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Holen MM, Vaaje-Kolstad G, Kent MP, Sandve SR. Gene family expansion and functional diversification of chitinase and chitin synthase genes in Atlantic salmon (Salmo salar). G3 (BETHESDA, MD.) 2023; 13:jkad069. [PMID: 36972305 PMCID: PMC10234404 DOI: 10.1093/g3journal/jkad069] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 03/16/2023] [Indexed: 12/07/2023]
Abstract
Chitin is one of the most abundant polysaccharides in nature, forming important structures in insects, crustaceans, and fungal cell walls. Vertebrates on the other hand are generally considered "nonchitinous" organisms, despite having highly conserved chitin metabolism-associated genes. Recent work has revealed that the largest group of vertebrates, the teleosts, have the potential to both synthesize and degrade endogenous chitin. Yet, little is known about the genes and proteins responsible for these dynamic processes. Here, we used comparative genomics, transcriptomics, and chromatin accessibility data to characterize the repertoire, evolution, and regulation of genes involved in chitin metabolism in teleosts, with a particular focus on Atlantic salmon. Reconstruction of gene family phylogenies provides evidence for an expansion of teleost and salmonid chitinase and chitin synthase genes after multiple whole-genome duplications. Analyses of multi-tissue gene expression data demonstrated a strong bias of gastrointestinal tract expression for chitin metabolism genes, but with different spatial and temporal tissue specificities. Finally, we integrated transcriptomes from a developmental time series of the gastrointestinal tract with chromatin accessibility data to identify putative transcription factors responsible for regulating chitin metabolism gene expression (CDX1 and CDX2) as well as tissue-specific divergence in the regulation of gene duplicates (FOXJ2). The findings presented here support the hypothesis that chitin metabolism genes in teleosts play a role in developing and maintaining a chitin-based barrier in the teleost gut and provide a basis for further investigations into the molecular basis of this barrier.
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Affiliation(s)
- Matilde Mengkrog Holen
- Section for Genome Biology, Department of Animal and Aquacultural Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, Ås NO-1432, Norway
| | - Gustav Vaaje-Kolstad
- Department of Chemistry, Biotechnology and Food Science (IKBM), Norwegian University of Life Sciences, Ås NO-1432, Norway
| | - Matthew Peter Kent
- Section for Genome Biology, Department of Animal and Aquacultural Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, Ås NO-1432, Norway
| | - Simen Rød Sandve
- Section for Genome Biology, Department of Animal and Aquacultural Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, Ås NO-1432, Norway
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Hunt R, Cable J, Ellison A. Daily patterns in parasite processes: diel variation in fish louse transcriptomes. Int J Parasitol 2022; 52:509-518. [PMID: 35533730 DOI: 10.1016/j.ijpara.2022.04.001] [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: 12/15/2021] [Revised: 04/07/2022] [Accepted: 04/07/2022] [Indexed: 11/05/2022]
Abstract
Parasites, similar to all other organisms, time themselves to environmental cues using a molecular clock to generate and maintain rhythms. Chronotherapeutic (timed treatment) techniques based on such rhythms offer great potential for improving control of chronic, problematic parasites. Fish lice are a key disease threat in aquaculture, with current control insufficient. Assessing the rhythmicity of fish lice transcriptomes offers not only insight into the viability of chronotherapy, but the opportunity to identify new drug targets. Here, for the first known time in any crustacean parasite, diel changes in gene transcription are examined, revealing that approximately half of the Argulus foliaceus annotated transcriptome displays significant daily rhythmicity. We identified rhythmically transcribed putative clock genes including core clock/cycle and period/timeless pairs, alongside rhythms in feeding-associated genes and processes involving immune response, as well as fish louse drug targets. A substantial number of gene pathways showed peak transcription in hours immediately preceding onset of light, potentially in anticipation of peak host anti-parasite responses or in preparation for increased feeding activity. Genes related to immune haemocyte activity and chitin development were more highly transcribed 4 h post light onset, although inflammatory gene transcription was highest during dark periods. Our study provides an important resource for application of chronotherapy in fish lice; timed application could increase efficacy and/or reduce dose requirement, improving the current landscape of drug resistance and fish health while reducing the economic cost of infection.
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Affiliation(s)
- R Hunt
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, United Kingdom
| | - J Cable
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, United Kingdom
| | - A Ellison
- School of Natural Sciences, Bangor University, Deiniol Road, Bangor, Gwynedd, LL57 2UW, United Kingdom.
