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Tuerdi M, Hu S, Wang Y, Zhou Y, Cao J, Zhang H, Zhou J. Engorgement of Rhipicephalus haemaphysaloides ticks blocked by silencing a protein inhibitor of apoptosis. EXPERIMENTAL & APPLIED ACAROLOGY 2021; 84:623-636. [PMID: 34136982 DOI: 10.1007/s10493-021-00637-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 06/14/2021] [Indexed: 06/12/2023]
Abstract
Inhibitors of apoptosis (IAPs) are regulators of cell death and may play a role in the salivary glands of ticks during blood-feeding. We cloned the open reading frame (ORF) sequence of the IAP gene in Rhipicephalus haemaphysaloides (RhIAP). The RhIAP ORF of 1887 bp encodes a predicted protein of 607 amino acids, which contains three baculovirus IAP repeat domains and a RING finger motif. A real-time PCR assay showed that RhIAP mRNA was expressed in all the tick developmental stages (eggs, larvae, nymphs, and adults) and in all tissues examined (midgut, ovary, salivary glands, fat body, and hemolymph). Western blot showed that the protein level of RhIAP in salivary glands increased during tick blood-feeding and decreased towards the end of tick engorgement. RhIAP gene silencing in vitro experiments with salivary glands demonstrated that RhIAP could be effectively knocked down within 48 h after dsRNA treatment, and as a consequence, salivary glands displayed apoptotic morphology. RhIAP gene silencing also inhibited tick blood-feeding and decreased the engorgement rate. These data suggest that RhIAP might be a suitable RNAi target for tick control.
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Affiliation(s)
- Mayinuer Tuerdi
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, China
| | - Shanming Hu
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, China
| | - Yanan Wang
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, China
| | - Yongzhi Zhou
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, China
| | - Jie Cao
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, China
| | - Houshuang Zhang
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, China
| | - Jinlin Zhou
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, China.
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Kaur R, Gupta M, Singh S, Joshi N, Sharma A. Enhancing RNAi Efficiency to Decipher the Functional Response of Potential Genes in Bemisia tabaci AsiaII-1 (Gennadius) Through dsRNA Feeding Assays. Front Physiol 2020; 11:123. [PMID: 32194431 PMCID: PMC7061899 DOI: 10.3389/fphys.2020.00123] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 02/03/2020] [Indexed: 01/09/2023] Open
Abstract
Whitefly Bemisia tabaci is a global invasive pest that causes substantial losses to agricultural crops worldwide either by direct feeding or vectoring numerous plant viruses. Management with insecticides remains a big challenge due to its rapid resistance development potential as well as the impact of these chemicals on non-target organisms. Thus, in search of alternate and novel pest management strategies RNA interference (RNAi) has come up as potential future tool in this direction. The present study targets nine potential genes (Aquaporin (AQP), Calcitonin (CAL), CyclophilinB (CYCP), Knottin-1 (k-1), Heat shock proteins (Hsp20, Hsp40 and Hsp70), SWItch/Sucrose Non-fermentable (SNF7) and inhibitor of apoptosis (IAP) of whitefly that have been implicated to play a role in various vital physiological functions and virus transmission. The RNAi mediated knockdown efficiency of these genes has been improved through the conjugation of respective target gene dsRNA with CQD (carbon quantum dots) nanoparticles or simultaneous knockdown of dsRNA specific gut nucleases. The studies revealed that feeding of dsRNA (40 μg/ml sucrose diet) of the target gene(s) either conjugated with CQD or along with dsRNA against dsRNase (dsdsRNase) (40 μg/ml sucrose diet) enhanced the RNAi efficiency by 24-89% compared to whiteflies fed with naked dsRNA of the same target gene. The studies provide insights about the functional role of various genes in whitefly, which can possibly be exploited for the management of this pest in the future.
