1
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Inwood SN, Harrop TWR, Shields MW, Goldson SL, Dearden PK. Immune system modulation & virus transmission during parasitism identified by multi-species transcriptomics of a declining insect biocontrol system. BMC Genomics 2024; 25:311. [PMID: 38532315 DOI: 10.1186/s12864-024-10215-3] [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: 12/30/2023] [Accepted: 03/12/2024] [Indexed: 03/28/2024] Open
Abstract
BACKGROUND The Argentine stem weevil (ASW, Listronotus bonariensis) is a significant pasture pest in Aotearoa New Zealand, primarily controlled by the parasitoid biocontrol agent Microctonus hyperodae. Despite providing effective control of ASW soon after release, M. hyperodae parasitism rates have since declined significantly, with ASW hypothesised to have evolved resistance to its biocontrol agent. While the parasitism arsenal of M. hyperodae has previously been investigated, revealing many venom components and an exogenous novel DNA virus Microctonus hyperodae filamentous virus (MhFV), the effects of said arsenal on gene expression in ASW during parasitism have not been examined. In this study, we performed a multi-species transcriptomic analysis to investigate the biology of ASW parasitism by M. hyperodae, as well as the decline in efficacy of this biocontrol system. RESULTS The transcriptomic response of ASW to parasitism by M. hyperodae involves modulation of the weevil's innate immune system, flight muscle components, and lipid and glucose metabolism. The multispecies approach also revealed continued expression of venom components in parasitised ASW, as well as the transmission of MhFV to weevils during parasitism and some interrupted parasitism attempts. Transcriptomics did not detect a clear indication of parasitoid avoidance or other mechanisms to explain biocontrol decline. CONCLUSIONS This study has expanded our understanding of interactions between M. hyperodae and ASW in a biocontrol system of critical importance to Aotearoa-New Zealand's agricultural economy. Transmission of MhFV to ASW during successful and interrupted parasitism attempts may link to a premature mortality phenomenon in ASW, hypothesised to be a result of a toxin-antitoxin system. Further research into MhFV and its potential role in ASW premature mortality is required to explore whether manipulation of this viral infection has the potential to increase biocontrol efficacy in future.
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Affiliation(s)
- Sarah N Inwood
- Bioprotection Aotearoa, Genomics Aotearoa, and the Biochemistry Department, University of Otago, Dunedin, New Zealand
| | - Thomas W R Harrop
- Bioprotection Aotearoa, Genomics Aotearoa, and the Biochemistry Department, University of Otago, Dunedin, New Zealand
- Melbourne Bioinformatics, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Morgan W Shields
- BioProtection Research Centre, Lincoln University, Lincoln, New Zealand
| | - Stephen L Goldson
- Biocontrol and Biosecurity Group, AgResearch Limited, Lincoln, Aotearoa, New Zealand
| | - Peter K Dearden
- Bioprotection Aotearoa, Genomics Aotearoa, and the Biochemistry Department, University of Otago, Dunedin, New Zealand.
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2
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Liang HF, Li XD. Locusta migratoria flight muscle troponin partially activates thin filament in a calcium-dependent manner. INSECT MOLECULAR BIOLOGY 2022; 31:346-355. [PMID: 35084070 DOI: 10.1111/imb.12763] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 10/16/2021] [Accepted: 01/17/2022] [Indexed: 06/14/2023]
Abstract
The troponin (Tn) complex, the sensor for Ca2+ to regulate contraction of striated muscle, is composed of three subunits, that is, TnT, TnI and TnC. Different isoforms of TnI and TnC are expressed in the thorax dorsal longitudinal muscle (flight muscle) and the hind leg extensor tibiae muscle (jump muscle) of the migratory locust, Locusta migratoria. The major Tn complexes in the flight muscle and the jump muscle are Tn-171 (TnT1/TnI7/TnC1) and Tn-153 (TnT1/TnI5/TnC3), respectively. Here, we prepared a number of recombinant Tn complexes and the reconstituted thin filaments, and investigated their regulation on thin filament. Although both Tn-171 and Tn-153 regulate thin filament in a Ca2+ -dependent manner, the extent of Ca2+ activation mediated by Tn-171 was significantly lower than that by Tn-153. We demonstrated that TnC1 and TnC3, rather than TnI5 and TnI7, are responsible for the different levels of the thin filament activation. Mutagenesis of TnC1 and TnC3 shows that the low level of TnC1-mediated thin filament activation can be attributed to the noncanonical residue Leu60 in the EF-hand-II of TnC1. We therefore propose that, in addition to Ca2+ , other regulatory mechanism(s) is required for the full activation of locust flight muscle.
