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Calamari ZT, Song A, Cohen E, Akter M, Roy RD, Hallikas O, Christensen MM, Li P, Marangoni P, Jernvall J, Klein OD. Vole genomics links determinate and indeterminate growth of teeth. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.12.18.572015. [PMID: 38187646 PMCID: PMC10769287 DOI: 10.1101/2023.12.18.572015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Continuously growing teeth are an important innovation in mammalian evolution, yet genetic regulation of continuous growth by stem cells remains incompletely understood. Dental stem cells responsible for tooth crown growth are lost at the onset of tooth root formation. Genetic signaling that initiates this loss is difficult to study with the ever-growing incisor and rooted molars of mice, the most common mammalian dental model species, because signals for root formation overlap with signals that pattern tooth size and shape (i.e., cusp patterns). Different species of voles (Cricetidae, Rodentia, Glires) have evolved rooted and unrooted molars that have similar size and shape, providing alternative models for studying roots. We assembled a de novo genome of Myodes glareolus, a vole with high-crowned, rooted molars, and performed genomic and transcriptomic analyses in a broad phylogenetic context of Glires (rodents and lagomorphs) to assess differential selection and evolution in tooth forming genes. We identified 15 dental genes with changing synteny relationships and six dental genes undergoing positive selection across Glires, two of which were undergoing positive selection in species with unrooted molars, Dspp and Aqp1. Decreased expression of both genes in prairie voles with unrooted molars compared to bank voles supports the presence of positive selection and may underlie differences in root formation. Bulk transcriptomics analyses of embryonic molar development in bank voles also demonstrated conserved patterns of dental gene expression compared to mice, with species-specific variation likely related to developmental timing and morphological differences between mouse and vole molars. Our results support ongoing evolution of dental genes across Glires, revealing the complex evolutionary background of convergent evolution for ever-growing molars.
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Affiliation(s)
- Zachary T. Calamari
- Baruch College, City University of New York, One Bernard Baruch Way, New York, NY 10010, USA
- The Graduate Center, City University of New York, 365 Fifth Ave, New York, NY 10016, USA
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California, San Francisco, San Francisco, CA 94158, USA
- Division of Paleontology, American Museum of Natural History, Central Park West at 79th Street, New York, NY, 10024, USA
| | - Andrew Song
- Baruch College, City University of New York, One Bernard Baruch Way, New York, NY 10010, USA
- Cornell University, 616 Thurston Ave, Ithaca, NY 14853, USA
| | - Emily Cohen
- Baruch College, City University of New York, One Bernard Baruch Way, New York, NY 10010, USA
- New York University College of Dentistry, 345 E 34th St, New York, NY 10010
| | - Muspika Akter
- Baruch College, City University of New York, One Bernard Baruch Way, New York, NY 10010, USA
| | - Rishi Das Roy
- Institute of Biotechnology, University of Helsinki, FI-00014 Helsinki, Finland
| | - Outi Hallikas
- Institute of Biotechnology, University of Helsinki, FI-00014 Helsinki, Finland
| | - Mona M. Christensen
- Institute of Biotechnology, University of Helsinki, FI-00014 Helsinki, Finland
| | - Pengyang Li
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California, San Francisco, San Francisco, CA 94158, USA
- Department of Pediatrics, Cedars-Sinai Guerin Children’s, 8700 Beverly Blvd., Suite 2416, Los Angeles, CA 90048, USA
| | - Pauline Marangoni
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California, San Francisco, San Francisco, CA 94158, USA
- Department of Pediatrics, Cedars-Sinai Guerin Children’s, 8700 Beverly Blvd., Suite 2416, Los Angeles, CA 90048, USA
| | - Jukka Jernvall
- Institute of Biotechnology, University of Helsinki, FI-00014 Helsinki, Finland
- Department of Geosciences and Geography, University of Helsinki, FI-00014 Helsinki, Finland
| | - Ophir D. Klein
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California, San Francisco, San Francisco, CA 94158, USA
- Department of Pediatrics, Cedars-Sinai Guerin Children’s, 8700 Beverly Blvd., Suite 2416, Los Angeles, CA 90048, USA
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2
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Sheppard EC, Martin CA, Armstrong C, González-Quevedo C, Illera JC, Suh A, Spurgin LG, Richardson DS. Genotype-environment associations reveal genes potentially linked to avian malaria infection in populations of an endemic island bird. Mol Ecol 2024; 33:e17329. [PMID: 38533805 DOI: 10.1111/mec.17329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 01/29/2024] [Accepted: 03/01/2024] [Indexed: 03/28/2024]
Abstract
Patterns of pathogen prevalence are, at least partially, the result of coevolutionary host-pathogen interactions. Thus, exploring the distribution of host genetic variation in relation to infection by a pathogen within and across populations can provide important insights into mechanisms of host defence and adaptation. Here, we use a landscape genomics approach (Bayenv) in conjunction with genome-wide data (ddRADseq) to test for associations between avian malaria (Plasmodium) prevalence and host genetic variation across 13 populations of the island endemic Berthelot's pipit (Anthus berthelotii). Considerable and consistent spatial heterogeneity in malaria prevalence was observed among populations over a period of 15 years. The prevalence of malaria infection was also strongly positively correlated with pox (Avipoxvirus) prevalence. Multiple host loci showed significant associations with malaria prevalence after controlling for genome-wide neutral genetic structure. These sites were located near to or within genes linked to metabolism, stress response, transcriptional regulation, complement activity and the inflammatory response, many previously implicated in vertebrate responses to malarial infection. Our findings identify diverse genes - not just limited to the immune system - that may be involved in host protection against malaria and suggest that spatially variable pathogen pressure may be an important evolutionary driver of genetic divergence among wild animal populations, such as Berthelot's pipit. Furthermore, our data indicate that spatio-temporal variation in multiple different pathogens (e.g. malaria and pox in this case) may have to be studied together to develop a more holistic understanding of host pathogen-mediated evolution.
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Affiliation(s)
| | - Claudia A Martin
- School of Biological Sciences, University of East Anglia, Norfolk, UK
- Terrestrial Ecology Unit, Biology Department, Ghent University, Ghent, Belgium
| | - Claire Armstrong
- School of Biological Sciences, University of East Anglia, Norfolk, UK
| | - Catalina González-Quevedo
- School of Biological Sciences, University of East Anglia, Norfolk, UK
- Grupo Ecología y Evolución de Vertebrados, Instituto de Biología, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Medellin, Colombia
| | - Juan Carlos Illera
- Biodiversity Research Institute (CSIC-Oviedo, University-Principality of Asturias), University of Oviedo, Mieres, Asturias, Spain
| | - Alexander Suh
- School of Biological Sciences, University of East Anglia, Norfolk, UK
- Centre for Molecular Biodiversity Research, Leibniz Institute for the Analysis of Biodiversity Change, Bonn, Germany
- Department of Organismal Biology - Systematic Biology, Evolutionary Biology Centre, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Lewis G Spurgin
- School of Biological Sciences, University of East Anglia, Norfolk, UK
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3
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Biedrzycka A, Konopiński MK, Popiołek M, Zawiślak M, Bartoszewicz M, Kloch A. Non-MHC immunity genes do not affect parasite load in European invasive populations of common raccoon. Sci Rep 2023; 13:15696. [PMID: 37735177 PMCID: PMC10514260 DOI: 10.1038/s41598-023-41721-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 08/30/2023] [Indexed: 09/23/2023] Open
Abstract
Understanding the evolutionary mechanisms behind invasion success enables predicting which alien species and populations are the most predisposed to become invasive. Parasites may mediate the success of biological invasions through their effect on host fitness. The evolution of increased competitive ability (EICA) hypothesis assumes that escape from parasites during the invasion process allows introduced species to decrease investment in immunity and allocate resources to dispersal and reproduction. Consequently, the selective pressure of parasites on host species in the invasive range should be relaxed. We used the case of the raccoon Procyon lotor invasion in Europe to investigate the effect of gastrointestinal pathogen pressure on non-MHC immune genetic diversity of newly established invasive populations. Despite distinct differences in parasite prevalence between analysed populations, we detected only marginal associations between two analysed SNPs and infection intensity. We argue that the differences in parasite prevalence are better explained by detected earlier associations with specific MHC-DRB alleles. While the escape from native parasites seems to allow decreased investment in overall immunity, which relaxes selective pressure imposed on immune genes, a wide range of MHC variants maintained in the invasive range may protect from newly encountered parasites.