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Affiliation(s)
- Ramandeep Kaur
- Department of Microbiology, Punjab Agricultural University, Ludhiana, India
| | - Mridula Gupta
- Regional Research Station, Punjab Agricultural University, Faridkot, India
| | - Satnam Singh
- Regional Research Station, Punjab Agricultural University, Faridkot, India
| | - Neelam Joshi
- Department of Entomology, Punjab Agricultural University, Ludhiana, India
| | - Abhishek Sharma
- Department of Vegetable Sciences, Punjab Agricultural University, Ludhiana, India
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Puglise JM, Estep AS, Becnel JJ. Expression Profiles and RNAi Silencing of Inhibitor of Apoptosis Transcripts in Aedes, Anopheles, and Culex Mosquitoes (Diptera: Culicidae). JOURNAL OF MEDICAL ENTOMOLOGY 2016; 53:304-14. [PMID: 26659858 DOI: 10.1093/jme/tjv191] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Effective mosquito control is vital to curtail the devastating health effects of many vectored diseases. RNA interference (RNAi)-mediated control of mosquitoes is an attractive alternative to conventional chemical pesticides. Previous studies have suggested that transcripts for inhibitors of apoptosis (IAPs) may be good RNAi targets. To revisit and extend previous reports, we examined the expression of Aedes aegypti (L.) IAPs (AaeIAPs) 1, 2, 5, 6, 9, and a viral IAP-associated factor (vIAF) as well as Anopheles quadrimaculatus Say and Culex quinquefasciatus Say IAP1 homologs (AquIAP1 and CquIAP1) in adult females. Expression profiles of IAPs suggested that some older female mosquitoes had significantly higher IAP mRNA levels when compared to the youngest ones. Minor differences in expression of AaeIAPs were observed in mosquitoes that imbibed a bloodmeal, but the majority of the time points (up to 48 h) were not significantly different. Although in vitro experiments with the Ae. aegypti Aag-2 cell line demonstrated that the various AaeIAPs could be effectively knocked down within one day after dsRNA treatment, only Aag-2 cells treated with dsIAP1 displayed apoptotic morphology. Gene silencing and mortality were also evaluated after topical application and microinjection of the same dsRNAs into female Ae. aegypti. In contrast to previous reports, topical administration of dsRNA against AaeIAP1 did not yield a significant reduction in gene expression or increased mortality. Knockdown of IAP1 and other IAPs by microinjection did not result in significant mortality. In toto, our findings suggest that IAPs may not be suitable RNAi targets for controlling adult mosquito populations.
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The role of innate immunity in conditioning mosquito susceptibility to West Nile virus. Viruses 2013; 5:3142-70. [PMID: 24351797 PMCID: PMC3967165 DOI: 10.3390/v5123142] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Revised: 11/13/2013] [Accepted: 12/09/2013] [Indexed: 01/02/2023] Open
Abstract
Arthropod-borne viruses (arboviruses) represent an emerging threat to human and livestock health globally. In particular, those transmitted by mosquitoes present the greatest challenges to disease control efforts. An understanding of the molecular basis for mosquito innate immunity to arbovirus infection is therefore critical to investigations regarding arbovirus evolution, virus-vector ecology, and mosquito vector competence. In this review, we discuss the current state of understanding regarding mosquito innate immunity to West Nile virus. We draw from the literature with respect to other virus-vector pairings to attempt to draw inferences to gaps in our knowledge about West Nile virus and relevant vectors.
