Interspecies Comparison Reveals Evolution of Control Regions in the Nematode Sex-Determining Gene Tra-2

AUTOR(ES)

Kuwabara, P. E.

RESUMO

The Caenorhabditis elegans sex-determining gene tra-2 promotes female development and expresses 4.7-, 1.9- and 1.8-kb mRNAs. The 4.7-kb mRNA encodes the major feminizing activity of the locus, a predicted membrane receptor that mediates cell-to-cell communication, named TRA-2A. The tra-2 gene was characterized from a close relative, C. briggsae. The Cb-tra-2 gene expresses only a 4.7-kb mRNA and alternatively spliced variants, which encode TRA-2A homologues. The Cb-TRA-2A and Ce-TRA-2A sequences are highly diverged, sharing only 43% identity, although their hydropathy profiles remain remarkably similar. Three potential regulatory sites of Ce-tra-2 activity were previously identified by analyzing tra-2(eg), tra-2(gf), and tra-2(mx) mutations. Two of these sites, the EG site and MX region, are conserved in Cb-tra-2. By contrast, the two direct repeat elements in the Ce-tra-2 3' untranslated region, which are disrupted in tra-2(gf) mutants, are absent. Injection of Cb-tra-2 antisense RNA into C. briggsae mimics the Ce-tra-2 loss-of-function phenotype. Thus, antisense RNA permits studies of gene activity in nematodes that lack extensive genetics.

Documentos Relacionados

• Differential control of yolk protein gene expression in fat bodies and gonads by the sex-determining gene tra-2 of Drosophila.
• Molecular Cloning and Duplication of the Nematode Sex-Determining Gene Tra-1
• Activity of the Sex-Determining Gene tra-2 Is Modulated to Allow Spermatogenesis in the C. ELEGANS Hermaphrodite
• Alternatively spliced transcripts of the sex-determining gene tra-2 of Drosophila encode functional proteins of different size.
• Convergent Evolution of Chromosomal Sex-Determining Regions in the Animal and Fungal Kingdoms