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Affiliation(s)
- Hui-Fang Liang
- State Key Laboratory of Integrated Management of Insect Pests and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xiang-Dong Li
- State Key Laboratory of Integrated Management of Insect Pests and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
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3
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Loya AK, Van Houten SK, Glasheen BM, Swank DM. Shortening deactivation: quantifying a critical component of cyclical muscle contraction. Am J Physiol Cell Physiol 2021; 322:C653-C665. [PMID: 34965153 DOI: 10.1152/ajpcell.00281.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A muscle undergoing cyclical contractions requires fast and efficient muscle activation and relaxation to generate high power with relatively low energetic cost. To enhance activation and increase force levels during shortening, some muscle types have evolved stretch activation (SA), a delayed increased in force following rapid muscle lengthening. SA's complementary phenomenon is shortening deactivation (SD), a delayed decrease in force following muscle shortening. SD increases muscle relaxation, which decreases resistance to subsequent muscle lengthening. While it might be just as important to cyclical power output, SD has received less investigation than SA. To enable mechanistic investigations into SD and quantitatively compare it to SA, we developed a protocol to elicit SA and SD from Drosophila and Lethocerus indirect flight muscles (IFM) and Drosophila jump muscle. When normalized to isometric tension, Drosophila IFM exhibited a 118% SD tension decrease, Lethocerus IFM dropped by 97%, and Drosophila jump muscle decreased by 37%. The same order was found for normalized SA tension: Drosophila IFM increased by 233%, Lethocerus IFM by 76%, and Drosophila jump muscle by only 11%. SD occurred slightly earlier than SA, relative to the respective length change, for both IFMs; but SD was exceedingly earlier than SA for jump muscle. Our results suggest SA and SD evolved to enable highly efficient IFM cyclical power generation and may be caused by the same mechanism. However, jump muscle SA and SD mechanisms are likely different, and may have evolved for a role other than to increase the power output of cyclical contractions.
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Affiliation(s)
- Amy K Loya
- Department of Biomedical Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, United States.,Department of Electrical, Computer, and Biomedical Engineering, Union College, Schenectady, NY, United States
| | - Sarah K Van Houten
- Department of Biomedical Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, United States
| | - Bernadette M Glasheen
- Department of Biological Sciences, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, United States
| | - Douglas M Swank
- Department of Biomedical Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, United States.,Department of Biological Sciences, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, United States
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4
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Liang HF, Li J, Li XD. Identification and characterization of troponin genes in Locusta migratoria. INSECT MOLECULAR BIOLOGY 2020; 29:391-403. [PMID: 32338426 DOI: 10.1111/imb.12644] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 11/12/2019] [Accepted: 04/15/2020] [Indexed: 06/11/2023]
Abstract
Troponin complex comprises three subunits, namely troponin C (TpnC), troponin I (TpnI) and troponin T (TpnT), and regulates the contraction of striated muscle. We found that the locust Locusta migratoria genome has one TpnT gene (LmTpnT), one TpnI gene (LmTpnI) and three TpnC genes (LmTpnC1, LmTpnC2 and LmTpnC3). Through alternative splicing, LmTpnT and LmTpnI potentially encode two and eight isoforms, respectively. The flight muscle and the jump muscle of L. migratoria express an identical LmTpnT isoform, but different LmTpnC isoforms and LmTpnI isoforms. LmTpnC2 and LmTpnC3 both contain highly conserved residues essential for calcium binding in the EF-hand II and IV, thus belonging two-site isoform. LmTpnC1 contains non-conserved substitutions in the EF-hand II and all highly conserved residues for calcium binding in the EF-hand IV. Mutagenesis and tyrosine fluorescence spectroscopic analysis show that both the EF-hand II and IV of LmTpnC1 can serve as calcium-binding site. Therefore, all three LmTpnC isoforms belong to two-site isoform. This is in contrast to the situation in the insect with asynchronous flight muscle, which expresses both one-site isoform and two-site isoform of TpnC. Those results suggest that the origination of insect asynchronous flight muscle is associated with the emergence of one-site isoform of TpnC.
