1
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Shokri Bousjein N, Tierney SM, Gardner MG, Schwarz MP. Does effective population size affect rates of molecular evolution: Mitochondrial data for host/parasite species pairs in bees suggests not. Ecol Evol 2022; 12:e8562. [PMID: 35154650 PMCID: PMC8820120 DOI: 10.1002/ece3.8562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 11/30/2021] [Accepted: 12/20/2021] [Indexed: 11/08/2022] Open
Abstract
Adaptive evolutionary theory argues that organisms with larger effective population size (N e) should have higher rates of adaptive evolution and therefore greater capacity to win evolutionary arm races. However, in some certain cases, species with much smaller N e may be able to survive besides their opponents for an extensive evolutionary time. Neutral theory predicts that accelerated rates of molecular evolution in organisms with exceedingly small N e are due to the effects of genetic drift and fixation of slightly deleterious mutations. We test this prediction in two obligate social parasite species and their respective host species from the bee tribe Allodapini. The parasites (genus Inquilina) have been locked into tight coevolutionary arm races with their exclusive hosts (genus Exoneura) for ~15 million years, even though Inquilina exhibit N e that are an order of magnitude smaller than their host. In this study, we compared rates of molecular evolution between host and parasite using nonsynonymous to synonymous substitution rate ratios (dN/dS) of eleven mitochondrial protein-coding genes sequenced from transcriptomes. Tests of selection on mitochondrial genes indicated no significant differences between host and parasite dN/dS, with evidence for purifying selection acting on all mitochondrial genes of host and parasite species. Several potential factors which could weaken the inverse relationship between N e and rate of molecular evolution are discussed.
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Affiliation(s)
- Nahid Shokri Bousjein
- College of Science and EngineeringFlinders UniversityAdelaideSouth AustraliaAustralia
- Faculty of Biological SciencesKharazmi UniversityTehranIran
| | - Simon M. Tierney
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityPenrithNew South WalesAustralia
| | - Michael G. Gardner
- College of Science and EngineeringFlinders UniversityAdelaideSouth AustraliaAustralia
- Evolutionary Biology Unit South Australian MuseumNorth Terrace AdelaideSouth AustraliaAustralia
| | - Michael P. Schwarz
- College of Science and EngineeringFlinders UniversityAdelaideSouth AustraliaAustralia
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2
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Tan WH, Talla V, Mongue AJ, de Roode JC, Gerardo NM, Walters JR. Population genomics reveals variable patterns of immune gene evolution in monarch butterflies (Danaus plexippus). Mol Ecol 2021; 30:4381-4391. [PMID: 34245613 DOI: 10.1111/mec.16071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Revised: 07/07/2021] [Accepted: 07/08/2021] [Indexed: 11/27/2022]
Abstract
Humoral and cellular immune responses provide animals with major defences against harmful pathogens. While it is often assumed that immune genes undergo rapid diversifying selection, this assumption has not been tested in many species. Moreover, it is likely that different classes of immune genes experience different levels of evolutionary constraint, resulting in varying selection patterns. We examined the evolutionary patterns for a set of 91 canonical immune genes of North American monarch butterflies (Danaus plexippus), using as an outgroup the closely related soldier butterfly (Danaus eresimus). As a comparison to these immune genes, we selected a set of control genes that were paired with each immune for approximate size and genomic location. As a whole, these immune genes had a significant but modest reduction in Tajima's D relative to paired-control genes, but otherwise did not show distinct patterns of population genetic variation or evolutionary rates. When further partitioning these immune genes into four functional classes (recognition, signalling, modulation, and effector), we found distinct differences among these groups. Relative to control genes, recognition genes exhibit increased nonsynonymous diversity and divergence, suggesting reduced constraints on evolution, and supporting the notion that coevolution with pathogens results in diversifying selection. In contrast, signalling genes showed an opposite pattern of reduced diversity and divergence, suggesting evolutionary constraints and conservation. Modulator and effector genes showed no statistical differences from controls. These results are consistent with patterns found in immune genes in fruit flies and Pieris butterflies, suggesting that consistent selective pressures on different classes of immune genes broadly govern the evolution of innate immunity among insects.
