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Yoshiaki Suzuki - One of the best experts on this subject based on the ideXlab platform.
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Involvement of the Bombyx Scr gene in development of the embryonic silk gland.
Developmental biology, 1997Co-Authors: Hiroki Kokubo, Kohji Ueno, Kazuhito Amanai, Yoshiaki SuzukiAbstract:Homeotic selector genes determine the identity of each segment and induce the differentiation of segment-specific organs. To analyze how the silk glands of the lepidopteran, Bombyx mori, develop, we cloned and identified two genes that encode the homeodomain and its flanking regions identical to the corresponding regions of Deformed and Sex combs reduced. Using in situ hybridization and immunohistochemistry, we analyzed the expression patterns of these genes during Bombyx embryogenesis. Bombyx Deformed is expressed in the mandibular and maxillary segments, whereas expression of Bombyx Sex combs reduced is first limited to the labial segment and at later stages extended to the anterior part of the prothoracic segment. The expression of Bombyx Sex combs reduced then disappears from the invaginating placodes of silk glands where expression of Bombyx fork head/SGF-1 follows. In the Nc/Nc mutant embryos, which lack the 3' end region of Bombyx Antennapedia, in addition to the expression in the labial segment, the Bombyx Sex combs reduced is expressed ectopically in the thoracic and abdominal regions, and Bombyx fork head/SGF-1 is also ectopically expressed in the T1, T2, and T3 segments, resulting the ectopic induction of the silk gland invaginations. These results suggest that Bombyx homeobox genes such as the Bombyx Deformed and Sex combs reduced are associated with determination of the segment identities and Bombyx Sex combs reduced is involved in the induction of silk gland development.
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Genes that are involved in Bombyx body plan and silk gene regulation
The International journal of developmental biology, 1994Co-Authors: Yoshiaki SuzukiAbstract:I have summed up how silk gene regulation studies in Bombyx mori have been carried out. This process has brought me naturally to realize the importance of understanding the Bombyx body plan in comparison with the body plans of other organisms. Although their current status remains preliminary, I have tried to summarize the ongoing projects and to reveal future problems to be answered.
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Molecular analysis of the deletion mutants in the E homeotic complex of the silkworm Bombyx mori.
Development (Cambridge England), 1992Co-Authors: Kohji Ueno, Chi-chung Hui, M. Fukuta, Yoshiaki SuzukiAbstract:The E loci in Bombyx mori are expected to contain a homeotic gene complex specifying the identities of the larval abdominal segments. However, the molecular structure of this complex remains to be determined. We have started to analyze the structural changes in the E complex mutations. We used three newly isolated Bombyx homeobox genes as probes. These genes are probably homologues of the Ultrabithorax (Ubx), abdominal-A (abd-A) and Abdominal-B (Abd-B) in the Drosophila bithorax complex, because the amino-acid sequences of the homeobox regions in these Bombyx genes are almost identical to those of Drosophila genes. We found that the Bombyx Ubx and abd-A genes are deleted in the EN chromosome, and the Bombyx abd-A gene is deleted in the ECa chromosome. From these results, we conclude that the Bombyx E complex consists of the Ubx, abd-A and possibly Abd-B genes, which may play similar roles to their homologues in the Drosophila bithorax complex.
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Molecular characterization and silk gland expression of Bombyx engrailed and invected genes
Proceedings of the National Academy of Sciences of the United States of America, 1992Co-Authors: Chi-chung Hui, Kohji Ueno, Kenji Matsuno, Yoshiaki SuzukiAbstract:Abstract Genetic analysis in Drosophila has shown that engrailed (en) plays an important role in segmentation and neurogenesis. A closely related gene, invected (in), is coexpressed with en in the posterior developmental compartments where en is known to specify cell state. We report here the isolation of two en-like cDNAs from the middle silk glands of Bombyx mori larvae. Sequence analysis revealed that they are the counterparts of Drosophila en and in. Four highly conserved domains, including the homeodomain, were identified in these En and In proteins from Bombyx and Drosophila. In addition, two en-specific and one in-specific domains could also be found. These structurally homologous genes might share a similar role in Bombyx development. They were found to be coexpressed in the middle silk gland but not in the posterior silk gland during the fourth molt/fifth intermolt period. We speculate that these Bombyx en-like genes might be involved in the compartmentalization of the silk gland.
