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Wang DY, Zhu J, Zhang YZ, Cui QY, Wang SS, Ning YW, Shen XJ. Upf2-Mediated Nonsense-Mediated Degradation Pathway Involved in Genetic Compensation of TrpA1 Knockout Mutant Silkworm ( Bombyx mori). INSECTS 2024; 15:313. [PMID: 38786869 PMCID: PMC11122591 DOI: 10.3390/insects15050313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 04/23/2024] [Accepted: 04/25/2024] [Indexed: 05/25/2024]
Abstract
Genetic mutations leading to premature termination codons are known to have detrimental effects. Using the Lepidoptera model insect, the silkworm (Bombyx mori), we explored the genetic compensatory response triggered by mutations with premature termination codons. Additionally, we delved into the molecular mechanisms associated with the nonsense-mediated mRNA degradation pathway. CRISPR/Cas9 technology was utilized to generate a homozygous bivoltine silkworm line BmTrpA1-/- with a premature termination. Transcript levels were assessed for the BmTrpA paralogs, BmPyrexia and BmPainless as well as for the essential factors Upf1, Upf2, and Upf3a involved in the nonsense-mediated mRNA degradation (NMD) pathway. Upf2 was specifically knocked down via RNA interference at the embryonic stage. The results comfirmed that the BmTrpA1 transcripts with a 2-base deletion generating a premature termination codon in the BmTrpA1-/- line. From day 6 of embryonic development, the mRNA levels of BmPyrexia, BmPainless, Upf1, and Upf2 were significantly elevated in the gene-edited line. Embryonic knockdown of Upf2 resulted in the suppression of the genetic compensation response in the mutant. As a result, the offspring silkworm eggs were able to hatch normally after 10 days of incubation, displaying a non-diapause phenotype. It was observed that a genetic compensation response does exist in BmTrpA1-/-B. mori. This study presents a novel discovery of the NMD-mediated genetic compensation response in B. mori. The findings offer new insights into understanding the genetic compensation response and exploring the gene functions in lepidopteran insects, such as silkworms.
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Affiliation(s)
- Dong-Yue Wang
- Jiangsu Key Laboratory of Sericultural and Animal Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China; (D.-Y.W.); (Y.-Z.Z.); (Q.-Y.C.); (S.-S.W.); (Y.-W.N.)
| | - Juan Zhu
- Jiangsu Key Laboratory of Sericultural and Animal Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China; (D.-Y.W.); (Y.-Z.Z.); (Q.-Y.C.); (S.-S.W.); (Y.-W.N.)
- Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture and Rural Affairs, Sericultural Scientific Research Center, Chinese Academy of Agricultural Sciences, Zhenjiang 212100, China
| | - Yi-Zhong Zhang
- Jiangsu Key Laboratory of Sericultural and Animal Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China; (D.-Y.W.); (Y.-Z.Z.); (Q.-Y.C.); (S.-S.W.); (Y.-W.N.)
| | - Qian-Yi Cui
- Jiangsu Key Laboratory of Sericultural and Animal Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China; (D.-Y.W.); (Y.-Z.Z.); (Q.-Y.C.); (S.-S.W.); (Y.-W.N.)
| | - Shan-Shan Wang
- Jiangsu Key Laboratory of Sericultural and Animal Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China; (D.-Y.W.); (Y.-Z.Z.); (Q.-Y.C.); (S.-S.W.); (Y.-W.N.)
| | - Yang-Wei Ning
- Jiangsu Key Laboratory of Sericultural and Animal Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China; (D.-Y.W.); (Y.-Z.Z.); (Q.-Y.C.); (S.-S.W.); (Y.-W.N.)
| | - Xing-Jia Shen
- Jiangsu Key Laboratory of Sericultural and Animal Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China; (D.-Y.W.); (Y.-Z.Z.); (Q.-Y.C.); (S.-S.W.); (Y.-W.N.)
- Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture and Rural Affairs, Sericultural Scientific Research Center, Chinese Academy of Agricultural Sciences, Zhenjiang 212100, China
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Liu BP, Hua BZ. Distinct roles of the Hox genes Ultrabithorax and abdominal-A in scorpionfly embryonic proleg development. INSECT MOLECULAR BIOLOGY 2024; 33:69-80. [PMID: 37792400 DOI: 10.1111/imb.12878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 09/21/2023] [Indexed: 10/05/2023]
Abstract
The abdominal appendages of larval insects have a complex evolutionary history of gain and loss, but the regulatory mechanisms underlying the abdominal appendage development remain largely unclear. Here, we investigated the embryogenesis of abdominal prolegs in the scorpionfly Panorpa liui Hua (Mecoptera: Panorpidae) using in situ hybridization and parental RNA interference. The results show that RNAi-mediated knockdown of Ultrabithorax (Ubx) led to a homeotic transformation of the first abdominal segment (A1) into the third thoracic segment (T3) and changed the distributions of the downstream target Distal-less (Dll) expression but did not affect the expression levels of Dll. Knockdown of abdominal-A (abd-A) resulted in malformed segments, abnormal prolegs and disrupted Dll expression. The results demonstrate that the gene Ubx maintains an ancestral role of modulating A1 appendage fate without preventing Dll initiation, and a secondary adaptation of abd-A evolves the ability to specify abdominal segments and proleg identity. We conclude that changes in abdominal Hox gene expression and their target genes regulate abdominal appendage morphology during the evolutionary course of holometabolous larvae.
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Affiliation(s)
- Bing-Peng Liu
- Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling, China
| | - Bao-Zhen Hua
- Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling, China
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Tendolkar A, Mazo-Vargas A, Livraghi L, Hanly JJ, Van Horne KC, Gilbert LE, Martin A. Cis-regulatory modes of Ultrabithorax inactivation in butterfly forewings. eLife 2024; 12:RP90846. [PMID: 38261357 PMCID: PMC10945631 DOI: 10.7554/elife.90846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2024] Open
Abstract
Hox gene clusters encode transcription factors that drive regional specialization during animal development: for example the Hox factor Ubx is expressed in the insect metathoracic (T3) wing appendages and differentiates them from T2 mesothoracic identities. Hox transcriptional regulation requires silencing activities that prevent spurious activation and regulatory crosstalks in the wrong tissues, but this has seldom been studied in insects other than Drosophila, which shows a derived Hox dislocation into two genomic clusters that disjoined Antennapedia (Antp) and Ultrabithorax (Ubx). Here, we investigated how Ubx is restricted to the hindwing in butterflies, amidst a contiguous Hox cluster. By analysing Hi-C and ATAC-seq data in the butterfly Junonia coenia, we show that a Topologically Associated Domain (TAD) maintains a hindwing-enriched profile of chromatin opening around Ubx. This TAD is bordered by a Boundary Element (BE) that separates it from a region of joined wing activity around the Antp locus. CRISPR mutational perturbation of this BE releases ectopic Ubx expression in forewings, inducing homeotic clones with hindwing identities. Further mutational interrogation of two non-coding RNA encoding regions and one putative cis-regulatory module within the Ubx TAD cause rare homeotic transformations in both directions, indicating the presence of both activating and repressing chromatin features. We also describe a series of spontaneous forewing homeotic phenotypes obtained in Heliconius butterflies, and discuss their possible mutational basis. By leveraging the extensive wing specialization found in butterflies, our initial exploration of Ubx regulation demonstrates the existence of silencing and insulating sequences that prevent its spurious expression in forewings.
