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Soghigian J, Livdahl T. Field Evidence of Mosquito Population Regulation by a Gregarine Parasite. JOURNAL OF MEDICAL ENTOMOLOGY 2021; 58:1188-1196. [PMID: 33570154 PMCID: PMC8122234 DOI: 10.1093/jme/tjab009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Indexed: 06/12/2023]
Abstract
Although parasites are by definition costly to their host, demonstrating that a parasite is regulating its host abundance in the field can be difficult. Here we present an example of a gregarine parasite, Ascogregarina taiwanensis Lien and Levine (Apicomplexa: Lecudinidae), regulating its mosquito host, Aedes albopictus Skuse (Diptera: Culicidae), in Bermuda. We sampled larvae from container habitats over 2 yr, assessed parasite prevalence, and estimated host abundance from egg counts obtained in neighboring ovitraps. We regressed change in average egg count from 1 yr to the next on parasite prevalence and found a significant negative effect of parasite prevalence. We found no evidence of host density affecting parasite prevalence. Our results demonstrate that even for a parasite with moderate virulence, host regulation can occur in the field.
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Affiliation(s)
- John Soghigian
- Department of Biology, Clark University, Worcester, MA
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC
| | - Todd Livdahl
- Department of Biology, Clark University, Worcester, MA
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XBP1-Mediated BiP/GRP78 Upregulation Copes with Oxidative Stress in Mosquito Cells during Dengue 2 Virus Infection. BIOMED RESEARCH INTERNATIONAL 2017; 2017:3519158. [PMID: 29098151 PMCID: PMC5642879 DOI: 10.1155/2017/3519158] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/03/2017] [Revised: 08/01/2017] [Accepted: 08/23/2017] [Indexed: 12/23/2022]
Abstract
Dengue viruses (DENVs) cause dengue fever which is an important mosquito-borne disease in tropical areas. Generally, DENV does not cause cellular damage in mosquito cells. However, alterations in cytosolic calcium ions ([Ca2+]cyt) and the mitochondrial membrane potential (MMP), as well as accumulated reactive oxygen species (ROS), including superoxide anions (O2∙-) and hydrogen peroxide (H2O2), can be detected in C6/36 cells with DENV2 infection. Evident upregulation of BiP/GRP78 also appeared at 24 h postinfection in DENV2-infected C6/36 cells. As expression of BiP/GRP78 mRNA was reduced when the transcription factor X-box-binding protein-1 (XBP1) was knocked down in C6/36 cells, it demonstrated that BiP/GRP78 is the target gene regulated by the XBP1 signal pathway. We further demonstrated that the expression and splicing activity of XBP1 were upregulated in parallel with DENV2 infection in C6/36 cells. In C6/36 cells with BiP/GRP78 overexpression, oxidative stress indicators including [Ca2+]cyt, MMP, O2∙-, and H2O2 were all pushed back to normal. Taken together, DENV2 activates XBP1 at earlier stage of infection, followed by upregulating BiP/GRP78 in mosquito cells. This regulatory pathway contributes a cascade in relation to oxidative stress alleviation. The finding provides insights into elucidating how mosquitoes can healthily serve as a vector of arboviruses in nature.
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Liu P, Li X, Gu J, Dong Y, Liu Y, Santhosh P, Chen X. Development of non-defective recombinant densovirus vectors for microRNA delivery in the invasive vector mosquito, Aedes albopictus. Sci Rep 2016; 6:20979. [PMID: 26879823 PMCID: PMC4754678 DOI: 10.1038/srep20979] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 01/14/2016] [Indexed: 12/11/2022] Open
Abstract
We previously reported that mosquito densoviruses (MDVs) are potential vectors for delivering foreign nucleic acids into mosquito cells. However, considering existing expression strategies, recombinant viruses would inevitably become replication-defective viruses and lose their ability for secondary transmission. The packaging limitations of the virion represent a barrier for the development of MDVs for viral paratransgenesis or as high-efficiency bioinsecticides. Herein, we report the development of a non-defective recombinant Aedes aegypti densovirus (AaeDV) miRNA expression system, mediated by an artificial intron, using an intronic miRNA expression strategy. We demonstrated that this recombinant vector could be used to overexpress endogenous miRNAs or to decrease endogenous miRNAs by generating antisense sponges to explore the biological functions of miRNAs. In addition, the vector could express antisense-miRNAs to induce efficient gene silencing in vivo and in vitro. The recombinant virus effectively self-replicated and retained its secondary transmission ability, similar to the wild-type virus. The recombinant virus was also genetically stable. This study demonstrated the first construction of a non-defective recombinant MDV miRNA expression system, which represents a tool for the functional analysis of mosquito genes and lays the foundation for the application of viral paratransgenesis for dengue virus control.