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Affiliation(s)
- Wen-Hao Tan
- Department of Biology, Emory University, Atlanta, GA, USA
| | - Venkat Talla
- Department of Biology, Emory University, Atlanta, GA, USA
| | - Andrew J Mongue
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS, USA
| | | | | | - James R Walters
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS, USA
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3
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A Population Genomic Investigation of Immune Cell Diversity and Phagocytic Capacity in a Butterfly. Genes (Basel) 2021; 12:genes12020279. [PMID: 33669297 PMCID: PMC7920040 DOI: 10.3390/genes12020279] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 02/12/2021] [Accepted: 02/13/2021] [Indexed: 12/27/2022] Open
Abstract
Insects rely on their innate immune system to successfully mediate complex interactions with their internal microbiota, as well as the microbes present in the environment. Given the variation in microbes across habitats, the challenges to respond to them are likely to result in local adaptations in the immune system. Here we focus upon phagocytosis, a mechanism by which pathogens and foreign particles are engulfed in order to be contained, killed, and processed. We investigated the phenotypic and genetic variation related to phagocytosis in two allopatric populations of the butterfly Pieris napi. Populations were found to differ in their hemocyte composition and overall phagocytic capability, driven by the increased phagocytic propensity of each cell type. Yet, genes annotated to phagocytosis showed no large genomic signal of divergence. However, a gene set enrichment analysis on significantly divergent genes identified loci involved in glutamine metabolism, which recently have been linked to immune cell differentiation in mammals. Together these results suggest that heritable variation in phagocytic capacity arises via a quantitative trait architecture with variation in genes affecting the activation and/or differentiation of phagocytic cells, suggesting them as potential candidate genes underlying these phenotypic differences.
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4
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Horton MB, Hawkins ED, Heinzel S, Hodgkin PD. Speculations on the evolution of humoral adaptive immunity. Immunol Cell Biol 2020; 98:439-448. [PMID: 32133683 PMCID: PMC7383592 DOI: 10.1111/imcb.12323] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Revised: 03/01/2020] [Accepted: 03/02/2020] [Indexed: 02/01/2023]
Abstract
The protection of a multicellular organism from infection, at both cell and humoral levels, has been a tremendous driver of gene selection and cellular response strategies. Here we focus on a critical event in the development of humoral immunity: The transition from principally innate responses to a system of adaptive cell selection, with all the attendant mechanical problems that must be solved in order for it to work effectively. Here we review recent advances, but our major goal is to highlight that the development of adaptive immunity resulted from the adoption, reuse and repurposing of an ancient, autonomous cellular program that combines and exploits three titratable cellular fate timers. We illustrate how this common cell machinery recurs and appears throughout biology, and has been essential for the evolution of complex organisms, at many levels of scale.
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Affiliation(s)
- Miles B Horton
- Division of Immunology, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia.,Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Edwin D Hawkins
- Division of Immunology, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia.,Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Susanne Heinzel
- Division of Immunology, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia.,Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Philip D Hodgkin
- Division of Immunology, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia.,Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia
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5
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Tissue Specificity in Social Context-Dependent lysozyme Expression in Bumblebees. Antibiotics (Basel) 2020; 9:antibiotics9030130. [PMID: 32245075 PMCID: PMC7148472 DOI: 10.3390/antibiotics9030130] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 02/02/2020] [Accepted: 02/05/2020] [Indexed: 11/27/2022] Open
Abstract
Group living at high densities may result in the enhanced transmission of pathogens. Social insects are obligate group-living species, which often also exhibit high relatedness and frequent social interactions amongst individuals, resulting in a high risk of disease spread. Social species seem to exhibit immune systems that provide colonies of social insects with a certain level of flexibility for adjustment of immune activity according to the risk of disease spread. In bumblebees, Bombus terrestris, it was demonstrated that in group-kept individuals, immune component activity and immune gene expression is increased, potentially as a prophylactic adaptation. Here, I tested whether social environment influences the gene expression pattern of two lysozyme genes, which are components of the antimicrobial response of the bumblebee. In addition, I tested gene expression activation in different tissues (gut, fat body). The analysis revealed that the gene, the density of individuals, the tissue, and the interaction of the latter are the main factors that influence the expression of lysozyme genes. This is the first report of a tissue-specific response towards the social environment. This has implications for gene regulation, which must be responsive to social context-dependent information.