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Affiliation(s)
- Amruta Tendolkar
- Department of Biological Sciences, The George Washington UniversityWashington, DCUnited States
| | - Anyi Mazo-Vargas
- Department of Biological Sciences, The George Washington UniversityWashington, DCUnited States
| | - Luca Livraghi
- Department of Biological Sciences, The George Washington UniversityWashington, DCUnited States
| | - Joseph J Hanly
- Department of Biological Sciences, The George Washington UniversityWashington, DCUnited States
- Smithsonian Tropical Research InstitutePanama CityPanama
| | - Kelsey C Van Horne
- Department of Biological Sciences, The George Washington UniversityWashington, DCUnited States
| | - Lawrence E Gilbert
- Department of Integrative Biology, University of Texas – AustinAustinUnited States
| | - Arnaud Martin
- Department of Biological Sciences, The George Washington UniversityWashington, DCUnited States
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Matsuoka Y, Murugesan SN, Prakash A, Monteiro A. Lepidopteran prolegs are novel traits, not leg homologs. SCIENCE ADVANCES 2023; 9:eadd9389. [PMID: 37824626 PMCID: PMC10569709 DOI: 10.1126/sciadv.add9389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 09/08/2023] [Indexed: 10/14/2023]
Abstract
Lepidopteran larvae have both thoracic legs and abdominal prolegs, yet it is unclear whether these are serial homologs. A RNA-seq analysis with various appendages of Bicyclus anynana butterfly larvae indicated that the proleg transcriptome resembles the head-horn transcriptome, a novel trait in the lepidoptera, but not a thoracic leg. Under a partial segment abdominal-A (abd-A) knockout, both thoracic leg homologs (pleuropodia) and prolegs developed in the same segment, arguing that both traits are not serial homologs. Further, three of the four coxal marker genes, Sp5, Sp6-9, and araucan, were absent from prolegs, but two endite marker genes, gooseberry and Distal-less, were expressed in prolegs, suggesting that prolegs may be using a modular endite gene-regulatory network (GRN) for their development. We propose that larval prolegs are novel traits derived from the activation of a pre-existing modular endite GRN in the abdomen using abd-A, the same Hox gene that still represses legs in more lateral positions.
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Affiliation(s)
| | - Suriya Narayanan Murugesan
- Department of Biological Sciences, National University of Singapore; 14 Science Drive, Singapore 117543 Singapore
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Li J, Kong Y, Sun L, Tang Y, Sun X, Qin S, Li M. Overexpression of Ultrabithorax Changes the Development of Silk Gland and the Expression of Fibroin Genes in Bombyx mori. Int J Mol Sci 2023; 24:ijms24076670. [PMID: 37047645 PMCID: PMC10095271 DOI: 10.3390/ijms24076670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 03/27/2023] [Accepted: 03/30/2023] [Indexed: 04/14/2023] Open
Abstract
Ultrabithorax (Ubx) is a member of the Hox gene group involved in cell fate decisions, cell proliferation and organ identity. Its function has been extensively researched in Drosophila melanogaster but little is known about it in Lepidoptera. To uncover the function of Ubx in the development of lepidopterans, we constructed the Ubx overexpression (UbxOE) strain based on the Nistari strain of Bombyx mori. The UbxOE strain showed a small body size, transparent intersegmental membrane and abnormal posterior silk gland (PSG). In the current study, we focused on the effect of Ubx overexpression on the posterior silk gland. As the major protein product of PSG, the mRNA expression of fibroin heavy chain (Fib-H) and fibroin light chain (Fib-L) was upregulated three times in UbxOE, but the protein expression of Fib-H and Fib-L was not significantly different. We speculated that the overexpression of Ubx downregulated the expression of Myc and further caused abnormal synthesis of the spliceosome and ribosome. Abnormalities of the spliceosome and ribosome affected the synthesis of protein in the PSG and changed its morphology.
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Affiliation(s)
- Jiashuang Li
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018, China
| | - Yunhui Kong
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018, China
| | - Lingling Sun
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018, China
| | - Yaling Tang
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018, China
| | - Xia Sun
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018, China
- The Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, Sericultural Research Institute, Chinese Academy of Agricultural Science, Zhenjiang 212018, China
| | - Sheng Qin
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018, China
- The Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, Sericultural Research Institute, Chinese Academy of Agricultural Science, Zhenjiang 212018, China
| | - Muwang Li
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018, China
- The Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, Sericultural Research Institute, Chinese Academy of Agricultural Science, Zhenjiang 212018, China
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Elias-Neto M, Alvarez N, Ventos-Alfonso A, Belles X. Flight or protection: the genes Ultrabithorax and apterous in the determination of membranous and sclerotized wings in insects. Proc Biol Sci 2022; 289:20220967. [PMID: 35975435 PMCID: PMC9382207 DOI: 10.1098/rspb.2022.0967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Present-day pterygote insects have two pairs of wings, one in the mesothorax (T2), the other in the metathorax (T3), and both have diverged in structure and function in different groups. Studies in endopterygote and paraneopteran species have shown that the gene Ultrabithorax (Ubx) specifies the identity and wing structure in T3, whereas the gene apterous (ap) significantly contributes to forming modified T2 wings. We wondered whether these Ubx and ap mechanisms operate in the lineage of polyneopterans. To explore this possibility, we used the cockroach Blattella germanica (Polyneoptera and Blattodea), in which the T2 wings are sclerotized (tegmina), whereas those of the T3 are membranous. We found that Ubx determines the structure of T3 and the membranous wing, while ap significantly contributes to form the sclerotized T2 tegmina. These results along with the studies carried out on the beetle Tribolium castaneum by Tomoyasu and collaborators suggest that ap plays an important role in the sclerotization and melanization of the T2 wings in neopteran groups that have sclerotized forewings. In turn, the sclerotizing properties of ap demonstrated in beetles and cockroaches suggest that the origin of this function goes back to the emergence of Neoptera, in the mid Devonian.
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Affiliation(s)
- Moysés Elias-Neto
- Institute of Evolutionary Biology, CSIC-Universitat Pompeu Fabra, Barcelona, Spain
| | - Niuska Alvarez
- Institute of Evolutionary Biology, CSIC-Universitat Pompeu Fabra, Barcelona, Spain
| | - Alba Ventos-Alfonso
- Institute of Evolutionary Biology, CSIC-Universitat Pompeu Fabra, Barcelona, Spain
| | - Xavier Belles
- Institute of Evolutionary Biology, CSIC-Universitat Pompeu Fabra, Barcelona, Spain
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Sakura K, Morita S, Niimi T. RNA Interference Method for Gene Function Analysis in the Japanese Rhinoceros Beetle Trypoxylus dichotomus. Bio Protoc 2022; 12:e4396. [PMID: 35800098 PMCID: PMC9081472 DOI: 10.21769/bioprotoc.4396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 12/20/2021] [Accepted: 03/14/2022] [Indexed: 12/29/2022] Open
Abstract
In the Japanese rhinoceros beetle Trypoxylus dichotomus, various candidate genes required for a specific phenotype of interest are listed by next-generation sequencing analysis. Their functions were investigated using RNA interference (RNAi) method, the only gene function analysis tool for T. dichotomusdeveloped so far. The summarized procedure for the RNAi method used for T. dichotomusis to synthesize double-stranded RNA (dsRNA), and inject it in larvae or pupae of T. dichotomus. Although some dedicated materials or equipment are generally required to inject dsRNA in insects, the advantage of the protocol described here is that it is possible to inject dsRNA in T. dichotomuswith one syringe.
