ISOLATION AND CHARACTERIZATION OF CAENORHABDITIS BRIGGSAE TRA MUTANTS.

Abstract

In order to aid in the reconstruction of the <em>Caenorhabditis briggsae</em> sex determination pathway, for the purposes of studying the convergent evolution of hermaphroditism and mating system change in nematodes, <em>Cb-tra</em> mutants have been isolated through forward mutagenesis. Based on phenotype, genetic linkage, molecular linkage, and in some cases sequence analysis, the <em>C. briggsae</em> homologs of <em>tra-1</em>, <em>tra-2</em>, and possibly <em>tra-3</em> have been identified. Upon further characterization, the function of the <em>tra</em> genes during sex determination between <em>C. elegans</em> and <em>C. briggsae</em> appears to be largely conserved. However, notable differences, with respect to the role of <em>tra-1</em> and potentially the role of <em>tra-3</em>, have been observed between these two species. In addition, intra-species suppression of the putative <em>tra-3</em> mutant (AF16 background) by genomic variants in the wild-type strain HK104 suggests that molecular interactions underlying sex determination are changing between these two <em>C. briggsae</em> populations.