Hiroshi Kataoka - One of the best experts on this subject based on the ideXlab platform.
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Bombyx prothoracicostatic peptides activate the sex peptide receptor to regulate ecdysteroid biosynthesis
Proceedings of the National Academy of Sciences of the United States of America, 2010Co-Authors: Naoki Yamanaka, Ivana Spalovska-valachova, Ladislav Roller, Akira Mizoguchi, Hiroshi Kataoka, Yoshiaki TanakaAbstract:Insect molting and metamorphosis are induced by steroid hormones named ecdysteroids, whose production is regulated by various neuropeptides. We cloned the gene and analyzed the expression of the prothoracicostatic peptide, a unique neuropeptide shown to suppress the production of ecdysteroids in the prothoracic gland of the silkworm, Bombyx mori. We also characterized a Bombyx G protein-coupled receptor, which has previously been identified as an ortholog of the Drosophila sex peptide receptor, as a functional prothoracicostatic peptide receptor. This receptor responded specifically to the prothoracicostatic peptides when examined using a heterologous expression system. The receptor was highly expressed in the prothoracic gland on the day before each larval and pupal ecdysis, when prothoracicostatic peptides are synthesized at a high level in the epiproctodeal glands. These results suggest that the sex peptide receptor functions as a prothoracicostatic peptide receptor in Bombyx and that the peripheral neurosecretory cells as well as the central neuroendocrine system play stage-specific roles in regulating ecdysteroidogenesis.
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The unique evolution of neuropeptide genes in the silkworm Bombyx mori.
Insect biochemistry and molecular biology, 2008Co-Authors: Ladislav Roller, Naoki Yamanaka, Hiroshi Kataoka, Ken Watanabe, Ivana Daubnerová, Dusan Zitnan, Yoshiaki TanakaAbstract:Cloning-based approach combining homology search in the Bombyx genome sequence and Rapid Amplification of cDNA Ends (RACE) resulted in annotation of 23 neuropeptide genes and different splicing variants of three genes. In total 37 neuropeptide genes in addition to Bombyxin gene family have been identified in Bombyx. Comparison of available insect neuropeptide genes revealed that the silkworm genome contains most conserved neuropeptide genes except those encoding proctolin, vasopressin-like peptide and neuropeptide-like precursor 2. In addition, we identified several paralogous neuropeptide genes which have not been found in other insects. The Bombyx genome contains a triplet of paralogous genes encoding adipokinetic hormones (AKH), two genes encoding different neuropeptide Fs (NPFs) and a tandem of related SIFamide and IMFamide genes. A novel gene coding for CCHamide was cloned and its expression in the CNS and midgut was demonstrated. Differential splicing was observed for the first time in transcripts for diuretic hormones and cardioacceleratory peptides 2b. Most paralogous genes or splicing variants of the same gene showed different expression patterns in the central nervous system (CNS). These results suggest that unique duplication and differential expression of several neuropeptide genes occurred during the evolution in Bombyx. This may be an effective mechanism for functional diversification of conserved neuropeptides.
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G protein-coupled receptor for diapause hormone, an inducer of Bombyx embryonic diapause.
Biochemical and Biophysical Research Communications, 2006Co-Authors: Takashi Homma, Hiroshi Kataoka, Teruyuki Niimi, Okitsugu Yamashita, Ken Watanabe, Shuichiro Tsurumaru, Kunio Imai, Mari Kamba, Toshinobu YaginumaAbstract:Abstract Bombyx diapause hormone was the first chemical substance identified as a maternal control factor that arrests offspring development. However, the molecular mechanisms by which the hormone transduces the signal to the oocyte that induces embryonic diapause immediately after mesoderm segmentation are not fully understood. Here, we describe a cDNA for a G protein-coupled diapause hormone receptor with seven transmembrane domains. Its amino-acid sequence shows a high level of similarity to the receptors of mammalian neuromedin U and insect regulatory peptide, an FXPRL-amide C-terminus. When expressed in a Xenopus oocyte system, the receptor exhibited the highest affinity (EC50, ∼70 nM) for diapause hormone, when compared with other Bombyx FXPR/KL-amide peptides. Diapause hormone without amidation at the C-terminus, which never induces embryonic diapause in vivo, had no effect in this heterologous expression system. The mRNA is expressed in the ovaries during Bombyx pupal–adult development. These results strongly indicate that the cDNA encodes the diapause hormone receptor.