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Liu B, Behura SK, Clem RJ, Schneemann A, Becnel J, Severson DW, Zhou L. P53-mediated rapid induction of apoptosis conveys resistance to viral infection in Drosophila melanogaster. PLoS Pathog 2013; 9:e1003137. [PMID: 23408884 PMCID: PMC3567152 DOI: 10.1371/journal.ppat.1003137] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Accepted: 12/03/2012] [Indexed: 11/30/2022] Open
Abstract
Arthropod-borne pathogens account for millions of deaths each year. Understanding the genetic mechanisms controlling vector susceptibility to pathogens has profound implications for developing novel strategies for controlling insect-transmitted infectious diseases. The fact that many viruses carry genes that have anti-apoptotic activity has long led to the hypothesis that induction of apoptosis could be a fundamental innate immune response. However, the cellular mechanisms mediating the induction of apoptosis following viral infection remained enigmatic, which has prevented experimental verification of the functional significance of apoptosis in limiting viral infection in insects. In addition, studies with cultured insect cells have shown that there is sometimes a lack of apoptosis, or the pro-apoptotic response happens relatively late, thus casting doubt on the functional significance of apoptosis as an innate immunity. Using in vivo mosquito models and the native route of infection, we found that there is a rapid induction of reaper-like pro-apoptotic genes within a few hours following exposure to DNA or RNA viruses. Recapitulating a similar response in Drosophila, we found that this rapid induction of apoptosis requires the function of P53 and is mediated by a stress–responsive regulatory region upstream of reaper. More importantly, we showed that the rapid induction of apoptosis is responsible for preventing the expression of viral genes and blocking the infection. Genetic changes influencing this rapid induction of reaper-like pro-apoptotic genes led to significant differences in susceptibility to viral infection. Arthropod-borne pathogens account for millions of deaths each year. Understanding the genetic mechanisms controlling arthropod susceptibility to pathogens has profound implications for developing novel strategies for controlling insect-transmitted infectious diseases. Although it was postulated that apoptosis (a genetically controlled form of cellular suicide) may play a very important role in insect innate immunity against viral infection, direct evidence has been lacking due to the lack of knowledge on the regulatory pathways responsible for the induction of apoptosis following viral infection. In this study, we found that there is a rapid induction of pro-apoptotic genes within 1–3 hours of exposure to virus. This rapid pro-apoptotic response was only observed in live animals but not in cultured cells. Genetic analysis indicated that animals lacking this rapid pro-apoptotic response were hypersensitive to viral infection. Thus our work provides unequivocal evidence indicating that rapid induction of apoptosis plays a very important role in mediating insect resistance to viral infection.
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Affiliation(s)
- Bo Liu
- Department of Molecular Genetics and Microbiology & UF Shands Cancer Center, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Susanta K. Behura
- Eck Institute for Global Health, Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Rollie J. Clem
- Division of Biology, Kansas State University, Manhattan, Kansas, United States of America
| | - Anette Schneemann
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, California, United States of America
| | - James Becnel
- Center for Medical, Agricultural and Veterinary Entomology, USDA/ARS, Gainesville, Florida, United States of America
| | - David W. Severson
- Eck Institute for Global Health, Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Lei Zhou
- Department of Molecular Genetics and Microbiology & UF Shands Cancer Center, College of Medicine, University of Florida, Gainesville, Florida, United States of America
- * E-mail:
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Fragkoudis R, Attarzadeh-Yazdi G, Nash AA, Fazakerley JK, Kohl A. Advances in dissecting mosquito innate immune responses to arbovirus infection. J Gen Virol 2009; 90:2061-72. [DOI: 10.1099/vir.0.013201-0] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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Patterns of variation in the inhibitor of apoptosis 1 gene of Aedes triseriatus, a transovarial vector of La Crosse virus. J Mol Evol 2009; 68:403-13. [PMID: 19308633 DOI: 10.1007/s00239-009-9216-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2008] [Revised: 02/10/2009] [Accepted: 02/19/2009] [Indexed: 10/21/2022]
Abstract
Aedes triseriatus mosquitoes transovarially transmit (TOT) La Crosse virus (LACV) to their offspring with minimal damage to infected ovaries. Ae. triseriatus inhibitor of apoptosis 1 (AtIAP1) is a candidate gene conditioning the ability to vertically transmit LACV. AtIAP1 was amplified and sequenced in adult mosquitoes reared from field-collected eggs. Sequence analysis showed that AtIAP1 has much higher levels of genetic diversity than genes found in other mosquitoes. Despite this large amount of diversity, strong purifying selection of polymorphisms located in the Baculovirus inhibitor of apoptosis repeat (BIR) domains and, to a lesser extent, in the 5' untranslated region seems to indicate that these portions of AtIAP1 are the most important. These results indicate that the 5'UTR plays an important role in transcription and translation and that the BIR domains are important functional domains in the protein. Single nucleotide polymorphisms (SNPs) were compared between LACV-positive and -negative mosquitoes to test for associations between segregating sites and the ability to be transovarially infected with LACV. Initial results indicated that five SNPs were associated with TOT of LACV; however, these results were not replicable with larger sample sizes.