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Zhou Z, Eichner C, Nilsen F, Jonassen I, Dondrup M. A novel approach to co-expression network analysis identifies modules and genes relevant for moulting and development in the Atlantic salmon louse (Lepeophtheirus salmonis). BMC Genomics 2021; 22:832. [PMID: 34789144 PMCID: PMC8600823 DOI: 10.1186/s12864-021-08054-7] [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] [Received: 05/03/2021] [Accepted: 10/04/2021] [Indexed: 11/25/2022] Open
Abstract
Background The salmon louse (Lepeophtheirus salmonis) is an obligate ectoparasitic copepod living on Atlantic salmon and other salmonids in the marine environment. Salmon lice cause a number of environmental problems and lead to large economical losses in aquaculture every year. In order to develop novel parasite control strategies, a better understanding of the mechanisms of moulting and development of the salmon louse at the transcriptional level is required. Methods Three weighted gene co-expression networks were constructed based on the pairwise correlations of salmon louse gene expression profiles at different life stages. Network-based approaches and gene annotation information were applied to identify genes that might be important for the moulting and development of the salmon louse. RNA interference was performed for validation. Regulatory impact factors were calculated for all the transcription factor genes by examining the changes in co-expression patterns between transcription factor genes and deferentially expressed genes in middle stages and moulting stages. Results Eight gene modules were predicted as important, and 10 genes from six of the eight modules have been found to show observable phenotypes in RNA interference experiments. We knocked down five hub genes from three modules and observed phenotypic consequences in all experiments. In the infection trial, no copepodids with a RAB1A-like gene knocked down were found on fish, while control samples developed to chalimus-1 larvae. Also, a FOXO-like transcription factor obtained highest scores in the regulatory impact factor calculation. Conclusions We propose a gene co-expression network-based approach to identify genes playing an important role in the moulting and development of salmon louse. The RNA interference experiments confirm the effectiveness of our approach and demonstrated the indispensable role of a RAB1A-like gene in the development of the salmon louse. We propose that our approach could be generalized to identify important genes associated with a phenotype of interest in other organisms. Supplementary Information The online version contains supplementary material available at (10.1186/s12864-021-08054-7).
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Affiliation(s)
- Zhaoran Zhou
- Department of Informatics & Sea Lice Research Centre, University of Bergen, Thormøhlensgate 55, Bergen, 5008, Norway
| | - Christiane Eichner
- Department of Biological Sciences & Sea Lice Research Centre, University of Bergen, Thormøhlensgate 55, Bergen, 5008, Norway
| | - Frank Nilsen
- Department of Biological Sciences & Sea Lice Research Centre, University of Bergen, Thormøhlensgate 55, Bergen, 5008, Norway
| | - Inge Jonassen
- Department of Informatics & Sea Lice Research Centre, University of Bergen, Thormøhlensgate 55, Bergen, 5008, Norway
| | - Michael Dondrup
- Department of Informatics & Sea Lice Research Centre, University of Bergen, Thormøhlensgate 55, Bergen, 5008, Norway.
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4
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Das P, Badhe MR, Sahoo PK, Reddy RRK, Suryawanshi AR, Mohanty J. Immunoproteomic analysis of fish ectoparasite, Argulus siamensis antigens. Parasite Immunol 2021; 43:e12837. [PMID: 33811350 DOI: 10.1111/pim.12837] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 03/24/2021] [Accepted: 03/25/2021] [Indexed: 12/25/2022]
Abstract
AIM An immunoproteomic approach was followed to identify immunoreactive antigens of fish ectoparasite, Argulus siamensis with rohu (Labeo rohita) immune sera for screening of potential vaccine candidates. MATERIALS AND RESULTS The whole adult Argulus antigen was run in 2D electrophoresis with IEF in 7 cm IPG strips of pH 4-7 and SDS-PAGE with 12% acrylamide concentration. Two parallel gels were run; one was stained with silver stain, and the other was Western blotted to nitrocellulose paper (NCP) and reacted with rohu anti-A siamensis sera. Fourteen protein spots corresponding to the spots developed in NCP were picked from the silver-stained gel and subjected to mass spectrometry in MALDI-TOF/TOF. The MS/MS spectra were analysed in MASCOT software with taxonomy 'other metazoa' and the proteins identified based on similarity with the proteins from heterologous species. The gene ontology analysis revealed a majority of proteins being involved in binding activity in 'molecular function' and belonging to metabolic processes in 'biologic process' categories. The possibility of these proteins as vaccine candidates against A siamensis is discussed in the paper. CONCLUSION Three of the identified proteins namely, bromodomain-containing protein, anaphase-promoting complex subunit 5 and elongation factor-2 could possibly serve as vaccine candidates against argulosis in carps.
