1. Fish diversity
Laura (6)

2. Species richness in vertebrates

3. Genome and biodiversity
- Genome duplication and differential rediploidisation
- Transposable elements
- Sex chromosomes and sex determination

4. Sex determination systems in vertebrates
Ezaz et al. 2006

5. Diversity of sex determination in fish
Others:
- Autosomal influence
- Polyfactorial
- With several sex chromosomes
With several pairs of sex chromosomes …
Mank et al. 2006

6. Diversity of sex determination in Poeciliids

7. Sex determination systems in vertebrates: master sex-determining genes
SRY
dmrt1 (?) (Z)
DM-W (?) (W)
dmrt1bY (Y)
medaka
XY/XX
Ezaz et al. 2006

8. Dmrt1bY, a recent master sex-determining gene from the medaka fish
Oryzias latipes

9. 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

10. 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?

11. “Speciation genes” on sex chromosomes
Qvarnström and Bailey 2009

12. Sex determination evolution and prezygotic reproductive isolationW Z

13. Fish models for the study of genetic sex determination

14. The genus Xiphophorus
Livebearing, freshwater fish, first described 1884 by Heckel,
Genus contains three groups: Northern and Southern swordtails and platyfish
~23 species described

15. Melanoma formation in Xiphophorus interspecific hybrids

16. X X -/- ; R-/R- Xmrk/Xmrk -/- ; R-/R- Xmrk/- Xmrk/- Xmrk/- - / -
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-

17. The sex-determining region of the platyfish X. maculatus
Melanoma-
inducing
oncogene
Sex-
determining
locus
Macromelanophore
determining locus
Red-yellow
locus
Proto-oncogene
Tel
Cen Y
Mdl
Xmrk RY SD
Egfr-b X
Mdl
Xmrk RY SD
Egfr-b W SD
Egfr-b P
Melanoma
puberty locus P
WX WY XX
XY YY

18. Positional cloning strategyX
XmrkX
X-linked
egfrbX Y
XmrkY
Y-linked
egfrbY
Bacterial artificial clones (BACs)

19. Homomorphic sex chromosomes in the platyfishXY XX

20. 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

21. 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

23. Equipe “Génomique Evolutive des Vertébrés“
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 23

24. 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)