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Affiliation(s)
- Kazuki Sakura
- Division of Evolutionary Developmental Biology, National Institute for Basic Biology, 38 Nishigonaka, Myodaiji, Okazaki, Japan
| | - Shinichi Morita
- Division of Evolutionary Developmental Biology, National Institute for Basic Biology, 38 Nishigonaka, Myodaiji, Okazaki, Japan
| | - Teruyuki Niimi
- Division of Evolutionary Developmental Biology, National Institute for Basic Biology, 38 Nishigonaka, Myodaiji, Okazaki, Japan,Department of Basic Biology, School of Life Science, The Graduate University for Advanced Studies, SOKENDAI, 38 Nishigonaka, Myodaiji, Okazaki, Japan,*For correspondence:
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8
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Tendolkar A, Pomerantz AF, Heryanto C, Shirk PD, Patel NH, Martin A. Ultrabithorax Is a Micromanager of Hindwing Identity in Butterflies and Moths. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.643661] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The forewings and hindwings of butterflies and moths (Lepidoptera) are differentiated from each other, with segment-specific morphologies and color patterns that mediate a wide range of functions in flight, signaling, and protection. The Hox geneUltrabithorax(Ubx) is a master selector gene that differentiates metathoracic from mesothoracic identities across winged insects, and previous work has shown this role extends to at least some of the color patterns from the butterfly hindwing. Here we used CRISPR targeted mutagenesis to generateUbxloss-of-function somatic mutations in two nymphalid butterflies (Junonia coenia,Vanessa cardui) and a pyralid moth (Plodia interpunctella). The resulting mosaic clones yielded hindwing-to-forewing transformations, showingUbxis necessary for specifying many aspects of hindwing-specific identities, including scale morphologies, color patterns, and wing venation and structure. These homeotic phenotypes showed cell-autonomous, sharp transitions between mutant and non-mutant scales, except for clones that encroached into the border ocelli (eyespots) and resulted in composite and non-autonomous effects on eyespot ring determination. In the pyralid moth, homeotic clones converted the folding and depigmented hindwing into rigid and pigmented composites, affected the wing-coupling frenulum, and induced ectopic scent-scales in male androconia. These data confirmUbxis a master selector of lepidopteran hindwing identity and suggest it acts on many gene regulatory networks involved in wing development and patterning.
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You L, Zhang F, Huang S, Merchant A, Zhou X, Li Z. Over-expression of RNA interference (RNAi) core machinery improves susceptibility to RNAi in silkworm larvae. INSECT MOLECULAR BIOLOGY 2020; 29:353-362. [PMID: 32086963 DOI: 10.1111/imb.12639] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 01/18/2020] [Accepted: 02/16/2020] [Indexed: 06/10/2023]
Abstract
RNA interference (RNAi), one of the strategies that organisms use to defend against invading viruses, is an important tool for functional genomic analysis. In insects, the efficacy of RNAi varies amongst taxa. Lepidopteran insects are, in large part, recalcitrant to RNAi. The overall goal of this study is to overcome such insensitivity in lepidopterans to RNAi. We hypothesize that over-expression of core RNAi machinery enzymes can improve RNAi efficacy in traditionally recalcitrant species. A transgenic Bombyx mori strain, Baculovirus Immediate-Early Gene, ie1, promoter driven expression of silkworm Dicer2 coding sequence (IE1-BmDicer2), which over-expresses BmDicer2, was generated by piggyBac transposon-mediated transgenesis. Two indexes, the ratio of animals that showed a silencing phenotype and the duration of silencing, were used to evaluate silencing efficiency. Significant knockdown of target gene expression was observed at 48 h postinjection at both the transcriptional and translational levels. Furthermore, we coexpressed B. mori Argonaute 2 BmAgo2)and BmDicer 2 and found that 22% of the animals (n = 18) showed an obvious silencing effect even at 72 h, suggesting that coexpression of these two RNAi core machinery enzymes further increased the susceptibility of B. mori to injected double-stranded RNAs. This study offers a new strategy for functional genomics research in RNAi-refractory insect taxa in general and for lepidopterans in particular.
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Affiliation(s)
- L You
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - F Zhang
- School of Life Science, Shanghai University, Shanghai, China
| | - S Huang
- Agricultrual and Medical Biotechnology, University of Kentucky, Lexington, KY, USA
| | - A Merchant
- Department of Entomology, University of Kentucky, Lexington, KY, USA
| | - X Zhou
- Department of Entomology, University of Kentucky, Lexington, KY, USA
| | - Z Li
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
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Ismail S, Tulsi Naik KS, Rajam MV, Mishra RK. Targeting genes involved in nucleopolyhedrovirus DNA multiplication through RNA interference technology to induce resistance against the virus in silkworms. Mol Biol Rep 2020; 47:5333-5342. [PMID: 32617957 DOI: 10.1007/s11033-020-05615-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Accepted: 06/22/2020] [Indexed: 11/28/2022]
Abstract
RNA interference (RNAi) has become an efficient tool for inducing resistance to viruses in many organisms. In this study, Escherichia coli cells were engineered to produce stable double-stranded RNA (dsRNA) against the nucleopolyhedrosis virus to elicit RNAi in silkworms. The immediate-early-1 (ie-1) and late expression factor-1 (lef-1) genes of the Bombyx mori nucleopolyhedrovirus (BmNPV) involved in viral DNA multiplication were cloned in the plasmid L4440 under the influence of the double T7 promoter and transformed to E. coli HT115 DE3 host cells. On induction with isopropyl β-D-thiogalactopyranoside, these cells efficiently produced dsRNA of the cloned genes. The B. mori larvae were fed with 50 µL of E. coli cells expressing ie-1 and lef-1 dsRNAs (each approximately 25 µg) to elicit RNAi. The semi-quantitative and quantitative PCR analysis of RNA from the midgut of the dsRNA-fed larvae revealed a significant reduction in the expression of the target genes involved in BmNPV multiplication, which restricted virus copy numbers to 100 compared with 1.9 × 105 in the infected controls. Furthermore, the dsRNA-fed infected larvae showed > 50% increased survivability compared with the infected controls. The study revealed the successful use of bacteria as vectors for efficiently delivering dsRNA to elicit RNAi against BmNPV in silkworms.
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Affiliation(s)
- Sahar Ismail
- Seri Biotech Research Laboratory, Central Silk Board, Kodathi, Bengaluru, Karnataka, 560035, India
| | - K S Tulsi Naik
- Seri Biotech Research Laboratory, Central Silk Board, Kodathi, Bengaluru, Karnataka, 560035, India.
| | - Manchikatla Venkat Rajam
- Department of Genetics, University of Delhi, Benito Juarez Marg, South Campus, New Delhi, 110021, India
| | - Rakesh Kumar Mishra
- Seri Biotech Research Laboratory, Central Silk Board, Kodathi, Bengaluru, Karnataka, 560035, India
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Fu SJ, Zhang JL, Chen SJ, Chen HH, Liu YL, Xu HJ. Functional analysis of Ultrabithorax in the wing-dimorphic planthopper Nilaparvata lugens (Stål, 1854) (Hemiptera: Delphacidae). Gene 2020; 737:144446. [DOI: 10.1016/j.gene.2020.144446] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 01/31/2020] [Accepted: 02/03/2020] [Indexed: 01/24/2023]
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Wang H, Hu H, Xiang Z, Lu C, Dai F, Tong X. Identification and characterization of a new long noncoding RNA iab-1 in the Hox cluster of silkworm, Bombyx mori identification of iab-1. J Cell Biochem 2019; 120:17283-17292. [PMID: 31106470 DOI: 10.1002/jcb.28990] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 04/06/2019] [Accepted: 04/11/2019] [Indexed: 02/04/2023]
Abstract
Long noncoding RNAs (lncRNAs) areinvolvedin a variety of biological processes. In silkworm, numerous lncRNAs have been predicted through deep transcriptome sequencing, but no functional role has been experimentally validated yet. Here, we characterized a new lncRNA iab-1 that was mainly encoded by the intergenic region between Bmabd-A and Bmabd-B in the Homeobox (Hox) cluster of the silkworm, Bombyx mori. More than seven alternative splicing isoforms of lncRNA iab-1 were cloned, which were subgrouped into types 1 and 2 based on the location of the 3'-ends. The iab-1 was expressed at a low level, but the expression of iab-1 peaked at several specific development stages, including 3 to 4 days during the embryonic stage, stages before fourth molting, and the sixth hour after the fourth molting, and early stages during metamorphosis. It was highly expressed in the nervus and epidermis, especially the epidermis of the posterior abdomen at the fourth instar premolting stage. The relationship between iab-1 and nearby Hox genes was analyzed at different developmental stages. Iab-1 expression was highly associated with Bmabd-A as well as Bmabd-B in the embryonic and larval stages, while this association was decreased at the metamorphic stage; iab-1 expression was highly associated with BmUbx only in the embryonic stage. Downregulation of iab-1 expression by small interfering RNA led to the death of most of the treated individuals at the larval stage, suggesting that iab-1 transcript expression might be involved in certain relevant physiological processes. The expression of Bmabd-A and Bmabd-B did not change in iab-1 downregulated individuals, indicating that the relevance between the two genes and iab-1 was not induced by iab-1 transcript. Collectively, the results showed that the newly identified iab-1 may be involved in some physiological processes, and the interaction between iab-1 and Hox genes was also preliminarily analyzed.