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Affiliation(s)
- Priyanka Das
- ICAR-Central Institute of Freshwater Aquaculture, Bhubaneswar, India
| | - Mohan R Badhe
- ICAR-Central Institute of Freshwater Aquaculture, Bhubaneswar, India
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Liu M, Chen C, Wu QC, Chen JL, Dai LS, Hui Chu S, Liu QN. Chitinase involved in immune regulation by mediated the toll pathway of crustacea Procambarus clarkii. FISH & SHELLFISH IMMUNOLOGY 2021; 110:67-74. [PMID: 33383178 DOI: 10.1016/j.fsi.2020.12.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 12/21/2020] [Accepted: 12/22/2020] [Indexed: 06/12/2023]
Abstract
Chitinase can degrade chitin and play an essential role in animal immunity and plant defense. The immune functions of Chitinase in Procambarus clarkii (P. clarkii) remain to elucidate. Here, we identified PcChitinase 2 gene sequence from P. clarkii and studied its spatial and temporal expression profiles. The PcChitinase 2 transcribed unequally in different tissues; however, its expression was highest in those of stomach, gut, and hepatopancreas. The challenge with lipolysaccharide or peptidoglycan significantly up-regulated the expression of PcChitinase 2 in hepatopancreas. The knockdown of the PcChitinase 2 gene by double-stranded RNA suppressed most of the Toll-pathway-related immune genes (phospholipase, lectin, sptazle Cactus, serine proteikinase, anti-lipopolysaccharide factor, and Toll) production were significantly increased. Our results suggest PcChitinase 2 may be involved in the innate immune responses of P. clarkii by modulating the toll pathway.
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Affiliation(s)
- Min Liu
- Key Laboratory of Xinjiang Phytomedicine Resource and Utilization, Ministry of Education, School of Pharmacy, Shihezi University, Shihezi, 832003, China; School of Wetlands, Yancheng Teachers University, Yancheng 224007, PR China; School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou 325035, PR China
| | - Chen Chen
- College of Life Science, Anhui Agricultural University, 130 Changjiang West Road 230036, PR China
| | - Qi-Cheng Wu
- School of Wetlands, Yancheng Teachers University, Yancheng 224007, PR China
| | - Jia-Le Chen
- School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou 325035, PR China
| | - Li-Shang Dai
- School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou 325035, PR China.
| | - Sheng Hui Chu
- Key Laboratory of Xinjiang Phytomedicine Resource and Utilization, Ministry of Education, School of Pharmacy, Shihezi University, Shihezi, 832003, China; School of Wetlands, Yancheng Teachers University, Yancheng 224007, PR China; School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou 325035, PR China.
| | - Qiu-Ning Liu
- School of Wetlands, Yancheng Teachers University, Yancheng 224007, PR China; Anhui Province Key Laboratory of Aquaculture & Stock Enhancement, Fishery Institute of Anhui Academy of Agricultural Sciences, Hefei, 230031, China.
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Identification of critical enzymes in the salmon louse chitin synthesis pathway as revealed by RNA interference-mediated abrogation of infectivity. Int J Parasitol 2020; 50:873-889. [PMID: 32745476 DOI: 10.1016/j.ijpara.2020.06.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 05/10/2020] [Accepted: 06/18/2020] [Indexed: 12/12/2022]
Abstract
Treatment of infestation by the ectoparasite Lepeophtheirus salmonis relies on a small number of chemotherapeutant treatments that currently meet with limited success. Drugs targeting chitin synthesis have been largely successful against terrestrial parasites where the pathway is well characterised. However, a comparable approach against salmon lice has been, until recently, less successful, likely due to a poor understanding of the chitin synthesis pathway. Post-transcriptional silencing of genes by RNA interference (RNAi) is a powerful method for evaluation of protein function in non-model organisms and has been successfully applied to the salmon louse. In the present study, putative genes coding for enzymes involved in L. salmonis chitin synthesis were characterised after knockdown by RNAi. Nauplii I stage L. salmonis were exposed to double-stranded (ds) RNA specific for several putative non-redundant points in the pathway: glutamine: fructose-6-phosphate aminotransferase (LsGFAT), UDP-N-acetylglucosamine pyrophosphorylase (LsUAP), N-acetylglucosamine phosphate mutase (LsAGM), chitin synthase 1 (LsCHS1), and chitin synthase 2 (LsCHS2). Additionally, we targeted three putative chitin deacetylases (LsCDA4557, 5169 and 5956) by knockdown. Successful knockdown was determined after moulting to the copepodite stage by real-time quantitative PCR (RT-qPCR), while infectivity potential (the number of attached chalimus II compared with the initial number of larvae in the system) was measured after exposure to Atlantic salmon and subsequent development on their host. Compared with controls, infectivity potential was not compromised in dsAGM, dsCHS2, dsCDA4557, or dsCDA5169 groups. In contrast, there was a significant effect in the dsUAP-treated group. However, of most interest was the treatment with dsGFAT, dsCHS1, dsCHS1+2, and dsCDA5956, which resulted in complete abrogation of infectivity, despite apparent compensatory mechanisms in the chitin synthesis pathway as detected by qPCR. There appeared to be a common phenotypic effect in these groups, characterised by significant aberrations in appendage morphology and an inability to swim. Ultrastructurally, dsGFAT showed a significantly distorted procuticle without distinct exo/endocuticle and intermittent electron dense (i.e. chitin) inclusions, and together with dsUAP and dsCHS1, indicated delayed entry to the pre-moult phase.