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Affiliation(s)
- H-F Liang
- State Key Laboratory of Integrated Management of Insect Pests and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - J Li
- State Key Laboratory of Integrated Management of Insect Pests and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - X-D Li
- State Key Laboratory of Integrated Management of Insect Pests and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
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5
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Nikonova E, Kao SY, Spletter ML. Contributions of alternative splicing to muscle type development and function. Semin Cell Dev Biol 2020; 104:65-80. [PMID: 32070639 DOI: 10.1016/j.semcdb.2020.02.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 02/05/2020] [Accepted: 02/07/2020] [Indexed: 12/30/2022]
Abstract
Animals possess a wide variety of muscle types that support different kinds of movements. Different muscles have distinct locations, morphologies and contractile properties, raising the question of how muscle diversity is generated during development. Normal aging processes and muscle disorders differentially affect particular muscle types, thus understanding how muscles normally develop and are maintained provides insight into alterations in disease and senescence. As muscle structure and basic developmental mechanisms are highly conserved, many important insights into disease mechanisms in humans as well as into basic principles of muscle development have come from model organisms such as Drosophila, zebrafish and mouse. While transcriptional regulation has been characterized to play an important role in myogenesis, there is a growing recognition of the contributions of alternative splicing to myogenesis and the refinement of muscle function. Here we review our current understanding of muscle type specific alternative splicing, using examples of isoforms with distinct functions from both vertebrates and Drosophila. Future exploration of the vast potential of alternative splicing to fine-tune muscle development and function will likely uncover novel mechanisms of isoform-specific regulation and a more holistic understanding of muscle development, disease and aging.
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Affiliation(s)
- Elena Nikonova
- Biomedical Center, Department of Physiological Chemistry, Ludwig-Maximilians-Universität München, Großhaderner Str. 9, 82152 Martinsried-Planegg, Germany
| | - Shao-Yen Kao
- Biomedical Center, Department of Physiological Chemistry, Ludwig-Maximilians-Universität München, Großhaderner Str. 9, 82152 Martinsried-Planegg, Germany
| | - Maria L Spletter
- Biomedical Center, Department of Physiological Chemistry, Ludwig-Maximilians-Universität München, Großhaderner Str. 9, 82152 Martinsried-Planegg, Germany; Center for Integrated Protein Science Munich (CIPSM) at the Department of Chemistry, Ludwig-Maximilians-Universität München, Munich, Germany.
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6
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Straight CR, Bell KM, Slosberg JN, Miller MS, Swank DM. A myosin-based mechanism for stretch activation and its possible role revealed by varying phosphate concentration in fast and slow mouse skeletal muscle fibers. Am J Physiol Cell Physiol 2019; 317:C1143-C1152. [PMID: 31532715 DOI: 10.1152/ajpcell.00206.2019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Stretch activation (SA) is a delayed increase in force following a rapid muscle length increase. SA is best known for its role in asynchronous insect flight muscle, where it has replaced calcium's typical role of modulating muscle force levels during a contraction cycle. SA also occurs in mammalian skeletal muscle but has previously been thought to be too low in magnitude, relative to calcium-activated (CA) force, to be a significant contributor to force generation during locomotion. To test this supposition, we compared SA and CA force at different Pi concentrations (0-16 mM) in skinned mouse soleus (slow-twitch) and extensor digitorum longus (EDL; fast-twitch) muscle fibers. CA isometric force decreased similarly in both muscles with increasing Pi, as expected. SA force decreased with Pi in EDL (40%), leaving the SA to CA force ratio relatively constant across Pi concentrations (17-25%). In contrast, SA force increased in soleus (42%), causing a quadrupling of the SA to CA force ratio, from 11% at 0 mM Pi to 43% at 16 mM Pi, showing that SA is a significant force modulator in slow-twitch mammalian fibers. This modulation would be most prominent during prolonged muscle use, which increases Pi concentration and impairs calcium cycling. Based upon our previous Drosophila myosin isoform studies and this work, we propose that in slow-twitch fibers a rapid stretch in the presence of Pi reverses myosin's power stroke, enabling quick rebinding to actin and enhanced force production, while in fast-twitch fibers, stretch and Pi cause myosin to detach from actin.