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Affiliation(s)
- Aleksandra Biedrzycka
- Institute of Nature Conservation, Polish Academy of Sciences, Al. Mickiewicza 33, 31-120, Kraków, Poland.
| | - Maciej K Konopiński
- Institute of Nature Conservation, Polish Academy of Sciences, Al. Mickiewicza 33, 31-120, Kraków, Poland
| | - Marcin Popiołek
- Department of Parasitology, Faculty of Biological Sciences, University of Wrocław, Przybyszewskiego 63/67, 51-148, Wrocław, Poland
| | - Marlena Zawiślak
- Department of Parasitology, Faculty of Biological Sciences, University of Wrocław, Przybyszewskiego 63/67, 51-148, Wrocław, Poland
| | | | - Agnieszka Kloch
- Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-089, Warszawa, Poland
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Phillips SR. MHC-B Diversity and Signs of Respiratory Illness in Wild, East African Chimpanzees ( Pan troglodytes schweinfurthii ). BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.02.551731. [PMID: 37577711 PMCID: PMC10418158 DOI: 10.1101/2023.08.02.551731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Many traits, intrinsic and extrinsic to an organism, contribute to interindividual variation in immunity in wild habitats. The vertebrate Major Histocompatibility Complex (MHC) includes genes encoding antigen-presenting molecules that are highly variable, and that variation often predicts susceptibility/resistance to and recovery from pathogen infection. I compare MHC-B variation at two long-term chimpanzee research sites, Kibale National Park in Uganda and Gombe National Park in Tanzania. Using decades of respiratory health data available for these chimpanzees, I test hypotheses associated with maintenance of diversity at MHC loci, including heterozygote, divergent allele, and rare allele advantage hypotheses, and predictions for unique function of MHC-B in great apes. I found, despite confirmation of recent shared ancestry between Kibale and Gombe chimpanzees, including an overlapping MHC-B allele repertoire and similar MHC-B phenotype compositions, chimpanzees from the two research sites experienced differences in the occurrence of respiratory signs and had different associations of MHC-B diversity with signs of respiratory illness. Kibale chimpanzees with heterozygous genotypes and different peptide-binding supertypes were observed less often with respiratory signs than those homozygous or possessing the same supertypes, but this same association was not observed among Gombe chimpanzees. Gombe chimpanzees with specific MHC-B phenotypes that enable engagement of Natural Killer (NK) cells were observed more often with respiratory signs than chimpanzees with other phenotypes, but this was not observed at Kanyawara. This study emphasizes local adaptation in shaping genetic and phenotypic traits in different infectious disease contexts, even among close genetic relatives of the same subspecies, and highlights utility for continued and simultaneous tracking of host immune genes and specific pathogens in wild species.
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Rekdal SL, Anmarkrud JA, Lifjeld JT, Johnsen A. Do female bluethroats without extra-pair offspring have more MHC-compatible social mates? Behav Ecol Sociobiol 2023. [DOI: 10.1007/s00265-023-03311-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
Abstract
Abstract
Genes of the major histocompatibility complex (MHC) are crucial for adaptive immunity in jawed vertebrates, and theory predicts that there should be mate choice for optimizing MHC constitution in the offspring. In a previous study, we demonstrated a non-random female choice of extra-pair males in the bluethroat (Luscinia svecica), yielding offspring that was closer to an intermediate MHC class II (MHCII) allele count than their within-pair halfsiblings. The present study tests whether social pairs with only within-pair young (WPY) in their brood, in the same study population, had a combined MHC-constitution closer to a presumed intermediate optimum, than social pairs with extra-pair young (EPY), with a corresponding pattern in their offspring. As expected, we found that WPY from pure WPY-broods were more MHC-optimal than WPY from mixed broods, but only in broods of young (second year) males. Correspondingly, there was a tendency for social pairs with only WPY in their brood to be more MHC-compatible than social pairs with EPY in their brood, when the male was young. Older bluethroat males have considerably larger testes than young males, and their higher sperm competitiveness could help them secure paternity in their own brood, also when they are not MHC-compatible. In other words, in the sexual conflict over paternity, females may be more likely to realise their preference for a MHC-compatible mate when paired to a young male. As a possible fitness indicator, immune responsiveness to an injected antigen (PHA) was elevated for offspring closer to “the golden mean” in MHCII allele count.
Significance statement
This study contributes to our understanding of MHC-based mate choice in extra-pair mating systems, by showing that female bluethroats (Luscinia svecica) with an MHCII-compatible social mate tend to have no extra-pair young in their brood, but only when the social male is young. This elucidates a possible sexual conflict, in which older social males are able to override female preferences and prevent other males from gaining paternity in their brood through higher sperm production. Studying systems in which extra-pair paternity occurs offers an insight into the genetic benefits of mate choice, as extra-pair males, in contrast to social males, generally contribute only sperm. Further, the strict and thorough genotyping scheme applied in this study enabled us to demonstrate a preference for “the golden mean” in MHC-diversity in a species with one of the highest MHC class II-diversity known to date.
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Kloch A, Mierzejewska EJ, Welc-Falęciak R, Bajer A, Biedrzycka A. Cytokine gene polymorphism and parasite susceptibility in free-living rodents: Importance of non-coding variants. PLoS One 2023; 18:e0258009. [PMID: 36693052 PMCID: PMC9873194 DOI: 10.1371/journal.pone.0258009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 01/06/2023] [Indexed: 01/25/2023] Open
Abstract
Associations between genetic variants and susceptibility to infections have long been studied in free-living hosts so as to infer the contemporary evolutionary forces that shape the genetic polymorphisms of immunity genes. Despite extensive studies of proteins interacting with pathogen-derived ligands, such as MHC (major histocompatilbility complex) or TLR (Toll-like receptors), little is known about the efferent arm of the immune system. Cytokines are signalling molecules that trigger and modulate the immune response, acting as a crucial link between innate and adaptive immunity. In the present study we investigated how genetic variation in cytokines in bank voles Myodes glareolus affects their susceptibility to infection by parasites (nematodes: Aspiculuris tianjensis, Heligmosomum mixtum, Heligmosomoides glareoli) and microparasites (Cryptosporidium sp, Babesia microti, Bartonella sp.). We focused on three cytokines: tumour necrosis factor (TNF), lymphotoxin alpha (LTα), and interferon beta (IFNβ1). Overall, we identified four single nucleotide polymorphisms (SNPs) associated with susceptibility to nematodes: two located in LTα and two in IFNβ1. One of those variants was synonymous, another located in an intron. Each SNP associated with parasite load was located in or next to a codon under selection, three codons displayed signatures of positive selection, and one of purifying selection. Our results indicate that cytokines are prone to parasite-driven selection and that non-coding variants, although commonly disregarded in studies of the genetic background of host-parasite co-evolution, may play a role in susceptibility to infections in wild systems.
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Affiliation(s)
- Agnieszka Kloch
- Department of Ecology, Faculty of Biology, University of Warsaw, Warszawa, Poland
- * E-mail:
| | - Ewa J. Mierzejewska
- Wild Urban Evolution and Ecology Laboratory, Centre of New Technologies, University of Warsaw, Warszawa, Poland
| | - Renata Welc-Falęciak
- Department of Parasitology, Faculty of Biology, University of Warsaw, Warszawa, Poland
| | - Anna Bajer
- Department of Eco-epidemiology of Parasitic Diseases, Faculty of Biology, University of Warsaw, Warszawa, Poland
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7
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A Review of Suggested Mechanisms of MHC Odor Signaling. BIOLOGY 2022; 11:biology11081187. [PMID: 36009814 PMCID: PMC9405088 DOI: 10.3390/biology11081187] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 07/26/2022] [Accepted: 08/04/2022] [Indexed: 11/23/2022]
Abstract
Simple Summary Immune genes of the vertebrate MHC vary among individuals. Each individual collection is optimally diverse to provide resistance against some infectious diseases but not too diverse to cause autoimmune diseases. MHC-dependent mate choice aims for optimally complementary MHC alleles. Each potential partner signals through body odor his/her MHC alleles. Identifying the signal molecules was a long-lasting puzzle solved only recently after many deviations as described. Commensal microbiota which are controlled by the individual MHC genes differ among individuals. They were suspected repeatedly to provide the signal, though mice raised germ-free could still smell MHC genes. Carrier hypotheses came in various versions, centered around the specificity of each MHC molecule for binding peptides from diseases, shown to T lymphocytes to induce the immune response. Volatiles of various origins were suggested to fill the place of the peptide and thus reflect the identity of the MHC molecule. Finally, the bound peptides themselves were identified as the sought info-chemicals. Synthesized peptides affect mate choice as predicted. Specific olfactory neurons were shown to react to these peptides but only to the anchors that define the binding specificity. Even eggs choose sperm to produce offspring with optimal MHC, though the signaling pathway needs further research. Abstract Although an individual’s mix of MHC immune genes determines its resistance, finding MHC-dependent mate choice occurred by accident in inbred mice. Inbred mice prefer MHC dissimilar mates, even when the choice was restricted to urine. It took decades to find the info-chemicals, which have to be as polymorphic as the MHC. Microbiota were suggested repeatedly as the origin of the odor signal though germ-free mice maintained normal preference. Different versions of the ‘carrier hypothesis’ suggested MHC molecules carry volatiles after the bound peptide is released. Theory predicted an optimal individual MHC diversity to maximize resistance. The optimally complementary mate should be and is preferred as several studies show. Thus, the odor signal needs to transmit the exact information of the sender’s MHC alleles, as do MHC ligand peptides but not microbiota. The ‘MHC peptide hypothesis’ assumes that olfactory perception of the peptide ligand provides information about the MHC protein in a key-lock fashion. Olfactory neurons react only to the anchors of synthesized MHC peptides, which reflect the binding MHC molecule’s identity. Synthesized peptides supplemented to a male’s signal affect choice in the predicted way, however, not when anchors are mutated. Also, the human brain detects smelled synthesized self-peptides as such. After mate choice, the lottery of meiosis of randomly paired oocyte and sperm haplotypes would often produce MHC non-optimal offspring. In sticklebacks, eggs select MHC-compatible sperm, thus prefer the best combination close to the population optimum.
