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Chen L, Zhang Z, Chen K, Yu Y, Hu B, Song H, Liu X. Transcriptional Dynamics Induced by Diapause Hormone in the Silkworm, Bombyx mori. BIOLOGY 2022; 11:1313. [PMID: 36138792 PMCID: PMC9495520 DOI: 10.3390/biology11091313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 06/03/2022] [Accepted: 06/08/2022] [Indexed: 06/16/2023]
Abstract
Diapause is a form of dormancy that organisms use to adapt to extreme environments by exhibiting developmental arrest. In the silkworm, Bombyx mori, diapause is thought to be elicited by diapause hormone (DH) signaling, which consists of interactions between DH and the DH receptor (DHR). However, the steps downstream of the DH signaling pathway are largely unknown. In the present study, we directly injected synthesized DH into the female pupae of a multivoltine, non-diapausing strain at 36 h after pupation. We found that the mRNA level of DHR declined at 4 h and recovered at 12 h after the injection of DH. Thus, we sequenced the transcriptome of the ovaries at 4 h and 12 h after the injection of DH. We identified 60 and 221 differentially expressed genes at 4 h and 12 h after the injection, respectively. All DEGs were identified, relating to 20E-related genes, JH-related genes, cellular detoxification, ribosomal proteins, lipid metabolism, and epigenetic modifications. Eleven genes were selected from the above categories to verify the transcriptome data. The qRT-PCR and RNA-Seq expression patterns of the genes were consistent, which indicated the authenticity and reliability of the transcriptome data. This study dramatically expands upon our knowledge of gene expression variation at the early phase of DH release.
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Affiliation(s)
- Lijuan Chen
- College of Life Sciences, Shanghai University, Shanghai 200444, China
| | - Zhongjie Zhang
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China
- Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, The Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212100, China
| | - Kai Chen
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China
- Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, The Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212100, China
| | - Ye Yu
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai 200032, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Bo Hu
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China
- Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, The Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212100, China
| | - Hongsheng Song
- College of Life Sciences, Shanghai University, Shanghai 200444, China
| | - Xiaojing Liu
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China
- Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, The Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212100, China
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Liu L, Zhang P, Gao Q, Feng X, Han L, Zhang F, Bai Y, Han M, Hu H, Dai F, Zhang G, Tong X. Comparative Transcriptome Analysis Reveals bmo-miR-6497-3p Regulate Circadian Clock Genes during the Embryonic Diapause Induction Process in Bivoltine Silkworm. INSECTS 2021; 12:739. [PMID: 34442305 PMCID: PMC8396838 DOI: 10.3390/insects12080739] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 08/08/2021] [Accepted: 08/12/2021] [Indexed: 12/26/2022]
Abstract
Diapause is one of the survival strategies of insects for confronting adverse environmental conditions. Bombyx mori displays typical embryonic diapause, and offspring diapause depends on the incubation environment of the maternal embryo in the bivoltine strains of the silkworm. However, the molecular mechanisms of the diapause induction process are still poorly understood. In this study, we compared the differentially expressed miRNAs (DEmiRs) in bivoltine silkworm embryos incubated at diapause- (25 °C) and non-diapause (15 °C)-inducing temperatures during the blastokinesis (BK) and head pigmentation (HP) phases using transcriptome sequencing. There were 411 known miRNAs and 71 novel miRNAs identified during the two phases. Among those miRNAs, there were 108 and 74 DEmiRs in the BK and HP groups, respectively. By the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of the predicted target genes of the DEmiRs, we found that aside from metabolism, the targets were also enriched in phototransduction-fly and insect hormone biosynthesis in the BK group and the HP group, respectively. Dual luciferase reporter assay illustrated that bmo-miR-6497-3p directly regulated Bmcycle and subsequently regulated the expression of circadian genes. These results imply that microRNAs, as vitally important regulators, respond to different temperatures and participate in the diapause induction process across species.
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Affiliation(s)
- Lulu Liu
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, College of Sericulture, Textile and Biomass Sciences, Southwest University, Chongqing 400715, China; (L.L.); (Q.G.); (Y.B.); (M.H.); (H.H.); (F.D.)
| | - Pan Zhang
- College of Sericulture, Textile and Biomass Sciences, Southwest University, Chongqing 400715, China; (P.Z.); (X.F.); (L.H.); (F.Z.)
| | - Qiang Gao
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, College of Sericulture, Textile and Biomass Sciences, Southwest University, Chongqing 400715, China; (L.L.); (Q.G.); (Y.B.); (M.H.); (H.H.); (F.D.)
| | - Xiaoge Feng
- College of Sericulture, Textile and Biomass Sciences, Southwest University, Chongqing 400715, China; (P.Z.); (X.F.); (L.H.); (F.Z.)
| | - Lan Han
- College of Sericulture, Textile and Biomass Sciences, Southwest University, Chongqing 400715, China; (P.Z.); (X.F.); (L.H.); (F.Z.)
| | - Fengbin Zhang
- College of Sericulture, Textile and Biomass Sciences, Southwest University, Chongqing 400715, China; (P.Z.); (X.F.); (L.H.); (F.Z.)
| | - Yanmin Bai
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, College of Sericulture, Textile and Biomass Sciences, Southwest University, Chongqing 400715, China; (L.L.); (Q.G.); (Y.B.); (M.H.); (H.H.); (F.D.)
