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Chen J, Setia G, Lin LH, Sun Q, Husseneder C. Weight and protozoa number but not bacteria diversity are associated with successful pair formation of dealates in the Formosan subterranean termite, Coptotermes formosanus. PLoS One 2023; 18:e0293813. [PMID: 37956140 PMCID: PMC10642788 DOI: 10.1371/journal.pone.0293813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 10/19/2023] [Indexed: 11/15/2023] Open
Abstract
New colonies of Formosan subterranean termites are founded by monogamous pairs. During swarming season, alates (winged reproductives) leave their parental colony. After swarming, they drop to the ground, shed their wings, and male and female dealates find suitable nesting sites where they mate and become kings and queens of new colonies. The first generation of offspring is entirely dependent on the nutritional resources of the founder pair consisting of the fat and protein reserves of the dealates and their microbiota, which include the cellulose-digesting protozoa and diverse bacteria. Since termite kings and queens can live for decades, mate for life and colony success is linked to those initial resources, we hypothesized that gut microbiota of founders affect pair formation. To test this hypothesis, we collected pairs found in nest chambers and single male and female dealates from four swarm populations. The association of three factors (pairing status, sex of the dealates and population) with dealate weights, total protozoa, and protozoa Pseudotrichonympha grassii numbers in dealate hindguts was determined. In addition, Illumina 16S rRNA gene sequencing and the QIIME2 pipeline were used to determine the impact of those three factors on gut bacteria diversity of dealates. Here we report that pairing status was significantly affected by weight and total protozoa numbers, but not by P. grassii numbers and bacteria diversity. Weight and total protozoa numbers were higher in paired compared to single dealates. Males contained significantly higher P. grassii numbers and bacteria richness and marginally higher phylogenetic diversity despite having lower weights than females. In conclusion, this study showed that dealates with high body weight and protozoa numbers are more likely to pair and become colony founders, probably because of competitive advantage. The combined nutritional resources provided by body weight and protozoa symbionts of the parents are important for successful colony foundation and development.
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Affiliation(s)
- Junyan Chen
- Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, Los Angeles, United States of America
| | - Garima Setia
- Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, Los Angeles, United States of America
| | - Li-Hsiang Lin
- Department of Experimental Statistics, Louisiana State University Agricultural Center, Baton Rouge, Los Angeles, United States of America
| | - Qian Sun
- Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, Los Angeles, United States of America
| | - Claudia Husseneder
- Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, Los Angeles, United States of America
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Nicolas P, Kiuru C, Wagah MG, Muturi M, Duthaler U, Hammann F, Maia M, Chaccour C. Potential metabolic resistance mechanisms to ivermectin in Anopheles gambiae: a synergist bioassay study. Parasit Vectors 2021; 14:172. [PMID: 33743783 PMCID: PMC7981804 DOI: 10.1186/s13071-021-04675-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 03/07/2021] [Indexed: 11/10/2022] Open
Abstract
Background Despite remarkable success obtained with current malaria vector control strategies in the last 15 years, additional innovative measures will be needed to achieve the ambitious goals for malaria control set for 2030 by the World Health Organization (WHO). New tools will need to address insecticide resistance and residual transmission as key challenges. Endectocides such as ivermectin are drugs that kill mosquitoes which feed on treated subjects. Mass administration of ivermectin can effectively target outdoor and early biting vectors, complementing the still effective conventional tools. Although this approach has garnered