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8
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Buzan E, Potušek S, Duniš L, Pokorny B. Neutral and Selective Processes Shape MHC Diversity in Roe Deer in Slovenia. Animals (Basel) 2022; 12:ani12060723. [PMID: 35327121 PMCID: PMC8944837 DOI: 10.3390/ani12060723] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 02/23/2022] [Accepted: 03/10/2022] [Indexed: 12/21/2022] Open
Abstract
Simple Summary Disease prevention and appropriate wildlife management are among the major challenges in wildlife conservation. In the present study, we made a first assessment of the variability of major histocompatibility complex (MHC) genes in roe deer in Slovenia and evaluated local population adaptation by comparing MHC variability with neutral microsatellites. We discovered three new MHC DRB exon 2 alleles in addition to seven previously described in the literature. Moreover, we found evidence of historical positive selection, as selection analysis indicated that approx. 10% of the encoded amino acids were subjected to episodic positive selection. This study provides the basis for further research on immunogenetic variation in roe deer and highlights opportunities to incorporate genetic data into science-based population management. Abstract Disease control and containment in free-ranging populations is one of the greatest challenges in wildlife management. Despite the importance of major histocompatibility complex (MHC) genes for immune response, an assessment of the diversity and occurrence of these genes is still rare in European roe deer, the most abundant and widespread large mammal in Europe. Therefore, we examined immunogenetic variation in roe deer in Slovenia to identify species adaptation by comparing the genetic diversity of the MHC genes with the data on neutral microsatellites. We found ten MHC DRB alleles, three of which are novel. Evidence for historical positive selection on the MHC was found using the maximum likelihood codon method. Patterns of MHC allelic distribution were not congruent with neutral population genetic findings. The lack of population genetic differentiation in MHC genes compared to existing structure in neutral markers suggests that MHC polymorphism was influenced primarily by balancing selection and, to a lesser extent, by neutral processes such as genetic drift, with no clear evidence of local adaptation. Selection analyses indicated that approx. 10% of amino acids encoded under episodic positive selection. This study represents one of the first steps towards establishing an immunogenetic map of roe deer populations across Europe, aiming to better support science-based management of this important game species.
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Affiliation(s)
- Elena Buzan
- Faculty of Mathematics, Natural Sciences, and Information Technologies, University of Primorska, Glagoljaška 8, 6000 Koper, Slovenia; (S.P.); (L.D.)
- Environmental Protection College, Trg Mladosti 7, 3320 Velenje, Slovenia;
- Correspondence: ; Tel.: +38-65-6117570; Fax: +38-65-61175
| | - Sandra Potušek
- Faculty of Mathematics, Natural Sciences, and Information Technologies, University of Primorska, Glagoljaška 8, 6000 Koper, Slovenia; (S.P.); (L.D.)
| | - Luka Duniš
- Faculty of Mathematics, Natural Sciences, and Information Technologies, University of Primorska, Glagoljaška 8, 6000 Koper, Slovenia; (S.P.); (L.D.)
| | - Boštjan Pokorny
- Environmental Protection College, Trg Mladosti 7, 3320 Velenje, Slovenia;
- Slovenian Forestry Institute, Večna pot 2, 1000 Ljubljana, Slovenia
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9
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Huang W, Dicks KL, Ballingall KT, Johnston SE, Sparks AM, Watt K, Pilkington JG, Pemberton JM. Associations between MHC class II variation and phenotypic traits in a free-living sheep population. Mol Ecol 2021; 31:902-915. [PMID: 34748666 DOI: 10.1111/mec.16265] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 10/22/2021] [Accepted: 11/03/2021] [Indexed: 01/03/2023]
Abstract
Pathogen-mediated selection (PMS) is thought to maintain the high level of allelic diversity observed in the major histocompatibility complex (MHC) class II genes. A comprehensive way to demonstrate contemporary selection is to examine associations between MHC variation and individual fitness. As individual fitness is hard to measure, many studies examine associations between MHC variation and phenotypic traits, including direct or indirect measures of adaptive immunity thought to contribute to fitness. Here, we tested associations between MHC class II variation and five phenotypic traits measured in free-living sheep captured in August: weight, strongyle faecal egg count, and plasma IgA, IgE and IgG immunoglobulin titres against the gastrointestinal nematode parasite Teladorsagia circumcincta. We found no association between MHC class II variation and weight or strongyle faecal egg count. We did, however, find associations between MHC class II variation and immunoglobulin levels which varied with isotype, age and sex. Our results suggest associations between MHC and phenotypic traits are more likely to be found for traits more closely associated with pathogen defence than integrative traits such as bodyweight and highlight the association between MHC variation and antibodies in wild populations.
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Affiliation(s)
- Wei Huang
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Kara L Dicks
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | | | - Susan E Johnston
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Alexandra M Sparks
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK.,School of Biology, University of Leeds, Leeds, UK
| | - Kathryn Watt
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Jill G Pilkington
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Josephine M Pemberton
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
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10
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Phillips KP, Cable J, Mohammed RS, Chmielewski S, Przesmycka KJ, van Oosterhout C, Radwan J. Functional immunogenetic variation, rather than local adaptation, predicts ectoparasite infection intensity in a model fish species. Mol Ecol 2021; 30:5588-5604. [PMID: 34415650 PMCID: PMC9292977 DOI: 10.1111/mec.16135] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 07/07/2021] [Accepted: 08/11/2021] [Indexed: 11/28/2022]
Abstract
Natural host populations differ in their susceptibility to infection by parasites, and these intrapopulation differences are still an incompletely understood component of host‐parasite dynamics. In this study, we used controlled infection experiments with wild‐caught guppies (Poecilia reticulata) and their ectoparasite Gyrodactylus turnbulli to investigate the roles of local adaptation and host genetic composition (immunogenetic and neutral) in explaining differences in susceptibility to infection. We found differences between our four study host populations that were consistent between two parasite source populations, with no indication of local adaptation by either host or parasite at two tested spatial scales. Greater values of host population genetic variability metrics broadly aligned with lower population mean infection intensity, with the best alignments associated with major histocompatibility complex (MHC) “supertypes”. Controlling for intrapopulation differences and potential inbreeding variance, we found a significant negative relationship between individual‐level functional MHC variability and infection: fish carrying more MHC supertypes experienced infections of lower severity, with limited evidence for supertype‐specific effects. We conclude that population‐level differences in host infection susceptibility probably reflect variation in parasite selective pressure and/or host evolutionary potential, underpinned by functional immunogenetic variation.
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Affiliation(s)
- Karl P Phillips
- Evolutionary Biology Group, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland.,School of Biological Earth & Environmental Sciences, University College Cork, Cork, Ireland.,Marine Institute, Newport, Co. Mayo, Ireland
| | - Joanne Cable
- School of Biosciences, Cardiff University, Cardiff, UK
| | - Ryan S Mohammed
- Evolutionary Biology Group, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland.,Department of Life Sciences, The University of the West Indies, St. Augustine, Trinidad and Tobago
| | - Sebastian Chmielewski
- Evolutionary Biology Group, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
| | - Karolina J Przesmycka
- Evolutionary Biology Group, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
| | - Cock van Oosterhout
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, UK
| | - Jacek Radwan
- Evolutionary Biology Group, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
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11
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Scherman K, Råberg L, Westerdahl H. Borrelia Infection in Bank Voles Myodes glareolus Is Associated With Specific DQB Haplotypes Which Affect Allelic Divergence Within Individuals. Front Immunol 2021; 12:703025. [PMID: 34381454 PMCID: PMC8350566 DOI: 10.3389/fimmu.2021.703025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 07/01/2021] [Indexed: 11/17/2022] Open
Abstract
The high polymorphism of Major Histocompatibility Complex (MHC) genes is generally considered to be a result of pathogen-mediated balancing selection. Such selection may operate in the form of heterozygote advantage, and/or through specific MHC allele–pathogen interactions. Specific MHC allele–pathogen interactions may promote polymorphism via negative frequency-dependent selection (NFDS), or selection that varies in time and/or space because of variability in the composition of the pathogen community (fluctuating selection; FS). In addition, divergent allele advantage (DAA) may act on top of these forms of balancing selection, explaining the high sequence divergence between MHC alleles. DAA has primarily been thought of as an extension of heterozygote advantage. However, DAA could also work in concert with NFDS though this is yet to be tested explicitly. To evaluate the importance of DAA in pathogen-mediated balancing selection, we surveyed allelic polymorphism of MHC class II DQB genes in wild bank voles (Myodes glareolus) and tested for associations between DQB haplotypes and infection by Borrelia afzelii, a tick-transmitted bacterium causing Lyme disease in humans. We found two significant associations between DQB haplotypes and infection status: one haplotype was associated with lower risk of infection (resistance), while another was associated with higher risk of infection (susceptibility). Interestingly, allelic divergence within individuals was higher for voles with the resistance haplotype compared to other voles. In contrast, allelic divergence was lower for voles with the susceptibility haplotype than other voles. The pattern of higher allelic divergence in individuals with the resistance haplotype is consistent with NFDS favouring divergent alleles in a natural population, hence selection where DAA works in concert with NFDS.
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Affiliation(s)
- Kristin Scherman
- Molecular Ecology and Evolution Lab, Department of Biology, Lund University, Lund, Sweden
| | - Lars Råberg
- Functional Zoology, Department of Biology, Lund University, Lund, Sweden
| | - Helena Westerdahl
- Molecular Ecology and Evolution Lab, Department of Biology, Lund University, Lund, Sweden
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12
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O'Connor EA, Westerdahl H. Trade-offs in expressed major histocompatibility complex diversity seen on a macroevolutionary scale among songbirds. Evolution 2021; 75:1061-1069. [PMID: 33666228 DOI: 10.1111/evo.14207] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 01/07/2021] [Accepted: 02/17/2021] [Indexed: 12/30/2022]
Abstract
To survive organisms must defend themselves against pathogens. Classical Major Histocompatibility Complex (MHC) genes play a key role in pathogen defense by encoding molecules involved in pathogen recognition. MHC gene diversity influences the variety of pathogens individuals can recognize and respond to and has consequently been a popular genetic marker for disease resistance in ecology and evolution. However, MHC diversity is predominantly estimated using genomic DNA (gDNA) with little knowledge of expressed diversity. This limits our ability to interpret the adaptive significance of variation in MHC diversity, especially in species with very many MHC genes such as songbirds. Here, we address this issue using phylogenetic comparative analyses of the number of MHC class I alleles (MHC-I diversity) in gDNA and complementary DNA (cDNA), that is, expressed alleles, across 13 songbird species. We propose three theoretical relationships that could be expected between genomic and expressed MHC-I diversity on a macroevolutionary scale and test which of these are best supported. In doing so, we show that significantly fewer MHC-I alleles than the number available are expressed, suggesting that optimal MHC-I diversity could be achieved by modulating gene expression. Understanding the relationship between genomic and expressed MHC diversity is essential for interpreting variation in MHC diversity in an evolutionary context.