| | - Minjin Han
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, College of Sericulture, Textile and Biomass Sciences, Southwest University, Chongqing 400715, China; (L.L.); (Q.G.); (Y.B.); (M.H.); (H.H.); (F.D.)
| | - Hai Hu
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, College of Sericulture, Textile and Biomass Sciences, Southwest University, Chongqing 400715, China; (L.L.); (Q.G.); (Y.B.); (M.H.); (H.H.); (F.D.)
| | - Fangyin Dai
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, College of Sericulture, Textile and Biomass Sciences, Southwest University, Chongqing 400715, China; (L.L.); (Q.G.); (Y.B.); (M.H.); (H.H.); (F.D.)
| | - Gaojun Zhang
- College of Sericulture, Textile and Biomass Sciences, Southwest University, Chongqing 400715, China; (P.Z.); (X.F.); (L.H.); (F.Z.)
| | - Xiaoling Tong
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, College of Sericulture, Textile and Biomass Sciences, Southwest University, Chongqing 400715, China; (L.L.); (Q.G.); (Y.B.); (M.H.); (H.H.); (F.D.)
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Gong J, Zheng X, Zhao S, Yang L, Xue Z, Fan Z, Tang M. Early Molecular Events during Onset of Diapause in Silkworm Eggs Revealed by Transcriptome Analysis. Int J Mol Sci 2020; 21:ijms21176180. [PMID: 32867045 PMCID: PMC7503879 DOI: 10.3390/ijms21176180] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/24/2020] [Accepted: 08/25/2020] [Indexed: 01/01/2023] Open
Abstract
Diapause is a form of dormancy, and Bombyx mori silkworm embryos are ideal models for studying diapause in insects. However, molecular events in eggs during the onset of diapause remain unclear. In this study, transcriptome analyses were performed on silkworm diapause eggs via RNA sequencing at 20 and 48 h after oviposition. A total of 6402 differentially expressed genes (DEGs) were detected in diapause eggs at 48 h versus that at 20 h after oviposition. Gene ontology enrichment analysis showed that DEGs in diapause eggs at 48 h versus that at 20 h after oviposition were involved in ribosome-related metabolism and hydrogen transport. Kyoto Encyclopedia of Genes and Genomes analysis revealed several significantly enriched biological pathways, namely the oxidative phosphorylation, Forkhead box protein O3 (FoxO) signaling, ribosome, endoplasmic reticular protein processing, and autophagy pathways. Fifteen DEGs from the FoxO signaling pathway were selected, and their expression profiles were consistent with the transcriptome results from real-time quantitative reverse transcription polymerase chain reaction. Our results can improve understanding of the diapause mechanism in silkworm eggs and identified key pathways for future studies.
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Affiliation(s)
- Jing Gong
- Correspondence: ; Tel.: +86-1521-316-8560
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Shen Z, Jiang X, Yan L, Chen Y, Wang W, Shi Y, Shi L, Liu D, Zhou N. Structural basis for the interaction of diapause hormone with its receptor in the silkworm, Bombyx mori. FASEB J 2018; 32:1338-1353. [PMID: 29101222 DOI: 10.1096/fj.201700931r] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Diapause hormone (DH) is a 24-aa amidated neuropeptide that elicits the embryonic diapause of the silkworm, Bombyx mori ( Bommo), via sensitive and selective interaction with its receptor, Bommo DH receptor ( Bommo-DHR). Previous studies of the structure-activity relationship of Bommo-DH were all based on an in vivo diapause-induction bioassay, which has provided little information on the structure of Bommo-DHR or its iteration with DH. Here, to unveil the interaction of Bommo-DH with its receptor, N-terminally truncated analogs and alanine-scanning mutants of Bommo-DH were chemically synthesized and functionally evaluated by using a Cy5.5-labeled Bommo-DH competitive binding assay and Bommo-DHR-based functional assays, including cAMP assay and Ca2+ mobilization assay. Our study demonstrates that the C-terminal residues of Arg23 and Leu24 of Bommo-DH are essential for the binding and activation of Bommo-DHR, and that Trp19 and Phe20 also contribute to the functional activity of Bommo-DH. In contrast, when Gly21 or Pro22 were replaced with alanine, both mutants exhibited binding and signaling activities that were indistinguishable from the wild-type peptide. Furthermore, our homology modeling and molecular dynamics simulations, together with experimental validations, have identified the residues of Glu89, Phe172, Phe194, and Tyr299 in Bommo-DHR that are critically involved in the interaction with Bommo-DH. These results may deepen our understanding of the interactions of class-A GPCRs with their peptidic ligands, particularly those between pheromone biosynthesis-activating neuropeptide/DH family neuropeptides and their cognate receptors.-Shen, Z., Jiang, X., Yan, L., Chen, Y., Wang, W., Shi, Y., Shi, L., Liu, D., Zhou, N. Structural basis for the interaction of diapause hormone with its receptor in the silkworm, Bombyx mori.