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Zhao Y, Li Z, Gu X, Su Y, Liu L. Imaginal Disc Growth Factor 6 (Idgf6) Is Involved in Larval and Adult Wing Development in Bactrocera correcta (Bezzi) (Diptera: Tephritidae). Front Genet 2020; 11:451. [PMID: 32435262 PMCID: PMC7218075 DOI: 10.3389/fgene.2020.00451] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Accepted: 04/14/2020] [Indexed: 01/13/2023] Open
Abstract
In insects, imaginal disk growth factors (IDGFs), an important component of the glycoside hydrolase 18 (GH18) family of chitinases, have been reported to be associated with the maintenance of the cuticle and molting. However, there is little knowledge of their function. In this study, imaginal disk growth factor 6 (Idgf6), which is an Idgf, was first identified and cloned from the guava fruit fly Bactrocera correcta (Bezzi) (Diptera: Tephritidae), one of the most serious pest insects in South China and surrounding Southeast Asian countries. This gene encodes IDGF6 protein with a conserved domain similar to ChiA chitinases, the glycoside hydrolase 18 (GH18) family of chitinases, according to NCBI BLAST. Phylogenetic analysis indicated that all Idgf6s were highly conserved among similar species. Subsequent temporal expression profiling revealed that Idgf6 was highly expressed in both the late-pupal and mid-adult stages, suggesting that this gene plays a predominant role in pupal and adult development. Furthermore, RNA interference experiments against Idgf6 in B. correcta, which led to the specific decrease in Idgf6 expression, resulted in larval death as well as adult wing malformation. The direct effects of Idgf6 silencing on B. correcta indicated its important role in development, and Idgf6 might be further exploited as a novel insecticide target in the context of pest management.
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Affiliation(s)
- Yan Zhao
- Department of Entomology, College of Plant Protection, China Agricultural University, Beijing, China
| | - Zhihong Li
- Department of Entomology, College of Plant Protection, China Agricultural University, Beijing, China
| | - Xinyue Gu
- Department of Entomology, College of Plant Protection, China Agricultural University, Beijing, China
| | - Yun Su
- Department of Entomology, College of Plant Protection, China Agricultural University, Beijing, China
| | - Lijun Liu
- Department of Entomology, College of Plant Protection, China Agricultural University, Beijing, China
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Effects of chitin synthesis inhibitor treatment on Lepeophtheirus salmonis (Copepoda, Caligidae) larvae. PLoS One 2019; 14:e0222520. [PMID: 31545833 PMCID: PMC6756749 DOI: 10.1371/journal.pone.0222520] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 09/02/2019] [Indexed: 01/30/2023] Open
Abstract
The salmon louse (Lepeophtheirus salmonis) is an ectoparasite infecting Atlantic salmon (Salmo salar), which causes substantial problems to the salmon aquaculture and threatens wild salmon. Chitin synthesis inhibitors (CSIs) are used to control L. salmonis in aquaculture. CSIs act by interfering with chitin formation and molting. In the present study, we investigated the action of four CSIs: diflubenzuron (DFB), hexaflumuron (HX), lufenuron (LF), and teflubenzuron (TFB) on larval molt. As the mode of action of CSIs remains unknown, we selected key enzymes in chitin metabolism and investigated if CSI treatment influenced the transcriptional level of these genes. All four CSIs interfered with the nauplius II molt to copepodids in a dose-dependent manner. The EC50 values were 93.2 nM for diflubenzuron, 1.2 nM for hexaflumuron, 22.4 nM for lufenuron, and 11.7 nM for teflubenzuron. Of the investigated genes, only the transcriptional level of L. salmonis chitin synthase 1 decreased significantly in hexaflumuron and diflubenzuron-treated larvae. All the tested CSIs affected the molt of nauplius II L. salmonis larvae but at different concentrations. The larvae were most sensitive to hexaflumuron and less sensitive to diflubenzuron. None of the CSIs applied had a strong impact on the transcriptional level of chitin synthesis or chitinases genes in L. salmonis. Further research is necessary to get more knowledge of the nature of the inhibition of CSI and may require methods such as studies of protein structure and enzymological studies.
