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Article in Journal ()

Genetics of sex determination in tilapiine species

Cnaani A, Lee B, Zilberman N, Ozouf-Costaz C, Hulata G, Ron M, D’Hont A, Baroiller J, D’Cotta H, Penman D, Tomasino E, Coutanceau J, Pepey E, Shirak A & Kocher TD (2008) Genetics of sex determination in tilapiine species, Sexual Development, 2 (1), pp. 43-54.

We identified DNA markers linked to sex determining genes in six closely related species of tilapiine fishes. The mode of sex determination differed among species. In Oreochromis karongae and Tilapia mariae the sex-determining locus is on linkage group (LG) 3 and the female is heterogametic (WZ-ZZ system). In O. niloticus and T. zillii the sex-determining locus is on LG1 and the male is heterogametic (XX-XY system). A more complex pattern was observed in O. aureus and O. mossambicus, in which markers on both LG1 and LG3 were associated with sex. We found evidence for sex-linked lethal effects on LG1, as well as interactions between loci in the two linkage groups. Comparison of genetic and physical maps demonstrated a broad region of recombination suppression harboring the sex-determining locus on LG3. Sex-specific recombination suppression was found in the female heterogametic sex. Sequence analysis showed the accumulation of repetitive elements in this region. Phylogenetic analysis suggests that at least two transitions in the mode of sex determination have occurred in this clade. This variation in sex determination mechanisms among closely related species makes tilapias an excellent model system for studying the evolution of sex chromosomes in vertebrates.

Cichlidae; heterogametic sex; inversion; Oreochromis; recombination suppression; sex chromosome; sex determination; Tilapia

Subject headings
Tilapia; Tilapia Genetics; Sex determination, Genetic; Sex Chromosomes genetics

AuthorsCnaani Avner, Lee Bo-Young, Zilberman Noam, Ozouf-Costaz Catherine, Hulata Gideon, Ron Micha, D’Hont Angelique, Baroiller Jean-Francois, D’Cotta Helena, Penman David, Tomasino Elizabeth, Coutanceau Jean-Pierre, Pepey Elodie, Shirak Andrey, Kocher Thomas D
Publication date04/2008
Date accepted by journal22/10/2007
ISSN 1661-5425

Sexual Development: Volume 2, Issue 1 (2008-04)

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