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Affiliation(s)
- Emily A O'Connor
- Molecular Ecology and Evolution Lab, Department of Biology, Lund University, Lund, Sweden
| | - Helena Westerdahl
- Molecular Ecology and Evolution Lab, Department of Biology, Lund University, Lund, Sweden
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13
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Lee C, Day J, Goodman SM, Pedrono M, Besnard G, Frantz L, Taylor PJ, Herrera MJ, Gongora J. Genetic origins and diversity of bushpigs from Madagascar (Potamochoerus larvatus, family Suidae). Sci Rep 2020; 10:20629. [PMID: 33244111 PMCID: PMC7693328 DOI: 10.1038/s41598-020-77279-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 11/09/2020] [Indexed: 11/08/2022] Open
Abstract
The island of Madagascar, situated off the southeast coast of Africa, shows the first evidence of human presence ~ 10,000 years ago; however, other archaeological data indicates a settlement of the modern peoples of the island distinctly more recent, perhaps > 1500 years ago. Bushpigs of the genus Potamochoerus (family Suidae), are today widely distributed in Madagascar and presumed to have been introduced from Africa at some stage by human immigrants to the island. However, disparities about their origins in Madagascar have been presented in the literature, including the possibility of endemic subspecies, and few empirical data are available. Furthermore, the separation of bushpigs in Madagascar from their mainland relatives may have favoured the evolution of a different repertoire of immune genes first due to a founder effect and then as a response to distinct pathogens compared to their ancestors. Molecular analysis confirmed the species status of the bushpig in Madagascar as P. larvatus, likely introduced from the central region of southern Africa, with no genetic evidence for the recognition of eastern and western subspecies as suggested from previous cranial morphology examination. Investigation of the immunologically important SLA-DQB1 peptide-binding region showed a different immune repertoire of bushpigs in Madagascar compared to those on the African mainland, with seventeen exon-2 haplotypes unique to bushpigs in Madagascar (2/28 haplotypes shared). This suggests that the MHC diversity of the Madagascar populations may have enabled Malagasy bushpigs to adapt to new environments.
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Affiliation(s)
- Carol Lee
- Sydney School of Veterinary Science, Faculty of Science, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Jenna Day
- Sydney School of Veterinary Science, Faculty of Science, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Steven M Goodman
- Field Museum of Natural History, Chicago, IL, 60605, USA
- Association Vahatra, 101, Antananarivo, Madagascar
| | - Miguel Pedrono
- UMR ASTRE, INRAE, CIRAD, Université de Montpellier, 34398, Montpellier Cedex 5, France
| | - Guillaume Besnard
- CNRS, UPS, IRD, Laboratoire Evolution et Diversité Biologique, UMR5174, Université Toulouse III Paul Sabatier, 31062, Toulouse, France
| | - Laurent Frantz
- Palaeogenomics Group, Department of Veterinary Sciences, Ludwig Maximilian University, Munich, Germany
- School of Biological and Chemical Sciences, Queen Mary University of London, London, UK
| | - Peter J Taylor
- School of Mathematical and Natural Sciences, University of Venda, Thohoyandou, Limpopo Province, South Africa
- Afromontane Research Unit and Zoology Department, University of the Free State, Qwa Qwa campus, Phuthaditjhaba, 9866, South Africa
| | - Michael J Herrera
- Archaeological Studies Program, University of the Philippines Diliman, 1101, Quezon City, Philippines
| | - Jaime Gongora
- Sydney School of Veterinary Science, Faculty of Science, The University of Sydney, Sydney, NSW, 2006, Australia.
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Liu C, Lei H, Ran X, Wang J. Genetic variation and selection in the major histocompatibility complex Class II gene in the Guizhou pony. PeerJ 2020; 8:e9889. [PMID: 32999762 PMCID: PMC7505079 DOI: 10.7717/peerj.9889] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 08/17/2020] [Indexed: 11/20/2022] Open
Abstract
The Guizhou pony (GZP) is an indigenous species of equid found in the mountains of the Guizhou province in southwest China. We selected four regions of the equine leukocyte antigen (ELA), including DQA, DRA, DQB, and DRB, and used them to assess the diversity of the major histocompatibility complex (MHC) class II gene using direct sequencing technology. DRA had the lowest dN/dS ratio (0.560) compared with the other three loci, indicating that DRA was conserved and could be conserved after undergoing selective processes. Nine DQA, five DQB, nine DRA, and seven DRB codons were under significant positive selection at the antigen binding sites (ABS), suggesting that the selected residues in ABS may play a significant role in the innate immune system of the GZP. Two GZP alleles were shared with Przewalski’s horse, and six older GZP haplotypes had a better relationship with other horse species by one or two mutational steps, indicating that the GZP may be a natural ancient variety of equid. The specific diversity of ABS and the numbers of unique haplotypes in the evolutionary process affords this species a better genetic fitness and ability to adapt to the native environment.
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Affiliation(s)
- Chang Liu
- College of Animal Sciences, Guizhou University, Guiyang, China.,College of Pharmacy, Guizhou University of Traditional Chinese Medicine, Guiyang, China
| | - Hongmei Lei
- College of Animal Sciences, Guizhou University, Guiyang, China
| | - Xueqin Ran
- College of Animal Sciences, Guizhou University, Guiyang, China
| | - Jiafu Wang
- College of Animal Sciences, Guizhou University, Guiyang, China.,Tongren University, Tongren, China
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15
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Kloch A, Biedrzycka A. Post-glacial phylogeography and variation in innate immunity loci in a sylvatic rodent, bank vole Myodes glareolus. Mamm Biol 2020. [DOI: 10.1007/s42991-020-00016-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
AbstractIn the northern hemisphere, the spatial structure of many taxa has been shaped by migration patterns after the last glaciation, and phylogeography based on mtDNA variation may reflect the post-glacial demography. The mtDNA lineages are expected to differ in their adaptations to local conditions but little is known about the impact of these conditions on functional genetic variation. Here, we answer this question through an analysis of geographic variation and selection patterns in seven innate immunity genes in free-living bank voles Myodes glareolus from 10 localities across species range assigned to different lineages based on mtDNA. We found clear discrepancies between population structure in mtDNA and each of the studied innate immunity genes. There was no uniform pattern of spatial variation at immunity loci, they differed in the levels of polymorphism, and the results of neutrality tests were not consistent over loci. Each locus comprised a few common haplotypes shared between mitochondrial lineages and studied locations, plus numerous haplotypes unique for each studied site. Our results suggest that the diversity of innate immunity genes cannot be explained solely in terms of demographic processes, and that the observed polymorphism may be attributed to local selection. The strength and direction of selection differed between loci, even within the same gene family, which underlines how crucial it is to take a complex approach while studying the selection patterns acting on immune-related genes.
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Radwan J, Babik W, Kaufman J, Lenz TL, Winternitz J. Advances in the Evolutionary Understanding of MHC Polymorphism. Trends Genet 2020; 36:298-311. [DOI: 10.1016/j.tig.2020.01.008] [Citation(s) in RCA: 106] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 01/13/2020] [Accepted: 01/14/2020] [Indexed: 12/26/2022]
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Bentkowski P, Radwan J. Mating preferences can drive expansion or contraction of major histocompatibility complex gene family. Proc Biol Sci 2020; 287:20192706. [PMID: 32097586 DOI: 10.1098/rspb.2019.2706] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Major histocompatibility complex (MHC)-based mating rules can evolve as a way to avoid inbreeding or to increase offspring immune competence. While the role of mating preference in shaping the MHC diversity in vertebrates has been acknowledged, its impact on individual MHC diversity has not been considered. Here, we use computer simulations to investigate how simple mating rules favouring MHC-dissimilar partners affect the evolution of the number of MHC variants in individual genomes, accompanying selection for resistance to parasites. We showed that the effect of such preferences could sometimes be dramatic. If preferences are aimed at avoiding identical alleles, the equilibrium number of MHC alleles is much smaller than under random mating. However, if the mating rule minimizes the ratio of shared to different alleles in partners, MHC number is higher than under random mating. Additionally, our simulations revealed that a negative correlation between the numbers of MHC variants in mated individuals can arise from simple rules of MHC-disassortative mating. Our results reveal unexpected potential of MHC-based mating preferences to drive MHC gene family expansions or contractions and highlight the need to study the mechanistic basis of such preferences, which is currently poorly understood.