attention, development of ivermectin resistance is a potential pitfall. Herein, we evaluate the potential role of xenobiotic pumps and cytochrome P450 enzymes in protecting mosquitoes against ivermectin by active efflux and metabolic detoxification, respectively. Methods We determined the lethal concentration 50 for ivermectin in colonized Anopheles gambiae; then we used chemical inhibitors and inducers of xenobiotic pumps and cytochrome P450 enzymes in combination with ivermectin to probe the mechanism of ivermectin detoxification. Results Dual inhibition of xenobiotic pumps and cytochromes was found to have a synergistic effect with ivermectin, greatly increasing mosquito mortality. Inhibition of xenobiotic pumps alone had no effect on ivermectin-induced mortality. Induction of xenobiotic pumps and cytochromes may confer partial protection from ivermectin. Conclusion There is a clear pathway for development of ivermectin resistance in malaria vectors. Detoxification mechanisms mediated by cytochrome P450 enzymes are more important than xenobiotic pumps in protecting mosquitoes against ivermectin.![]()
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Affiliation(s)
- Patricia Nicolas
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Rosello 132, 5ª 2ª, 08036, Barcelona, Spain.,Centro de Investigação em Saúde de Manhiça, 1929, Maputo, Mozambique
| | - Caroline Kiuru
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Rosello 132, 5ª 2ª, 08036, Barcelona, Spain.,Centro de Investigação em Saúde de Manhiça, 1929, Maputo, Mozambique
| | - Martin G Wagah
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, CB10 91SA, UK.,Department of Biosciences, KEMRI Wellcome Trust Research Programme, Kilifi, 230-80108, Kenya
| | - Martha Muturi
- Department of Biosciences, KEMRI Wellcome Trust Research Programme, Kilifi, 230-80108, Kenya
| | - Urs Duthaler
- Division of Clinical Pharmacology and Toxicology, Department of Biomedicine, University and University Hospital Basel, 4056, Basel, Switzerland.,Division of Clinical Pharmacology and Toxicology, Department of Pharmaceutical Sciences, University of Basel, 4056, Basel, Switzerland
| | - Felix Hammann
- Division of Clinical Pharmacology and Toxicology, Department of Internal Medicine, University Hospital Bern, 3010, Bern, Switzerland
| | - Marta Maia
- Department of Biosciences, KEMRI Wellcome Trust Research Programme, Kilifi, 230-80108, Kenya.,Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Carlos Chaccour
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Rosello 132, 5ª 2ª, 08036, Barcelona, Spain. .,Ifakara Health Institute, Ifakara, 67501, United Republic of Tanzania. .,Facultad de Medicina, Universidad de Navarra, 31008, Pamplona, Spain.
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Scharf ME, Peterson BF. A Century of Synergy in Termite Symbiosis Research: Linking the Past with New Genomic Insights. ANNUAL REVIEW OF ENTOMOLOGY 2021; 66:23-43. [PMID: 33417825 DOI: 10.1146/annurev-ento-022420-074746] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Termites have long been studied for their symbiotic associations with gut microbes. In the late nineteenth century, this relationship was poorly understood and captured the interest of parasitologists such as Joseph Leidy; this research led to that of twentieth-century biologists and entomologists including Cleveland, Hungate, Trager, and Lüscher. Early insights came via microscopy, organismal, and defaunation studies, which led to descriptions of microbes present, descriptions of the roles of symbionts in lignocellulose digestion, and early insights into energy gas utilization by the host termite. Focus then progressed to culture-dependent microbiology and biochemical studies of host-symbiont complementarity, which revealed specific microhabitat requirements for symbionts and noncellulosic mechanisms of symbiosis (e.g., N2 fixation). Today, knowledge on termite symbiosis has accrued exponentially thanks to omic technologies that reveal symbiont identities, functions, and interdependence, as well as intricacies of host-symbiont complementarity. Moving forward, the merging of classical twentieth-century approaches with evolving omic tools should provide even deeper insights into host-symbiont interplay.