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Affiliation(s)
- Chad R Straight
- Department of Kinesiology, School of Public Health and Health Sciences, University of Massachusetts, Amherst, Massachusetts
| | - Kaylyn M Bell
- Department of Biological Sciences, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York
| | - Jared N Slosberg
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, New York
| | - Mark S Miller
- Department of Kinesiology, School of Public Health and Health Sciences, University of Massachusetts, Amherst, Massachusetts
| | - Douglas M Swank
- Department of Biological Sciences, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York.,Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, New York
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7
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Glasheen BM, Ramanath S, Patel M, Sheppard D, Puthawala JT, Riley LA, Swank DM. Five Alternative Myosin Converter Domains Influence Muscle Power, Stretch Activation, and Kinetics. Biophys J 2019. [PMID: 29539400 DOI: 10.1016/j.bpj.2017.12.045] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Muscles have evolved to power a wide variety of movements. A protein component critical to varying power generation is the myosin isoform present in the muscle. However, how functional variation in muscle arises from myosin structure is not well understood. We studied the influence of the converter, a myosin structural region at the junction of the lever arm and catalytic domain, using Drosophila because its single myosin heavy chain gene expresses five alternative converter versions (11a-e). We created five transgenic fly lines, each forced to express one of the converter versions in their indirect flight muscle (IFM) fibers. Electron microscopy showed that the converter exchanges did not alter muscle ultrastructure. The four lines expressing converter versions (11b-e) other than the native IFM 11a converter displayed decreased flight ability. IFM fibers expressing converters normally found in the adult stage muscles generated up to 2.8-fold more power and displayed up to 2.2-fold faster muscle kinetics than fibers with converters found in the embryonic and larval stage muscles. Small changes to stretch-activated force generation only played a minor role in altering power output of IFM. Muscle apparent rate constants, derived from sinusoidal analysis of the chimeric converter fibers, showed a strong positive correlation between optimal muscle oscillation frequency and myosin attachment kinetics to actin, and an inverse correlation with detachment related cross-bridge kinetics. This suggests the myosin converter alters at least two rate constants of the cross-bridge cycle with changes to attachment and power stroke related kinetics having the most influence on setting muscle oscillatory power kinetics.
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Affiliation(s)
| | - Seemanti Ramanath
- Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, New York
| | - Monica Patel
- Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, New York
| | - Debra Sheppard
- Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, New York
| | - Joy T Puthawala
- Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, New York
| | - Lauren A Riley
- Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, New York
| | - Douglas M Swank
- Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, New York; Department of Biomedical Engineering and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York.
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8
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Barnes DE, Watabe E, Ono K, Kwak E, Kuroyanagi H, Ono S. Tropomyosin isoforms differentially affect muscle contractility in the head and body regions of the nematode Caenorhabditis elegans. Mol Biol Cell 2018; 29:1075-1088. [PMID: 29496965 PMCID: PMC5921574 DOI: 10.1091/mbc.e17-03-0152] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 02/21/2018] [Accepted: 02/23/2018] [Indexed: 11/11/2022] Open
Abstract
Tropomyosin, one of the major actin filament-binding proteins, regulates actin-myosin interaction and actin-filament stability. Multicellular organisms express a number of tropomyosin isoforms, but understanding of isoform-specific tropomyosin functions is incomplete. The nematode Caenorhabditis elegans has a single tropomyosin gene, lev-11, which has been reported to express four isoforms by using two separate promoters and alternative splicing. Here, we report a fifth tropomyosin isoform, LEV-11O, which is produced by alternative splicing that includes a newly identified seventh exon, exon 7a. By visualizing specific splicing events in vivo, we find that exon 7a is predominantly selected in a subset of the body wall muscles in the head, while exon 7b, which is the alternative to exon 7a, is utilized in the rest of the body. Point mutations in exon 7a and exon 7b cause resistance to levamisole--induced muscle contraction specifically in the head and the main body, respectively. Overexpression of LEV-11O, but not LEV-11A, in the main body results in weak levamisole resistance. These results demonstrate that specific tropomyosin isoforms are expressed in the head and body regions of the muscles and contribute differentially to the regulation of muscle contractility.