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Affiliation(s)
- Piotr Bentkowski
- Evolutionary Biology Group, Faculty of Biology, Adam Mickiewicz University in Poznań, Poznań 61-614, Poland
| | - Jacek Radwan
- Evolutionary Biology Group, Faculty of Biology, Adam Mickiewicz University in Poznań, Poznań 61-614, Poland
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Grzybek M, Cybulska A, Tołkacz K, Alsarraf M, Behnke-Borowczyk J, Szczepaniak K, Strachecka A, Paleolog J, Moskwa B, Behnke JM, Bajer A. Seroprevalence of Trichinella spp. infection in bank voles ( Myodes glareolus) - A long term study. INTERNATIONAL JOURNAL FOR PARASITOLOGY-PARASITES AND WILDLIFE 2019; 9:144-148. [PMID: 31193257 PMCID: PMC6524169 DOI: 10.1016/j.ijppaw.2019.03.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 02/15/2019] [Accepted: 03/09/2019] [Indexed: 11/03/2022]
Abstract
Rodents play an important role as reservoir hosts of zoonotic diseases. As a component of our long-term programme of monitoring parasitic infections in bank vole populations in three ecologically similar sites in NE Poland, we screened blood samples for signs of a serological response to the presence of Trichinella spp. The overall seroprevalence of Trichinella spp. was 1.52%, but prevalence was largely concentrated in one of our three study sites and confined to the oldest individuals in the study. Seroprevalence of Trichinella spp. did not differ between the sexes. Although a local prevalence of 1.52% may seem low, when this is extrapolated to the national population of bank voles in peak years, perhaps numbering hundreds of millions of animals, the number of infected bank voles on a country wide scale is likely to be huge. Our results suggest that bank voles may be reservoirs of Trichinella spp. However, on the basis of our results we consider their importance as epidemiologically significant hosts for Trichinella spp. to be moderate and their role in this context to require further investigation.
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Affiliation(s)
- Maciej Grzybek
- Department of Tropical Parasitology, Medical University of Gdansk, Poland
| | - Aleksandra Cybulska
- Witold Stefański Institute of Parasitology, Polish Academy of Sciences, Warsaw, Poland
| | | | | | | | - Klaudiusz Szczepaniak
- Department of Parasitology and Invasive Diseases, University of Life Sciences in Lublin, Poland
| | - Aneta Strachecka
- Laboratory of Environmental Biology and Apidologie, University of Life Sciences in Lublin, Lublin, Poland
| | - Jerzy Paleolog
- Department of Zoology, Ecology and Wildlife Management, University of Life Science in Lublin, Lublin, Poland
| | - Bożena Moskwa
- Witold Stefański Institute of Parasitology, Polish Academy of Sciences, Warsaw, Poland
| | - Jerzy M Behnke
- School of Life Sciences, University of Nottingham, Nottingham, UK
| | - Anna Bajer
- Department of Parasitology, University of Warsaw, Warsaw, Poland
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Obanda V, Maingi N, Muchemi G, Ng’ang’a CJ, Angelone S, Archie EA. Infection dynamics of gastrointestinal helminths in sympatric non-human primates, livestock and wild ruminants in Kenya. PLoS One 2019; 14:e0217929. [PMID: 31181093 PMCID: PMC6557494 DOI: 10.1371/journal.pone.0217929] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 05/21/2019] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Gastrointestinal parasites are neglected infections, yet they cause significant burden to animal and human health globally. To date, most studies of gastrointestinal parasites focus on host-parasite systems that involve either a single parasite or a host species. However, when hosts share habitat and resources, they may also cross-transmit generalist gastrointestinal parasites. Here we explore multi-host-parasite interactions in a single ecosystem to understand the infection patterns, especially those linked to livestock-wildlife interfaces and zoonotic risk. METHODS We used both coprological methods (flotation and sedimentation; N = 1,138 fecal samples) and molecular identification techniques (rDNA and mtDNA; N = 18 larvae) to identify gastrointestinal parasites in nine sympatric host species (cattle, sheep, goats, wildebeest, Grant's gazelles, Thomson's gazelles, impala, vervet monkeys and baboons) in the Amboseli ecosystem, Kenya. RESULTS We found that the host community harbored a diverse community of gastrointestinal helminths, including 22 species and/or morphotypes that were heterogeneously distributed across the hosts. Six zoonotic gastrointestinal helminths were identified: Trichuris spp., Trichostrongylus colubriformis, Enterobius spp. Oesophagostomum bifurcum, Strongyloides stercoralis and Strongyloides fuelleborni. The dominant parasite was Trichuris spp, whose ova occurred in two morphological types. Baboons were co-infected with Strongyloides fuelleborni and S. stercoralis. CONCLUSIONS We found that the interface zone shared by wild ungulates, livestock and non-human primates is rich in diversity of gastrointestinal helminths, of which some are extensively shared across the host species. Closely related host species were most likely to be infected by the same parasite species. Several parasites showed genetic sub-structuring according to either geography or host species. Of significance and contrary to expectation, we found that livestock had a higher parasite richness than wild bovids, which is a health risk for both conservation and livestock production. The zoonotic parasites are of public health risk, especially to pastoralist communities living in areas contiguous to wildlife areas. These results expand information on the epidemiology of these parasites and highlights potential zoonotic risk in East African savanna habitats.
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Affiliation(s)
- Vincent Obanda
- Department of Veterinary Services, Kenya Wildlife Service, Nairobi, Kenya
- Department of Pathology, Microbiology and Parasitology, Faculty of Veterinary Medicine, University of Nairobi, Nairobi, Kenya
| | - Ndichu Maingi
- Department of Pathology, Microbiology and Parasitology, Faculty of Veterinary Medicine, University of Nairobi, Nairobi, Kenya
| | - Gerald Muchemi
- Department of Pathology, Microbiology and Parasitology, Faculty of Veterinary Medicine, University of Nairobi, Nairobi, Kenya
| | - Chege J. Ng’ang’a
- Department of Pathology, Microbiology and Parasitology, Faculty of Veterinary Medicine, University of Nairobi, Nairobi, Kenya
| | - Samer Angelone
- Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas (CSIC), Avda, Américo Vespucio s/n, Sevilla, Spain
- Institute of Evolutionary Biology and Environmental Studies (IEU), University of Zürich Winterthurerstrasse, Zürich, Switzerland
| | - Elizabeth A. Archie
- Department of Biological Sciences, University of Notre Dame, South Bend, Indiana, United States of America
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20
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Evolution of major histocompatibility complex gene copy number. PLoS Comput Biol 2019; 15:e1007015. [PMID: 31095555 PMCID: PMC6541284 DOI: 10.1371/journal.pcbi.1007015] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 05/29/2019] [Accepted: 04/09/2019] [Indexed: 01/05/2023] Open
Abstract
MHC genes, which code for proteins responsible for presenting pathogen-derived antigens to the host immune system, show remarkable copy-number variation both between and within species. However, the evolutionary forces driving this variation are poorly understood. Here, we use computer simulations to investigate whether evolution of the number of MHC variants in the genome can be shaped by the number of pathogen species the host population encounters (pathogen richness). Our model assumed that while increasing a range of pathogens recognised, expressing additional MHC variants also incurs costs such as an increased risk of autoimmunity. We found that pathogen richness selected for high MHC copy number only when the costs were low. Furthermore, the shape of the association was modified by the rate of pathogen evolution, with faster pathogen mutation rates selecting for increased host MHC copy number, but only when pathogen richness was low to moderate. Thus, taking into account factors other than pathogen richness may help explain wide variation between vertebrate species in the number of MHC genes. Within population, variation in the number of unique MHC variants carried by individuals (INV) was observed under most parameter combinations, except at low pathogen richness. This variance gave rise to positive correlations between INV and host immunocompetence (proportion of pathogens recognised). However, within-population variation in host immunocompetence declined with pathogen richness. Thus, counterintuitively, pathogens can contribute more to genetic variance for host fitness in species exposed to fewer pathogen species, with consequences to predictions from “Hamilton-Zuk” theory of sexual selection. Highly polymorphic genes of the Major Histocompatibility Complex (MHC) code for proteins responsible for presenting antigens to lymphocytes, thus initiating adaptive immune response. The polymorphism is driven by coevolution with parasites which are selected to evade recognition by MHC proteins. Expressing many MHC molecules could ensure that an individual could present antigens of most pathogen species encountered, but this comes at a cost, such as enhanced negative selection on lymphocytes leading to holes in T-cell receptor repertoire. Our simulations showed that evolution of the number of MHC genes in the genome is driven by a complex interaction between three factors we explored: pathogen richness, the intrinsic cost of expressing additional MHC variants, and pathogen mutation rate. In contrast to verbal arguments, our results indicate that pathogen richness does not always selects for MHC gene family expansion. Taking into account factors other than pathogen richness, in particular costs of expressing additional MHC variants which are still poorly understood, may help explain striking interspecific variation in the number of MHC genes. Counterintuitively, our results also demonstrated that opportunity for selection on immunocompetence should decrease with MHC gene family expansion.
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Portanier E, Garel M, Devillard S, Maillard D, Poissant J, Galan M, Benabed S, Poirel MT, Duhayer J, Itty C, Bourgoin G. Both candidate gene and neutral genetic diversity correlate with parasite resistance in female Mediterranean mouflon. BMC Ecol 2019; 19:12. [PMID: 30836982 PMCID: PMC6402107 DOI: 10.1186/s12898-019-0228-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 02/23/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Parasite infections can have substantial impacts on population dynamics and are accordingly a key challenge for wild population management. Here we studied genetic mechanisms driving parasite resistance in a large herbivore through a comprehensive approach combining measurements of neutral (16 microsatellites) and adaptive (MHC DRB1 exon 2) genetic diversity and two types of gastrointestinal parasites (nematodes and coccidia). RESULTS While accounting for other extrinsic and intrinsic predictors known to impact parasite load, we show that both neutral genetic diversity and DRB1 are associated with resistance to gastrointestinal nematodes. Intermediate levels of multi-locus heterozygosity maximized nematodes resistance, suggesting that both in- and outbreeding depression might occur in the population. DRB1 heterozygosity and specific alleles effects were detected, suggesting the occurrence of heterozygote advantage, rare-allele effects and/or fluctuating selection. On the contrary, no association was detected between genetic diversity and resistance to coccidia, indicating that different parasite classes are impacted by different genetic drivers. CONCLUSIONS This study provides important insights for large herbivores and wild sheep pathogen management, and in particular suggests that factors likely to impact genetic diversity and allelic frequencies, including global changes, are also expected to impact parasite resistance.
