title: BmTGIF, a Bombyx mori homolog of Drosophila DmTGIF, regulates progression of spermatogenesis.
abstract: TG-interacting factor (TGIF) in Drosophila consists of two tandemly-repeated genes, achintya (Dmachi) and vismay (Dmvis), which act as transcriptional activators in Drosophila spermatogenesis. In contrast, TGIF in humans is a transcriptional repressor that binds directly to DNA or interacts with corepressors to repress the transcription of target genes. In this study, we investigated the characteristics and functions of BmTGIF, a Bombyx mori homolog of DmTGIF. Like DmTGIF, BmTGIF is predominantly expressed in the testes and ovaries. Four alternatively spliced isoforms could be isolated from testes, and two isoforms from ovaries. Quantitative polymerase chain reaction indicated BmTGIF was abundantly expressed in the testis of 3rd instar larvae, when the testis is almost full of primary spermatocytes. The results of luciferase assays indicated that BmTGIF contains two adjacent acidic domains that activate the transcription of reporter genes. Immunofluorescence assay in BmN cells showed that the BmTGIF protein was located mainly in the nucleus, and paraffin sections of testis showed BmTGIF was grossly expressed in primary spermatocytes and mature sperms. Consistent with the role of DmVis in Drosophila development, BmTGIF significantly affected spermatid differentiation, as indicated by hematoxylin-eosin staining of paraffin sections of testis from BmTGIF-small interfering RNA (siRNA)-injected male silkworms. Co-immunoprecipitation experiments suggested that BmTGIF interacted with BmAly, and that they may recruit other factors to form a complex to regulate the genes required for meiotic divisions and spermatid differentiation. The results of this analysis of BmTGIF will improve our understanding of the mechanism of spermatid differentiation in B. mori, with potential applications for pest control.
authors.affiliation: School of Biology and Basic Medical Science, Soochow University, Suzhou, People's Republic of China.
authors.forename: Pengjie
authors.initials: P
authors.lastname: Zhang
authors.forename: Guangli
authors.initials: G
authors.lastname: Cao
authors.forename: Jie
authors.initials: J
authors.lastname: Sheng
authors.forename: Renyu
authors.initials: R
authors.lastname: Xue
authors.forename: Chengliang
authors.initials: C
authors.lastname: Gong
mesh_terms: D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies / Q000276:immunology; D012831:Bombyx / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005260:Female; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D023061:Gene Order; D006434:Hemocytes / Q000378:metabolism; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D007814:Larva; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D010053:Ovary / Q000378:metabolism; D010802:Phylogeny; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D021381:Protein Transport; D034622:RNA Interference; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D016415:Sequence Alignment; D013091:Spermatogenesis / Q000235:genetics*; D013094:Spermatozoa / Q000378:metabolism; D013737:Testis / Q000378:metabolism; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000378:metabolism
chemical_list: D000906:Antibodies; D029721:Drosophila Proteins; D019476:Insect Proteins; D011994:Recombinant Proteins; D014157:Transcription Factors; C476930:achi protein, Drosophila