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6
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Detecting coevolution of positively selected in turtles sperm-egg fusion proteins. Mech Dev 2019; 156:1-7. [DOI: 10.1016/j.mod.2019.02.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 02/15/2019] [Accepted: 02/15/2019] [Indexed: 12/12/2022]
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7
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Behrman EL, Howick VM, Kapun M, Staubach F, Bergland AO, Petrov DA, Lazzaro BP, Schmidt PS. Rapid seasonal evolution in innate immunity of wild Drosophila melanogaster. Proc Biol Sci 2019; 285:rspb.2017.2599. [PMID: 29321302 DOI: 10.1098/rspb.2017.2599] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Accepted: 12/05/2017] [Indexed: 12/12/2022] Open
Abstract
Understanding the rate of evolutionary change and the genetic architecture that facilitates rapid adaptation is a current challenge in evolutionary biology. Comparative studies show that genes with immune function are among the most rapidly evolving genes across a range of taxa. Here, we use immune defence in natural populations of Drosophila melanogaster to understand the rate of evolution in natural populations and the genetics underlying rapid change. We probed the immune system using the natural pathogens Enterococcus faecalis and Providencia rettgeri to measure post-infection survival and bacterial load of wild D. melanogaster populations collected across seasonal time along a latitudinal transect along eastern North America (Massachusetts, Pennsylvania and Virginia). There are pronounced and repeatable changes in the immune response over the approximately 10 generations between spring and autumn collections, with a significant but less distinct difference observed among geographical locations. Genes with known immune function are not enriched among alleles that cycle with seasonal time, but the immune function of a subset of seasonally cycling alleles in immune genes was tested using reconstructed outbred populations. We find that flies containing seasonal alleles in Thioester-containing protein 3 (Tep3) have different functional responses to infection and that epistatic interactions among seasonal Tep3 and Drosomycin-like 6 (Dro6) alleles underlie the immune phenotypes observed in natural populations. This rapid, cyclic response to seasonal environmental pressure broadens our understanding of the complex ecological and genetic interactions determining the evolution of immune defence in natural populations.
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Affiliation(s)
- Emily L Behrman
- Department of Biology, University of Pennsylvania, 433 S. University Ave., Philadelphia, PA 19104, USA
| | - Virginia M Howick
- Department of Entomology, Cornell University, 3125 Comstock Hall, Ithaca, NY 14853, USA
| | - Martin Kapun
- Department of Ecology and Evolution, University of Lausanne, Lausanne 1015, Switzerland
| | - Fabian Staubach
- Department of Biology, Stanford University, 371 Serra St, Stanford, CA 94305-5020, USA.,Albert-Ludwigs University, Freiburg, Germany
| | - Alan O Bergland
- Department of Biology, Stanford University, 371 Serra St, Stanford, CA 94305-5020, USA.,Department of Biology, University of Virginia, 409 McCormic Rd, Charlottesville, VA 22904, USA
| | - Dmitri A Petrov
- Department of Biology, Stanford University, 371 Serra St, Stanford, CA 94305-5020, USA
| | - Brian P Lazzaro
- Department of Entomology, Cornell University, 3125 Comstock Hall, Ithaca, NY 14853, USA
| | - Paul S Schmidt
- Department of Biology, University of Pennsylvania, 433 S. University Ave., Philadelphia, PA 19104, USA
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8
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Keehnen NL, Hill J, Nylin S, Wheat CW. Microevolutionary selection dynamics acting on immune genes of the green-veined white butterfly,Pieris napi. Mol Ecol 2018; 27:2807-2822. [DOI: 10.1111/mec.14722] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 04/08/2018] [Accepted: 04/23/2018] [Indexed: 12/15/2022]
Affiliation(s)
| | - Jason Hill
- Department of Zoology; Stockholm University; Stockholm Sweden
| | - Sören Nylin
- Department of Zoology; Stockholm University; Stockholm Sweden
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9
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Kozic M, Fox SJ, Thomas JM, Verma CS, Rigden DJ. Large scale ab initio modeling of structurally uncharacterized antimicrobial peptides reveals known and novel folds. Proteins 2018; 86:548-565. [DOI: 10.1002/prot.25473] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 01/16/2018] [Accepted: 01/29/2018] [Indexed: 12/20/2022]
Affiliation(s)
- Mara Kozic
- Institute of Integrative Biology, University of Liverpool; Liverpool L69 7ZB U.K
- Agency for Science, Technology and Research (A*STAR), Bioinformatics Institute; Singapore
| | - Stephen J. Fox
- Agency for Science, Technology and Research (A*STAR), Bioinformatics Institute; Singapore
| | - Jens M. Thomas
- Institute of Integrative Biology, University of Liverpool; Liverpool L69 7ZB U.K
| | - Chandra S. Verma
- Agency for Science, Technology and Research (A*STAR), Bioinformatics Institute; Singapore
- Department of Biological Sciences; National University of Singapore; Singapore
- School of Biological Sciences; Nanyang Technological University; Singapore
| | - Daniel J. Rigden