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Affiliation(s)
- Elodie Portanier
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Laboratoire de Biométrie et Biologie Évolutive, 69100 Villeurbanne, France
- Office National de la Chasse et de la Faune Sauvage, Unité Ongulés Sauvages, 5 allée de Bethléem, Z.I. Mayencin, 38610 Gières, France
- Université de Lyon, VetAgro Sup, Campus Vétérinaire de Lyon, 1 Avenue Bourgelat, BP 83, 69280 Marcy l’Etoile, France
| | - Mathieu Garel
- Office National de la Chasse et de la Faune Sauvage, Unité Ongulés Sauvages, 5 allée de Bethléem, Z.I. Mayencin, 38610 Gières, France
| | - Sébastien Devillard
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Laboratoire de Biométrie et Biologie Évolutive, 69100 Villeurbanne, France
| | - Daniel Maillard
- Office National de la Chasse et de la Faune Sauvage, Unité Ongulés Sauvages, 5 allée de Bethléem, Z.I. Mayencin, 38610 Gières, France
| | - Jocelyn Poissant
- Department of Ecosystem and Public Health, University of Calgary, Calgary, Canada
| | - Maxime Galan
- CBGP, INRA, CIRAD, IRD, Montpellier SupAgro, Université de Montpellier, 34980 Montferrier Sur Lez, France
| | - Slimania Benabed
- Université de Lyon, VetAgro Sup, Campus Vétérinaire de Lyon, 1 Avenue Bourgelat, BP 83, 69280 Marcy l’Etoile, France
| | - Marie-Thérèse Poirel
- Université de Lyon, VetAgro Sup, Campus Vétérinaire de Lyon, 1 Avenue Bourgelat, BP 83, 69280 Marcy l’Etoile, France
| | - Jeanne Duhayer
- Office National de la Chasse et de la Faune Sauvage, Unité Ongulés Sauvages, 5 allée de Bethléem, Z.I. Mayencin, 38610 Gières, France
| | - Christian Itty
- Office National de la Chasse et de la Faune Sauvage, Unité Ongulés Sauvages, 5 allée de Bethléem, Z.I. Mayencin, 38610 Gières, France
| | - Gilles Bourgoin
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Laboratoire de Biométrie et Biologie Évolutive, 69100 Villeurbanne, France
- Université de Lyon, VetAgro Sup, Campus Vétérinaire de Lyon, 1 Avenue Bourgelat, BP 83, 69280 Marcy l’Etoile, France
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Major histocompatibility complex class I diversity limits the repertoire of T cell receptors. Proc Natl Acad Sci U S A 2019; 116:5021-5026. [PMID: 30796191 DOI: 10.1073/pnas.1807864116] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Major histocompatibility complex (MHC) genes encode proteins that initiate adaptive immune responses through the presentation of foreign antigens to T cells. The high polymorphism found at these genes, thought to be promoted and maintained by pathogen-mediated selection, contrasts with the limited number of MHC loci found in most vertebrates. Although expressing many diverse MHC genes should broaden the range of detectable pathogens, it has been hypothesized to also cause deletion of larger fractions of self-reactive T cells, leading to a detrimental reduction of the T cell receptor (TCR) repertoire. However, a key prediction of this TCR depletion hypothesis, that the TCR repertoire should be inversely related to the individual MHC diversity, has never been tested. Here, using high-throughput sequencing and advanced sequencing error correction, we provide evidence of such an association in a rodent species with high interindividual variation in the number of expressed MHC molecules, the bank vole (Myodes glareolus). Higher individual diversity of MHC class I, but not class II, was associated with smaller TCR repertoires. Our results thus provide partial support for the TCR depletion model, while also highlighting the complex, potentially MHC class-specific mechanisms by which autoreactivity may trade off against evolutionary expansion of the MHC gene family.
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Pérez-Espona S, Goodall-Copestake WP, Savirina A, Bobovikova J, Molina-Rubio C, Pérez-Barbería FJ. First assessment of MHC diversity in wild Scottish red deer populations. EUR J WILDLIFE RES 2019. [DOI: 10.1007/s10344-019-1254-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Minias P, Pikus E, Whittingham LA, Dunn PO. Evolution of Copy Number at the MHC Varies across the Avian Tree of Life. Genome Biol Evol 2019; 11:17-28. [PMID: 30476037 PMCID: PMC6319602 DOI: 10.1093/gbe/evy253] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/20/2018] [Indexed: 12/24/2022] Open
Abstract
The evolution of the major histocompatibility complex (MHC) is shaped by frequent gene duplications and deletions, which generate extensive variation in the number of loci (gene copies) between different taxa. Here, we collected estimates of copy number at the MHC for over 250 bird species from 68 families. We found contrasting patterns of copy number evolution between MHC class I and class IIB, which encode receptors for intra- and extracellular pathogens, respectively. Across the avian evolutionary tree, there was evidence of accelerated evolution and stabilizing selection acting on copy number at class I, while copy number at class IIB was primarily influenced by fluctuating selection and drift. Reconstruction of MHC copy number variation showed ancestrally low numbers of MHC loci in nonpasserines and evolution toward larger numbers of loci in passerines. Different passerine lineages had the highest duplication rates for MHC class I (Sylvioidea) and class IIB (Muscicapoidea and Passeroidea). We also found support for the correlated evolution of MHC copy number and life-history traits such as lifespan and migratory behavior. These results suggest that MHC copy number evolution in birds has been driven by life histories and differences in exposure to intra- and extracellular pathogens.
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Affiliation(s)
- Piotr Minias
- Department of Biodiversity Studies and Bioeducation, Faculty of Biology and Environmental Protection, University of Lódz, Poland
| | - Ewa Pikus
- Department of Biodiversity Studies and Bioeducation, Faculty of Biology and Environmental Protection, University of Lódz, Poland
| | - Linda A Whittingham
- Behavioral and Molecular Ecology Group, Department of Biological Sciences, University of Wisconsin-Milwaukee
| | - Peter O Dunn
- Department of Biodiversity Studies and Bioeducation, Faculty of Biology and Environmental Protection, University of Łódź, Poland.,Behavioral and Molecular Ecology Group, Department of Biological Sciences, University of Wisconsin-Milwaukee
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25
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Lenz TL, Hafer N, Samonte IE, Yeates SE, Milinski M. Cryptic haplotype-specific gamete selection yields offspring with optimal MHC immune genes. Evolution 2018; 72:2478-2490. [PMID: 30246285 PMCID: PMC6282957 DOI: 10.1111/evo.13591] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 08/13/2018] [Indexed: 12/13/2022]
Abstract
Females choose specific mates in order to produce fitter offspring. However, several factors interfere with females' control over fertilization of their eggs, including sneaker males and phenotypically unpredictable allele segregation during meiosis. Mate choice at the individual level thus provides only a poor approximation for obtaining the best genetic match. Consequently, postcopulatory sperm selection by female oocytes has been proposed as a mechanism to achieve complementary combinations of parental haplotypes. Here, using controlled in vitro fertilization of three‐spined stickleback eggs, we find haplotype‐specific fertilization bias toward gametes with complementary major histocompatibility complex (MHC) immunogenes. The resulting zygote (and thus offspring) genotypes exhibit an intermediate level of individual MHC diversity that was previously shown to confer highest pathogen resistance. Our finding of haplotype‐specific gamete selection thus represents an intriguing mechanism for fine‐tuned optimization of the offspring's immune gene composition and an evolutionary advantage in the Red Queen dynamics of host‐parasite coevolution.
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Affiliation(s)
- Tobias L Lenz
- Department of Evolutionary Ecology, Max Planck Institute for Evolutionary Biology, August-Thienemann-Str. 2, 24306 Plön, Germany
| | - Nina Hafer
- Department of Evolutionary Ecology, Max Planck Institute for Evolutionary Biology, August-Thienemann-Str. 2, 24306 Plön, Germany
| | - Irene E Samonte
- Department of Evolutionary Ecology, Max Planck Institute for Evolutionary Biology, August-Thienemann-Str. 2, 24306 Plön, Germany
| | - Sarah E Yeates
- Department of Evolutionary Ecology, Max Planck Institute for Evolutionary Biology, August-Thienemann-Str. 2, 24306 Plön, Germany.,Current Address: School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
| | - Manfred Milinski
- Department of Evolutionary Ecology, Max Planck Institute for Evolutionary Biology, August-Thienemann-Str. 2, 24306 Plön, Germany
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26
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Grzybek M, Alsarraf M, Tołkacz K, Behnke-Borowczyk J, Biernat B, Stańczak J, Strachecka A, Guz L, Szczepaniak K, Paleolog J, Behnke JM, Bajer A. Seroprevalence of TBEV in bank voles from Poland-a long-term approach. Emerg Microbes Infect 2018; 7:145. [PMID: 30108201 PMCID: PMC6092418 DOI: 10.1038/s41426-018-0149-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 05/31/2018] [Accepted: 07/15/2018] [Indexed: 12/18/2022]
Abstract
Rodents are known to play a significant role as reservoir hosts for TBEV. During three sequential expeditions at 4-year intervals to three ecologically similar study sites in NE Poland, we trapped bank voles (Myodes glareolus) and then tested their blood for the presence of specific antiviral antibodies to TBEV. The strongest effects on seroprevalence were the extrinsic factors, site of capture of voles and year of sampling. Seroprevalence increased markedly with increasing host age, and our analysis revealed significant interactions among these three factors. Seroprevalence did not differ between the sexes. Therefore, based on the seroprevalence results, the dynamics of TBEV infection differ significantly in time, between local sub-populations of bank voles and with increasing host age. To fully understand the circulation of the virus among these reservoir hosts and in the environment, long-term monitoring is required and should employ a multi-site approach, such as the one adopted in the current study.