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Affiliation(s)
- Peiwen Liu
- Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Pathogen Biology, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, Guangdong, 510515, China
| | - Xiaocong Li
- Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Pathogen Biology, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, Guangdong, 510515, China
| | - Jinbao Gu
- Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Pathogen Biology, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, Guangdong, 510515, China
| | - Yunqiao Dong
- Reproductive Medical Center of Guangdong Women and Children Hospital, Guangzhou, Guangdong, 511442, China
| | - Yan Liu
- Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Pathogen Biology, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, Guangdong, 510515, China
| | - Puthiyakunnon Santhosh
- Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Pathogen Biology, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, Guangdong, 510515, China
| | - Xiaoguang Chen
- Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Pathogen Biology, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, Guangdong, 510515, China
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Lantova L, Volf P. Mosquito and sand fly gregarines of the genus Ascogregarina and Psychodiella (Apicomplexa: Eugregarinorida, Aseptatorina)--overview of their taxonomy, life cycle, host specificity and pathogenicity. INFECTION GENETICS AND EVOLUTION 2014; 28:616-27. [PMID: 24797386 DOI: 10.1016/j.meegid.2014.04.021] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Revised: 04/16/2014] [Accepted: 04/24/2014] [Indexed: 11/15/2022]
Abstract
Mosquitoes and sand flies are important blood-sucking vectors of human diseases such as malaria or leishmaniasis. Nevertheless, these insects also carry their own parasites, such as gregarines; these monoxenous pathogens are found exclusively in invertebrates, and some of them have been considered useful in biological control. Mosquito and sand fly gregarines originally belonging to a single genus Ascogregarina were recently divided into two genera, Ascogregarina comprising parasites of mosquitoes, bat flies, hump-backed flies and fleas and Psychodiella parasitizing sand flies. Currently, nine mosquito Ascogregarina and five Psychodiella species are described. These gregarines go through an extraordinarily interesting life cycle; the mosquito and sand fly larvae become infected by oocysts, the development continues transtadially through the larval and pupal stages to adults and is followed by transmission to the offspring by genus specific mechanisms. In adult mosquitoes, ascogregarines develop in the Malpighian tubules, and oocysts are defecated, while in the sand flies, the gregarines are located in the body cavity, their oocysts are injected into the accessory glands of females and released during oviposition. These life history differences are strongly supported by phylogenetical study of SSU rDNA proving disparate position of Ascogregarina and Psychodiella gregarines. This work reviews the current knowledge about Ascogregarina and Psychodiella gregarines parasitizing mosquitoes and sand flies, respectively. It gives a comprehensive insight into their taxonomy, life cycle, host specificity and pathogenicity, showing a very close relationship of gregarines with their hosts, which suggests a long and strong parasite-host coevolution.
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Affiliation(s)
- Lucie Lantova
- Institute of Histology and Embryology, First Faculty of Medicine, Charles University in Prague, Albertov 4, 128 00 Prague 2, Czech Republic.
| | - Petr Volf
- Department of Parasitology, Faculty of Science, Charles University in Prague, Vinicna 7, 128 44 Prague 2, Czech Republic.