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Affiliation(s)
- Dawn E. Barnes
- Department of Pathology, Department of Cell Biology, and Winship Cancer Institute, Emory University, Atlanta, GA 30322
| | - Eichi Watabe
- Laboratory of Gene Expression, Medical Research Institute, Tokyo Medical and Dental University, Tokyo 113-8510, Japan
| | - Kanako Ono
- Department of Pathology, Department of Cell Biology, and Winship Cancer Institute, Emory University, Atlanta, GA 30322
| | - Euiyoung Kwak
- Department of Pathology, Department of Cell Biology, and Winship Cancer Institute, Emory University, Atlanta, GA 30322
| | - Hidehito Kuroyanagi
- Laboratory of Gene Expression, Medical Research Institute, Tokyo Medical and Dental University, Tokyo 113-8510, Japan
| | - Shoichiro Ono
- Department of Pathology, Department of Cell Biology, and Winship Cancer Institute, Emory University, Atlanta, GA 30322
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9
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Lan H, Hong X, Huang R, Lin X, Li Q, Li K, Zhou T. RNA interference-mediated knockdown and virus-induced suppression of Troponin C gene adversely affect the behavior or fitness of the green rice leafhopper, Nephotettix cincticeps. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2018; 97:e21438. [PMID: 29193300 DOI: 10.1002/arch.21438] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The green rice leafhopper, Nephotettix cincticeps, is a major rice pest in Southeast Asia and Southern China. Novel control strategies must be explored to control the rice pest. Behavior or fitness regulation of insect by modulating the Troponin C (TnC) may be a novel strategy in the comprehensive management of the insect pest. However, characterizations and functions of TnC, especially regarding effect of its RNA interference-mediated gene knockdown on the behavior or fitness of N. cincticeps remain unknown. Here, we successfully cloned and characterized TnC gene from N. cincticeps (Nc-TnC). We demonstrated that Nc-TnC ubiquitously transcribed at all development stages and special tissues in adult insects, with relative higher levels at the adult stage and in the intestinal canal. Microinjection- or oral membrane feeding-based transient knockdown of Nc-TnC adversely affected the performance or fitness, such as the decreased survival, feeding capacity, weight, and fecundity of N. cincticeps. Furthermore, we revealed that the expression of Nc-TnC was suppressed by its interaction with rice dwarf virus-encoded nonstructural protein 10, which ultimately affected detrimentally the corresponding parameters of the performance or fitness of N. cincticeps. In conclusion, our data deepen understanding of Nc-TnC functions during the development of and viral infection in N. cincticeps. It imply Nc-TnC may serve as a potential target for N. cincticeps control in future.
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Affiliation(s)
- Hanhong Lan
- School of Biological Sciences and Biotechnology, Minnan Normal University, Zhangzhou, PR China
| | - Xiaojing Hong
- School of Biological Sciences and Biotechnology, Minnan Normal University, Zhangzhou, PR China
| | - Ranran Huang
- School of Biological Sciences and Biotechnology, Minnan Normal University, Zhangzhou, PR China
| | - Xin Lin
- School of Biological Sciences and Biotechnology, Minnan Normal University, Zhangzhou, PR China
| | - Qinghuang Li
- School of Biological Sciences and Biotechnology, Minnan Normal University, Zhangzhou, PR China
| | - Kaihui Li
- School of Biological Sciences and Biotechnology, Minnan Normal University, Zhangzhou, PR China
| | - Tao Zhou
- School of Biological Sciences and Biotechnology, Minnan Normal University, Zhangzhou, PR China
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10
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Glasheen BM, Eldred CC, Sullivan LC, Zhao C, Reedy MK, Edwards RJ, Swank DM. Stretch activation properties of Drosophila and Lethocerus indirect flight muscle suggest similar calcium-dependent mechanisms. Am J Physiol Cell Physiol 2017; 313:C621-C631. [PMID: 28835434 DOI: 10.1152/ajpcell.00110.2017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Muscle stretch activation (SA) is critical for optimal cardiac and insect indirect flight muscle (IFM) power generation. The SA mechanism has been investigated for decades with many theories proposed, but none proven. One reason for the slow progress could be that multiple SA mechanisms may have evolved in multiple species or muscle types. Laboratories studying IFM SA in the same or different species have reported differing SA functional properties which would, if true, suggest divergent mechanisms. However, these conflicting results might be due to different experimental methodologies. Thus, we directly compared SA characteristics of IFMs from two SA model systems, Drosophila and Lethocerus, using two different fiber bathing solutions. Compared with Drosophila IFM, Lethocerus IFM isometric tension is 10- or 17-fold higher and SA tension was 5- or 10-fold higher, depending on the bathing solution. However, the rate of SA tension generation was 9-fold faster for Drosophila IFM. The inverse differences between rate and tension in the two species causes maximum power output to be similar, where Drosophila power is optimized in the bathing solution that favors faster muscle kinetics and Lethocerus in the solution that favors greater tension generation. We found that isometric tension and SA tension increased with calcium concentration for both species in both solutions, reaching a maximum plateau around pCa 5.0. Our results favor a similar mechanism for both species, perhaps involving a troponin complex that does not fully calcium activate the thin filament thus leaving room for further tension generation by SA.