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Structure and expression of the gene for the prothoracicotropic hormone of the silkmoth Bombyx mori
European journal of biochemistry, 1994Co-Authors: Takashi Adachi-yamada, Akinori Suzuki, Hiroshi Kataoka, Masafumi Iwami, Hironori IshizakiAbstract:We cloned and characterized two allelic variants of the gene for the Bombyx mori prothoracicotropic hormone (PTTH), a homodimeric 30-kDa brain secretory protein. These PTTH genes contain five exons that encode a precursor protein consisting of 224 amino acid residues whose C-terminal 109 residues represent the PTTH subunit. The Bombyx haploid genome contains a single copy of the PTTH gene. The major site of PTTH expression is the brain but expression at a very low level occurs in the gut. One Bombyx brain at day 0 of the fifth larval instar contained 2.4-2.8 pg PTTH mRNA, and this amount did not change markedly during larval-pupal development.
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Isolation and Identification of Adipokinetic Hormone of the Silkworm, Bombyx mori
Bioscience Biotechnology and Biochemistry, 1992Co-Authors: Jun Ishibashi, Hiromichi Nagasawa, Akira Isogai, Hiroshi Kataoka, Akinori SuzukiAbstract:An adipokinetic hormone (AKH) was isolated from the adult heads of the silkworm, Bombyx mori. Fast atom bombardment mass spectrometry (FAB-MS) of the intact AKH and sequence analysis of the AKH after deblocked with pyroglutamate aminopeptidase revealed that the structure of Bombyx AKH is pGlu-Leu-Thr-Phe-Thr-Ser-Ser-Trp-Gly-NH2, which is identical with those of Manduca sexta and Heliothis zea AKH. Bombyx AKH is released just after adult eclosion and elevates the lipid level but not the carbohydrate level in the hemolymph.
Yoshiaki Tanaka - One of the best experts on this subject based on the ideXlab platform.
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Bombyx prothoracicostatic peptides activate the sex peptide receptor to regulate ecdysteroid biosynthesis
Proceedings of the National Academy of Sciences of the United States of America, 2010Co-Authors: Naoki Yamanaka, Ivana Spalovska-valachova, Ladislav Roller, Akira Mizoguchi, Hiroshi Kataoka, Yoshiaki TanakaAbstract:Insect molting and metamorphosis are induced by steroid hormones named ecdysteroids, whose production is regulated by various neuropeptides. We cloned the gene and analyzed the expression of the prothoracicostatic peptide, a unique neuropeptide shown to suppress the production of ecdysteroids in the prothoracic gland of the silkworm, Bombyx mori. We also characterized a Bombyx G protein-coupled receptor, which has previously been identified as an ortholog of the Drosophila sex peptide receptor, as a functional prothoracicostatic peptide receptor. This receptor responded specifically to the prothoracicostatic peptides when examined using a heterologous expression system. The receptor was highly expressed in the prothoracic gland on the day before each larval and pupal ecdysis, when prothoracicostatic peptides are synthesized at a high level in the epiproctodeal glands. These results suggest that the sex peptide receptor functions as a prothoracicostatic peptide receptor in Bombyx and that the peripheral neurosecretory cells as well as the central neuroendocrine system play stage-specific roles in regulating ecdysteroidogenesis.
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The unique evolution of neuropeptide genes in the silkworm Bombyx mori.
Insect biochemistry and molecular biology, 2008Co-Authors: Ladislav Roller, Naoki Yamanaka, Hiroshi Kataoka, Ken Watanabe, Ivana Daubnerová, Dusan Zitnan, Yoshiaki TanakaAbstract:Cloning-based approach combining homology search in the Bombyx genome sequence and Rapid Amplification of cDNA Ends (RACE) resulted in annotation of 23 neuropeptide genes and different splicing variants of three genes. In total 37 neuropeptide genes in addition to Bombyxin gene family have been identified in Bombyx. Comparison of available insect neuropeptide genes revealed that the silkworm genome contains most conserved neuropeptide genes except those encoding proctolin, vasopressin-like peptide and neuropeptide-like precursor 2. In addition, we identified several paralogous neuropeptide genes which have not been found in other insects. The Bombyx genome contains a triplet of paralogous genes encoding adipokinetic hormones (AKH), two genes encoding different neuropeptide Fs (NPFs) and a tandem of related SIFamide and IMFamide genes. A novel gene coding for CCHamide was cloned and its expression in the CNS and midgut was demonstrated. Differential splicing was observed for the first time in transcripts for diuretic hormones and cardioacceleratory peptides 2b. Most paralogous genes or splicing variants of the same gene showed different expression patterns in the central nervous system (CNS). These results suggest that unique duplication and differential expression of several neuropeptide genes occurred during the evolution in Bombyx. This may be an effective mechanism for functional diversification of conserved neuropeptides.
