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

Mank et al. 2006

Diversity of sex determination in fish

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

Ezaz et al. 2006medakaXY/XX

dmrt1bY (Y)

dmrt1 (?) (Z)

DM-W (?) (W)

SRY

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

Dmrt1bY is not the universal master sex-determining gene in

fish

Tanaka et al. 2007

Sex determination evolves very rapidly in fish

Possible association with the formation of new sex-determininggenes 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

Fish models for the study of genetic sex determination

www.Xiphophorus.org

The genus Xiphophorus

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

X

X

Xiphophorus maculatus Xiphophorus hellerii

Xmrk/Xmrk; R+/R+

Xmrk/- ; R+/R-

-/- ; R-/R-

-/- ; R-/R-

Xmrk/- ; R+/R-Xmrk/- ; R-/R- - / - ; R+/R- - /- ; R-/R-

The sex-determining region of the platyfish X. maculatus

Tel

XmrkMdl RY

Cen

Egfr-bSD

XmrkMdl RY SD

P

Egfr-b

Melanoma-inducingoncogene Proto-oncogene

SD Egfr-b

Y

X

W

Sex-determining

locus

Melanoma

Macromelanophoredetermining locus

Ppuberty locus

Red-yellowlocus

WX WY XX XY YY

Positional cloning strategy

egfrbYXmrkYY

egfrbXXmrkXX X-linked

Y-linked

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 andsex 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 2007Equipe “Génomique Evolutive des Vertébrés“Institut de Génomique Fonctionnelle de LyonCNRS/INRA/UCBL/ENSL

Astrid Böhne Frédéric BrunetDelphine Galiana-Arnoux Christina SchultheisAmandine Darras Karim MadaniEmilie Deleva Laurie NaveDomittile Chalopin Vincent MartinJean-Nicolas Volff

Until 2006BioFuture Research Group “Evolutionary Fish Genomics”Biozentrum, University of Würzburg, Germany

Christina Schultheis Qingchun ZhouCornelia Schmidt Agnès DettaiAnne-Marie Veith Alexander FroschauerYvonne Selz Marina VucicSabine Matschl Jürgen BrandtAstrid Böhne Wolfgang BernhardtMarc Rathmann Reinhold HanelIngo 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 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)