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Affiliation(s)
- Michael E Scharf
- Department of Entomology, Purdue University, West Lafayette, Indiana 47907, USA;
| | - Brittany F Peterson
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, Illinois 62026, USA;
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Wu W, Gu D, Yan S, Li Z. RNA interference of endoglucanases in the formosan subterranean termite Coptotermes formosanus shiraki (Blattodea: Rhinotermitidae) by dsRNA injection or ingestion. JOURNAL OF INSECT PHYSIOLOGY 2019; 112:15-22. [PMID: 30472007 DOI: 10.1016/j.jinsphys.2018.11.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 11/14/2018] [Accepted: 11/21/2018] [Indexed: 06/09/2023]
Abstract
Termites obtain energy and nutrition from wood and wood-related materials by utilizing endogenous and symbiotic cellulases. Endoglucanase is one of the key cellulases in cellulose digestion. Previous studies have shown that the inhibition of the cellulase enzyme system would be a plausible approach for termite control. In the present study, we studied the effect of RNAi on termites by targeting a conserved region of five endoglucanase genes from Coptotermes formosanus (CfEGs). Both dsRNA injection and oral delivery resulted in significant gene silencing of CfEGs and consequently led to mortality, reduced enzyme activity, and reduced weight compared to control worker termites. An injection dose of 150 ng and a feeding dose of 2 μg/cm2 provided for the best RNAi efficiency. dsCfEG was further combined with flufenoxuron, an insect growth regulator used to manage/suppress subterranean termites, and when fed to workers, caused a lower enzyme activity compared to the dsCfEG- or flufenoxuron-only treatment. The weight loss (∼0.598 mg) and mortality (∼28%) observed in the combined dsCfEG and flufenoxuron treatment differed significantly from those observed in the flufenoxuron-only treatment (∼0.208 mg and ∼16%, respectively). Although the effects of these dsCfEG treatments on mortality were insufficient to serve as termiticides, dsCfEGs could be used in combination with other treatments to increase efficacy. This study provides a research basis for the use of RNAi in termiticides.
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Affiliation(s)
- Wenjing Wu
- Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Guangdong Institute of Applied Biological Resources, 105 Xingang Road West, Guangzhou 510260, PR China
| | - Daifei Gu
- College of Forestry, Northeast Forestry University, No. 26, Hexing Road, Harbin 150040, PR China
| | - Shanchun Yan
- College of Forestry, Northeast Forestry University, No. 26, Hexing Road, Harbin 150040, PR China
| | - Zhiqiang Li
- Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Guangdong Institute of Applied Biological Resources, 105 Xingang Road West, Guangzhou 510260, PR China.
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Wu W, Li Z. dsRNA Injection Successfully Inhibited Two Endogenous β-Glucosidases in Coptotermes formosanus (Isoptera: Rhinotermitidae). JOURNAL OF ECONOMIC ENTOMOLOGY 2018; 111:860-867. [PMID: 29360999 DOI: 10.1093/jee/tox371] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Indexed: 06/07/2023]
Abstract
Cellulose digestion is an essential process of termites, and it is accomplished by three types of cellulases. β-Glucosidase (BG), one of the critical cellulases responsible for cellulose degradation and glucose production, has been considered as a potential target for pest management strategies. Previous experiments identified two new endogenous BG homologs, CfBG-Ia and CfBG-Ib, in the digestive system of Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae). The objectives of this study were to assess the impact of RNA interference on CfBG-Ia and CfBG-Ib expression and on termite survival. We tested the expression profiles of worker termites which were injected with gene-specific double-stranded RNA (dsRNA, targeting one gene at a time) and a dsRNA cocktail (targeting CfBG-Ia and CfBG-Ib simultaneously). The expression of CfBG-Ib showed a sharp decline in both dsCfBG-Ib and dsRNA cocktail treatments. The expression of CfBG-Ia reduced quickly and significantly in the dsRNA cocktail treatment; while in dsCfBG-Ia treatment, it decreased on the fifth day. Results showed that treatment with the dsRNA cocktail caused greater inhibition of the transcript expression and a shorter response time. However, the expression of nontarget BG homologs was increased as the target BG homologs were being repressed during the testing period in dsRNA cocktail treatment. These results demonstrate that targeting cellulase-coding genes may be a potential strategy to inhibit termite digestion process, or at least dsRNA cocktails serve as a means for identifying the most susceptible target gene families or biological processes.
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Affiliation(s)
- Wenjing Wu
- Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Guangdong Institute of Applied Biological Resources, Guangzhou, Guangdong, China
| | - Zhiqiang Li
- Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Guangdong Institute of Applied Biological Resources, Guangzhou, Guangdong, China
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