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Chen WJ, Huang CG, Fan-Chiang MH, Liu YH, Lee YF. Apoptosis of Ascogregarina taiwanensis (Apicomplexa: Lecudinidae), which failed to migrate within its natural host. J Exp Biol 2013; 216:230-5. [PMID: 22996442 DOI: 10.1242/jeb.072918] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Sexual reproduction of Ascogregarina taiwanensis (Apicomplexa: Lecudinidae), a parasite specific to the mosquito Aedes albopictus, in Malpighian tubules is initiated by the entry of the trophotozoites developed in the midgut shortly after pupation (usually <5 h). However, only a low proportion of trophozoites are able to migrate; others end up dying. In this study, we demonstrated that those trophozoites that failed to migrate eventually died of apoptosis. Morphological changes such as shrinkage, chromatin aggregations and formation of blunt ridges on the surface were seen in moribund trophozoites. In addition, DNA fragmentation of trophozoites isolated from the midgut of pupae was demonstrated by the presence of DNA ladders, Annexin V staining and TUNEL assays. Detection of caspase-like activity suggests that apoptosis of those trophozoites may have occurred through a mechanism of an intrinsic or mitochondrial-mediated pathway. Although apoptosis has been observed in various protozoan species, it is not clear how apoptosis in single-celled organisms might result from evolution by natural selection. However, we speculate that apoptosis may regulate the parasite load of A. taiwanensis within its natural mosquito host, leading to an optimized state of the survival rate for both parasite and host.
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Affiliation(s)
- Wei-June Chen
- Department of Public Health and Parasitology, Chang Gung University, Kwei-San, Tao-Yuan 33332, Taiwan.
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Duncan AB, Agnew P, Noel V, Demettre E, Seveno M, Brizard JP, Michalakis Y. Proteome of Aedes aegypti in response to infection and coinfection with microsporidian parasites. Ecol Evol 2012; 2:681-94. [PMID: 22837817 PMCID: PMC3399191 DOI: 10.1002/ece3.199] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Accepted: 12/01/2011] [Indexed: 12/24/2022] Open
Abstract
Hosts are frequently infected with more than one parasite or pathogen at any one time, but little is known as to how they respond to multiple immune challenges compared to those involving single infections. We investigated the proteome of Aedes aegypti larvae following infection with either Edhazardia aedis or Vavraia culicis, and coinfections involving both. They are both obligate intracellular parasites belonging to the phylum microsporidia and infect natural populations of Ae. aegypti. The results found some proteins only showing modified abundance in response to infections involving E. aedis, while others were only differentially abundant when infections involved V. culicis. Some proteins only responded with modified abundance to the coinfection condition, while others were differentially abundant in response to all three types of infection. As time since infection increased, the response to each of the single parasite infections diverged, while the response to the E. aedis and coinfection treatments converged. Some of the proteins differentially abundant in response to infection were identified. They included two vacuolar ATPases, proteins known to have a role in determining the infection success of intracellular parasites. This result suggests microsporidia could influence the infection success of other intracellular pathogens infecting vector species of mosquito, including viruses, Plasmodium and Wolbachia.
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Gu J, Liu M, Deng Y, Peng H, Chen X. Development of an efficient recombinant mosquito densovirus-mediated RNA interference system and its preliminary application in mosquito control. PLoS One 2011; 6:e21329. [PMID: 21698129 PMCID: PMC3116905 DOI: 10.1371/journal.pone.0021329] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Accepted: 05/26/2011] [Indexed: 11/18/2022] Open
Abstract
The Aedes aegypti densovirus (AeDNV) has potential as a delivery vector for foreign nucleic acids into mosquito cells. In this study, we investigated the ability of plasmids containing recombinant viral transducing genome to induce RNA interference (RNAi) effects in C6/C36 cells. We then evaluated the efficiency of a recombinant AeDNV vector to induce RNAi in Aedes albopictus larvae. We found that the expression of V-ATPase was inhibited by up to 90% at 96 h post-transfection in transfected C6/C36 cells. In addition, the bioinsecticidal activities of various RNAi-expressing AeDNV vectors used to infect Ae. albopictus larvae were also tested. We found that when Ae. albopictus larvae were infected with recombinant AeDNV, expression of V-ATPase was downregulated by nearly 70% compared to controls. Furthermore, the median survival time bioassays demonstrated that recombinant AeDNV caused more serious pathogenic effects than the wild type virus. This is the first report showing that recombinant virus plasmid and corresponding recombinant AeDNV can be used as an effective in vitro and in vivo RNAi delivery system, respectively.