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Affiliation(s)
- Honglei Wang
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing, China
| | - Hai Hu
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing, China
| | - Zhonghuai Xiang
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing, China
| | - Cheng Lu
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing, China
| | - Fangyin Dai
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing, China
| | - Xiaoling Tong
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing, China
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Santos-Ortega Y, Killiny N. Silencing of sucrose hydrolase causes nymph mortality and disturbs adult osmotic homeostasis in Diaphorina citri (Hemiptera: Liviidae). INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2018; 101:131-143. [PMID: 30205149 DOI: 10.1016/j.ibmb.2018.09.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 09/06/2018] [Accepted: 09/07/2018] [Indexed: 06/08/2023]
Abstract
Plant piercing sucking insects mainly feed on phloem sap containing a high amount of sucrose. To enhance the absorption of sucrose from the midgut, sucrose hydrolase digests sucrose into glucose and fructose. In this study, a sucrose hydrolase homolog (DcSuh) was identified and targeted in Diaphorina citri, the vector of huanglongbing (HLB), by RNA interference (RNAi). In silico analysis revealed the presence of an Aamy domain in the DcSUH protein, which is characteristic of the glycoside hydrolase family 13 (GH13). Phylogenetic analysis showed DcSuh was closely related to the sucrose hydrolase of other Hemiptera members. The highest gene expression levels of DcSuh was found in the 4th and 5th instar nymphs. dsRNA-mediated RNAi of DcSuh was achieved through topical feeding. Our results showed that application of 0.2 μL of 500 ng μL-1 (100 ng) dsRNA-DcSuh was sufficient to repress the expression of the targeted gene and cause nymph mortality and reduce adult lifespan. The reduction in gene expression, mortality, and lifespan was dose-dependent. In agreement with the gene expression results, treatment with dsRNA-DcSuh significantly reduced sucrose hydrolase activity in treated nymphs and emerged adults from treated nymphs. Interestingly, some emerged adults from treated nymphs showed a swollen abdomen phenotype, indicating that these insects were under osmotic stress. Although the percentage of swollen abdomens was low, their incidence was significantly correlated with the concentration of applied dsRNA-DcSuh. Metabolomic analyses using GC-MS showed an accumulation of sucrose and a reduction in fructose, glucose and trehalose in treated nymphs, confirming the inhibition of sucrose hydrolase activity. Additionally, most of the secondary metabolites were reduced in the treated nymphs, indicating a reduction in the biological activities in D. citri and that they are under stress. Our findings indicate that sucrose hydrolase might be a potential target for effective RNAi control of D. citri.
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Affiliation(s)
- Yulica Santos-Ortega
- Department of Plant Pathology, IFAS, Citrus Research and Education Center, University of Florida, Lake Alfred, FL, USA
| | - Nabil Killiny
- Department of Plant Pathology, IFAS, Citrus Research and Education Center, University of Florida, Lake Alfred, FL, USA.
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14
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Tong XL, Fu MY, Chen P, Chen L, Xiang ZH, Lu C, Dai FY. Ultrabithorax and abdominal-A specify the abdominal appendage in a dosage-dependent manner in silkworm, Bombyx mori. Heredity (Edinb) 2017; 118:578-584. [PMID: 28121309 DOI: 10.1038/hdy.2016.131] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 10/21/2016] [Accepted: 12/05/2016] [Indexed: 11/09/2022] Open
Abstract
In insects, there is a considerable diversity in leg distribution on the body, including number, segmental arrangement, morphological identity and consequent function, but the genetic basis for these differences is not well understood. Here by positional cloning, we showed that a ~355 kb region, including Bombyx mori Ultrabithorax (BmUbx) and abdominal-A (Bmabd-A), was responsible for the silkworm mutant Kh-extra-crescents-like (EKh-l) that displayed additional thoracic limb-like legs on the first abdominal segment (A1) and occasionally on the second abdominal segment (A2). We found that BmUbx gene was downregulated at both messenger RNA level and protein level in EKh-l embryo, while its expression domain in the EKh-l embryo was almost the same as that in the wild type. Whereas Bmabd-A was upregulated at both levels and was ectopically overexpressed on the supernumerary leg-bearing segments in EKh-l. Compared with the previously reported Ecs-l mutant in which increased expression of both BmUbx and Bmabd-A gave rise to ectopic proleg-like appendages on the same segments, we propose that overexpressed Bmabd-A gene is capable to promote the outgrowth of extra leg appendages on A1 and A2 segments, whereas BmUbx gene is required to specify accurate morphologies of the ectopic legs in a dosage-dependent manner in silkworm. These results provide insights into how these hox genes regulate the leg morphologic diversity on the same segments.
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Affiliation(s)
- X L Tong
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China.,Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing, China
| | - M Y Fu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China.,Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing, China
| | - P Chen
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - L Chen
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Z H Xiang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China.,Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing, China
| | - C Lu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China.,Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing, China
| | - F Y Dai
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China.,Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing, China
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15
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Wang H, Tong X, Liu M, Hu H, Li Z, Xiang Z, Dai F, Lu C. Fine Mapping of a Degenerated Abdominal Legs Mutant (Edl) in Silkworm, Bombyx mori. PLoS One 2017; 12:e0169224. [PMID: 28081147 PMCID: PMC5231277 DOI: 10.1371/journal.pone.0169224] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 12/13/2016] [Indexed: 12/05/2022] Open
Abstract
In insects, abdominal appendages, also called prolegs, vary due to adaptive evolution. Mutations on prolegs within species provide insights to better understand the mechanisms underlying appendage development and diversity. In silkworm Bombyx mori, extra-crescents and degenerated abdominal legs (Edl) mutant, belonging to the E pseudoallele group, is a spontaneous mutation that adds crescents and degenerates prolegs on the third abdominal segment (A3). This mutation may be a homeotic transformation of A3 to A2. In this study, the Edl locus was mapped within approximately a 211 Kb region that is 10 Kb upstream of Bmabdominal-A (Bmabd-A). RT-quantitative PCR (RT-qPCR) and Western blot analysis of Bmabd-A expression showed a slight but significant decrease, while the expression of BmUltrabithorax (BmUbx) was up-regulated in the Edl mutant compared to wildtype (Dazao). Moreover, we also found that BmDistal-less (BmDll), which regulated the development of distal proleg structures, was missing at the tips of the A3 prolegs in the Edl mutant compared to BmDll expression in normally developed prolegs in both the wildtype and mutant. Collectively, we identified approximately a 211 Kb region in the Edl locus that regulates BmUbx and Bmabd-A expression and found that changes in BmUbx and Bmabd-A expression may lead to the loss of distal proleg structures in B. mori.