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Affiliation(s)
- Bernadette M Glasheen
- Department of Biological Sciences, Biomedical Engineering, & Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute , Troy, New York
| | - Catherine C Eldred
- Department of Biological Sciences, Biomedical Engineering, & Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute , Troy, New York
| | - Leah C Sullivan
- Department of Biological Sciences, Biomedical Engineering, & Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute , Troy, New York
| | - Cuiping Zhao
- Department of Biological Sciences, Biomedical Engineering, & Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute , Troy, New York
| | - Michael K Reedy
- Department of Cell Biology, Duke University , Durham North Carolina
| | - Robert J Edwards
- Department of Cell Biology, Duke University , Durham North Carolina
| | - Douglas M Swank
- Department of Biological Sciences, Biomedical Engineering, & Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute , Troy, New York
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11
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Chechenova MB, Maes S, Oas ST, Nelson C, Kiani KG, Bryantsev AL, Cripps RM. Functional redundancy and nonredundancy between two Troponin C isoforms in Drosophila adult muscles. Mol Biol Cell 2017; 28:760-770. [PMID: 28077621 PMCID: PMC5349783 DOI: 10.1091/mbc.e16-07-0498] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 01/05/2017] [Accepted: 01/06/2017] [Indexed: 11/18/2022] Open
Abstract
Knockout of either of two Drosophila Troponin C genes that are expressed in either the flight muscle or the jump muscle resulted in expansion of transcription of its paralogue into the affected muscle. Although either isoform can support normal jumping, only the flight isoform can support flight. We investigated the functional overlap of two muscle Troponin C (TpnC) genes that are expressed in the adult fruit fly, Drosophila melanogaster: TpnC4 is predominantly expressed in the indirect flight muscles (IFMs), whereas TpnC41C is the main isoform in the tergal depressor of the trochanter muscle (TDT; jump muscle). Using CRISPR/Cas9, we created a transgenic line with a homozygous deletion of TpnC41C and compared its phenotype to a line lacking functional TpnC4. We found that the removal of either of these genes leads to expression of the other isoform in both muscle types. The switching between isoforms occurs at the transcriptional level and involves minimal enhancers located upstream of the transcription start points of each gene. Functionally, the two TpnC isoforms were not equal. Although ectopic TpnC4 in TDT muscles was able to maintain jumping ability, TpnC41C in IFMs could not effectively support flying. Simultaneous functional disruption of both TpnC genes resulted in jump-defective and flightless phenotypes of the survivors, as well as abnormal sarcomere organization. These results indicated that TpnC is required for myofibril assembly, and that there is functional specialization among TpnC isoforms in Drosophila.
