschauer Marina Vucic Jürgen Brandt Wolfgang Bernhardt Reinhold Hanel Jean-Nicolas Volff
Collaborations Manfred Schartl (University of Würzburg, Germany) Sylvie Samain, Jean Weissenbach (Genoscope, Evry) Catherine Ozouf-Costaz, Agnés Dettai (Muséum Natl d’Histoire Naturelle, Paris) Yann Guigen, Julien Bobe (INRA SCRIBE, Rennes) Jean-Francois Baroiller, Helena D‘Cotta (CIRAD Montpellier) Indrajit Nanda, Michael Schmid (University of Würzburg, Germany) Stefan Chilmonczyk (INRA, Jouy en Josas, France) Carsten Hoffman, Martin Lohse (University of Würzburg, Germany) Christoph Winkler (University of Singapore)
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