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Affiliation(s)
- Zhangfei Shen
- Department of Economic Zoology, College of Animal Sciences, Zhejiang University, Hangzhou, China
| | - Xue Jiang
- Department of Economic Zoology, College of Animal Sciences, Zhejiang University, Hangzhou, China
| | - Lili Yan
- Institute of Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Yu Chen
- Institute of Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Weiwei Wang
- Institute of Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Ying Shi
- Institute of Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Liangen Shi
- Department of Economic Zoology, College of Animal Sciences, Zhejiang University, Hangzhou, China
| | - Dongxiang Liu
- Department of Pharmacology III, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Naiming Zhou
- Institute of Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, China
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Ye HL, Li DR, Yang JS, Chen DF, De Vos S, Vuylsteke M, Sorgeloos P, Van Stappen G, Bossier P, Nagasawa H, Yang WJ. Molecular characterization and functional analyses of a diapause hormone receptor-like gene in parthenogenetic Artemia. Peptides 2017; 90:100-110. [PMID: 28174072 DOI: 10.1016/j.peptides.2017.01.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Revised: 01/19/2017] [Accepted: 01/23/2017] [Indexed: 01/03/2023]
Abstract
In arthropods, mature females under certain conditions produce and release encysted gastrula embryos that enter diapause, a state of obligate dormancy. The process is presumably regulated by diapause hormone (DH) and diapause hormone receptor (DHR) that were identified in the silkworm, Bombyx mori and other insects. However, the molecular structure and function of DHR in crustaceans remains unknown. Here, a DHR-like gene from parthenogenetic Artemia (Ar-DHR) was isolated and sequenced. The cDNA sequence consists of 1410bp with a 1260-bp open reading frame encoding a protein consisting of 420 amino acid residues. The results of real-time PCR (qRT-PCR) and Western blot analysis showed that the mRNA and protein of Ar-DHR were mainly expressed at the diapause stage. Furthermore, we found that Ar-DHR was located on the cell membrane of the pre-diapause cyst but in the cytoplasm of the diapause cyst by analysis of immunofluorescence. In vivo knockdown of Ar-DHR by RNA interference (RNAi) and antiserum neutralization consistently inhibited diapause cysts formation. The results indicated that Ar-DHR plays an important role in the induction and maintenance of embryonic diapause in Artemia. Thus, our findings provide an insight into the regulation of diapause formation in Artemia and the function of Ar-DHR.
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Affiliation(s)
- Hui-Li Ye
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, PR China
| | - Dong-Rui Li
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, PR China
| | - Jin-Shu Yang
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, PR China
| | - Dian-Fu Chen
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, PR China
| | - Stephanie De Vos
- Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Belgium
| | - Marnik Vuylsteke
- Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Belgium
| | - Patrick Sorgeloos
- Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Belgium
| | - Gilbert Van Stappen
- Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Belgium
| | - Peter Bossier
- Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Belgium
| | - Hiromichi Nagasawa
- Department of Applied Biological Chemistry, The University of Tokyo, Yayoi, Bunkyo, Tokyo 113-8657, Japan.
| | - Wei-Jun Yang
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, PR China.
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Jiang X, Yang J, Shen Z, Chen Y, Shi L, Zhou N. Agonist-mediated activation of Bombyx mori diapause hormone receptor signals to extracellular signal-regulated kinases 1 and 2 through Gq-PLC-PKC-dependent cascade. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2016; 75:78-88. [PMID: 27318251 DOI: 10.1016/j.ibmb.2016.06.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 06/07/2016] [Accepted: 06/14/2016] [Indexed: 06/06/2023]
Abstract
Diapause is a developmental strategy adopted by insects to survive in challenging environments such as the low temperatures of a winter. This unique process is regulated by diapause hormone (DH), which is a neuropeptide hormone that induces egg diapause in Bombyx mori and is involved in terminating pupal diapause in heliothis moths. An G protein-coupled receptor from the silkworm, B. mori, has been identified as a specific cell surface receptor for DH. However, the detailed information on the DH-DHR system and its mechanism(s) involved in the induction of embryonic diapause remains unknown. Here, we combined functional assays with various specific inhibitors to elucidate the DHR-mediated signaling pathways. Upon activation by DH, B. mori DHR is coupled to the Gq protein, leading to a significant increase of intracellular Ca(2+) and cAMP response element-driven luciferase activity in an UBO-QIC, a specific Gq inhibitor, sensitive manner. B. mori DHR elicited ERK1/2 phosphorylation in a dose- and time-dependent manner in response to DH. This effect was almost completely inhibited by co-incubation with UBO-QIC and was also significantly suppressed by PLC inhibitor U73122, PKC inhibitors Gö6983 and the Ca(2+) chelator EGTA. Moreover, DHR-induced activation of ERK1/2 was significantly attenuated by treatment with the Gβγ specific inhibitors gallein and M119K and the PI3K specific inhibitor Wortmannin, but not by the Src specific inhibitor PP2. Our data also demonstrates that the EGFR-transactivation pathway is not involved in the DHR-mediated ERK1/2 phosphorylation. Future efforts are needed to clarify the role of the ERK1/2 signaling pathway in the DH-mediated induction of B. mori embryonic diapause.
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Affiliation(s)
- Xue Jiang
- Department of Economic Zoology, College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Jingwen Yang
- National Engineering Research Center of Marine Facilities Aquaculture, Zhejiang Ocean University, Zhoushan, Zhejiang 316022, China
| | - Zhangfei Shen
- Department of Economic Zoology, College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Yajie Chen
- Department of Economic Zoology, College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Liangen Shi
- Department of Economic Zoology, College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Naiming Zhou
- Institute of Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China.
