The effects of ectopic white and transformer expression on Drosophila courtship behavior.
The sex determining genes of Drosophila males and females function to establish the potential for sex-specific behaviors. Previous studies suggest that ectopic GAL4-directed misexpression of the female-specific isoform of the sex-determining gene transformer (tra) in specific sub-domains of an otherwise male brain can lead to bisexual courtship behavior, thus identifying brain domains that may mediate sex-specific behavior. However, expression of mini-white, the marker gene used in both P[GAL4] and P[UAS(G)] constructs, also induces males to court other males, questioning whether GAL4-mediated tra expression alone can induce bisexual behavior. Here we demonstrate the consequences of inducing mutations in the mini-white genes within P[GAL4] and P[UAS(G)] constructs to generate flies in which a white mutant phenotype is revealed. In these mini-white mutant strains, P[GAL4]-mediated transformer expression alone is both sufficient and necessary to generate bisexual behavior. In addition, using RT-PCR, we reveal the presence of female transcripts of doublesex and fruitless in the brains of otherwise male (XY) flies exhibiting P[GAL4]-directed tra-expression, demonstrating that P[GAL4]-directed tra is functional at the molecular level. We conclude that P[GAL4]-directed misexpression of tra is responsible for the bisexual behavior previously described and that this is mediated via sex-specific splicing of dsx and fru. Our results support the validity of such strategies for identifying regions of the fly brain that underlie sex-specific behaviors.
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IBLS Division of Molecular Genetics, University of Glasgow, 54 Dumbarton Road, Glasgow G11 6NU, UK.
Armstrong
J D
JD
Kaiser
K
K
O'Dell
K M
KM
D018528:ATP-Binding Cassette Transporters; D000818:Animals; D015152:Blotting, Northern; D004268:DNA-Binding Proteins / Q000235:genetics; D004330:Drosophila / Q000235:genetics / Q000502:physiology*; D029721:Drosophila Proteins; D005136:Eye Proteins / Q000235:genetics; D005260:Female; D005656:Fungal Proteins / Q000235:genetics; D005786:Gene Expression Regulation; D017344:Genes, Insect; D005819:Genetic Markers; D019476:Insect Proteins / Q000235:genetics; D008297:Male; D016296:Mutagenesis; D009419:Nerve Tissue Proteins / Q000235:genetics; D009687:Nuclear Proteins / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D029701:Saccharomyces cerevisiae Proteins; D012726:Sexual Behavior, Animal / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics; D019076:Transgenes
D018528:ATP-Binding Cassette Transporters; D004268:DNA-Binding Proteins; C070369:DSX protein, Drosophila; D029721:Drosophila Proteins; D005136:Eye Proteins; D005656:Fungal Proteins; C052130:GAL4 protein, S cerevisiae; D005819:Genetic Markers; D019476:Insect Proteins; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D029701:Saccharomyces cerevisiae Proteins; C097162:Tra protein, Drosophila; D014157:Transcription Factors; C103226:fru protein, Drosophila; C059254:w protein, Drosophila