Tribolium castaneum Transformer-2 regulates sex determination and development in both males and females.
Tribolium castaneum Transformer (TcTra) is essential for female sex determination and maintenance through the regulation of sex-specific splicing of doublesex (dsx) pre-mRNA. In females, TcTra also regulates the sex-specific splicing of its own pre-mRNA to ensure continuous production of functional Tra protein. Transformer protein is absent in males and hence dsx pre-mRNA is spliced in a default mode. The mechanisms by which males inhibit the production of functional Tra protein are not known. Here, we report on functional characterization of transformer-2 (tra-2) gene (an ortholog of Drosophila transformer-2) in T. castaneum. RNA interference-mediated knockdown in the expression of gene coding for tra-2 in female pupae or adults resulted in the production of male-specific isoform of dsx and both female and male isoforms of tra suggesting that Tra-2 is essential for the female-specific splicing of tra and dsx pre-mRNAs. Interestingly, knockdown of tra-2 in males did not affect the splicing of dsx but resulted in the production of both female and male isoforms of tra suggesting that Tra-2 suppresses female-specific splicing of tra pre-mRNA in males. This dual regulation of sex-specific splicing of tra pre-mRNA ensures a tight regulation of sex determination and maintenance. These data suggest a critical role for Tra-2 in suppression of female sex determination cascade in males. In addition, RNAi studies showed that Tra-2 is also required for successful embryonic and larval development in both sexes.
Department of Entomology, College of Agriculture, S-225 Agriculture Science Center North, University of Kentucky, Lexington, KY 40546, United States.
Jayendra Nath
JN
Shukla
Subba Reddy
SR
Palli
D000818:Animals; D029721:Drosophila Proteins / Q000235:genetics*; D004331:Drosophila melanogaster / Q000235:genetics; D005260:Female; D008297:Male; D034622:RNA Interference; D012322:RNA Precursors / Q000235:genetics*; D012326:RNA Splicing; D012261:Ribonucleoproteins / Q000235:genetics*; D019849:Sex Determination Processes; D014231:Tribolium / Q000235:genetics / Q000254:growth & development*
D029721:Drosophila Proteins; D012322:RNA Precursors; D012261:Ribonucleoproteins; C066174:tra2 protein, Drosophila
Alternative splicing; Doublesex; RNAi; Sex determination; Transformer