title: fruitless Gene products truncated of their male-like qualities promote neural and behavioral maleness in Drosophila if these proteins are produced in the right places at the right times.
abstract: To bring GAL4 production under the control of the sex promoter (P1) contained within Drosophila's fruitless gene, a gal4 cassette was previously inserted downstream of P1. This insert should eliminate male-specific FRU(M) proteins, which normally contain 101 amino acids (aa's) at their N termini. Thus males homozygous for the P1-gal4 insert should be courtless, as was briefly stated to be so in the initial report of this transgenic type. But XY flies whose only fru form is P1-gal4 have now been found to court vigorously. P1-gal4 females displayed no appreciable male-like actions except courtship rejection behaviors; yet, they developed a male-specific abdominal muscle. No immunoreactivity against the male-specific aa's was detectable in P1-gal4 flies. But male-like neural signals were observed in XY or XX P1-gal4 pupae and adults after applying an antibody that detects all FRU isoforms; transgenic females displayed reduced expression of such proteins. RT-PCR's rationalized these findings: P1 transcripts include anomalous splice forms from which gal4 was removed, allowing FRU's lacking M aa's to be produced in male-like patterns in both sexes. Within males, such defective proteins promote neural differentiation and function that is sufficient to support spirited P1-gal4 courtship. But dispensability of the male-specific FRU N-terminus is tempered by the finding that intra-fru sequences encoding these 101 aa's are highly conserved among interspecific relatives of D. melanogaster.
authors: Department of Biology, Brandeis University, Waltham, Massachusettes 02454-9110, USA.
authors: Sarah L
authors: SL
authors: Ferri
authors: Rudolf A
authors: RA
authors: Bohm
authors: Hayden E
authors: HE
authors: Lincicome
authors: Jeffrey C
authors: JC
authors: Hall
authors: Adriana
authors: A
authors: Villella
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D001921:Brain / Q000378:metabolism; D003380:Courtship; D029721:Drosophila Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000502:physiology; D004331:Drosophila melanogaster / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D005260:Female; D005298:Fertility / Q000235:genetics; D017344:Genes, Insect; D005838:Genotype; D008297:Male; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D012727:Sex Characteristics; D012726:Sexual Behavior, Animal / Q000502:physiology*; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics* / Q000502:physiology; D014158:Transcription, Genetic; D014921:Wings, Animal / Q000033:anatomy & histology
chemical_list: D029721:Drosophila Proteins; D009419:Nerve Tissue Proteins; D014157:Transcription Factors; C103226:fru protein, Drosophila