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Affiliation(s)
- Jinbao Gu
- Key Laboratory of Prevention and Control of Emerging Infectious Diseases of Guangdong Higher Education Institutes, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, Guangdong, China
| | - Min Liu
- Key Laboratory of Prevention and Control of Emerging Infectious Diseases of Guangdong Higher Education Institutes, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, Guangdong, China
| | - Yuhua Deng
- Key Laboratory of Prevention and Control of Emerging Infectious Diseases of Guangdong Higher Education Institutes, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, Guangdong, China
| | - Hongjuan Peng
- Key Laboratory of Prevention and Control of Emerging Infectious Diseases of Guangdong Higher Education Institutes, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, Guangdong, China
| | - Xiaoguang Chen
- Key Laboratory of Prevention and Control of Emerging Infectious Diseases of Guangdong Higher Education Institutes, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, Guangdong, China
- * E-mail:
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Hunt SR, Hernandez R, Brown DT. Role of the vacuolar-ATPase in Sindbis virus infection. J Virol 2011; 85:1257-66. [PMID: 21084471 PMCID: PMC3020509 DOI: 10.1128/jvi.01864-10] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Accepted: 11/03/2010] [Indexed: 11/20/2022] Open
Abstract
Bafilomycin A(1) is a specific inhibitor of the vacuolar-ATPase (V-ATPase), which is responsible for pH homeostasis of the cell and for the acidification of endosomes. Bafilomycin A(1) has been commonly used as a method of inhibition of infection by viruses known or suspected to follow the path of receptor-mediated endocytosis and low-pH-mediated membrane fusion. The exact method of entry for Sindbis virus, the prototype alphavirus, remains undetermined. To further investigate the role of the V-ATPase in Sindbis virus infection, the effects of bafilomycin A(1) on the infection of BHK and insect cells by Sindbis virus were studied. Bafilomycin A(1) was found to block the expression of a virus-encoded reporter gene in both infection and transfection of BHK cells. The inhibitory effects of bafilomycin A(1) were found to be reversible. The results suggest that in BHK cells in the presence of bafilomycin A(1), virus RNA enters the cell and is translated, but replication and proper folding of the product proteins requires the function of the V-ATPase. Bafilomycin A(1) had no significant effect on the outcome of infection in insect cells.
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Affiliation(s)
- Sabrina R. Hunt
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695
| | - Raquel Hernandez
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695
| | - Dennis T. Brown
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695
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Shih YT, Yang CF, Chen WJ. Upregulation of a novel eukaryotic translation initiation factor 5A (eIF5A) in dengue 2 virus-infected mosquito cells. Virol J 2010; 7:214. [PMID: 20819232 PMCID: PMC2942825 DOI: 10.1186/1743-422x-7-214] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2010] [Accepted: 09/07/2010] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Dengue virus, a mosquito-borne flavivirus, is the etiological agent of dengue fever, dengue hemorrhagic fever, and dengue shock syndrome. It generally induces apoptosis in mammalian cells, but frequently results in persistent infection in mosquito cells. That mechanism remains to be explored. In turn, a genomic survey through subtractive hybridization (PCR-select cDNA subtraction) was conducted in order to find gene(s) that may play a role in interactions between the virus and its host cells. RESULTS Through this technique, we identified a novel eukaryotic translation initiation factor 5A (eIF5A) which is upregulated in Aedes albopictus-derived C6/36 cells infected by the type 2 dengue (Den-2) virus. The full-length of the identified eIF5A gene consisted of 1498 bp of nucleotides with a 41.39% G+C content, and it possessed a higher similarity and shorter evolutionary distance with insects than with other organisms. Upregulation of eIF5A in response to Den-2 virus infection was validated at both the RNA and protein levels. This phenomenon was also observed by confocal microscopy. In addition, cell death obviously occurred when eIF5A activity was inhibited in C6/36 cells even when they were infected by the virus. However, viral multiplication was not obviously affected in infected C6/36 cells when eIF5A activity was reduced. CONCLUSIONS Taken together, we postulated that eIF5A plays a role in preventing mosquito cells from death in response to Den-2 viral infection, thus facilitating continued viral growth and potential persistent infection in mosquito cells. It would be worthwhile to further investigate how its downstream factors or cofactors contribute to this phenomenon of dengue infection.