- Institute of Integrative Biology, University of Liverpool; Liverpool L69 7ZB U.K
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10
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Rolff J, Schmid-Hempel P. Perspectives on the evolutionary ecology of arthropod antimicrobial peptides. Philos Trans R Soc Lond B Biol Sci 2017; 371:rstb.2015.0297. [PMID: 27160599 DOI: 10.1098/rstb.2015.0297] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/23/2016] [Indexed: 12/27/2022] Open
Abstract
Antimicrobial peptides (AMPs) are important elements of the innate immune defence in multicellular organisms that target and kill microbes. Here, we reflect on the various points that are raised by the authors of the 11 contributions to a special issue of Philosophical Transactions on the 'evolutionary ecology of arthropod antimicrobial peptides'. We see five interesting topics emerging. (i) AMP genes in insects, and perhaps in arthropods more generally, evolve much slower than most other immune genes. One explanation refers to the constraints set by AMPs being part of a finely tuned defence system. A new view argues that AMPs are under strong stabilizing selection. Regardless, this striking observation still invites many more questions than have been answered so far. (ii) AMPs almost always are expressed in combinations and sometimes show expression patterns that are dependent on the infectious agent. While it is often assumed that this can be explained by synergistic interactions, such interactions have rarely been demonstrated and need to be studied further. Moreover, how to define synergy in the first place remains difficult and needs to be addressed. (iii) AMPs play a very important role in mediating the interaction between a host and its mutualistic or commensal microbes. This has only been studied in a very small number of (insect) species. It has become clear that the very same AMPs play different roles in different situations and hence are under concurrent selection. (iv) Different environments shape the physiology of organisms; especially the host-associated microbial communities should impact on the evolution host AMPs. Studies in social insects and some organisms from extreme environments seem to support this notion, but, overall, the evidence for adaptation of AMPs to a given environment is scant. (v) AMPs are considered or already developed as new drugs in medicine. However, bacteria can evolve resistance to AMPs. Therefore, in the light of our limited understanding of AMP evolution in the natural context, and also the very limited understanding of the evolution of resistance against AMPs in bacteria in particular, caution is recommended. What is clear though is that study of the ecology and evolution of AMPs in natural systems could inform many of these outstanding questions, including those related to medical applications and pathogen control.This article is part of the themed issue 'Evolutionary ecology of arthropod antimicrobial peptides'.
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Affiliation(s)
- Jens Rolff
- Evolutionary Biology, Institute of Biology, Freie Universität Berlin, Königin-Luise-Strasse 1-3, 14195 Berlin, Germany Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), 14195 Berlin, Germany
| | - Paul Schmid-Hempel
- ETH Zürich, Institute of Integrative Biology (IBZ), ETH-Zentrum CHN, Universitätsstrasse 16, 8092 Zürich, Switzerland
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11
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Yuan J, Zhang X, Liu C, Duan H, Li F, Xiang J. Convergent Evolution of the Osmoregulation System in Decapod Shrimps. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2017; 19:76-88. [PMID: 28204969 DOI: 10.1007/s10126-017-9729-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 01/09/2017] [Indexed: 06/06/2023]
Abstract
In adaptating to different aquatic environments, seawater (SW) and freshwater (FW) shrimps have exploited different adaptation strategies, which should generate clusters of genes with different adaptive features. However, little is known about the genetic basis of these physiological adaptations. Thus, in this study, we performed comparative transcriptomics and adaptive evolution analyses on SW and FW shrimps and found that convergent evolution may have happened on osmoregulation system of shrimps. We identified 275 and 234 positively selected genes in SW and FW shrimps, respectively, which enriched in the functions of ion-binding and membrane-bounded organelles. Among them, five (CaCC, BEST2, GPDH, NKA, and Integrin) and four (RasGAP, RhoGDI, CNK3, and ODC) osmoregulation-related genes were detected in SW and FW shrimps, respectively. All five genes in SW shrimps have been reported to have positive effects on ion transportation, whereas RasGAP and RhoGDI in FW shrimps are associated with negative control of ion transportation, and CNK3 and ODC play central roles in cation homeostasis. Besides, the phylogenetic tree reconstructed from the positively selected sites separated the SW and FW shrimps into two groups. Distinct subsets of parallel substitutions also have been found in these osmoregulation-related genes in SW and FW shrimps. Therefore, our results suggest that distinct convergent evolution may have occurred in the osmoregulation systems of SW and FW shrimps. Furthermore, positive selection of osmoregulation-related genes may be beneficial for the regulation of water and salt balance in decapod shrimps.