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Affiliation(s)
- Maciej Grzybek
- Department of Tropical Parasitology, Medical University of Gdańsk, Gdańsk, Poland.
| | | | | | | | - Beata Biernat
- Department of Tropical Parasitology, Medical University of Gdańsk, Gdańsk, Poland
| | - Joanna Stańczak
- Department of Tropical Parasitology, Medical University of Gdańsk, Gdańsk, Poland
| | - Aneta Strachecka
- Department of Biological Basis of Animal Production, University of Life Sciences in Lublin, Lublin, Poland
| | - Leszek Guz
- Department of Biology and Fish Disease, University of Life Sciences in Lublin, Lublin, Poland
| | - Klaudiusz Szczepaniak
- Department of Parasitology and Invasive Diseases, University of Life Sciences in Lublin, Lublin, Poland
| | - Jerzy Paleolog
- Department of Zoology, Animal Ecology & Wildlife Management, University of Life Sciences in Lublin, Lublin, Poland
| | - Jerzy M Behnke
- School of Life Sciences, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Anna Bajer
- Department of Parasitology, University of Warsaw, Warsaw, Poland
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27
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Signatures of balancing selection in toll-like receptor (TLRs) genes - novel insights from a free-living rodent. Sci Rep 2018; 8:8361. [PMID: 29849060 PMCID: PMC5976762 DOI: 10.1038/s41598-018-26672-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 05/15/2018] [Indexed: 01/12/2023] Open
Abstract
Selective pressure from pathogens is considered a key selective force driving the evolution of components of the immune system. Since single components of the immune system may interact with many pathogens, and single pathogens may be recognized by multiple components of the immune system, gaining a better understanding of the mechanisms of parasite-driven selection requires the study of multiple genes and pathogens. Toll-like receptors (TLRs) are a large gene family that code for antigen-presenting components of the innate immune response. In the present paper we characterize polymorphism and signatures of selection in seven TLRs in free-living bank voles Myodes glareolus. We report the first evidence of balancing selection in several TLR genes, supported by positive values of Fu and Li's D* in TLR2 and TLR5, and positive values of Tajima's D in LRR regions within TLR1 and TLR2. We further found significant associations between amino-acid alleles of TLR1 and TLR5 and susceptibility to infection with the blood pathogen Bartonella. Interestingly, selection patterns in TLRs presenting virus-derived motifs (TLR7 and TLR9) differed considerably from those interacting with bacterial PAMPs. In contrast to the highly variable TLRs presenting bacterial motifs, TLR7 and TLR9 had low polymorphism and displayed signatures of directional selection. These findings suggest different functional responses across the TLR gene family and highlight the complexity of parasite-driven selection.
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28
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Biedrzycka A, Bielański W, Ćmiel A, Solarz W, Zając T, Migalska M, Sebastian A, Westerdahl H, Radwan J. Blood parasites shape extreme major histocompatibility complex diversity in a migratory passerine. Mol Ecol 2018; 27:2594-2603. [PMID: 29654666 DOI: 10.1111/mec.14592] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 03/14/2018] [Accepted: 03/26/2018] [Indexed: 12/15/2022]
Abstract
Pathogens are one of the main forces driving the evolution and maintenance of the highly polymorphic genes of the vertebrate major histocompatibility complex (MHC). Although MHC proteins are crucial in pathogen recognition, it is still poorly understood how pathogen-mediated selection promotes and maintains MHC diversity, and especially so in host species with highly duplicated MHC genes. Sedge warblers (Acrocephalus schoenobaenus) have highly duplicated MHC genes, and using data from high-throughput MHC genotyping, we were able to investigate to what extent avian malaria parasites explain temporal MHC class I supertype fluctuations in a long-term study population. We investigated infection status and infection intensities of two different strains of Haemoproteus, that is avian malaria parasites that are known to have significant fitness consequences in sedge warblers. We found that prevalence of avian malaria in carriers of specific MHC class I supertypes was a significant predictor of their frequency changes between years. This finding suggests that avian malaria infections partly drive the temporal fluctuations of the MHC class I supertypes. Furthermore, we found that individuals with a large number of different supertypes had higher resistance to avian malaria, but there was no evidence for an optimal MHC class I diversity. Thus, the two studied malaria parasite strains appear to select for a high MHC class I supertype diversity. Such selection may explain the maintenance of the extremely high number of MHC class I gene copies in sedge warblers and possibly also in other passerines where avian malaria is a common disease.
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Affiliation(s)
| | - Wojciech Bielański
- Institute of Nature Conservation, Polish Academy of Sciences, Kraków, Poland
| | - Adam Ćmiel
- Institute of Nature Conservation, Polish Academy of Sciences, Kraków, Poland
| | - Wojciech Solarz
- Institute of Nature Conservation, Polish Academy of Sciences, Kraków, Poland
| | - Tadeusz Zając
- Institute of Nature Conservation, Polish Academy of Sciences, Kraków, Poland
| | - Magdalena Migalska
- Evolutionary Biology Group, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
| | - Alvaro Sebastian
- Evolutionary Biology Group, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
| | | | - Jacek Radwan
- Evolutionary Biology Group, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
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29
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Fuselli S, Baptista RP, Panziera A, Magi A, Guglielmi S, Tonin R, Benazzo A, Bauzer LG, Mazzoni CJ, Bertorelle G. A new hybrid approach for MHC genotyping: high-throughput NGS and long read MinION nanopore sequencing, with application to the non-model vertebrate Alpine chamois (Rupicapra rupicapra). Heredity (Edinb) 2018; 121:293-303. [PMID: 29572469 PMCID: PMC6133961 DOI: 10.1038/s41437-018-0070-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 01/24/2018] [Accepted: 02/25/2018] [Indexed: 12/13/2022] Open
Abstract
The major histocompatibility complex (MHC) acts as an interface between the immune system and infectious diseases. Accurate characterization and genotyping of the extremely variable MHC loci are challenging especially without a reference sequence. We designed a combination of long-range PCR, Illumina short-reads, and Oxford Nanopore MinION long-reads approaches to capture the genetic variation of the MHC II DRB locus in an Italian population of the Alpine chamois (Rupicapra rupicapra). We utilized long-range PCR to generate a 9 Kb fragment of the DRB locus. Amplicons from six different individuals were fragmented, tagged, and simultaneously sequenced with Illumina MiSeq. One of these amplicons was sequenced with the MinION device, which produced long reads covering the entire amplified fragment. A pipeline that combines short and long reads resolved several short tandem repeats and homopolymers and produced a de novo reference, which was then used to map and genotype the short reads from all individuals. The assembled DRB locus showed a high level of polymorphism and the presence of a recombination breakpoint. Our results suggest that an amplicon-based NGS approach coupled with single-molecule MinION nanopore sequencing can efficiently achieve both the assembly and the genotyping of complex genomic regions in multiple individuals in the absence of a reference sequence.
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Affiliation(s)
- S Fuselli
- Department of Life Sciences and Biotechnology, University of Ferrara, Via L. Borsari 46, Ferrara, 44121, Italy.
| | - R P Baptista
- Center for Tropical & Emerging Global Diseases, University of Georgia, 107 Paul D. Coverdell Center, 500 D. W. Brooks Drive, Athens, GA, 30602-7394, USA
| | - A Panziera
- Department of Life Sciences and Biotechnology, University of Ferrara, Via L. Borsari 46, Ferrara, 44121, Italy.,Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, Via Edmund Mach 1, San Michele all'Adige, I-38010, Italy
| | - A Magi
- Department of Experimental and Clinical Medicine, University of Florence, Largo Brambilla, Florence, 3-50134, Italy
| | - S Guglielmi
- Department of Life Sciences and Biotechnology, University of Ferrara, Via L. Borsari 46, Ferrara, 44121, Italy
| | - R Tonin
- Department of Life Sciences and Biotechnology, University of Ferrara, Via L. Borsari 46, Ferrara, 44121, Italy.,Faculty of Science and Technology, Free University of Bozen-Bolzano, Piazza Università 5, Bolzano, Italy
| | - A Benazzo
- Department of Life Sciences and Biotechnology, University of Ferrara, Via L. Borsari 46, Ferrara, 44121, Italy
| | - L G Bauzer
- Laboratório de Fisiologia e Controle de Artrópodes Vetores, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, Brazil.,Berlin Center for Genomics in Biodiversity Research, Königin-Luise-Str. 6-8, Berlin, 14195, Germany
| | - C J Mazzoni
- Berlin Center for Genomics in Biodiversity Research, Königin-Luise-Str. 6-8, Berlin, 14195, Germany
| | - G Bertorelle
- Department of Life Sciences and Biotechnology, University of Ferrara, Via L. Borsari 46, Ferrara, 44121, Italy
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30
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Genetic variation and selection of MHC class I loci differ in two congeneric frogs. Genetica 2018; 146:125-136. [PMID: 29450668 DOI: 10.1007/s10709-018-0016-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 02/09/2018] [Indexed: 10/18/2022]
Abstract
Major histocompatibility complex (MHC) genes encode proteins in the acquired immune response pathway that often show distinctive selection-driven patterns in wild vertebrate populations. We examined genetic variation and signatures of selection in the MHC class I alpha 1 (A1)- and alpha 2 (A2)-domain encoding exons of two frog congeners [Agalychnis callidryas (n = 20) and A. lemur (n = 20)] from a single locality in Panama. We also investigated how historical demographic processes may have impacted MHC genetic diversity by analyzing a neutral mitochondrial marker. We found that both MHC domains were highly variable in both species, with both species likely expressing three loci. Our analyses revealed different signatures of selection between the two species, most notably that the A. callidryas A2 domain had experienced positive selection while the A2 domain of A. lemur had not. Diversifying selection acted on the same number of A1 and A2 allelic lineages, but on a higher percentage of A1 sites compared to A2 sites. Neutrality tests of mitochondrial haplotypes predominately indicated that the two species were at genetic equilibrium when the samples were collected. In addition, two historical tests of demography indicated both species have had relatively stable population sizes over the past 100,000 years; thus large population size changes are unlikely to have greatly influenced MHC diversity in either species during this time period. In conclusion, our results suggest that the impact of selection on MHC diversity varied between these two closely related species, likely due to a combination of distinct ecological conditions and past pathogenic pressures.