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Affiliation(s)
- Yu-Tzu Shih
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Kwei-San, Tao-Yuan 33332, Taiwan
| | - Chao-Fu Yang
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Kwei-San, Tao-Yuan 33332, Taiwan
| | - Wei-June Chen
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Kwei-San, Tao-Yuan 33332, Taiwan
- Department of Public Health and Parasitology, College of Medicine, Chang Gung University, Kwei-San, Tao-Yuan 33332, Taiwan
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Susceptibility of Aedes aegypti (Diptera: Culicidae) to Acanthamoeba polyphaga (Sarcomastigophora: Acanthamoebidae). Parasitol Res 2010; 107:195-8. [PMID: 20379834 DOI: 10.1007/s00436-010-1843-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2009] [Accepted: 03/11/2010] [Indexed: 10/19/2022]
Abstract
To date there is no report on mosquitoes infected with free-living amoebae. For this reason, the aim of this study was to verify if Aedes aegypti could be susceptible to Acanthamoeba polyphaga under laboratory conditions, so trophozoites were offered as a unique food resource for larvae of first instar. The results show that those amoebae are able to infect and colonize the mosquito gut and could be re-isolated of all stages of the mosquito (larvae, pupae, and adults).
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Templeton TJ, Enomoto S, Chen WJ, Huang CG, Lancto CA, Abrahamsen MS, Zhu G. A genome-sequence survey for Ascogregarina taiwanensis supports evolutionary affiliation but metabolic diversity between a Gregarine and Cryptosporidium. Mol Biol Evol 2009; 27:235-48. [PMID: 19778951 DOI: 10.1093/molbev/msp226] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We have performed a whole-genome-sequence survey for the gregarine, Ascogregarina taiwanensis and herein describe both features unique to this early diverging apicomplexan and properties that unite it with Cryptosporidium, the Coccidia, and the Apicomplexa. Phylogenetic trees inferred from a concatenated protein sequence comprised of 10,750 amino acid positions, as well as the large subunit rRNA genes, robustly support phylogenetic affinity of Ascogregarina with Cryptosporidium at the base of the apicomplexan clade. Unlike Cryptosporidium, Ascogregarina possesses numerous mitochondrion-associated pathways and proteins, including enzymes within the Krebs cycle and a cytochrome-based respiratory chain. Ascogregarina further differs in the capacity for de novo synthesis of pyrimidines and amino acids. Ascogregarina shares with Cryptosporidium a Type I fatty acid synthase and likely a polyketide synthase. Cryptosporidium and Ascogregarina possess a large repertoire of multidomain surface proteins that align it with Toxoplasma and are proposed to be involved in coccidian-like functions. Four families of retrotransposable elements were identified, and thus, retroelements are present in Ascogregarina and Eimeria but not in other apicomplexans that have been analyzed. The sum observations suggest that Ascogregarina and Cryptosporidium share numerous molecular similarities, not only including coccidian-like features to the exclusion of Haemosporidia and Piroplasmida but also differ from each other significantly in their metabolic capacity.
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Affiliation(s)
- Thomas J Templeton
- Department of Microbiology and Immunology, Weill Cornell Medical College, USA
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Ramalho-Ortigão JM, Pitaluga AN, Telleria EL, Marques C, Souza AA, Traub-Cseko YM. Cloning and characterization of a V-ATPase subunit C from the American visceral leishmaniasis vector Lutzomyia longipalpis modulated during development and blood ingestion. Mem Inst Oswaldo Cruz 2008; 102:509-15. [PMID: 17607496 DOI: 10.1590/s0074-02762007000400013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2006] [Accepted: 03/07/2007] [Indexed: 11/22/2022] Open
Abstract
Visceral leishmaniasis (VL) is a serious tropical disease that affects approximately 500 thousand people worldwide every year. In the Americas, VL is caused by the parasite Leishmania (Leishmania) infantum chagasi mainly transmitted by the bite of the sand fly vector Lutzomyia longipalpis. Despite recent advances in the study of interaction between Leishmania and sand flies, very little is known about sand fly protein expression profiles. Understanding how the expression of proteins may be affected by blood feeding and/or presence of parasite in the vector's midgut might allow us to devise new strategies for controlling the spread of leishmaniasis. In this work, we report the characterization of a vacuolar ATPase subunit C from L. longipalpis by screening of a midgut cDNA library with a 220 bp fragment identified by means of differential display reverse transcriptase-polymerase chain reaction analysis. The expression of the gene varies along insect development and is upregulated in males and bloodfed L. longipalpis, compared to unfed flies.