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Pridgeon JW, Zhao L, Becnel JJ, Clark GG, Linthicum KJ. Developmental and environmental regulation of AaeIAP1 transcript in Aedes aegypti. JOURNAL OF MEDICAL ENTOMOLOGY 2008; 45:1071-1079. [PMID: 19058631 DOI: 10.1603/0022-2585(2008)45[1071:daeroa]2.0.co;2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Apoptosis (programmed cell death) is a tightly regulated physiological process. The inhibitors of apoptosis proteins (IAPs) are key regulators for apoptosis. An inhibitor of apoptosis protein gene IAP1 was recently cloned from Aedes aegypti (L.) (AaeIAP1, GenBank accession no. DQ993355); however, it is not clear whether AaeIAP1 is developmentally and environmentally regulated. In this study, we applied quantitative polymerase chain reaction (PCR) to investigate the expression levels of the AaeIAPI transcript in different developmental stages and under different environmental conditions. Our results revealed that the expression of the AaeIAP1 transcript was detectable in all life stages ofAe. aegypti, with significantly higher levels in pupal and adult stages than in larval stages. Furthermore, when Ae. aegypti was exposed to all stressful environmental conditions (e.g., low and high temperatures, UV radiation, acetone, and permethrin insecticide treatment), the expression level of AaeIAP1 transcript was increased significantly. Our results suggest that AaeIAP1 might play an important role in both the physiological development ofAe. aegypti and stress-induced apoptosis.
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Affiliation(s)
- Julia W Pridgeon
- Center for Medical, Agricultural, and Veterinary Entomology, USDA-ARS, 1600 SW 23rd Drive, Gainesville, FL 32608, USA.
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Beck ET, Blair CD, Black WC, Beaty BJ, Blitvich BJ. Alternative splicing generates multiple transcripts of the inhibitor of apoptosis protein 1 in Aedes and Culex spp. mosquitoes. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2007; 37:1222-1233. [PMID: 17916508 PMCID: PMC2065863 DOI: 10.1016/j.ibmb.2007.07.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2006] [Revised: 07/16/2007] [Accepted: 07/20/2007] [Indexed: 05/25/2023]
Abstract
We determined the sequences of cDNA encoding Inhibitor of Apoptosis Protein 1 (IAP1) homologues from Aedes triseriatus, Aedes albopictus, Aedes aegypti, Culex pipiens and Culex tarsalis. The cDNAs encode translation products that share > or = 84% sequence similarity. The IAP1 mRNA of each mosquito species exists as 3-5 distinct variants due to the presence of heterogeneous sequences at the distal end of their 5'UTRs. Partial genomic sequencing upstream of the 5' end of the Ae. triseriatus IAP1 gene, and analysis of the Ae. aegypti genomic sequence, suggest that these mRNA variants are generated by alternative splicing. Each IAP1 mRNA variant from Ae. triseriatus and Cx. pipiens was detected by RT-PCR in all mosquito life-stages and adult tissues examined, and the relative concentration of each Ae. triseriatus IAP mRNA variant in various tissues was determined.
