The sex-determining gene doublesex in the fly Megaselia scalaris: conserved structure and sex-specific splicing.
The well-known sex-determining cascade of Drosophila melanogaster serves as a paradigm for the pathway to sexual development in insects. But the primary sex-determining signal and the subsequent step, Sex-lethal (Sxl), have been shown not to be functionally conserved in non-Drosophila flies. We isolated doublesex (dsx), which is a downstream step in the cascade, from the phorid fly Megaselia scalaris, which is a distant relative of D. melanogaster. Conserved properties, e.g., sex-specific splicing, structure of the female-specific 3' splice site, a splicing enhancer region with binding motifs for the TRA2/RBP1/TRA complex that activates female-specific splicing in Drosophila, and conserved domains for DNA-binding and oligomerization in the putative DSX protein, indicate functional conservation of dsx in M. scalaris. Hence, the dsx step of the sex-determining pathway appears to be conserved among flies and probably in an even wider group of insects, as the analysis of a published cDNA from the silkmoth indicates.
Kuhn
S
S
Institut für Biologie, Medizinische Universität Lübeck, Germany.
Sievert
V
V
Traut
W
W
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017124:Conserved Sequence / Q000235:genetics*; D018076:DNA, Complementary / Q000032:analysis; D004268:DNA-Binding Proteins / Q000145:classification / Q000235:genetics*; D004175:Diptera / Q000235:genetics*; D029721:Drosophila Proteins; D019143:Evolution, Molecular; D005091:Exons; D018628:Gene Dosage; D019476:Insect Proteins / Q000145:classification / Q000235:genetics*; D007438:Introns; D008969:Molecular Sequence Data; D010802:Phylogeny; D012313:RNA / Q000032:analysis; D012326:RNA Splicing / Q000235:genetics*; D012045:Regulatory Sequences, Nucleic Acid; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D019849:Sex Determination Processes
D018076:DNA, Complementary; D004268:DNA-Binding Proteins; C070369:DSX protein, Drosophila; D029721:Drosophila Proteins; D019476:Insect Proteins; D012313:RNA