Hironori Ishizaki - One of the best experts on this subject based on the ideXlab platform.
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Structure and expression of the gene for the prothoracicotropic hormone of the silkmoth Bombyx mori
European journal of biochemistry, 1994Co-Authors: Takashi Adachi-yamada, Akinori Suzuki, Hiroshi Kataoka, Masafumi Iwami, Hironori IshizakiAbstract:We cloned and characterized two allelic variants of the gene for the Bombyx mori prothoracicotropic hormone (PTTH), a homodimeric 30-kDa brain secretory protein. These PTTH genes contain five exons that encode a precursor protein consisting of 224 amino acid residues whose C-terminal 109 residues represent the PTTH subunit. The Bombyx haploid genome contains a single copy of the PTTH gene. The major site of PTTH expression is the brain but expression at a very low level occurs in the gut. One Bombyx brain at day 0 of the fifth larval instar contained 2.4-2.8 pg PTTH mRNA, and this amount did not change markedly during larval-pupal development.
Toshinobu Yaginuma - One of the best experts on this subject based on the ideXlab platform.
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G protein-coupled receptor for diapause hormone, an inducer of Bombyx embryonic diapause.
Biochemical and Biophysical Research Communications, 2006Co-Authors: Takashi Homma, Hiroshi Kataoka, Teruyuki Niimi, Okitsugu Yamashita, Ken Watanabe, Shuichiro Tsurumaru, Kunio Imai, Mari Kamba, Toshinobu YaginumaAbstract:Abstract Bombyx diapause hormone was the first chemical substance identified as a maternal control factor that arrests offspring development. However, the molecular mechanisms by which the hormone transduces the signal to the oocyte that induces embryonic diapause immediately after mesoderm segmentation are not fully understood. Here, we describe a cDNA for a G protein-coupled diapause hormone receptor with seven transmembrane domains. Its amino-acid sequence shows a high level of similarity to the receptors of mammalian neuromedin U and insect regulatory peptide, an FXPRL-amide C-terminus. When expressed in a Xenopus oocyte system, the receptor exhibited the highest affinity (EC50, ∼70 nM) for diapause hormone, when compared with other Bombyx FXPR/KL-amide peptides. Diapause hormone without amidation at the C-terminus, which never induces embryonic diapause in vivo, had no effect in this heterologous expression system. The mRNA is expressed in the ovaries during Bombyx pupal–adult development. These results strongly indicate that the cDNA encodes the diapause hormone receptor.
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The profiles of mRNA levels for BHR39, a Bombyx homolog of Drosophila hormone receptor 39, and Bombyx FTZ-F1 in the course of embryonic development and diapause
Development genes and evolution, 1997Co-Authors: Teruyuki Niimi, S. Morita, Okitsugu Yamashita, Toshinobu YaginumaAbstract:In the silkworm, Bombyx mori, the 5’-upstream region of the sorbitol dehydrogenase (SDH) gene contains nucleotide sequences that might be recognized and bound by steroid hormone receptors such as Drosophila hormone receptor 39 (DHR39) and Fushi tarazu transcription factor 1 (FTZ-F1). As a first trial to find out regulator(s) involved in gene expression for SDH in Bombyx eggs, we have cloned a cDNA encoding a Bombyx homolog (BHR39) of DHR39, and examined levels of mRNA expressions for BHR39 and Bombyx FTZ-F1 (BmFTZ-F1) during the entire embryonic development and diapause. During embryonic development of non-diapause eggs, mRNA expression for BmFTZ-F1, but not for BHR39, was shown to occur in parallel with that for SDH, although such a parallelism was not found at the termination of diapause, when SDH mRNA was expressed.