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7
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Tan D, Tong XL, Hu H, Wu SY, Li CL, Xiong G, Xiang ZH, Dai FY, Lu C. Morphological characterization and molecular mapping of an irradiation-induced Speckled mutant in the silkworm, Bombyx mori. INSECT MOLECULAR BIOLOGY 2016; 25:93-104. [PMID: 26661290 DOI: 10.1111/imb.12205] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Speckled (Spc), an X-ray-induced lethal mutant of Bombyx mori, exhibits a mosaic dark-brown-spotted larval epidermis in both sexes and egg-laying problems only in females. Here, we report the morphological characterization and molecular mapping of the Spc mutant. Morphological investigations revealed that the epidermal ultrastructure of the small, dark-brown spots was more dense than that of the white regions in both Spc/+ mutants and wild type, and that the lethality of the Spc/Spc mutants occurred during early embryogenesis. Furthermore, the ovarioles and ovipositor were disconnected in approximately 85.5% of Spc/+ females, a further 2.5% had a connection between the ovarioles and ovipositor that was too narrow to lay eggs. The remaining females showed a normal connection similar to that of the wild type. We successfully narrowed down the location of the Spc mutation to a region on chromosome 4 that was ∼1041 kb long. Gene-prediction analysis identified 25 candidate genes in this region. Chromosome structure analysis indicated that a ∼305 kb deletion was included in the mapping region. Temporal and spatial reverse transcription PCR (RT-PCR) analysis showed that several genes in the mapped region are associated with the Spc mutant. Although the genes responsible for the Spc mutation were not definitively identified, our results further the current understanding of the complex mechanism underlying the multiple morphological defects in Spc mutants.
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Affiliation(s)
- D Tan
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
| | - X-L Tong
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
| | - H Hu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
| | - S-Y Wu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
| | - C-L Li
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
| | - G Xiong
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
| | - Z-H Xiang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
| | - F-Y Dai
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
| | - C Lu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
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Embryonic thermosensitive TRPA1 determines transgenerational diapause phenotype of the silkworm, Bombyx mori. Proc Natl Acad Sci U S A 2014; 111:E1249-55. [PMID: 24639527 DOI: 10.1073/pnas.1322134111] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
In the bivoltine strain of the silkworm, Bombyx mori, embryonic diapause is induced transgenerationally as a maternal effect. Progeny diapause is determined by the environmental temperature during embryonic development of the mother; however, its molecular mechanisms are largely unknown. Here, we show that the Bombyx TRPA1 ortholog (BmTrpA1) acts as a thermosensitive transient receptor potential (TRP) channel that is activated at temperatures above ∼ 21 °C and affects the induction of diapause in progeny. In addition, we show that embryonic RNAi of BmTrpA1 affects diapause hormone release during pupal-adult development. This study identifying a thermosensitive TRP channel that acts as a molecular switch for a relatively long-term predictive adaptive response by inducing an alternative phenotype to seasonal polyphenism is unique.
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9
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Zhao LC, Hou YS, Sima YH. Changes in glutathione redox cycle during diapause determination and termination in the bivoltine silkworm, Bombyx mori. INSECT SCIENCE 2014; 21:39-46. [PMID: 23956095 DOI: 10.1111/1744-7917.12015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/21/2013] [Indexed: 06/02/2023]
Abstract
To explore whether glutathione regulates diapause determination and termination in the bivoltine silkworm Bombyx mori, we monitored the changes in glutathione redox cycle in the ovary of both diapause- and nondiapause-egg producers, as well as those in diapause eggs incubated at different temperatures. The activity of thioredoxin reductase (TrxR) was detected in ovaries but not in eggs, while neither ovaries nor eggs showed activity of glutathione peroxidase. A lower reduced glutathione/oxidized glutathione (GSH/GSSG) ratio was observed in the ovary of diapause-egg producers, due to weaker reduction of oxidized glutathione (GSSG) to the reduced glutathione (GSH) catalyzed by glutathione reductase (GR) and TrxR. This indicates an oxidative shift in the glutathione redox cycle during diapause determination. Compared with the 25°C-treated diapause eggs, the 5°C-treated diapause eggs showed lower GSH/GSSG ratio, a result of stronger oxidation of GSH catalyzed by thioredoxin peroxidase and weaker reduction of GSSG catalyzed by GR. Our study demonstrated the important regulatory role of glutathione in diapause determination and termination of the bivoltine silkworm.
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Affiliation(s)
- Lin-Chuan Zhao
- College of Biological and Basic Medicine Sciences, Soochow University, Suzhou, Jiangsu Province, China
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Schiesari L, O'Connor MB. Diapause: delaying the developmental clock in response to a changing environment. Curr Top Dev Biol 2013; 105:213-46. [PMID: 23962844 DOI: 10.1016/b978-0-12-396968-2.00008-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Seasonal changes can induce organisms to modify their developmental growth. Many holometabolous insects, especially Lepidoptera, trigger diapause, an "actively induced" dormancy, for overwintering. Diapause is an alternative developmental pathway that reversibly blocks developmental growth during specific transitions and enhances the hibernating potential of the organism. Changes in environmental cues, such as light and temperature, trigger modifications in the levels, or in the timing, of developmental hormones. These in turn switch the developmental trajectory (diapause or direct development), strongly altering larval/pupal growth and inducing the appearance of diapause-bound seasonal morphs (polyphenism). We also discuss an example of vertebrate diapause using the killifish embryo as an example where diapause is an environmentally determined developmental switch analogous to that observed in lepidopteran dormancy. Based on the examples discussed here, we propose that the complex physiological responses leading to diapause might evolve quickly by relatively limited genetic changes in the regulation of hormonal signals that program normal developmental transitions.