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Affiliation(s)
- Jianbo Yuan
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7, Nanhai Road, Qingdao, 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China
| | - Xiaojun Zhang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7, Nanhai Road, Qingdao, 266071, China.
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China.
| | - Chengzhang Liu
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7, Nanhai Road, Qingdao, 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China
| | - Hu Duan
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7, Nanhai Road, Qingdao, 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China
| | - Fuhua Li
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7, Nanhai Road, Qingdao, 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China
| | - Jianhai Xiang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7, Nanhai Road, Qingdao, 266071, China.
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China.
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12
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Survey of Global Genetic Diversity Within the Drosophila Immune System. Genetics 2016; 205:353-366. [PMID: 27815361 DOI: 10.1534/genetics.116.195016] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 10/28/2016] [Indexed: 11/18/2022] Open
Abstract
Numerous studies across a wide range of taxa have demonstrated that immune genes are routinely among the most rapidly evolving genes in the genome. This observation, however, does not address what proportion of immune genes undergo strong selection during adaptation to novel environments. Here, we determine the extent of very recent divergence in genes with immune function across five populations of Drosophila melanogaster and find that immune genes do not show an overall trend of recent rapid adaptation. Our population-based approach uses a set of carefully matched control genes to account for the effects of demography and local recombination rate, allowing us to identify whether specific immune functions are putative targets of strong selection. We find evidence that viral-defense genes are rapidly evolving in Drosophila at multiple timescales. Local adaptation to bacteria and fungi is less extreme and primarily occurs through changes in recognition and effector genes rather than large-scale changes to the regulation of the immune response. Surprisingly, genes in the Toll pathway, which show a high rate of adaptive substitution between the D. melanogaster and D. simulans lineages, show little population differentiation. Quantifying the flies for resistance to a generalist Gram-positive bacterial pathogen, we found that this genetic pattern of low population differentiation was recapitulated at the phenotypic level. In sum, our results highlight the complexity of immune evolution and suggest that Drosophila immune genes do not follow a uniform trajectory of strong directional selection as flies encounter new environments.
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13
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Lattorff HMG, Popp M, Parsche S, Helbing S, Erler S. Effective population size as a driver for divergence of an antimicrobial peptide (Hymenoptaecin) in two common European bumblebee species. Biol J Linn Soc Lond 2016. [DOI: 10.1111/bij.12835] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- H. Michael G. Lattorff
- Institut für Biologie; Molekulare Ökologie; Martin-Luther-Universität Halle-Wittenberg; Hoher Weg 4 06099 Halle (Saale) Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig; Deutscher Platz 5e; Leipzig 04103 Germany
| | - Mario Popp
- Institut für Biologie; Molekulare Ökologie; Martin-Luther-Universität Halle-Wittenberg; Hoher Weg 4 06099 Halle (Saale) Germany
| | - Susann Parsche
- Institut für Biologie; Molekulare Ökologie; Martin-Luther-Universität Halle-Wittenberg; Hoher Weg 4 06099 Halle (Saale) Germany
| | - Sophie Helbing
- Institut für Biologie; Molekulare Ökologie; Martin-Luther-Universität Halle-Wittenberg; Hoher Weg 4 06099 Halle (Saale) Germany
| | - Silvio Erler
- Institut für Biologie; Molekulare Ökologie; Martin-Luther-Universität Halle-Wittenberg; Hoher Weg 4 06099 Halle (Saale) Germany
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14
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Unckless RL, Lazzaro BP. The potential for adaptive maintenance of diversity in insect antimicrobial peptides. Philos Trans R Soc Lond B Biol Sci 2016; 371:20150291. [PMID: 27160594 PMCID: PMC4874389 DOI: 10.1098/rstb.2015.0291] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/12/2016] [Indexed: 02/07/2023] Open
Abstract
Genes involved in immune defence are among the fastest evolving in the genomes of many species. Interestingly, however, genes encoding antimicrobial peptides (AMPs) have shown little evidence for adaptive divergence in arthropods, despite the centrality of these peptides in direct killing of microbial pathogens. This observation, coupled with a failure to detect phenotypic consequence of genetic variation in AMPs, has led to the hypothesis that individual AMPs make minor contributions to overall immune defence and that AMPs instead act as a collective cocktail. Recent data, however, have suggested an alternative explanation for the apparent lack of adaptive divergence in AMP genes. Molecular evolutionary and phenotypic data have begun to suggest that variant AMP alleles may be maintained through balancing selection in invertebrates, a pattern similar to that observed in several vertebrate AMPs. Signatures of balancing selection include high rates of non-synonymous polymorphism, trans-species amino acid polymorphisms, and convergence of amino acid states across the phylogeny. In this review, we revisit published literature on insect AMP genes and analyse newly available population genomic datasets in Drosophila, finding enrichment for patterns consistent with adaptive maintenance of polymorphism.This article is part of the themed issue 'Evolutionary ecology of arthropod antimicrobial peptides'.
