310 likes | 800 Views
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.
E N D
Fish diversity Laura (6)
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 • Others: • - Autosomal influence • - Polyfactorial • - With several sex chromosomes • With several pairs of sex chromosomes • … Mank et al. 2006
dmrt1 (?) (Z) DM-W (?) (W) Sex determination systems in vertebrates: master sex-determining genes SRY dmrt1bY (Y) medaka XY/XX Ezaz et al. 2006
Dmrt1bY, a recent master sex-determining gene from the medaka fish Oryzias latipes
Dmrt1bY, a recent master sex-determining gene from the medaka fish Oryzias latipes Tanaka et al. 2007 Dmrt1bY 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 X Y W Z
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
Xiphophorus maculatus Xiphophorus hellerii X -/- ;R-/R- Xmrk/Xmrk ;R+/R+ X -/- ;R-/R- Xmrk/- ;R+/R- Xmrk/- ;R-/R- Xmrk/- ;R+/R- - / - ;R+/R- - /- ;R-/R-
The sex-determining region of the platyfish X. maculatus Sex- determining locus Melanoma- inducing oncogene Macromelanophore determining locus Red-yellow locus Proto-oncogene Tel Cen Y Mdl Xmrk RY SD Egfr-b X Xmrk SD Mdl RY Egfr-b SD Egfr-b W P Melanoma P puberty locus WX WY XX XYYY
Positional cloning strategy X egfrbX XmrkX X-linked Y Y-linked XmrkY egfrbY Bacterial artificial clones (BACs)
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 ancient / unique recent / multiple Master gene unique (Sry) multiple (?) Differentiation yes restricted Degeneration yes (Y) restricted Suppres. recombination yes yes Sex-specific gonad genes yes (Y) yes Gene duplications yes yes Transposable elements 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 BioFuture Research Group “Evolutionary Fish Genomics” Biozentrum, University of Würzburg, Germany Christina Schultheis Qingchun Zhou Cornelia Schmidt Agnès Dettai Anne-Marie Veith Alexander Froschauer Yvonne Selz Marina Vucic Sabine Matschl Jürgen Brandt Astrid Böhne Wolfgang Bernhardt Marc Rathmann Reinhold Hanel Ingo Braasch Jean-Nicolas Volff Mariam Naciri
Collaborations Manfred Schartl (University of Würzburg, Germany) Sylvie Samain, Jean Weissenbach (Genoscope, Evry) Catherine Ozouf-Costaz, Agnés Dettai (Muséum Natld’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)