Sequence conservation and expression of the sex-lethal homologue in the fly Megaselia scalaris.
Sex-lethal (Sxl) is Drosophila melanogaster's key regulating gene in the sex-determining cascade. Its homologue in Megaselia scalaris, the chromosome 3 gene Megsxl, codes for a protein with an overall similarity of 77% with the corresponding D. melanogaster sequence. Expression in M. scalaris, however, is very unlike that in D. melanogaster. Megsxl transcripts with a long ORF occur in both sexes. Differential splicing is conserved but not sex-specific. There are several splice variants, among them one is common to gonads and somatic tissues of all developmental stages investigated, one is specific for ovaries and embryos, and a third one is not found in ovaries. In the ovary, Megsxl is heavily transcribed in nurse cells and transported into eggs. These results suggest a non-sex-determining function during early embryogenesis; the presence of Megsxl RNA in testes and somatic tissues calls for other (or more) functions.
Sievert
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V
Institut für Biologie, Medizinische Universität Lübeck, Germany.
Kuhn
S
S
Paululat
A
A
Traut
W
W
D000367:Age Factors; D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D017124:Conserved Sequence; D018076:DNA, Complementary / Q000235:genetics; D004175:Diptera / Q000235:genetics*; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics; D015723:Gene Library; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D016601:RNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019849:Sex Determination Processes; D012737:Sex Factors
D018076:DNA, Complementary; D029721:Drosophila Proteins; D016601:RNA-Binding Proteins; C067777:Sxl protein, Drosophila