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Affiliation(s)
- J M Ramalho-Ortigão
- Laboratório de Biologia Molecular de Tripanossomatídios e Flebotomíneos, Departamento de Bioquímica e Biologia Molecular, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, RJ, 21045-900, Brasil
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Hunke C, Chen WJ, Schäfer HJ, Grüber G. Cloning, purification, and nucleotide-binding traits of the catalytic subunit A of the V1VO ATPase from Aedes albopictus. Protein Expr Purif 2007; 53:378-83. [PMID: 17321148 DOI: 10.1016/j.pep.2007.01.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2006] [Revised: 01/11/2007] [Accepted: 01/12/2007] [Indexed: 11/30/2022]
Abstract
The Asian tiger mosquito, Aedes albopictus, is commonly infected by the gregarine parasite Ascogregarina taiwanensis, which develops extracellularly in the midgut of infected larvae. The intracellular trophozoites are usually confined within a parasitophorous vacuole, whose acidification is generated and controlled by the V(1)V(O) ATPase. This proton pump is driven by ATP hydrolysis, catalyzed inside the major subunit A. The subunit A encoding gene of the Aedes albopictus V(1)V(O) ATPase was cloned in pET9d1-His(3) and the recombinant protein, expressed in the Escherichia coli Rosetta 2 (DE3) strain, purified by immobilized metal affinity- and ion-exchange chromatography. The purified protein was soluble and properly folded. Analysis of secondary structure by circular dichroism spectroscopy showed that subunit A comprises 43% alpha-helix, 25% beta-sheet and 40% random coil content. The ability of subunit A of eukaryotic V-ATPases to bind ATP and/or ADP is demonstrated by photoaffinity labeling and fluorescence correlation spectroscopy (FCS). Quantitation of the FCS data indicates that the ADP-analogues bind slightly weaker to subunit A than the ATP-analogues. Tryptophan fluorescence quenching of subunit A after binding of different nucleotides provides evidence for secondary structural alterations in this subunit caused by nucleotide-binding.
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Affiliation(s)
- Cornelia Hunke
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
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Levin M. Is the early left-right axis like a plant, a kidney, or a neuron? The integration of physiological signals in embryonic asymmetry. ACTA ACUST UNITED AC 2006; 78:191-223. [PMID: 17061264 DOI: 10.1002/bdrc.20078] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Embryonic morphogenesis occurs along three orthogonal axes. While the patterning of the anterior-posterior and dorsal-ventral axes has been increasingly well-characterized, the left-right (LR) axis has only relatively recently begun to be understood at the molecular level. The mechanisms that ensure invariant LR asymmetry of the heart, viscera, and brain involve fundamental aspects of cell biology, biophysics, and evolutionary biology, and are important not only for basic science but also for the biomedicine of a wide range of birth defects and human genetic syndromes. The LR axis links biomolecular chirality to embryonic development and ultimately to behavior and cognition, revealing feedback loops and conserved functional modules occurring as widely as plants and mammals. This review focuses on the unique and fascinating physiological aspects of LR patterning in a number of vertebrate and invertebrate species, discusses several profound mechanistic analogies between biological regulation in diverse systems (specifically proposing a nonciliary parallel between kidney cells and the LR axis based on subcellular regulation of ion transporter targeting), highlights the possible importance of early, highly-conserved intracellular events that are magnified to embryo-wide scales, and lays out the most important open questions about the function, evolutionary origin, and conservation of mechanisms underlying embryonic asymmetry.
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Affiliation(s)
- Michael Levin
- Forsyth Center for Regenerative and Developmental Biology, The Forsyth Institute, and the Department of Developmental Biology, Harvard School of Dental Medicine, Boston, Massachusetts 02115, USA.
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