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Affiliation(s)
- Luca Schiesari
- Department of Biology, University of Padova, Padova, Italy
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Masumoto M, Ohde T, Shiomi K, Yaginuma T, Niimi T. A Baculovirus immediate-early gene, ie1, promoter drives efficient expression of a transgene in both Drosophila melanogaster and Bombyx mori. PLoS One 2012; 7:e49323. [PMID: 23152896 PMCID: PMC3496687 DOI: 10.1371/journal.pone.0049323] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Accepted: 10/10/2012] [Indexed: 11/19/2022] Open
Abstract
Many promoters have been used to drive expression of heterologous transgenes in insects. One major obstacle in the study of non-model insects is the dearth of useful promoters for analysis of gene function. Here, we investigated whether the promoter of the immediate-early gene, ie1, from the Bombyx mori nucleopolyhedrovirus (BmNPV) could be used to drive efficient transgene expression in a wide variety of insects. We used a piggyBac-based vector with a 3xP3-DsRed transformation marker to generate a reporter construct; this construct was used to determine the expression patterns driven by the BmNPV ie1 promoter; we performed a detailed investigation of the promoter in transgene expression pattern in Drosophila melanogaster and in B. mori. Drosophila and Bombyx belong to different insect orders (Diptera and Lepidoptera, respectively); however, and to our surprise, ie1 promoter-driven expression was evident in several tissues (e.g., prothoracic gland, midgut, and tracheole) in both insects. Furthermore, in both species, the ie1 promoter drove expression of the reporter gene from a relatively early embryonic stage, and strong ubiquitous ie1 promoter-driven expression continued throughout the larval, pupal, and adult stages by surface observation. Therefore, we suggest that the ie1 promoter can be used as an efficient expression driver in a diverse range of insect species.
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Affiliation(s)
- Mika Masumoto
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, Japan
- Division of Biology, College of Liberal Arts and Sciences, Kitasato University, Sagamihara, Kanagawa, Japan
| | - Takahiro Ohde
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, Japan
| | - Kunihiro Shiomi
- Faculty of Textile Science and Technology, Shinshu University, Ueda, Nagano, Japan
| | - Toshinobu Yaginuma
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, Japan
| | - Teruyuki Niimi
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, Japan
- * E-mail:
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Sima YH, Yao JM, Hou YS, Wang L, Zhao LC. Variations of hydrogen peroxide and catalase expression in Bombyx eggs during diapause initiation and termination. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2011; 77:72-80. [PMID: 21433065 DOI: 10.1002/arch.20422] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Accepted: 02/18/2011] [Indexed: 05/15/2023]
Abstract
For diapause eggs of the silkworm, Bombyx mori, diapause initiation is prevented with hydrochloric acid (HCl) at around 20 h post-oviposition while diapause status is terminated with chilling around 5°C. To investigate whether hydrogen peroxide (H(2)O(2)) and catalase expression are involved in diapause initiation and termination, the concentration of H(2)O(2), relatively higher levels of catalase mRNA and activity of catalase were compared between (1) 20-h-old diapause eggs and the HCl-treated diapause eggs, and (2) 10-day-old diapause eggs and the 5°C-chilled diapause eggs. Compared to diapause eggs, the HCl-treated eggs had significantly higher H(2)O(2) concentrations (up from approximately 1-3 µmol/g fresh mass to 5-8 µmol/g fresh mass), higher relative level of catalase mRNA (up from 0 to 35.2%) and higher catalase activity (up from 2.51 units/mg protein to 4.97 units/mg protein) at 96 h post-treatment. On the other hand, the 5°C chilling resulted in significant increases of H(2)O(2) concentration (up from 0.79 µmol/g fresh mass to 5.57 µmol/g fresh mass), relative level of catalase mRNA (up from 0 to 71.4%) and catalase activity (up from 0.88 units/mg protein to 3.42 units/mg protein) within 120 days. The results obtained in this work suggest that variations of H(2)O(2) and catalase expression in Bombyx eggs are involved in diapause initiation and termination.
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Affiliation(s)
- Yang-Hu Sima
- Department of Life Science, Soochow University, Suzhou, PR China
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Immunoreactive intensity of FXPRL amide neuropeptides in response to environmental conditions in the silkworm, Bombyx mori. Cell Tissue Res 2010; 342:459-69. [PMID: 21103995 DOI: 10.1007/s00441-010-1083-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2010] [Accepted: 10/27/2010] [Indexed: 11/26/2022]
Abstract
In the silkworm Bombyx mori, the diapause hormone-pheromone biosynthesis activating neuropeptide gene, DH-PBAN, is a neuropeptide gene that encodes a polypeptide precursor consisting in five Phe-X-Pro-Arg-Leu-NH(2) (FXPRL) amide (FXPRLa) neuropeptides; DH (diapause hormone), PBAN (pheromone-biosynthesis-activating neuropeptide) and α-, β- and γ-SGNPs (subesophageal ganglion neuropeptides). These neuropeptides are synthesized in DH-PBAN-producing neurosecretory cells contained within three neuromeres, four mandibular cells, six maxillary cells, two labial cells (SLb) and four lateral cells of the subesophageal ganglion. DH is solely responsible, among the FXPRLa peptide family, for embryonic diapause. Functional differentiation has been previously suggested to occur at each neuromere, with the SLb cells releasing DH through brain innervation in order to induce embryonic diapause. We have investigated the immunoreactive intensity of DH in the SLb when thermal (25°C or 15°C) and light (continuous illumination or darkness) conditions are altered and following brain surgery that induces diapause or non-diapause eggs in the progeny. We have also examined the immunoreactivity of the other FXPRLa peptides by using anti-β-SGNP and anti-PBAN antibodies. Pupal SLb somata immunoreactivities seem to be affected by both thermal and light conditions during embryogenesis. Thus, we have been able to identify a close correlation between the immunoreactive intensity of neuropeptides and environmental conditions relating to the determination of embryonic diapause in B. mori.