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Affiliation(s)
- Honglei Wang
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
| | - Xiaoling Tong
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
| | - Meijing Liu
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
| | - Hai Hu
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
| | - Zhiquan Li
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
| | - Zhonghuai Xiang
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
| | - Fangyin Dai
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
- * E-mail: (FD); (CL)
| | - Cheng Lu
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
- * E-mail: (FD); (CL)
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16
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Xu J, Wang XF, Chen P, Liu FT, Zheng SC, Ye H, Mo MH. RNA Interference in Moths: Mechanisms, Applications, and Progress. Genes (Basel) 2016; 7:E88. [PMID: 27775569 PMCID: PMC5083927 DOI: 10.3390/genes7100088] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 10/13/2016] [Accepted: 10/14/2016] [Indexed: 12/14/2022] Open
Abstract
The vast majority of lepidopterans, about 90%, are moths. Some moths, particularly their caterpillars, are major agricultural and forestry pests in many parts of the world. However, some other members of moths, such as the silkworm Bombyx mori, are famous for their economic value. Fire et al. in 1998 initially found that exogenous double-stranded RNA (dsRNA) can silence the homolog endogenous mRNA in organisms, which is called RNA interference (RNAi). Soon after, the RNAi technique proved to be very promising not only in gene function determination but also in pest control. However, later studies demonstrate that performing RNAi in moths is not as straightforward as shown in other insect taxa. Nevertheless, since 2007, especially after 2010, an increasing number of reports have been published that describe successful RNAi experiments in different moth species either on gene function analysis or on pest management exploration. So far, more than 100 peer-reviewed papers have reported successful RNAi experiments in moths, covering 10 families and 25 species. By using classic and novel dsRNA delivery methods, these studies effectively silence the expression of various target genes and determine their function in larval development, reproduction, immunology, resistance against chemicals, and other biological processes. In addition, a number of laboratory and field trials have demonstrated that RNAi is also a potential strategy for moth pest management. In this review, therefore, we summarize and discuss the mechanisms and applications of the RNAi technique in moths by focusing on recent progresses.
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Affiliation(s)
- Jin Xu
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650091, China.
- Institute of Plant Protection, Yunnan Academy of Forestry, Kunming 650201, China.
| | - Xia-Fei Wang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650091, China.
| | - Peng Chen
- Institute of Plant Protection, Yunnan Academy of Forestry, Kunming 650201, China.
| | - Fang-Tao Liu
- School of Physical Education, Wenshan Institute, Wenshan 663000, China.
| | - Shuai-Chao Zheng
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650091, China.
| | - Hui Ye
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650091, China.
| | - Ming-He Mo
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650091, China.
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17
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Takiya S, Tsubota T, Kimoto M. Regulation of Silk Genes by Hox and Homeodomain Proteins in the Terminal Differentiated Silk Gland of the Silkworm Bombyx mori. J Dev Biol 2016; 4:E19. [PMID: 29615585 PMCID: PMC5831788 DOI: 10.3390/jdb4020019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 05/08/2016] [Accepted: 05/17/2016] [Indexed: 12/15/2022] Open
Abstract
The silk gland of the silkworm Bombyx mori is a long tubular organ that is divided into several subparts along its anteroposterior (AP) axis. As a trait of terminal differentiation of the silk gland, several silk protein genes are expressed with unique regional specificities. Most of the Hox and some of the homeobox genes are also expressed in the differentiated silk gland with regional specificities. The expression patterns of Hox genes in the silk gland roughly correspond to those in embryogenesis showing "colinearity". The central Hox class protein Antennapedia (Antp) directly regulates the expression of several middle silk gland-specific silk genes, whereas the Lin-1/Isl-1/Mec3 (LIM)-homeodomain transcriptional factor Arrowhead (Awh) regulates the expression of posterior silk gland-specific genes for silk fiber proteins. We summarize our results and discuss the usefulness of the silk gland of Bombyx mori for analyzing the function of Hox genes. Further analyses of the regulatory mechanisms underlying the region-specific expression of silk genes will provide novel insights into the molecular bases for target-gene selection and regulation by Hox and homeodomain proteins.
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Affiliation(s)
- Shigeharu Takiya
- Shigeharu Takiya, Division of Biological Sciences and Center for Genome Dynamics, Faculty of Science, Hokkaido University, North 10, West 8, Kita-ku, Sapporo, Hokkaido 060-0810, Japan.
- Graduate School of Life Science, Hokkaido University, North 10, West 8, Kita-ku, Sapporo 060-0810, Japan.
| | - Takuya Tsubota
- Transgenic Silkworm Research Unit, Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, 1-2 Owashi, Tsukuba, Ibaraki 305-8634, Japan.
| | - Mai Kimoto
- Graduate School of Life Science, Hokkaido University, North 10, West 8, Kita-ku, Sapporo 060-0810, Japan.
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18
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Huang MX, Du J, Su BJ, Zhao GD, Shen WD, Wei ZG. The expression profile and promoter analysis of ultraspiracle gene in the silkworm Bombyx mori. Mol Biol Rep 2014; 41:7955-65. [DOI: 10.1007/s11033-014-3690-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Accepted: 08/21/2014] [Indexed: 12/01/2022]
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19
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Kobayashi N, Takahashi M, Kihara S, Niimi T, Yamashita O, Yaginuma T. Cloning of cDNA encoding a Bombyx mori homolog of human oxidation resistance 1 (OXR1) protein from diapause eggs, and analyses of its expression and function. JOURNAL OF INSECT PHYSIOLOGY 2014; 68:58-68. [PMID: 25010546 DOI: 10.1016/j.jinsphys.2014.06.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 05/24/2014] [Accepted: 06/19/2014] [Indexed: 06/03/2023]
Abstract
To better understand the molecular mechanisms of diapause initiation, we used the sensitive cDNA subtraction (selective amplification via biotin- and restriction-mediated enrichment) method and isolated a novel gene expressed abundantly in diapause eggs of the silkworm, Bombyx mori, which encodes a homolog of the human oxidation resistance 1 (OXR1) protein. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting analyses confirmed that BmOXR1 mRNA and its 140-kDa protein were differentially expressed in diapause eggs compared to non-diapause eggs. OXR1 double-stranded RNA (dsRNA) was injected into diapause-destined eggs before the cellular blastoderm stage, and 4days later, when untreated eggs reached the diapause stage, the OXR1 protein disappeared; however, these eggs remained in diapause, suggesting that BmOXR1 is not essential for diapause initiation and/or maintenance. To further investigate the in vivo function of BmOXR1 apart from its role in diapause, we overexpressed BmOXR1 in Drosophila melanogaster. The fruit fly male adult life-span was significantly extended in the 50%-survival time when adults were reared on diets both with and without H2O2 solution under 25°C incubation. These results suggest that BmOXR1 functions in D. melanogaster via a possible antioxidant effect. As BmOXR1 was expressed mainly in the nuclei of D. melanogaster cells, the mechanism underlying its antioxidation effect appears to be different from that in humans where it is expressed mainly in the mitochondria. Taken together, these results suggest that BmOXR1 might serve as an antioxidant regulator during the early diapause stage.
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Affiliation(s)
- Noriko Kobayashi
- Laboratory of Sericulture & Entomoresources, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, Aichi 464-8601, Japan
| | - Masaki Takahashi
- Laboratory of Sericulture & Entomoresources, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, Aichi 464-8601, Japan
| | - Shouhei Kihara
- Laboratory of Sericulture & Entomoresources, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, Aichi 464-8601, Japan
| | - Teruyuki Niimi
- Laboratory of Sericulture & Entomoresources, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, Aichi 464-8601, Japan
| | - Okitsugu Yamashita
- Laboratory of Sericulture & Entomoresources, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, Aichi 464-8601, Japan
| | - Toshinobu Yaginuma
- Laboratory of Sericulture & Entomoresources, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, Aichi 464-8601, Japan.