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Harðardóttir HM, Male R, Nilsen F, Eichner C, Dondrup M, Dalvin S. Chitin synthesis and degradation in Lepeophtheirus salmonis: Molecular characterization and gene expression profile during synthesis of a new exoskeleton. Comp Biochem Physiol A Mol Integr Physiol 2019; 227:123-133. [DOI: 10.1016/j.cbpa.2018.10.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 10/09/2018] [Indexed: 02/06/2023]
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10
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Poley JD, Braden LM, Messmer AM, Igboeli OO, Whyte SK, Macdonald A, Rodriguez J, Gameiro M, Rufener L, Bouvier J, Wadowska DW, Koop BF, Hosking BC, Fast MD. High level efficacy of lufenuron against sea lice (Lepeophtheirus salmonis) linked to rapid impact on moulting processes. Int J Parasitol Drugs Drug Resist 2018; 8:174-188. [PMID: 29627513 PMCID: PMC6039351 DOI: 10.1016/j.ijpddr.2018.02.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 02/26/2018] [Accepted: 02/28/2018] [Indexed: 11/29/2022]
Abstract
Drug resistance in the salmon louse Lepeophtheirus salmonis is a global issue for Atlantic salmon aquaculture. Multiple resistance has been described across most available compound classes with the exception of the benzoylureas. To target this gap in effective management of L. salmonis and other species of sea lice (e.g. Caligus spp.), Elanco Animal Health is developing an in-feed treatment containing lufenuron (a benzoylurea) to be administered prior to seawater transfer of salmon smolts and to provide long-term protection of salmon against sea lice infestations. Benzoylureas disrupt chitin synthesis, formation, and deposition during all moulting events. However, the mechanism(s) of action are not yet fully understood and most research completed to date has focused on insects. We exposed the first parasitic stage of L. salmonis to 700 ppb lufenuron for three hours and observed over 90% reduction in survival to the chalimus II life stage on the host, as compared to vehicle controls. This agrees with a follow up in vivo administration study on the host, which showed >95% reduction by the chalimus I stage. Transcriptomic responses of salmon lice exposed to lufenuron included genes related to moulting, epithelial differentiation, solute transport, and general developmental processes. Global metabolite profiles also suggest that membrane stability and fluidity is impacted in treated lice. These molecular signals are likely the underpinnings of an abnormal moulting process and cuticle formation observed ultrastructurally using transmission electron microscopy. Treated nauplii-staged lice exhibited multiple abnormalities in the integument, suggesting that the coordinated assembly of the epi- and procuticle is impaired. In all cases, treatment with lufenuron had rapid impacts on L. salmonis development. We describe multiple experiments to characterize the efficacy of lufenuron on eggs, larvae, and parasitic stages of L. salmonis, and provide the most comprehensive assessment of the physiological responses of a marine arthropod to a benzoylurea chemical.
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Affiliation(s)
- Jordan D Poley
- Hoplite Lab, Department of Pathology & Microbiology, Atlantic Veterinary College, University of Prince Edward Island, 550 University Ave, Charlottetown PE, C1A 4P3, Canada.
| | - Laura M Braden
- Hoplite Lab, Department of Pathology & Microbiology, Atlantic Veterinary College, University of Prince Edward Island, 550 University Ave, Charlottetown PE, C1A 4P3, Canada.
| | - Amber M Messmer
- Centre for Biomedical Research, Department of Biology, University of Victoria, Victoria BC, V8W 3N5, Canada.
| | - Okechukwu O Igboeli
- Hoplite Lab, Department of Pathology & Microbiology, Atlantic Veterinary College, University of Prince Edward Island, 550 University Ave, Charlottetown PE, C1A 4P3, Canada.
| | - Shona K Whyte
- Hoplite Lab, Department of Pathology & Microbiology, Atlantic Veterinary College, University of Prince Edward Island, 550 University Ave, Charlottetown PE, C1A 4P3, Canada.
| | - Alicia Macdonald
- Elanco Canada Limited, 150 Research Lane, Guelph, Ontario N1G 4T2, Canada.
| | - Jose Rodriguez
- Elanco Canada Limited, 150 Research Lane, Guelph, Ontario N1G 4T2, Canada.
| | - Marta Gameiro
- Elanco Canada Limited, 150 Research Lane, Guelph, Ontario N1G 4T2, Canada.
| | - Lucien Rufener
- Elanco Centre de Recherche Santé Animale SA, CH-1566 St.-Aubin, Switzerland; INVENesis LLC, Chemin de Belleroche 14, 2000 Neuchâtel, Switzerland.
| | - Jacques Bouvier
- Elanco Centre de Recherche Santé Animale SA, CH-1566 St.-Aubin, Switzerland; INVENesis LLC, Chemin de Belleroche 14, 2000 Neuchâtel, Switzerland.
| | - Dorota W Wadowska
- Electron Microscopy Laboratory, Atlantic Veterinary College, University of Prince Edward Island, 550 University Ave, Charlottetown, PEI, C1A 4P3, Canada.
| | - Ben F Koop
- Centre for Biomedical Research, Department of Biology, University of Victoria, Victoria BC, V8W 3N5, Canada.
| | - Barry C Hosking
- Elanco Canada Limited, 150 Research Lane, Guelph, Ontario N1G 4T2, Canada.
| | - Mark D Fast
- Hoplite Lab, Department of Pathology & Microbiology, Atlantic Veterinary College, University of Prince Edward Island, 550 University Ave, Charlottetown PE, C1A 4P3, Canada.