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Affiliation(s)
| | - Brian P Lazzaro
- Department of Entomology, Cornell University, Ithaca, NY 14853, USA
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15
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Marxer M, Vollenweider V, Schmid-Hempel P. Insect antimicrobial peptides act synergistically to inhibit a trypanosome parasite. Philos Trans R Soc Lond B Biol Sci 2016; 371:20150302. [PMID: 27160603 PMCID: PMC4874398 DOI: 10.1098/rstb.2015.0302] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/08/2016] [Indexed: 11/12/2022] Open
Abstract
The innate immune system provides protection from infection by producing essential effector molecules, such as antimicrobial peptides (AMPs) that possess broad-spectrum activity. This is also the case for bumblebees, Bombus terrestris, when infected by the trypanosome, Crithidia bombi Furthermore, the expressed mixture of AMPs varies with host genetic background and infecting parasite strain (genotype). Here, we used the fact that clones of C. bombi can be cultivated and kept as strains in medium to test the effect of various combinations of AMPs on the growth rate of the parasite. In particular, we used pairwise combinations and a range of physiological concentrations of three AMPs, namely Abaecin, Defensin and Hymenoptaecin, synthetized from the respective genomic sequences. We found that these AMPs indeed suppress the growth of eight different strains of C. bombi, and that combinations of AMPs were typically more effective than the use of a single AMP alone. Furthermore, the most effective combinations were rarely those consisting of maximum concentrations. In addition, the AMP combination treatments revealed parasite strain specificity, such that strains varied in their sensitivity towards the same mixtures. Hence, variable expression of AMPs could be an alternative strategy to combat highly variable infections.This article is part of the themed issue 'Evolutionary ecology of arthropod antimicrobial peptides'.
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Affiliation(s)
- Monika Marxer
- ETH Zurich, Institute of Integrative Biology (IBZ), Universitätsstrasse 16, 8092 Zürich, Switzerland
| | - Vera Vollenweider
- ETH Zurich, Institute of Integrative Biology (IBZ), Universitätsstrasse 16, 8092 Zürich, Switzerland
| | - Paul Schmid-Hempel
- ETH Zurich, Institute of Integrative Biology (IBZ), Universitätsstrasse 16, 8092 Zürich, Switzerland
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16
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Patterns of molecular evolution of RNAi genes in social and socially parasitic bumblebees. INFECTION GENETICS AND EVOLUTION 2016; 42:53-9. [PMID: 27117935 DOI: 10.1016/j.meegid.2016.04.028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 04/19/2016] [Accepted: 04/22/2016] [Indexed: 01/16/2023]
Abstract
The high frequency of interactions amongst closely related individuals in social insect colonies enhances pathogen transmission. Group-mediated behavior supporting immune defenses tends to decrease selection acting on immune genes. Along with low effective population sizes this might result in relaxed constraint and rapid evolution of immune system genes. Here, we show that antiviral siRNA genes show high rates of molecular evolution with argonaute 2, armitage and maelstrom evolving faster in social bumblebees compared to their socially parasitic cuckoo bumblebees that lack a worker caste. RNAi genes show frequent positive selection at the codon level additionally supported by the occurrence of parallel evolution. Their evolutionary rate is linked to their pathway specific position with genes directly interacting with viruses showing the highest rates of molecular evolution. We suggest that higher pathogen load in social insects indeed drives the molecular evolution of immune genes including antiviral siRNA, if not compensated by behavior.