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20
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Suzuki MG, Ito H, Aoki F. Effects of RNAi-mediated knockdown of histone methyltransferases on the sex-specific mRNA expression of Imp in the silkworm Bombyx mori. Int J Mol Sci 2014; 15:6772-96. [PMID: 24758924 PMCID: PMC4013661 DOI: 10.3390/ijms15046772] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 03/25/2014] [Accepted: 04/10/2014] [Indexed: 12/11/2022] Open
Abstract
Sexual differentiation in Bombyx mori is controlled by sex-specific splicing of Bmdsx, which results in the omission of exons 3 and 4 in a male-specific manner. In B. mori, insulin-like growth factor II mRNA-binding protein (Imp) is a male-specific factor involved in male-specific splicing of Bmdsx. Male-specific Imp mRNA results from the male-specific inclusion of exon 8. To verify the link between histone methylation and alternative RNA processing in Imp, we examined the effects of RNAi-mediated knockdown of several histone methyltransferases on the sex-specific mRNA expression of Imp. As a result, male-specific expression of Imp mRNA was completely abolished when expression of the H3K79 methyltransferase DOT1L was repressed to <10% of that in control males. Chromatin immunoprecipitation-quantitative PCR analysis revealed a higher distribution of H3K79me2 in normal males than in normal females across Imp. RNA polymerase II (RNAP II) processivity assays indicated that RNAi knockdown of DOT1L in males caused a twofold decrease in RNAP II processivity compared to that in control males, with almost equivalent levels to those observed in normal females. Inhibition of RNAP II-mediated elongation in male cells repressed the male-specific splicing of Imp. Our data suggest the possibility that H3K79me2 accumulation along Imp is associated with the male-specific alternative processing of Imp mRNA that results from increased RNAP II processivity.
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Affiliation(s)
- Masataka G Suzuki
- Division of Biological Sciences, Department of Integrated Biosciences, Graduate School of Frontier Sciences, the University of Tokyo, 302 Bioscience-Bldg, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan.
| | - Haruka Ito
- Division of Biological Sciences, Department of Integrated Biosciences, Graduate School of Frontier Sciences, the University of Tokyo, 302 Bioscience-Bldg, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan.
| | - Fugaku Aoki
- Division of Biological Sciences, Department of Integrated Biosciences, Graduate School of Frontier Sciences, the University of Tokyo, 302 Bioscience-Bldg, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan.
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21
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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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22
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Konopova B, Akam M. The Hox genes Ultrabithorax and abdominal-A specify three different types of abdominal appendage in the springtail Orchesella cincta (Collembola). EvoDevo 2014; 5:2. [PMID: 24398075 PMCID: PMC3910676 DOI: 10.1186/2041-9139-5-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Accepted: 11/20/2013] [Indexed: 12/18/2022] Open
Abstract
Background In Drosophila and many other insects, the Hox genes Ultrabithorax (Ubx) and abdominal-A (abd-A) suppress limb formation on most or all segments of the abdomen. However, a number of basal hexapod lineages retain multiple appendages on the abdomen. In the collembolans or springtails, three abdominal segments develop specialized organs that originate from paired appendage primordia which fuse at the midline: the first abdominal segment bears the collophore (ventral tube), involved in osmoregulation; the fourth segment bears the furca, the leaping organ, and the third segment bears the retinaculum, which retains the furca at rest. Ubx and abd-A are known to be expressed in the springtail abdomen, but what role they play in specifying these distinct abdominal appendages is not known. This is largely because no genetic model has been established in collembolans or any other non-insect hexapod. Results We have developed a convenient method for laboratory culture of the collembolan Orchesella cincta on defined media, a method for in-situ hybridization to embryos and a procedure for gene knockdown by parental injection of double-stranded RNA (RNAi). We show that Orchesella Ubx transcripts are detectable in the first to third abdominal segments, and abd-A transcripts in the second to fourth segments. Knockdown of Oc-Ubx leads to the homeotic transformation of the collophore into a pair of walking legs (a more anterior identity) but the retinaculum into a furca (a more posterior identity). Knockdown of Oc-abd-A leads to the transformation of the retinaculum into a collophore and of the furca into legs (both anterior transformations). Simultaneous silencing of both Oc-Ubx and Oc-abd-A transformed all three of these appendages into paired legs, but did not cause appendages to develop on the second, or on the most posterior abdominal segments. Conclusions We conclude that, in Orchesella, Oc-Ubx alone specifies the collophore on the first and Oc-abd-A alone specifies the furca on the fourth abdominal segment. Oc-Ubx and Oc-abd-A function together, apparently combinatorially, to specify the retinaculum on the third segment. The efficiency of RNAi in Orchesella makes this an attractive model for further genetic studies of development and physiology in basal hexapods. Electronic supplementary material The online version of this article (doi:10.1186/2041-9139-5-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Barbora Konopova
- Laboratory for Development and Evolution, Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK.
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23
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Chen P, Tong XL, Li DD, Liang PF, Fu MY, Li CF, Hu H, Xiang ZH, Lu C, Dai FY. Fine mapping of a supernumerary proleg mutant (E(Cs) -l) and comparative expression analysis of the abdominal-A gene in silkworm, Bombyx mori. INSECT MOLECULAR BIOLOGY 2013; 22:497-504. [PMID: 23803144 DOI: 10.1111/imb.12039] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Patterning and phenotypic variations of appendages in insects provide important clues on developmental genetics. In the silkworm Bombyx mori, morphological variations associated with the E complex, an analogue of the Drosophila melanogaster bithorax complex, mainly determine the shape and number of prolegs on abdominal segments. Here, we report the identification and characterization of the allele responsible for the supernumerary crescents and legs-like (E(Cs) -l) mutant, a model derived from spontaneous mutation of the E complex, with supernumerary legs and extra crescents. Fine mapping with 1605 individuals revealed a ∼68 kb sequence in the upstream intergenic region of B. mori abdominal-A (Bmabd-A) clustered with the E(Cs) -l locus. Quantitative real-time PCR (qRT-PCR) and Western blotting analyses disclosed a marked increase in Bmabd-A expression in the E(Cs) -l mutant at both the transcriptional and translational levels, compared to wild-type Dazao. Furthermore, we observed ectopic expression of the Bmabd-A protein in the second abdominal segment (A2) of the E(Cs) -l mutant. Our results collectively suggest that the 68 kb region contains important regulatory elements of the Bmabd-A gene, and provide evidence that the gene is required for limb development in abdominal segments in the silkworm.
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Affiliation(s)
- P Chen
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
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24
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El-Shesheny I, Hajeri S, El-Hawary I, Gowda S, Killiny N. Silencing abnormal wing disc gene of the Asian citrus psyllid, Diaphorina citri disrupts adult wing development and increases nymph mortality. PLoS One 2013; 8:e65392. [PMID: 23734251 PMCID: PMC3667074 DOI: 10.1371/journal.pone.0065392] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Accepted: 04/29/2013] [Indexed: 12/16/2022] Open
Abstract
Huanglongbing (HLB) causes considerable economic losses to citrus industries worldwide. Its management depends on controlling of the Asian citrus Psyllid (ACP), the vector of the bacterium, Candidatus Liberibacter asiaticus (CLas), the causal agent of HLB. Silencing genes by RNA interference (RNAi) is a promising tool to explore gene functions as well as control pests. In the current study, abnormal wing disc (awd) gene associated with wing development in insects is used to interfere with the flight of psyllids. Our study showed that transcription of awd is development-dependent and the highest level was found in the last instar (5(th)) of the nymphal stage. Micro-application (topical application) of dsRNA to 5(th) instar of nymphs caused significant nymphal mortality and adult wing-malformation. These adverse effects in ACP were positively correlated with the amounts of dsRNA used. A qRT-PCR analysis confirmed the dsRNA-mediated transcriptional down-regulation of the awd gene. Significant down-regulation was required to induce a wing-malformed phenotype. No effect was found when dsRNA-gfp was used, indicating the specific effect of dsRNA-awd. Our findings suggest a role for awd in ACP wing development and metamorphosis. awd could serve as a potential target for insect management either via direct application of dsRNA or by producing transgenic plants expressing dsRNA-awd. These strategies will help to mitigate HLB by controlling ACP.