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11
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Eichner C, Dondrup M, Nilsen F. RNA sequencing reveals distinct gene expression patterns during the development of parasitic larval stages of the salmon louse (Lepeophtheirus salmonis). JOURNAL OF FISH DISEASES 2018; 41:1005-1029. [PMID: 29368347 DOI: 10.1111/jfd.12770] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 11/08/2017] [Accepted: 11/10/2017] [Indexed: 06/07/2023]
Abstract
The salmon louse (Lepeophtheirus salmonis), an ectoparasitic copepod on salmonids, has become a major threat for the aquaculture industry. In search for new drugs and vaccines, transcriptome analysis is increasingly used to find differently regulated genes and pathways in response to treatment. However, the underlying gene expression changes going along with developmental processes could confound such analyses. The life cycle of L. salmonis consists of eight stages divided by moults. The developmental rate of salmon lice on the host is not uniform. Individual- and sex-related differences are found leading to individuals of unlike developmental status at same sampling time point after infection. In this study, we analyse L. salmonis from a time series by RNA sequencing applying a method of separating individuals of different instar age independent of sampling time point. Lice of four stages divided into up to four age groups within the stage were analysed in triplicate (total of 66 samples). Gene expression analysis shows that the method for sorting individuals was successful. Many genes show cyclic expression patterns over the moulting cycles. Overall gene expression differs more between lice of different age within the same stage than between lice of different stage but same instar age.
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Affiliation(s)
- C Eichner
- Sea Lice Research Centre, Department of Molecular Biology, University of Bergen, Bergen, Norway
| | - M Dondrup
- Sea Lice Research Centre, Department of Informatics, University of Bergen, Bergen, Norway
| | - F Nilsen
- Sea Lice Research Centre, Department of Biology, University of Bergen, Bergen, Norway
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12
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Sun Y, Zhang J, Xiang J. A CRISPR/Cas9-mediated mutation in chitinase changes immune response to bacteria in Exopalaemon carinicauda. FISH & SHELLFISH IMMUNOLOGY 2017; 71:43-49. [PMID: 28962883 DOI: 10.1016/j.fsi.2017.09.065] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 09/15/2017] [Accepted: 09/26/2017] [Indexed: 06/07/2023]
Abstract
Chitinase, belonging to family 18 glycosyl hydrolase, is a multi-gene family and it has many functions. Generation of loss-of-function mutant targeting an interesting gene is a common way to clarify its function based on reverse genetics. In this study, we first reported the immune defense of a chitinase gene (EcChi4) in Exopalaemon carinicauda using its EcChi4-deletion mutant. EcChi4 was predominantly expressed in hepatopancreas and was upregulated after challenge with Vibrio parahaemolyticus or Aeromonas hydrophila. After knockout EcChi4 gene using CRISPR/Cas9 tool, the prawns in EcChi4-deletion group had significant higher mortality than those in wild-type group when the prawns were challenged with V. parahaemolyticus or A. hydrophila. In conclusion, we first demonstrate the function of a chitinase gene in immune defense of E. carinicauda by performing directed, heritable gene mutagenesis. In the future, CRISPR/Cas9 should be widely applicable as a feasible means for gene editing in E. carinicauda for the study of important biological questions that cannot be easily addressed in other decapods.
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Affiliation(s)
- Yuying Sun
- College of Marine Life and Fisheries, Huaihai Institute of Technology, 59 Cangwu Road, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Huaihai Institute of Technology, Lianyungang 222005, China
| | - Jiquan Zhang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266000, China.
| | - Jianhai Xiang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266000, China
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13
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Øvergård AC, Hamre LA, Kongshaug H, Nilsen F. RNAi-mediated treatment of two vertically transmitted rhabdovirus infecting the salmon louse (Lepeophtheirus salmonis). Sci Rep 2017; 7:14030. [PMID: 29070796 PMCID: PMC5656668 DOI: 10.1038/s41598-017-14282-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 10/06/2017] [Indexed: 12/21/2022] Open
Abstract
Rhabdoviruses are a family of enveloped negative-sense single-stranded RNA viruses infecting a variety of hosts. Recently, two vertically transmitted salmon louse (Lepeophtheirus salmonis) rhabdoviruses (LsRV) have been identified. The prevalence of these viruses was measured along the Norwegian coast and found to be close to 100%, and with the present lack of suitable cell lines to propagate these viruses, it is challenging to obtain material to study their host impact and infection routes. Thus, virus free lice strains were established from virus infected lice carrying one or both LsRVs by treating them with N protein dsRNA twice during development. The viral replication of the N protein was specifically down-regulated following introduction of virus-specific dsRNA, and virus-free lice strains were maintained for several generations. A preliminary study on infection routes suggested that the LsRV-No9 is maternally transmitted, and that the virus transmits from males to females horizontally. The ability to produce virus free strains allows for further studies on transmission modes and how these viruses influences on the L.salmonis interaction with its salmonid host. Moreover, this study provides a general fundament for future studies on how vertically transmitted rhabdoviruses influence the biology of their arthropod hosts.