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14
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Zhao LC, Shi LG. Metabolism of hydrogen peroxide between diapause and non-diapause eggs of the silkworm, Bombyx mori during chilling at 5 degrees C. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2010; 74:127-134. [PMID: 20513060 DOI: 10.1002/arch.20367] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
When diapause and non-diapause eggs of the same bivoltine strain of Bombyx mori were chilled at 5 degrees C for more than 30 days, the hatchability of diapause eggs increased while that of non-diapause eggs decreased, respectively. To investigate the relationship between effects of chilling on the hatchability and the metabolism of hydrogen peroxide (H2O2), content of H2O2 and activities of superoxide dismutase (SOD), xanthine oxidase (XO), and catalase (CAT) between diapause and non-diapause eggs were determined during the chilling at 5 degrees C. The significant enhancement of H2O2 occurred prior to the quick increase of the hatchability in diapause eggs and coincided with the quick decline of the hatchability in non-diapause eggs, respectively. Diapause eggs contained significantly higher H2O2 and XO activity and lower CAT activity compared to non-diapause eggs. Our results showed that there were significant differences in the metabolism of H2O2 between diapause and non-diapause eggs during chilling and that significant enhancement of H2O2 may be involved in the diapause termination of diapause eggs and the cell damage of non-diapause eggs.
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Affiliation(s)
- L C Zhao
- College of Animal Science, Zhejiang University, Hangzhou, China
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15
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Tsuchida K, Yokoyama T, Sakudoh T, Katagiri C, Tsurumaru S, Takada N, Fujimoto H, Ziegler R, Iwano H, Hamano K, Yaginuma T. Apolipophorin-III expression and low density lipophorin formation during embryonic development of the silkworm, Bombyx mori. Comp Biochem Physiol B Biochem Mol Biol 2010; 155:363-70. [DOI: 10.1016/j.cbpb.2009.12.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Revised: 12/16/2009] [Accepted: 12/20/2009] [Indexed: 10/20/2022]
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Functional analysis of Ultrabithorax in the silkworm, Bombyx mori, using RNAi. Dev Genes Evol 2009; 219:437-44. [PMID: 19908062 DOI: 10.1007/s00427-009-0305-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2009] [Accepted: 10/15/2009] [Indexed: 10/20/2022]
Abstract
The formation of abdominal appendages in insects is suppressed by the Hox genes Ultrabithorax (Ubx) and abdominal-A (abd-A), but mechanisms of the suppression can differ among species. As the function of Ubx and abd-A has been described in only a few species, more data from various insects are necessary to elucidate the evolutionary transition of regulation on abdominal appendages. We examined the function of Ubx in the silkworm Bombyx mori (Bm-Ubx) by embryonic RNA interference (RNAi). This is the first case in which functional analysis for Ubx is performed in lepidopteran insects. Larvae treated with Bm-Ubx dsRNA displayed an additional pair of thoracic leg-like protuberances in A1, whereas the other abdominal segments had no transformation. Our results suggest that Bm-Ubx is a suppressor of leg development in A1.
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Liu S, Zhang L, Li Q, Zhao P, Duan J, Cheng D, Xiang Z, Xia Q. MicroRNA expression profiling during the life cycle of the silkworm (Bombyx mori). BMC Genomics 2009; 10:455. [PMID: 19785751 PMCID: PMC2761947 DOI: 10.1186/1471-2164-10-455] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2009] [Accepted: 09/28/2009] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND MicroRNAs (miRNAs) are expressed by a wide range of eukaryotic organisms, and function in diverse biological processes. Numerous miRNAs have been identified in Bombyx mori, but the temporal expression profiles of miRNAs corresponding to each stage transition over the entire life cycle of the silkworm remain to be established. To obtain a comprehensive overview of the correlation between miRNA expression and stage transitions, we performed a whole-life test and subsequent stage-by-stage examinations on nearly one hundred miRNAs in the silkworm. RESULTS Our results show that miRNAs display a wide variety of expression profiles over the whole life of the silkworm, including continuous expression from embryo to adult (miR-184), up-regulation over the entire life cycle (let-7 and miR-100), down-regulation over the entire life cycle (miR-124), expression associated with embryogenesis (miR-29 and miR-92), up-regulation from early 3rd instar to pupa (miR-275), and complementary pulses in expression between miR-34b and miR-275. Stage-by-stage examinations revealed further expression patterns, such as emergence at specific time-points during embryogenesis and up-regulation of miRNA groups in late embryos (miR-1 and bantam), expression associated with stage transition between instar and molt larval stages (miR-34b), expression associated with silk gland growth and spinning activity (miR-274), continuous high expression from the spinning larval to pupal and adult stages (miR-252 and miR-31a), a coordinate expression trough in day 3 pupae of both sexes (miR-10b and miR-281), up-regulation in pupal metamorphosis of both sexes (miR-29b), and down-regulation in pupal metamorphosis of both sexes (miR-275). CONCLUSION We present the full-scale expression profiles of miRNAs throughout the life cycle of Bombyx mori. The whole-life expression profile was further investigated via stage-by-stage analysis. Our data provide an important resource for more detailed functional analysis of miRNAs in this animal.