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Shokri Bousjein N, Gardner MG, Schwarz MP. Small effective population sizes of bee social parasites compared to their hosts raise important questions for evolutionary arms race. J Zool (1987) 2016. [DOI: 10.1111/jzo.12325] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - M. G. Gardner
- Biological Sciences Flinders University Adelaide SA Australia
- Evolutionary Biology Unit South Australian Museum Adelaide SA Australia
| | - M. P. Schwarz
- Biological Sciences Flinders University Adelaide SA Australia
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18
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Zare-Zardini H, Taheri-Kafrani A, Ordooei M, Ebrahimi L, Tolueinia B, Soleimanizadeh M. Identification and biochemical characterization of a new antibacterial and antifungal peptide derived from the insect Sphodromantis viridis. BIOCHEMISTRY (MOSCOW) 2016; 80:433-40. [PMID: 25869360 DOI: 10.1134/s0006297915040069] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Antimicrobial peptides are members of the immune system that protect the host from infection. In this study, a potent and structurally novel antimicrobial peptide was isolated and characterized from praying mantis Sphodromantis viridis. This 14-amino acid peptide was purified by RP-HPLC. Tandem mass spectrometry was used for sequencing this peptide, and the results showed that the peptide belongs to the Mastoparan family. The peptide was named Mastoparan-S. Mastoparan-S demonstrated that it has antimicrobial activities against a broad spectrum of microorganisms (Gram-positive and Gram-negative bacteria and fungi), and it was found to be more potent than common antibiotics such as kanamycin. Mastoparan-S showed higher antimicrobial activity against Gram-negative bacteria compared to Gram-positive ones and fungi. The minimum inhibitory concentration (MIC) values of Mastoparan-S are 15.1-28.3 µg/ml for bacterial and 19.3-24.6 µg/ml for fungal pathogens. In addition, this newly described peptide showed low hemolytic activity against human red blood cells. The in vitro cytotoxicity of Mastoparan-S was also evaluated on monolayer of normal human cells (HeLa) by MTT assay, and the results illustrated that Mastoparan-S had significant cytotoxicity at concentrations higher than 40 µg/ml and had no any cytotoxicity at the MIC (≤30 µg/ml). The findings of the present study reveal that this newly described peptide can be introduced as an appropriate candidate for treatment of topical infection.
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Affiliation(s)
- Hadi Zare-Zardini
- Young Researchers and Elite Club, Yazd Branch, Islamic Azad University, Yazd, Iran
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19
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Barribeau SM, Sadd BM, du Plessis L, Brown MJF, Buechel SD, Cappelle K, Carolan JC, Christiaens O, Colgan TJ, Erler S, Evans J, Helbing S, Karaus E, Lattorff HMG, Marxer M, Meeus I, Näpflin K, Niu J, Schmid-Hempel R, Smagghe G, Waterhouse RM, Yu N, Zdobnov EM, Schmid-Hempel P. A depauperate immune repertoire precedes evolution of sociality in bees. Genome Biol 2015; 16:83. [PMID: 25908406 PMCID: PMC4408586 DOI: 10.1186/s13059-015-0628-y] [Citation(s) in RCA: 112] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 03/11/2015] [Indexed: 11/10/2022] Open
Abstract
Background Sociality has many rewards, but can also be dangerous, as high population density and low genetic diversity, common in social insects, is ideal for parasite transmission. Despite this risk, honeybees and other sequenced social insects have far fewer canonical immune genes relative to solitary insects. Social protection from infection, including behavioral responses, may explain this depauperate immune repertoire. Here, based on full genome sequences, we describe the immune repertoire of two ecologically and commercially important bumblebee species that diverged approximately 18 million years ago, the North American Bombus impatiens and European Bombus terrestris. Results We find that the immune systems of these bumblebees, two species of honeybee, and a solitary leafcutting bee, are strikingly similar. Transcriptional assays confirm the expression of many of these genes in an immunological context and more strongly in young queens than males, affirming Bateman’s principle of greater investment in female immunity. We find evidence of positive selection in genes encoding antiviral responses, components of the Toll and JAK/STAT pathways, and serine protease inhibitors in both social and solitary bees. Finally, we detect many genes across pathways that differ in selection between bumblebees and honeybees, or between the social and solitary clades. Conclusions The similarity in immune complement across a gradient of sociality suggests that a reduced immune repertoire predates the evolution of sociality in bees. The differences in selection on immune genes likely reflect divergent pressures exerted by parasites across social contexts. Electronic supplementary material The online version of this article (doi:10.1186/s13059-015-0628-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Seth M Barribeau
- Experimental Ecology, Institute of Integrative Biology, ETH Zürich, CH-8092, Zürich, Switzerland. .,Department of Biology, East Carolina University, Greenville, NC, 27858, USA.