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Affiliation(s)
- Aina-Cathrine Øvergård
- SLCR-Sea Lice Research Centre, Department of Biology, University of Bergen, Thormøhlensgt. 55, Pb. 7803, NO-5020, Bergen, Norway.
| | - Lars Are Hamre
- SLCR-Sea Lice Research Centre, Department of Biology, University of Bergen, Thormøhlensgt. 55, Pb. 7803, NO-5020, Bergen, Norway
| | - Heidi Kongshaug
- SLCR-Sea Lice Research Centre, Department of Biology, University of Bergen, Thormøhlensgt. 55, Pb. 7803, NO-5020, Bergen, Norway
| | - Frank Nilsen
- SLCR-Sea Lice Research Centre, Department of Biology, University of Bergen, Thormøhlensgt. 55, Pb. 7803, NO-5020, Bergen, Norway
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14
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Song Y, Villeneuve DL, Toyota K, Iguchi T, Tollefsen KE. Ecdysone Receptor Agonism Leading to Lethal Molting Disruption in Arthropods: Review and Adverse Outcome Pathway Development. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:4142-4157. [PMID: 28355071 PMCID: PMC6135102 DOI: 10.1021/acs.est.7b00480] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Molting is critical for growth, development, reproduction, and survival in arthropods. Complex neuroendocrine pathways are involved in the regulation of molting and may potentially become targets of environmental endocrine disrupting chemicals (EDCs). Based on several known ED mechanisms, a wide range of pesticides has been developed to combat unwanted organisms in food production activities such as agriculture and aquaculture. Meanwhile, these chemicals may also pose hazards to nontarget species by causing molting defects, and thus potentially affecting the health of the ecosystems. The present review summarizes the available knowledge on molting-related endocrine regulation and chemically mediated disruption in arthropods (with special focus on insects and crustaceans), to identify research gaps and develop a mechanistic model for assessing environmental hazards of these compounds. Based on the review, multiple targets of EDCs in the molting processes were identified and the link between mode of action (MoA) and adverse effects characterized to inform future studies. An adverse outcome pathway (AOP) describing ecdysone receptor agonism leading to incomplete ecdysis associated mortality was developed according to the OECD guideline and subjected to weight of evidence considerations by evolved Bradford Hill Criteria. This review proposes the first invertebrate ED AOP and may serve as a knowledge foundation for future environmental studies and AOP development.
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Affiliation(s)
- You Song
- Norwegian Institute for Water Research (NIVA), Section of Ecotoxicology and Risk Assessment, Gaustadalléen 21, N-0349 Oslo, Norway
- Corresponding Author: Knut Erik Tollefsen, Norwegian Institute for Water Research (NIVA), Gaustadalléen 21, NO-0349 Oslo, Norway. Tlf.: 02348, Fax: (+47) 22 18 52 00, , You Song, Norwegian Institute for Water Research (NIVA), Gaustadalléen 21, NO-0349 Oslo, Norway. Tlf.: 02348, Fax: (+47) 22 18 52 00,
| | | | - Kenji Toyota
- Environmental Genomics Group, School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Taisen Iguchi
- Department of Basic Biology, Faculty of Life Science, SOKENDAI (Graduate University for Advanced Studies), Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, Okazaki, Aichi, 444-8787, Japan
- Graduate School of Nanobioscience, Yokohama City University, Yokohama 236-0027, Japan
| | - Knut Erik Tollefsen
- Norwegian Institute for Water Research (NIVA), Section of Ecotoxicology and Risk Assessment, Gaustadalléen 21, N-0349 Oslo, Norway
- Norwegian University of Life Sciences (NMBU), Faculty of Environmental Science and Technology, Department of Environmental Sciences (IMV). P.O. Box 5003, N-1432 Ås, Norway
- Corresponding Author: Knut Erik Tollefsen, Norwegian Institute for Water Research (NIVA), Gaustadalléen 21, NO-0349 Oslo, Norway. Tlf.: 02348, Fax: (+47) 22 18 52 00, , You Song, Norwegian Institute for Water Research (NIVA), Gaustadalléen 21, NO-0349 Oslo, Norway. Tlf.: 02348, Fax: (+47) 22 18 52 00,
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15
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Gui T, Zhang J, Song F, Sun Y, Xie S, Yu K, Xiang J. CRISPR/Cas9-Mediated Genome Editing and Mutagenesis of EcChi4 in Exopalaemon carinicauda. G3 (BETHESDA, MD.) 2016; 6:3757-3764. [PMID: 27605521 PMCID: PMC5100874 DOI: 10.1534/g3.116.034082] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 08/25/2016] [Indexed: 12/26/2022]
Abstract
The development of the type II clustered regularly interspaced short palindromic repeats (CRISPR) system has resulted in the revolution of genetic engineering, and this technology has been applied in the genome editing of various species. However, there are no reports about target-specific genome editing in shrimp. In this research, we developed a microinjection method for the ridgetail white prawn Exopalaemon carinicauda and successfully applied CRISPR/Cas9 technology to the genome editing of E. carinicauda Through coinjection of mRNA of Cas9 nuclease and gRNA specialized for E. carinicauda chitinase 4 (EcChi4), shrimps with indel mutations were obtained. Further analysis showed that the mutations could be transmitted to the next generation. This is the first time that site-specific genome editing has been successfully demonstrated in a decapod, and will further contribute to the study of functional genomics in decapods.