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Affiliation(s)
- Shiping Liu
- The Key Sericultural Laboratory of Agricultural Ministry, College of Biotechnology, Southwest University, Chongqing 400715, PR China
| | - Liang Zhang
- National Engineering Center for Beijing Biochip Technology, Life Science Parkway, Changping District, Beijing 102206, PR China
| | - Qibin Li
- Beijing Genomics Institute at Shenzhen, Shenzhen 518083, PR China
- Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100000, PR China
| | - Ping Zhao
- The Key Sericultural Laboratory of Agricultural Ministry, College of Biotechnology, Southwest University, Chongqing 400715, PR China
| | - Jun Duan
- Institute of Agricultural and Life Sciences, Chongqing University, Chongqing, 400030, PR China
| | - Daojun Cheng
- The Key Sericultural Laboratory of Agricultural Ministry, College of Biotechnology, Southwest University, Chongqing 400715, PR China
| | - Zhonghuai Xiang
- The Key Sericultural Laboratory of Agricultural Ministry, College of Biotechnology, Southwest University, Chongqing 400715, PR China
| | - Qingyou Xia
- The Key Sericultural Laboratory of Agricultural Ministry, College of Biotechnology, Southwest University, Chongqing 400715, PR China
- Institute of Agricultural and Life Sciences, Chongqing University, Chongqing, 400030, PR China
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Mitsumasu K, Tanaka Y, Niimi T, Yamashita O, Yaginuma T. Novel gene encoding precursor protein consisting of possible several neuropeptides expressed in brain and frontal ganglion of the silkworm, Bombyx mori. Peptides 2009; 30:1233-40. [PMID: 19540422 DOI: 10.1016/j.peptides.2009.03.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2008] [Revised: 03/04/2009] [Accepted: 03/09/2009] [Indexed: 11/30/2022]
Abstract
A novel gene (BmK5) expressed in the central nervous system of the silkworm, Bombyx mori, was isolated using a cDNA subtraction method. BmK5 was first cloned as a candidate regulator of diapause hormone release from subesophageal ganglion via corpus cardiacum-corpus allatum into the hemolymph; however, subsequent analyses revealed that the gene expression patterns in brain-subesophageal ganglion complexes did not differ between diapause and nondiapause egg producers. The deduced amino acid sequence showed the characteristics of secretory protein precursor or nuclear localization protein. Immunohistochemical experiments with an anti-BmK5 antibody revealed that BmK5 precursor protein exists in the cytoplasm of specific cells of brain and frontal ganglion, but not in the nuclei. In addition, a peptide (GSGTKVGGAGAATKVVTKSGS-NH(2)) possibly processed from the BmK5 precursor protein was immunohistochemically detected in the axons connecting the anti-BmK5 antibody-positive cells to the neurohemal organ, corpus cardiacum-corpus allatum. These results suggest that BmK5 encodes a precursor of the novel neurosecretory protein and that several mature peptides are released into the hemolymph via the corpus cardiacum-corpus allatum, although the functions of these peptides are yet unclear.
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Affiliation(s)
- Kanako Mitsumasu
- Sericulture and Entomoresources, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan
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Zhao L, Shi L. Metabolism of hydrogen peroxide in univoltine and polyvoltine strains of silkworm (Bombyx mori). Comp Biochem Physiol B Biochem Mol Biol 2009; 152:339-45. [DOI: 10.1016/j.cbpb.2008.12.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2008] [Revised: 12/25/2008] [Accepted: 12/29/2008] [Indexed: 10/21/2022]
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20
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Mitsumasu K, Ohta H, Tsuchihara K, Asaoka K, Ozoe Y, Niimi T, Yamashita O, Yaginuma T. Molecular cloning and characterization of cDNAs encoding dopamine receptor-1 and -2 from brain-suboesophageal ganglion of the silkworm, Bombyx mori. INSECT MOLECULAR BIOLOGY 2008; 17:185-195. [PMID: 18353107 DOI: 10.1111/j.1365-2583.2008.00792.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
In order to better understand the relationship between dopamine and the release of diapause hormone into the blood, we cloned and characterized cDNAs encoding Bombyx mori dopamine receptor-1 and -2 (BmDopR1 and 2) from the pupal brain-suboesophageal ganglion. BmDopR1 and 2 had high similarities to group 1 (Drosophila melanogaster DOP1 and Apis mellifera DOP1) and group 2 (D. melanogaster DopR99B, A. mellifera DOP2 and Papilio xuthus DOP1), respectively. When BmDopR1 and 2 were expressed in human embryonic kidney (HEK) cells, they responded to dopamine by increasing intracellular cAMP levels, thus indicating the presence of D1-like receptors. There were no clear differences in BmDopR1 and 2 mRNA levels between brain-suboesophageal ganglion complexes of diapause and nondiapause egg producers during pupal-adult development. BmDopR1 and 2 mRNAs were concentrated in the mushroom body calyx rather than in the suboesophageal ganglion. Taking into account the results of earlier experiments on excised regions corresponding to mushroom bodies, BmDopR1 and 2 in the mushroom body apparently play a role in the release of diapause hormone.
