article published yes Mario de Bono author 4E3FF80E-F248-11E8-B48F-1D18A9856A870000-0001-8347-0443 J. Hodgkin author 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 defined several conserved regions likely to be important for tra-1 function. The phenotype 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. Genetics Society of America1996 eng amino acid sequencearticlecaenorhabditis elegansevolutiongenetic variabilitynonhumanpriority journalsex determinationAmino Acid SequenceAnimalsAnimalsGenetically ModifiedBase SequenceCaenorhabditisCaenorhabditis elegansCaenorhabditis elegans ProteinsDNAHelminthDNA-Binding ProteinsEvolutionMolecularFemaleHelminth ProteinsMembrane ProteinsMolecular Sequence DataMutagenesisRNAMessengerSequence HomologyAmino AcidSex Determination (Analysis)Transcription FactorsTransgenesTurner SyndromeAnimaliaCaenorhabditisCaenorhabditis briggsaeCaenorhabditis elegansNematoda 00166731 8889522 1442587-595 yes M. de Bono, J. Hodgkin, Genetics 144 (1996) 587–595. de Bono, M., &#38; Hodgkin, J. (1996). Evolution of sex determination in Caenorhabditis: Unusually high divergence of tra-1 and its functional consequences. <i>Genetics</i>. Genetics Society of America. de Bono M, Hodgkin J. Evolution of sex determination in Caenorhabditis: Unusually high divergence of tra-1 and its functional consequences. <i>Genetics</i>. 1996;144(2):587-595. Bono, Mario de, and J. Hodgkin. “Evolution of Sex Determination in Caenorhabditis: Unusually High Divergence of Tra-1 and Its Functional Consequences.” <i>Genetics</i>. Genetics Society of America, 1996. de Bono, Mario, and J. Hodgkin. “Evolution of Sex Determination in Caenorhabditis: Unusually High Divergence of Tra-1 and Its Functional Consequences.” <i>Genetics</i>, vol. 144, no. 2, Genetics Society of America, 1996, pp. 587–95. de Bono M, Hodgkin J. 1996. Evolution of sex determination in Caenorhabditis: Unusually high divergence of tra-1 and its functional consequences. Genetics. 144(2), 587–595. M. de Bono and J. Hodgkin, “Evolution of sex determination in Caenorhabditis: Unusually high divergence of tra-1 and its functional consequences,” <i>Genetics</i>, vol. 144, no. 2. Genetics Society of America, pp. 587–595, 1996. 61612019-03-21T11:50:37Z2021-01-12T08:06:28Z