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Affiliation(s)
- Eric T Beck
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523-1692, USA
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Cooper DM, Thi EP, Chamberlain CM, Pio F, Lowenberger C. Aedes Dronc: a novel ecdysone-inducible caspase in the yellow fever mosquito, Aedes aegypti. INSECT MOLECULAR BIOLOGY 2007; 16:563-72. [PMID: 17725799 DOI: 10.1111/j.1365-2583.2007.00758.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Caspases are cysteinyl-aspartate-specific proteases known for their role in apoptosis. Here, we describe the characterization of Aedes Dronc, a novel caspase in the yellow fever mosquito, Aedes aegypti. Aedes Dronc is predicted to contain an N-terminal caspase recruitment domain and is a homologue of Drosophila Dronc and human caspase-9. An increase in transcripts and caspase activity coincides with developmental changes in the mosquito, suggesting that Aedes Dronc plays a role in developmental apoptosis. Exposure of third instar larvae to ecdysone resulted in a significant increase in both transcript levels and caspase activity. We present here a functional characterization of the first caspase recruitment domain-containing caspase in mosquitoes, and will initiate studies on the role of apoptosis in the innate immune response of vectors.
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Affiliation(s)
- D M Cooper
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada.
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Li Q, Li H, Blitvich BJ, Zhang J. The Aedes albopictus inhibitor of apoptosis 1 gene protects vertebrate cells from bluetongue virus-induced apoptosis. INSECT MOLECULAR BIOLOGY 2007; 16:93-105. [PMID: 17257212 DOI: 10.1111/j.1365-2583.2007.00705.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
We sequenced and characterized the inhibitor of apoptosis (iap) 1 gene from Aedes albopictus, designated as Aaiap1. The Aaiap1 gene rescued Spodoptera frugiperda (Sf9) cells from apoptosis when cotransfected with the Drosophila pro-apoptotic hid gene. The antiapoptotic function of the Aaiap1 gene was evaluated in the bluetongue virus (BTV)-induced apoptosis system. BTV infection induced apoptosis in vertebrate cells via the intrinsic apoptotic pathway. This was shown by the translocation of cytochrome C and the second mitochondria-derived activator of caspase (Smac, also known as DIABLO) from the mitochondria and the subsequent activation of caspase-9 and -3. Stable expression of the Aaiap1 gene in derivative baby hamster kidney cells delayed BTV-induced apoptosis by 24 h and reduced the BTV progeny yield by 10-fold. This study provides the first evidence that the mosquito AaIAP1 protein possesses antiapoptotic activity.
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Affiliation(s)
- Q Li
- Division of Geographic Medicine, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
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Vaidyanathan R, Scott TW. Apoptosis in mosquito midgut epithelia associated with West Nile virus infection. Apoptosis 2006; 11:1643-51. [PMID: 16820968 DOI: 10.1007/s10495-006-8783-y] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The mosquito Culex pipiens pipiens is a documented vector of West Nile virus (WNV, Flaviviridae, Flavivirus). Our laboratory colony of C. p. pipiens, however, was repeatedly refractory to experimental transmission of WNV. Our goal was to identify if a cellular process was inhibiting virus infection of the midgut. We examined midguts of mosquitoes fed control and WNV-infected blood meals. Three days after feeding, epithelial cells from abdominal midguts of mosquitoes fed on WNV fluoresced under an FITC filter following Acridine Orange staining, indicating apoptosis in this region. Epithelial cells from experimental samples examined by TEM exhibited ultrastructural changes consistent with apoptosis, including shrinkage and detachment from neighbors, heterochromatin condensation, nuclear degranulation, and engulfment of apoptotic bodies by adjacent cells. Virions were present in cytoplasm and within cytoplasmic vacuoles of apoptotic cells. No apoptosis was detected by TEM in control samples. In parallel, we used Vero cell plaque assays to quantify infection after 7 and 10 day extrinsic incubation periods and found that none of the mosquitoes (0/55 and 0/10) which imbibed infective blood were infected. We propose that programmed cell death limits the number of WNV-infected epithelial cells and inhibits disseminated viral infections from the mosquito midgut.
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Affiliation(s)
- Rajeev Vaidyanathan
- Department of Entomology, University of California, One Shields Avenue, Davis, 95616, USA.