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Affiliation(s)
- Ibrahim El-Shesheny
- Department of Entomology and Nematology, Citrus Research and Education Center, IFAS, University of Florida, Lake Alfred, Florida, United States of America
- Department of Plant Protection, Faculty of Agriculture, Tanta University, Tanta, Egypt
| | - Subhas Hajeri
- Department of Plant Pathology, Citrus Research and Education Center, IFAS, University of Florida, Lake Alfred, Florida, United States of America
| | - Ibrahim El-Hawary
- Department of Plant Protection, Faculty of Agriculture, Tanta University, Tanta, Egypt
| | - Siddarame Gowda
- Department of Plant Pathology, Citrus Research and Education Center, IFAS, University of Florida, Lake Alfred, Florida, United States of America
| | - Nabil Killiny
- Department of Entomology and Nematology, Citrus Research and Education Center, IFAS, University of Florida, Lake Alfred, Florida, United States of America
- * E-mail:
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25
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Chen P, Tong XL, Li DD, Fu MY, He SZ, Hu H, Xiang ZH, Lu C, Dai FY. Antennapedia is involved in the development of thoracic legs and segmentation in the silkworm, Bombyx mori. Heredity (Edinb) 2013; 111:182-8. [PMID: 23652563 DOI: 10.1038/hdy.2013.36] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Revised: 03/19/2013] [Accepted: 03/26/2013] [Indexed: 11/09/2022] Open
Abstract
Homeotic genes, which are associated closely with body patterning of various species, specify segment identity. The Wedge eye-spot (Wes) is a new homeotic mutant located on the sixth linkage group. Homozygous Wes/Wes embryos are lethal and display a pair of antenna-like appendages under the mouthparts as well as fused thoracic segments. These mutants also exhibit a narrower eye-spot at the larval stage compared with the wild type. By positional cloning, we identified the candidate gene of the Wes locus, Bombyx mori Antennapedia (BmAntp). Two BmAntp transcripts were identified in the homozygote of the Wes mutant, including a normal form and an abnormal form with a 1570-bp insertion. Our data showed that the insertion element was a long interspersed nuclear element (LINE)-like transposon that destroyed the original open reading frame of BmAntp. Quantitative RT-PCR analysis showed that the expression levels of normal BmAntp transcripts were increased markedly in the Wes heterozygous larvae compared with the wild type. Furthermore, we performed RNAi of BmAntp and observed fused thoracic segments and defective thoracic legs in the developing embryos. Our results indicated that BmAntp is responsible for the Wes mutant and has an important role in determining the proper development of the thoracic segments. Our identification of a homeotic mutation in the silkworm is an important contribution to our understanding of the regulation of Hox genes at different levels of expression.
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Affiliation(s)
- P Chen
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
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26
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Lee JM, Kojin Y, Tatsuke T, Mon H, Miyagawa Y, Kusakabe T. Coexpression of Escherichia coli RNase III in silkworm cells improves the efficiency of RNA interference induced by long hairpin dsRNAs. INSECT SCIENCE 2013; 20:69-77. [PMID: 23955827 DOI: 10.1111/j.1744-7917.2012.01569.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Long hairpin dsRNA transcribed from chromosomal DNA can induce RNA interference in Bombyx mori cells, although its gene silencing efficiency is lower than that of exogenously introduced double-stranded RNAs (dsRNAs). To solve this problem, we monitored the nuclear cytoplasmic translocation of the transcribed hairpin dsRNA and analyzed the processing efficiency into mature small interfering RNA (siRNA). Northern blot analysis revealed that the transcribed hairpin dsRNAs were spliced and transported into the cytoplasm, but were not effectively diced into siRNAs. Interestingly, RNAi with hairpin dsRNAs from genome-integrated IR transgene was stimulated by the coexpression of Escherichia coli RNase III, although this exogenous enzyme seemed to bring about nonspecific cleavage of cellular mRNA.
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Affiliation(s)
- Jae Man Lee
- Laboratory of Silkworm Sciences, Kyushu University Graduate School of Bioresource and Bioenvironmental Sciences, Fukuoka, Japan
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27
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Horn T, Boutros M. Design of RNAi reagents for invertebrate model organisms and human disease vectors. Methods Mol Biol 2013; 942:315-346. [PMID: 23027059 DOI: 10.1007/978-1-62703-119-6_17] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
RNAi has become a very versatile tool to silence gene expression in a variety of organisms, in particular when classical genetic methods are missing. However, the application of this method in functional studies has raised new challenges in order to design RNAi reagents that minimize false positives and false negatives. Because the performance of reagents cannot be validated on a genome-wide scale, improved computational methods are required that consider experimentally derived quality measures. In this chapter, we describe computational methods for the design of RNAi reagents for invertebrate model organisms and human disease vectors, such as Anopheles. We describe procedures for designing short and long double-stranded RNAs for single genes, and evaluate their predicted specificity and efficiency. Using a bioinformatics pipeline we also describe how to design a genome-wide RNAi library for Anopheles gambiae.
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Affiliation(s)
- Thomas Horn
- Department of Cell and Molecular Biology, Heidelberg University, Heidelberg, Germany
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28
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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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29
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Kobayashi I, Tsukioka H, Kômoto N, Uchino K, Sezutsu H, Tamura T, Kusakabe T, Tomita S. SID-1 protein of Caenorhabditis elegans mediates uptake of dsRNA into Bombyx cells. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2012; 42:148-154. [PMID: 22178129 DOI: 10.1016/j.ibmb.2011.11.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Revised: 11/28/2011] [Accepted: 11/29/2011] [Indexed: 05/28/2023]
Abstract
RNA interference is one of the most revolutionary tools in the study of gene function, particularly in non-model systems. However, in Bombyx mori, as with many lepidopteran species, attempts at systemic RNAi have had mixed success. Gene identification and phylogenetic analyses suggest that Bombyx has the core RNAi machinery, which is necessary to undergo RNAi as a cellular response. We introduced sid genes from Caenorhabditis elegans into Bombyx BmN4 cells to enhance the uptake of dsRNA and revealed that the SID-1 protein, but not SID-2, has the ability to endow the RNAi effect with the addition of dsRNA to the medium. Observed RNAi effect was dependent on both the levels of sid-1 expression and the concentration of the dsRNA. These results suggest that SID-1 promotes the uptake of dsRNA from the medium into Bombyx cells. We generated transgenic animals that express sid-1 but have not detected significant enhancements of in vivo phenotype in response to the injection of the dsRNA into hemocoel.
