title: Testis-specific products of the Drosophila melanogaster sbr gene, encoding nuclear export factor 1, are necessary for male fertility.
abstract: The evolutionarily conserved nuclear export factor 1 (NXF1) provides mRNA export from the nucleus to the cytoplasm. We described several testis-specific transcripts of the Drosophila melanogaster nxf1 gene designated “sbr” in this species via different PCR approaches and CAGE-seq analysis. Characteristically, most of them have truncated 3′UTRs compared with those in other organs. In addition to regular transcripts, there are shorter transcripts that begin in intron 3 of the sbr gene. These short, 5′-truncated testis-specific transcripts vary in terms of transcription start site and their ability to exclude or retain the last 237 nucleotides of intron 3 in their 5′UTR. Using an anti-SBR antibody against the C-terminal portion of this protein, we detected the major SBR protein (74 kDa) in all analyzed organs of the fly as well as a new smaller protein (60 kDa) found only in the testes. This protein corresponds to the detected sbr transcripts that start in intron 3, based on its molecular mass. We investigated the sbr12 allele of the sbr gene, which is lethal in homozygous females and causes dominant sterility in heterozygous males. Sequencing of the sbr12 gene allele revealed a 30-bp deletion in exon 9 without a frame shift.Western blot analysiswith an SBR-specific antibody revealed two bands of the expected size in the testes of heterozygous males. Thus, a mutant protein along with the normal protein presents in the testes of lethal allele-bearing flies and the described shorter testis-specific variant of SBR may account for male sterility.
authors.affiliation: Animal Genetics Laboratory, Department of Genetics and Biotechnology, Faculty of Biology, Saint-Petersburg State University, Universitetskaya nab. 7-9, Saint-Petersburg 199034, Russia.
authors.forename: Victoria
authors.initials: V
authors.lastname: Ginanova
authors.affiliation: Animal Genetics Laboratory, Department of Genetics and Biotechnology, Faculty of Biology, Saint-Petersburg State University, Universitetskaya nab. 7-9, Saint-Petersburg 199034, Russia.
authors.forename: Elena
authors.initials: E
authors.lastname: Golubkova
authors.affiliation: Animal Genetics Laboratory, Department of Genetics and Biotechnology, Faculty of Biology, Saint-Petersburg State University, Universitetskaya nab. 7-9, Saint-Petersburg 199034, Russia.
authors.forename: Sergei
authors.initials: S
authors.lastname: Kliver
authors.affiliation: Animal Genetics Laboratory, Department of Genetics and Biotechnology, Faculty of Biology, Saint-Petersburg State University, Universitetskaya nab. 7-9, Saint-Petersburg 199034, Russia.
authors.forename: Elina
authors.initials: E
authors.lastname: Bychkova
authors.affiliation: Animal Genetics Laboratory, Department of Genetics and Biotechnology, Faculty of Biology, Saint-Petersburg State University, Universitetskaya nab. 7-9, Saint-Petersburg 199034, Russia.
authors.forename: Katerina
authors.initials: K
authors.lastname: Markoska
authors.affiliation: Animal Genetics Laboratory, Department of Genetics and Biotechnology, Faculty of Biology, Saint-Petersburg State University, Universitetskaya nab. 7-9, Saint-Petersburg 199034, Russia.
authors.forename: Natalia
authors.initials: N
authors.lastname: Ivankova
authors.affiliation: Animal Genetics Laboratory, Department of Genetics and Biotechnology, Faculty of Biology, Saint-Petersburg State University, Universitetskaya nab. 7-9, Saint-Petersburg 199034, Russia.
authors.forename: Irina
authors.initials: I
authors.lastname: Tretyakova
authors.affiliation: Institute of Cell Biophysics RAS, Pushchino, Moscow region 142290, Russia; Engelhardt Institute of Molecular Biology RAS, Vavilov str. 32, Moscow 119991, Russia. Electronic address: misha672011@yahoo.com.
authors.forename: Michael
authors.initials: M
authors.lastname: Evgen'ev
authors.affiliation: Animal Genetics Laboratory, Department of Genetics and Biotechnology, Faculty of Biology, Saint-Petersburg State University, Universitetskaya nab. 7-9, Saint-Petersburg 199034, Russia.
authors.forename: Ludmila
authors.initials: L
authors.lastname: Mamon
mesh_terms: D020121:5' Untranslated Regions; D000595:Amino Acid Sequence; D000818:Animals; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism; D004331:Drosophila melanogaster; D005260:Female; D007248:Infertility, Male / Q000235:genetics*; D008297:Male; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D012326:RNA Splicing; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D013737:Testis / Q000378:metabolism*
chemical_list: D020121:5' Untranslated Regions; D029721:Drosophila Proteins; D009687:Nuclear Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; C445086:SBR protein, Drosophila
keywords: Alternative polyadenylation; Alternative transcription; D. melanogaster; Nuclear export factor (nxf); Spermatogenesis; sbr gene