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Affiliation(s)
- K Mitsumasu
- Sericulture & Entomoresources, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, Aichi, Japan
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21
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Abstract
The anatomical locations of three components of insect photoperiodism--the photoperiodic photoreceptor, photoperiodic clock and hormonal effector--are summarized and compared between species. Among photoperiodic photoreceptors, either the retinal or extraretinal types or both are operative, and there is no general relationship between phylogeny and photoreceptor type. The photoperiodic clock comprises time measurement and counter systems. Currently, it is generally accepted that circadian oscillators are involved in the photoperiodic clock. Several recent studies have raised the possibility that timeless, a circadian clock gene, plays a role in the photoperiodic clock in flies. The dorsal protocerebrum has been identified as an important region regulating the endocrine system for adult, pupal and embryonic diapause controlled by photoperiod. In the blow fly Protophormia terraenovae, neural connections between circadian clock neurons and indispensable neurons in the pars lateralis for diapause induction in the dorsal protocerebrum have been demonstrated. This neural network may provide the access needed to investigate the neural components of the photoperiodic clock.
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Affiliation(s)
- Sakiko Shiga
- Department of Biology and Geosciences, Graduate School of Science, Osaka City University, Osaka, Japan.
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Shiomi K, Fujiwara Y, Yasukochi Y, Kajiura Z, Nakagaki M, Yaginuma T. The Pitx homeobox gene in Bombyx mori: Regulation of DH-PBAN neuropeptide hormone gene expression. Mol Cell Neurosci 2007; 34:209-18. [PMID: 17166739 DOI: 10.1016/j.mcn.2006.10.015] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2006] [Accepted: 10/31/2006] [Indexed: 11/18/2022] Open
Abstract
The diapause hormone-pheromone biosynthesis activating neuropeptide gene, DH-PBAN, is expressed exclusively in seven pairs of DH-PBAN-producing neurosecretory cells (DHPCs) on the terminally differentiated processes of the subesophageal ganglion (SG). To help reveal the regulatory mechanisms of cell-specific DH-PBAN expression, we identified a cis-regulatory element that regulates expression in DHPCs using the recombinant AcNPV-mediated gene transfer system and a gel-mobility shift assay. Bombyx mori Pitx (BmPitx), a bicoid-like homeobox transcription factor, binds this element and activates DH-PBAN expression. The BmPitx was expressed in various tissues, including DHPCs in the SG. Suppression of DH-PBAN expression by silencing of the BmPitx successfully induced non-diapaused eggs from a diapause egg producer. To the best of our knowledge, this report is the first to identify a neuropeptide-encoding gene as a target of the Pitx transcriptional regulator in invertebrates. Thus, it is tempting to speculate that functional conservation of Pitx family members on neuropeptide gene expression occurs through a "combinational code mechanism" in both vertebrate and invertebrate in neuroendocrine systems.
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Affiliation(s)
- Kunihiro Shiomi
- Faculty of Textile Science and Technology, Shinshu University, Ueda, Nagano 386-8567, Japan.
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Homma T, Watanabe K, Tsurumaru S, Kataoka H, Imai K, Kamba M, Niimi T, Yamashita O, Yaginuma T. G protein-coupled receptor for diapause hormone, an inducer of Bombyx embryonic diapause. Biochem Biophys Res Commun 2006; 344:386-93. [PMID: 16600181 DOI: 10.1016/j.bbrc.2006.03.085] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2006] [Accepted: 03/10/2006] [Indexed: 01/05/2023]
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 (EC(50), approximately 70nM) 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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Affiliation(s)
- Takashi Homma
- Sericulture and Entomoresources, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan
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Kitagawa N, Shiomi K, Imai K, Niimi T, Yaginuma T, Yamashita O. Establishment of a Sandwich ELISA System to Detect Diapause Hormone, and Developmental Profile of Hormone Levels in Egg and Subesophageal Ganglion of the Silkworm, Bombyx mori. Zoolog Sci 2005; 22:213-21. [PMID: 15738641 DOI: 10.2108/zsj.22.213] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In the silkworm Bombyx mori, diapause hormone (DH) is produced in the female subesophageal ganglion (SG) and induces embryonic diapause by targeting developing ovaries. DH is processed from a precursor protein consisting of DH, pheromone biosynthesis activating neuropeptide (PBAN) and three other neuropeptides (SGNPs). Because these five neuropeptides share a common sequence, FXPRLamide, at the C-terminus, a direct and specific assay for DH itself is required in order to understand the profile of concentration changes. In this study, we produced a mouse monoclonal antibody (anti-DH[N] mAb) against the N-terminal region of DH and developed a sandwich enzyme-linked immunosorbent assay using the anti-DH[N] mAb and a rabbit polyclonal antibody against the C-terminus of DH. This procedure enabled us to specifically quantify the DH molecule at femtomolar levels (equivalent to 1/10 of SG). We then plotted DH levels in eggs and SGs during embryonic and post-embryonic development. DH was present in late-stage embryos that had been destined for the production of both diapause and nondiapause eggs. DH levels in SG gradually increased in both types during larval development and peaked at the early pupal stage. At the middle pupal stage, DH levels in SG and SG-brain complex decreased markedly in the diapause-egg producing type, thus indicating active release of DH into the hemolymph. From 5th instar larva to adult, no sexual differences in DH levels were observed in SGs or SG-brain complexes from diapause and nondiapause egg-producing types.
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Affiliation(s)
- Norio Kitagawa
- Laboratory of Sericulture and Entomoresources, Graduate School of Bioagricultural Sciences, Nagoya University, Japan
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