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Affiliation(s)
- Isao Kobayashi
- Transgenic Silkworm Research Unit, National Institute of Agrobiological Sciences, 1-2 Ohwashi, Tsukuba, Ibaraki 305-8634, Japan
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30
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siRNAs induce efficient RNAi response in Bombyx mori embryos. PLoS One 2011; 6:e25469. [PMID: 21980469 PMCID: PMC3184131 DOI: 10.1371/journal.pone.0025469] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Accepted: 09/05/2011] [Indexed: 02/02/2023] Open
Abstract
Short interference RNA (siRNA) is widely used in mammalian cells. In insects, however, reports concerning the suitablility of siRNA in vivo is very limited compared with that of long dsRNA, which is thought to be more effective. There is insufficient information on the essential rules of siRNA design in insects, as very few siRNAs have been tested in this context. To establish an effective method of gene silencing using siRNA in vivo in insects, we determined the effects of siRNA on seven target genes. We designed siRNAs according to a new guideline and injected them into eggs of Bombyx mori. At the mRNA level, the expression of most of these genes was successfully silenced, down to less than half the constitutive level, which in some cases led to the development of distinctive phenotypes. In addition, we observed stronger effect of siRNA both on the mRNA level and the phenotype than that of long dsRNA under comparable conditions. These results indicate that direct injection of siRNA is an effective reverse-genetics tool for the analysis of embryogenesis in vivo in insects.
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31
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Turchyn N, Chesebro J, Hrycaj S, Couso JP, Popadić A. Evolution of nubbin function in hemimetabolous and holometabolous insect appendages. Dev Biol 2011; 357:83-95. [PMID: 21708143 DOI: 10.1016/j.ydbio.2011.06.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2010] [Revised: 06/10/2011] [Accepted: 06/11/2011] [Indexed: 10/18/2022]
Abstract
Insects display a whole spectrum of morphological diversity, which is especially noticeable in the organization of their appendages. A recent study in a hemipteran, Oncopeltus fasciatus (milkweed bug), showed that nubbin (nub) affects antenna morphogenesis, labial patterning, the length of the femoral segment in legs, and the formation of a limbless abdomen. To further determine the role of this gene in the evolution of insect morphology, we analyzed its functions in two additional hemimetabolous species, Acheta domesticus (house cricket) and Periplaneta americana (cockroach), and re-examined its role in Drosophila melanogaster (fruit fly). While both Acheta and Periplaneta nub-RNAi first nymphs develop crooked antennae, no visible changes are observed in the morphologies of their mouthparts and abdomen. Instead, the main effect is seen in legs. The joint between the tibia and first tarsomere (Ta-1) is lost in Acheta, which in turn, causes a fusion of these two segments and creates a chimeric nub-RNAi tibia-tarsus that retains a tibial identity in its proximal half and acquires a Ta-1 identity in its distal half. Similarly, our re-analysis of nub function in Drosophila reveals that legs lack all true joints and the fly tibia also exhibits a fused tibia and tarsus. Finally, we observe a similar phenotype in Periplaneta except that it encompasses different joints (coxa-trochanter and femur-tibia), and in this species we also show that nub expression in the legs is regulated by Notch signaling, as had previously been reported in flies and spiders. Overall, we propose that nub acts downstream of Notch on the distal part of insect leg segments to promote their development and growth, which in turn is required for joint formation. Our data represent the first functional evidence defining a role for nub in leg segmentation and highlight the varying degrees of its involvement in this process across insects.
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Affiliation(s)
- Nataliya Turchyn
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
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32
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Kamei Y, Hasegawa Y, Niimi T, Yamashita O, Yaginuma T. Trehalase-2 protein contributes to trehalase activity enhanced by diapause hormone in developing ovaries of the silkworm, Bombyx mori. JOURNAL OF INSECT PHYSIOLOGY 2011; 57:608-613. [PMID: 20965194 DOI: 10.1016/j.jinsphys.2010.10.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2010] [Revised: 10/02/2010] [Accepted: 10/06/2010] [Indexed: 05/30/2023]
Abstract
Diapause hormone (DH) targets developing ovaries in female pupae to induce embryonic diapause immediately after completion of mesoderm segregation of the silkworm, Bombyx mori. At the same time, DH enhances trehalase activity on the oolemma, which leads to higher concentrations of glycogen in oocytes through the stimulated incorporation of hemolymph trehalose. In B. mori, the treh-1 and -2 genes encoding soluble trehalase (68 kDa) and integral-membrane trehalase (74kDa) have been isolated. DH stimulates mRNA expression of both of these genes. In this study, we aimed to clarify whether ovarian trehalase originates from Treh-1 or Treh-2. Western blotting of the developing ovaries showed positive bands in the membrane-bound fraction, containing trehalase activity, only with antibodies against Treh-1&2 and Treh-2, but not Treh-1, irrespective of nondiapause or diapause egg-producers. The intensities of the positively stained 74 kDa bands were increased approximately 4-fold in ovaries from pupae with intact subesophageal ganglion (SG, a unique DH-biosynthesizing organ), and from pupae that were injected with DH at the middle pupal stage after their SGs were removed on the day of pupation. Furthermore, quantitative real-time PCR data showed that in developing ovaries, copy number of treh-2 mRNA per one copy of rp49 mRNA was approximately 1000-fold higher than that of treh-1 mRNA. These results demonstrate that trehalase activities enhanced by DH originate mainly from treh-2 protein regulated at the transcriptional level.
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Affiliation(s)
- Yuhki Kamei
- Laboratory of Sericulture & Entomoresources, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan
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Terenius O, Papanicolaou A, Garbutt JS, Eleftherianos I, Huvenne H, Kanginakudru S, Albrechtsen M, An C, Aymeric JL, Barthel A, Bebas P, Bitra K, Bravo A, Chevalier F, Collinge DP, Crava CM, de Maagd RA, Duvic B, Erlandson M, Faye I, Felföldi G, Fujiwara H, Futahashi R, Gandhe AS, Gatehouse HS, Gatehouse LN, Giebultowicz JM, Gómez I, Grimmelikhuijzen CJP, Groot AT, Hauser F, Heckel DG, Hegedus DD, Hrycaj S, Huang L, Hull JJ, Iatrou K, Iga M, Kanost MR, Kotwica J, Li C, Li J, Liu J, Lundmark M, Matsumoto S, Meyering-Vos M, Millichap PJ, Monteiro A, Mrinal N, Niimi T, Nowara D, Ohnishi A, Oostra V, Ozaki K, Papakonstantinou M, Popadic A, Rajam MV, Saenko S, Simpson RM, Soberón M, Strand MR, Tomita S, Toprak U, Wang P, Wee CW, Whyard S, Zhang W, Nagaraju J, Ffrench-Constant RH, Herrero S, Gordon K, Swevers L, Smagghe G. RNA interference in Lepidoptera: an overview of successful and unsuccessful studies and implications for experimental design. JOURNAL OF INSECT PHYSIOLOGY 2011; 57:231-45. [PMID: 21078327 DOI: 10.1016/j.jinsphys.2010.11.006] [Citation(s) in RCA: 540] [Impact Index Per Article: 41.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Revised: 11/03/2010] [Accepted: 11/04/2010] [Indexed: 05/03/2023]
Abstract
Gene silencing through RNA interference (RNAi) has revolutionized the study of gene function, particularly in non-model insects. However, in Lepidoptera (moths and butterflies) RNAi has many times proven to be difficult to achieve. Most of the negative results have been anecdotal and the positive experiments have not been collected in such a way that they are possible to analyze. In this review, we have collected detailed data from more than 150 experiments including all to date published and many unpublished experiments. Despite a large variation in the data, trends that are found are that RNAi is particularly successful in the family Saturniidae and in genes involved in immunity. On the contrary, gene expression in epidermal tissues seems to be most difficult to silence. In addition, gene silencing by feeding dsRNA requires high concentrations for success. Possible causes for the variability of success in RNAi experiments in Lepidoptera are discussed. The review also points to a need to further investigate the mechanism of RNAi in lepidopteran insects and its possible connection to the innate immune response. Our general understanding of RNAi in Lepidoptera will be further aided in the future as our public database at http://insectacentral.org/RNAi will continue to gather information on RNAi experiments.
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Affiliation(s)
- Olle Terenius
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
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