Evolution of Sex Determination in Caenorhabditis: Unusually High Divergence of Tra-1 and Its Functional Consequences
AUTOR(ES)
de-Bono, M.
RESUMO
The tra-1 gene is a terminal regulator of somatic sex in Caenorhabditis elegans: high tra-1 activity elicits female development, low tra-1 activity elicits male development. To investigate the function and evolution of tra-1, we examined the tra-1 gene from the closely related nematode C. briggsae. Ce-tra-1 and Cb-tra-1 are unusually divergent. Each gene generates two transcripts, but only one of these is present in both species. This common transcript encodes TRA-1A, which shows only 44% amino acid identity between the species, a figure much lower than that for previously compared genes. A Cb-tra-1 transgene rescues many tissues of tra-1(null) mutants of C. elegans but not the somatic gonad or germ line. This transgene also causes nongonadal feminization of XO animals, indicating incorrect sexual regulation. Alignment of Ce-TRA-1A and Cb-TRA-1A defines several conserved regions likely to be important for tra-1 function. The phenotypic differences between Ce-tra-1(null) mutants rescued by Cb-tra-1 transgenes and wild-type C. elegans indicate significant divergence of regulatory regions. These molecular and functional studies suggest that evolution of sex determination in nematodes is rapid and genetically complex.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1207552Documentos Relacionados
- Analysis of the Role of Tra-1 in Germline Sex Determination in the Nematode Caenorhabditis Elegans
- Conservation of the global sex determination gene tra-1 in distantly related nematodes
- The TRA-1 transcription factor binds TRA-2 to regulate sexual fates in Caenorhabditis elegans
- Molecular Cloning and Duplication of the Nematode Sex-Determining Gene Tra-1
- Zinc fingers in sex determination: only one of the two C. elegans Tra-1 proteins binds DNA in vitro.