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Nishiura JT, Ray K, Murray J. Expression of nuclear receptor-transcription factor genes during Aedes aegypti midgut metamorphosis and the effect of methoprene on expression. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2005; 35:561-573. [PMID: 15857762 DOI: 10.1016/j.ibmb.2005.01.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2004] [Revised: 01/28/2005] [Accepted: 01/28/2005] [Indexed: 05/24/2023]
Abstract
Exposure of mosquito 4th instars to the juvenile hormone analogue methoprene prevents the emergence of adults by interfering with metamorphosis. One metamorphic processes that is disrupted is midgut remodeling. To investigate the molecular mechanisms by which this occurs, the pattern of transcription factor gene expression during the Aedes aegypti (L.) 4th instar was investigated by the method of real time PCR. The results indicate that in untreated larvae, expression of transcription factors genes AHR3 and AaE75B increases within 24h after the last larval-larval molt, transcription of AaEcR-B, AaUSP-a and AassFTZ-F1 increases approximately 24h later, and transcription of AaE75A increases just before the larval-pupal molt. There is uniform expression of AaUSP-b throughout the 4th instar. The effect of methoprene exposure on transcription factor gene expression during midgut remodeling was investigated. The results indicate that, in a dose and stage dependent manner, methoprene affects increases in expression that normally occur during midgut remodeling. The coincident effects of methoprene on metamorphic midgut remodeling and on transcription factor gene expression suggests that the two processes are related.
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Affiliation(s)
- James T Nishiura
- Biology Department, Brooklyn College, City University of New York, 2900 Bedford Ave., Brooklyn, NY 11210, USA.
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Irusta PM, Lamos E, Galonek HL, Vander Maten MA, Boersma MCH, Chen YB, Hardwick JM. Regulation of apoptosis by viruses that infect insects. ARCHIVES OF VIROLOGY. SUPPLEMENTUM 2004:171-8. [PMID: 15119772 DOI: 10.1007/978-3-7091-0572-6_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
Orthobunyviruses and alphaviruses cause encephalitis, neuronal apoptosis and mortality in mammals, but fail to kill the mosquitoes that transmit these viruses. Therefore, host cell factors, as well as viral factors, regulate the outcome of infection. Drosophila Reaper is a pro-death factor in the Drosophila nervous system during development but homologues were not previously known to exist outside flies. Recent discovery of a Reaper protein encoded by orthobunyaviruses provides interesting insight into the mechanisms by which viruses modulate the death pathway in both vertebrate and invertebrate hosts.
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Affiliation(s)
- P M Irusta
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins School of Public Health, Baltimore, Maryland 21205, USA
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Graham DH, Holmes JL, Beaty BJ, Black WC. Quantitative trait loci conditioning transovarial transmission of La Crosse virus in the eastern treehole mosquito, Ochlerotatus triseriatus. INSECT MOLECULAR BIOLOGY 2003; 12:307-318. [PMID: 12864911 DOI: 10.1046/j.1365-2583.2003.00412.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Quantitative trait loci (QTL) affecting the ability of the Eastern treehole mosquito, Ochlerotatus triseriatus, to transovarially transmit (TOT) La Crosse virus (LAC) were mapped in an F1 intercross. The Holmen strain of O. triseriatus, previously selected for TOT refractoriness, was crossed to the AIDL strain that had been selected for TOT permissiveness. In P1 and F1 parents and 49 F2 individuals, regions of 10 cDNA loci were analysed with single strand conformation polymorphism (SSCP) analysis to identify and orientate linkage groups. Genotypes were also scored at fifty-six random amplified polymorphic DNA (RAPD)-SSCP loci. Twenty-eight F2 offspring were individually analysed for TOT. Three QTL for TOT were detected with standard interval mapping on chromosomes II and III. Alleles at the three loci contributed additively towards determining the overall TOT rate and cumulatively accounted for approximately 53% of the phenotypic variance in TOT.
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Affiliation(s)
- Douglas H Graham
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523-1677, USA
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