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Affiliation(s)
- Maria B Chechenova
- Department of Biology, University of New Mexico, Albuquerque, NM 87131.,Department of Molecular and Cellular Biology, Kennesaw State University, Kennesaw, GA 30144
| | - Sara Maes
- Department of Biology, University of New Mexico, Albuquerque, NM 87131
| | - Sandy T Oas
- Department of Biology, University of New Mexico, Albuquerque, NM 87131
| | - Cloyce Nelson
- Department of Biology, University of New Mexico, Albuquerque, NM 87131
| | - Kaveh G Kiani
- Department of Molecular and Cellular Biology, Kennesaw State University, Kennesaw, GA 30144
| | - Anton L Bryantsev
- Department of Biology, University of New Mexico, Albuquerque, NM 87131.,Department of Molecular and Cellular Biology, Kennesaw State University, Kennesaw, GA 30144
| | - Richard M Cripps
- Department of Biology, University of New Mexico, Albuquerque, NM 87131
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12
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Zhao C, Swank DM. The Drosophila indirect flight muscle myosin heavy chain isoform is insufficient to transform the jump muscle into a highly stretch-activated muscle type. Am J Physiol Cell Physiol 2016; 312:C111-C118. [PMID: 27881413 DOI: 10.1152/ajpcell.00284.2016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 11/16/2016] [Accepted: 11/17/2016] [Indexed: 11/22/2022]
Abstract
Stretch activation (SA) is a delayed increase in force that enables high power and efficiency from a cyclically contracting muscle. SA exists in various degrees in almost all muscle types. In Drosophila, the indirect flight muscle (IFM) displays exceptionally high SA force production (FSA), whereas the jump muscle produces only minimal FSA We previously found that expressing an embryonic (EMB) myosin heavy chain (MHC) isoform in the jump muscle transforms it into a moderately SA muscle type and enables positive cyclical power generation. To investigate whether variation in MHC isoforms is sufficient to produce even higher FSA, we substituted the IFM MHC isoform (IFI) into the jump muscle. Surprisingly, we found that IFI only caused a 1.7-fold increase in FSA, less than half the increase previously observed with EMB, and only at a high Pi concentration, 16 mM. This IFI-induced FSA is much less than what occurs in IFM, relative to isometric tension, and did not enable positive cyclical power generation by the jump muscle. Both isometric tension and FSA of control fibers decreased with increasing Pi concentration. However, for IFI-expressing fibers, only isometric tension decreased. The rate of FSA generation was ~1.5-fold faster for IFI fibers than control fibers, and both rates were Pi dependent. We conclude that MHC isoforms can alter FSA and hence cyclical power generation but that isoforms can only endow a muscle type with moderate FSA Highly SA muscle types, such as IFM, likely use a different or additional mechanism.
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Affiliation(s)
- Cuiping Zhao
- Department of Biological Sciences, Department of Biomedical Engineering, and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York
| | - Douglas M Swank
- Department of Biological Sciences, Department of Biomedical Engineering, and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York
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Chechenova MB, Maes S, Cripps RM. Expression of the Troponin C at 41C Gene in Adult Drosophila Tubular Muscles Depends upon Both Positive and Negative Regulatory Inputs. PLoS One 2015; 10:e0144615. [PMID: 26641463 PMCID: PMC4671713 DOI: 10.1371/journal.pone.0144615] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 11/20/2015] [Indexed: 12/05/2022] Open
Abstract
Most animals express multiple isoforms of structural muscle proteins to produce tissues with different physiological properties. In Drosophila, the adult muscles include tubular-type muscles and the fibrillar indirect flight muscles. Regulatory processes specifying tubular muscle fate remain incompletely understood, therefore we chose to analyze the transcriptional regulation of TpnC41C, a Troponin C gene expressed in the tubular jump muscles, but not in the fibrillar flight muscles. We identified a 300-bp promoter fragment of TpnC41C sufficient for the fiber-specific reporter expression. Through an analysis of this regulatory element, we identified two sites necessary for the activation of the enhancer. Mutations in each of these sites resulted in 70% reduction of enhancer activity. One site was characterized as a binding site for Myocyte Enhancer Factor-2. In addition, we identified a repressive element that prevents activation of the enhancer in other muscle fiber types. Mutation of this site increased jump muscle-specific expression of the reporter, but more importantly reporter expression expanded into the indirect flight muscles. Our findings demonstrate that expression of the TpnC41C gene in jump muscles requires integration of multiple positive and negative transcriptional inputs. Identification of the transcriptional regulators binding the cis-elements that we identified will reveal the regulatory pathways controlling muscle fiber differentiation.
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Affiliation(s)
- Maria B Chechenova
- Department of Biology, University of New Mexico, Albuquerque, NM, 87131, United States of America
| | - Sara Maes
- Department of Biology, University of New Mexico, Albuquerque, NM, 87131, United States of America
| | - Richard M Cripps
- Department of Biology, University of New Mexico, Albuquerque, NM, 87131, United States of America
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