| | - Ben M Sadd
- Experimental Ecology, Institute of Integrative Biology, ETH Zürich, CH-8092, Zürich, Switzerland. .,School of Biological Sciences, Illinois State University, Normal, IL, 61790, USA.
| | - Louis du Plessis
- Theoretical Biology, Institute of Integrative Biology, ETH Zürich, CH-8092, Zürich, Switzerland. .,Computational Evolution, Department of Biosystems Science and Evolution, ETH Zürich, 4058, Basel, Switzerland. .,Swiss Institute of Bioinformatics, 1211, Lausanne, Switzerland.
| | - Mark J F Brown
- School of Biological Sciences, Royal Holloway University of London, London, TW20 0EX, UK.
| | - Severine D Buechel
- Experimental Ecology, Institute of Integrative Biology, ETH Zürich, CH-8092, Zürich, Switzerland.
| | - Kaat Cappelle
- Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, 9000, Ghent, Belgium.
| | - James C Carolan
- Maynooth University Department of Biology, Maynooth University, Maynooth, Kildare, Ireland.
| | - Olivier Christiaens
- Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, 9000, Ghent, Belgium.
| | - Thomas J Colgan
- Department of Zoology, School of Natural Sciences, Trinity College Dublin, Dublin, 2, Ireland. .,School of Biological and Chemical Sciences, Queen Mary University of London, E1 41NS, London, UK.
| | - Silvio Erler
- Department of Apiculture and Sericulture, University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca, Cluj-Napoca, 400372, Romania. .,Institut für Biologie, Molekulare Ökologie, Martin-Luther-Universität Halle-Wittenberg, Wittenberg, 06120, Germany.
| | - Jay Evans
- USDA-ARS Bee Research Laboratory, Beltsville, MD, 20705, USA.
| | - Sophie Helbing
- Institut für Biologie, Molekulare Ökologie, Martin-Luther-Universität Halle-Wittenberg, Wittenberg, 06120, Germany.
| | - Elke Karaus
- Experimental Ecology, Institute of Integrative Biology, ETH Zürich, CH-8092, Zürich, Switzerland.
| | - H Michael G Lattorff
- Institut für Biologie, Molekulare Ökologie, Martin-Luther-Universität Halle-Wittenberg, Wittenberg, 06120, Germany. .,German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, 04103, Leipzig, Germany. .,Institut für Biologie, Tierphysiologie, Martin-Luther-Universität Halle-Wittenberg, Wittenberg, 06099, Germany.
| | - Monika Marxer
- Experimental Ecology, Institute of Integrative Biology, ETH Zürich, CH-8092, Zürich, Switzerland.
| | - Ivan Meeus
- Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, 9000, Ghent, Belgium.
| | - Kathrin Näpflin
- Experimental Ecology, Institute of Integrative Biology, ETH Zürich, CH-8092, Zürich, Switzerland.
| | - Jinzhi Niu
- Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, 9000, Ghent, Belgium. .,College of Plant Protection, Southwest University, Chongqing, 400716, PR China.
| | - Regula Schmid-Hempel
- Experimental Ecology, Institute of Integrative Biology, ETH Zürich, CH-8092, Zürich, Switzerland.
| | - Guy Smagghe
- Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, 9000, Ghent, Belgium. .,College of Plant Protection, Southwest University, Chongqing, 400716, PR China.
| | - Robert M Waterhouse
- Swiss Institute of Bioinformatics, 1211, Lausanne, Switzerland. .,Department of Genetic Medicine and Development, University of Geneva Medical School, 1211, Geneva, Switzerland. .,Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA. .,The Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA.
| | - Na Yu
- Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, 9000, Ghent, Belgium.
| | - Evgeny M Zdobnov
- Swiss Institute of Bioinformatics, 1211, Lausanne, Switzerland. .,Department of Genetic Medicine and Development, University of Geneva Medical School, 1211, Geneva, Switzerland.
| | - Paul Schmid-Hempel
- Experimental Ecology, Institute of Integrative Biology, ETH Zürich, CH-8092, Zürich, Switzerland.
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