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Affiliation(s)
- Tianshu Gui
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jiquan Zhang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266000, China
| | - Fengge Song
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yuying Sun
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- College of Marine Life and Fisheries, Huaihai Institute of Technology, Lianyungang 222005, China
| | - Shijun Xie
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kuijie Yu
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
| | - Jianhai Xiang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266000, China
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16
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Xia WK, Shen XM, Ding TB, Niu JZ, Zhong R, Liao CY, Feng YC, Dou W, Wang JJ. Functional analysis of a chitinase gene during the larval-nymph transition in Panonychus citri by RNA interference. EXPERIMENTAL & APPLIED ACAROLOGY 2016; 70:1-15. [PMID: 27388447 DOI: 10.1007/s10493-016-0063-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2016] [Accepted: 06/29/2016] [Indexed: 06/06/2023]
Abstract
Chitinases are hydrolytic enzymes that are required for chitin degradation and reconstruction in arthropods. In this study, we report a cDNA sequence encoding a putative chitinase (PcCht1) from the citrus red mite, Panonychus citri. The PcCht1 (564 aa) possessed a signal peptide, a conserver domain, and a chitin-binding domain. Structural and phylogenetic analyses found that PcCht1 had high sequence similarity to chitinases in Tetranychus urticae. Real-time quantitative PCR analyses showed that the transcript levels of PcCht1 peaked periodically in larval and nymph stages. Moreover, significant increase of PcCht1 transcript level in the larvae was observed upon the exposure of diflubenzuron. In contrast, exposures of the larvae to diflubenzuron resulted in the decreased chitin content. Furthermore, through a feeding-based RNA interference approach, we were able to reduce the PcCht1 transcript level by 59.7 % in the larvae, and consequently the treated larvae showed a very low molting rate compared with the control. Our results expanded the understanding of the important role of PcCht1 in the growth and development of P. citri.
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Affiliation(s)
- Wen-Kai Xia
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, 400716, China
| | - Xiao-Min Shen
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, 400716, China
| | - Tian-Bo Ding
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, 400716, China
| | - Jin-Zhi Niu
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, 400716, China
| | - Rui Zhong
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, 400716, China
| | - Chong-Yu Liao
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, 400716, China
| | - Ying-Cai Feng
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, 400716, China
| | - Wei Dou
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, 400716, China
| | - Jin-Jun Wang
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, 400716, China.
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17
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Sandlund L, Nilsen F, Male R, Dalvin S. The ecdysone receptor (EcR) is a major regulator of tissue development and growth in the marine salmonid ectoparasite, Lepeophtheirus salmonis (Copepoda, Caligidae). Mol Biochem Parasitol 2016; 208:65-73. [DOI: 10.1016/j.molbiopara.2016.06.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 06/15/2016] [Accepted: 06/20/2016] [Indexed: 01/23/2023]
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18
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Chitinases and Imaginal disc growth factors organize the extracellular matrix formation at barrier tissues in insects. Sci Rep 2016; 6:18340. [PMID: 26838602 PMCID: PMC4738247 DOI: 10.1038/srep18340] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 11/16/2015] [Indexed: 12/27/2022] Open
Abstract
The cuticle forms an apical extracellular-matrix (ECM) that covers exposed organs, such as epidermis, trachea and gut, for organizing morphogenesis and protection of insects. Recently, we reported that cuticle proteins and chitin are involved in ECM formation. However, molecular mechanisms that control assembly, maturation and replacement of the ECM and its components are not well known. Here we investigated the poorly described glyco-18-domain hydrolase family in Drosophila and identified the Chitinases (Chts) and imaginal-disc-growth-factors (Idgfs) that are essential for larval and adult molting. We demonstrate that Cht and idgf depletion results in deformed cuticles, larval and adult molting defects, and insufficient protection against wounding and bacterial infection, which altogether leads to early lethality. We show that Cht2/Cht5/Cht7/Cht9/Cht12 and idgf1/idgf3/idgf4/idgf5/idgf6 are needed for organizing proteins and chitin-matrix at the apical cell surface. Our data indicate that normal ECM formation requires Chts, which potentially hydrolyze chitin-polymers. We further suggest that the non-enzymatic idgfs act as structural proteins to maintain the ECM scaffold against chitinolytic degradation. Conservation of Chts and Idgfs proposes analogous roles in ECM dynamics across the insect taxa, indicating that Chts/Idgfs are new targets for species specific pest control.
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