The transformer gene in Ceratitis capitata provides a genetic basis for selecting and remembering the sexual fate.
The medfly Ceratitis capitata contains a gene (Cctra) with structural and functional homology to the Drosophila melanogaster sex-determining gene transformer (tra). Similar to tra in Drosophila, Cctra is regulated by alternative splicing such that only females can encode a full-length protein. In contrast to Drosophila, however, where tra is a subordinate target of Sex-lethal (Sxl), Cctra seems to initiate an autoregulatory mechanism in XX embryos that provides continuous tra female-specific function and act as a cellular memory maintaining the female pathway. Indeed, a transient interference with Cctra expression in XX embryos by RNAi treatment can cause complete sexual transformation of both germline and soma in adult flies, resulting in a fertile male XX phenotype. The male pathway seems to result when Cctra autoregulation is prevented and instead splice variants with truncated open reading frames are produced. We propose that this repression is achieved by the Y-linked male-determining factor (M).
Dipartimento di Genetica, Biologia Generale e Molecolare, Università degli Studi di Napoli Federico II, Via Mezzocannone 8, 80134 Napoli, Italy.
Attilio
A
Pane
Marco
M
Salvemini
Pasquale
P
Delli Bovi
Catello
C
Polito
Giuseppe
G
Saccone
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D004175:Diptera / Q000033:anatomy & histology / Q000235:genetics* / Q000254:growth & development; D029721:Drosophila Proteins; D005260:Female; D018507:Gene Expression Regulation, Developmental; D017344:Genes, Insect; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism*; D007621:Karyotyping; D008297:Male; D008954:Models, Biological; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D010641:Phenotype; D012313:RNA / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D019849:Sex Determination Processes; D026801:Synteny
D029721:Drosophila Proteins; D019476:Insect Proteins; D009687:Nuclear Proteins; C097162:Tra protein, Drosophila; D012313:RNA