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31
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Lee C, Moroldo M, Perdomo-Sabogal A, Mach N, Marthey S, Lecardonnel J, Wahlberg P, Chong AY, Estellé J, Ho SYW, Rogel-Gaillard C, Gongora J. Inferring the evolution of the major histocompatibility complex of wild pigs and peccaries using hybridisation DNA capture-based sequencing. Immunogenetics 2017; 70:401-417. [PMID: 29256177 DOI: 10.1007/s00251-017-1048-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 11/25/2017] [Indexed: 12/20/2022]
Abstract
The major histocompatibility complex (MHC) is a key genomic model region for understanding the evolution of gene families and the co-evolution between host and pathogen. To date, MHC studies have mostly focused on species from major vertebrate lineages. The evolution of MHC classical (Ia) and non-classical (Ib) genes in pigs has attracted interest because of their antigen presentation roles as part of the adaptive immune system. The pig family Suidae comprises over 18 extant species (mostly wild), but only the domestic pig has been extensively sequenced and annotated. To address this, we used a DNA-capture approach, with probes designed from the domestic pig genome, to generate MHC data for 11 wild species of pigs and their closest living family, Tayassuidae. The approach showed good efficiency for wild pigs (~80% reads mapped, ~87× coverage), compared to tayassuids (~12% reads mapped, ~4× coverage). We retrieved 145 MHC loci across both families. Phylogenetic analyses show that the class Ia and Ib genes underwent multiple duplications and diversifications before suids and tayassuids diverged from their common ancestor. The histocompatibility genes mostly form orthologous groups and there is genetic differentiation for most of these genes between Eurasian and sub-Saharan African wild pigs. Tests of selection showed that the peptide-binding region of class Ib genes was under positive selection. These findings contribute to better understanding of the evolutionary history of the MHC, specifically, the class I genes, and provide useful data for investigating the immune response of wild populations against pathogens.
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Affiliation(s)
- Carol Lee
- Sydney School of Veterinary Science, Faculty of Science, The University of Sydney, Sydney, Australia
| | - Marco Moroldo
- GABI, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Alvaro Perdomo-Sabogal
- Sydney School of Veterinary Science, Faculty of Science, The University of Sydney, Sydney, Australia.,Institute of Animal Science (460i), Department of Bioinformatics, University of Hohenheim, Stuttgart, Germany
| | - Núria Mach
- GABI, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Sylvain Marthey
- GABI, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Jérôme Lecardonnel
- GABI, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Per Wahlberg
- GABI, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Amanda Y Chong
- Sydney School of Veterinary Science, Faculty of Science, The University of Sydney, Sydney, Australia.,Earlham Institute, Norwich Research Park, Norwich, UK
| | - Jordi Estellé
- GABI, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Simon Y W Ho
- School of Life and Environmental Sciences, Faculty of Science, The University of Sydney, Sydney, Australia
| | | | - Jaime Gongora
- Sydney School of Veterinary Science, Faculty of Science, The University of Sydney, Sydney, Australia.
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32
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Acevedo-Whitehouse K, Gulland FMD, Bowen L. MHC class II DRB diversity predicts antigen recognition and is associated with disease severity in California sea lions naturally infected with Leptospira interrogans. INFECTION GENETICS AND EVOLUTION 2017; 57:158-165. [PMID: 29183820 DOI: 10.1016/j.meegid.2017.11.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 11/07/2017] [Accepted: 11/23/2017] [Indexed: 12/26/2022]
Abstract
We examined the associations between California sea lion MHC class II DRB (Zaca-DRB) configuration and diversity, and leptospirosis. As Zaca-DRB gene sequences are involved with antigen presentation of bacteria and other extracellular pathogens, we predicted that they would play a role in determining responses to these pathogenic spirochaetes. Specifically, we investigated whether Zaca-DRB diversity (number of genes) and configuration (presence of specific genes) explained differences in disease severity, and whether higher levels of Zaca-DRB diversity predicted the number of specific Leptospira interrogans serovars that a sea lion's serum would react against. We found that serum from diseased sea lions with more Zaca-DRB loci reacted against a wider array of serovars. Specific Zaca-DRB loci were linked to reactions with particular serovars. Interestingly, sea lions with clinical manifestation of leptospirosis that had higher numbers of Zaca-DRB loci were less likely to recover from disease than those with lower diversity, and those that harboured Zaca-DRB.C or -G were 4.5 to 5.3 times more likely to die from leptospirosis, regardless of the infective serovars. We propose that for leptospirosis, a disadvantage of having a wider range of antigen presentation might be increased disease severity due to immunopathology. Ours is the first study to examine the importance of Zaca-DRB diversity for antigen detection and disease severity following natural exposure to infective leptospires.
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Affiliation(s)
- Karina Acevedo-Whitehouse
- Unit for Basic and Applied Microbiology, School of Natural Sciences, Autonomous University of Queretaro, Av. de las Ciencias S/N, Queretaro 76230, Mexico; The Marine Mammal Center, 2000 Bunker Road, Sausalito, CA 94965, USA.
| | | | - Lizabeth Bowen
- USGS Western Ecological Research Center, 1 Shields Ave., University of California, Davis, CA 95616-5224, USA
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33
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Biedrzycka A, O'Connor E, Sebastian A, Migalska M, Radwan J, Zając T, Bielański W, Solarz W, Ćmiel A, Westerdahl H. Extreme MHC class I diversity in the sedge warbler (Acrocephalus schoenobaenus); selection patterns and allelic divergence suggest that different genes have different functions. BMC Evol Biol 2017; 17:159. [PMID: 28679358 PMCID: PMC5497381 DOI: 10.1186/s12862-017-0997-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 06/14/2017] [Indexed: 11/23/2022] Open
Abstract
Background Recent work suggests that gene duplications may play an important role in the evolution of immunity genes. Passerine birds, and in particular Sylvioidea warblers, have highly duplicated major histocompatibility complex (MHC) genes, which are key in immunity, compared to other vertebrates. However, reasons for this high MHC gene copy number are yet unclear. High-throughput sequencing (HTS) allows MHC genotyping even in individuals with extremely duplicated genes. This HTS data can reveal evidence of selection, which may help to unravel the putative functions of different gene copies, i.e. neofunctionalization. We performed exhaustive genotyping of MHC class I in a Sylvioidea warbler, the sedge warbler, Acrocephalus schoenobaenus, using the Illumina MiSeq technique on individuals from a wild study population. Results The MHC diversity in 863 genotyped individuals by far exceeds that of any other bird species described to date. A single individual could carry up to 65 different alleles, a large proportion of which are expressed (transcribed). The MHC alleles were of three different lengths differing in evidence of selection, diversity and divergence within our study population. Alleles without any deletions and alleles containing a 6 bp deletion showed characteristics of classical MHC genes, with evidence of multiple sites subject to positive selection and high sequence divergence. In contrast, alleles containing a 3 bp deletion had no sites subject to positive selection and had low divergence. Conclusions Our results suggest that sedge warbler MHC alleles that either have no deletion, or contain a 6 bp deletion, encode classical antigen presenting MHC molecules. In contrast, MHC alleles containing a 3 bp deletion may encode molecules with a different function. This study demonstrates that highly duplicated MHC genes can be characterised with HTS and that selection patterns can be useful for revealing neofunctionalization. Importantly, our results highlight the need to consider the putative function of different MHC genes in future studies of MHC in relation to disease resistance and fitness. Electronic supplementary material The online version of this article (doi:10.1186/s12862-017-0997-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Aleksandra Biedrzycka
- Institute of Nature Conservation, Polish Academy of Sciences, Al. Mickiewicza 33, 31-120, Kraków, Poland.
| | - Emily O'Connor
- Molecular Ecology and Evolution Lab, Department of Biology, Lund University, Ecology Building, Sölvegatan 37, 223 62, Lund, Sweden
| | - Alvaro Sebastian
- Evolutionary Biology Group, Faculty of Biology, Adam Mickiewicz University in Poznań, ul. Umultowska 89, 61-614, Poznań, Poland
| | - Magdalena Migalska
- Evolutionary Biology Group, Faculty of Biology, Adam Mickiewicz University in Poznań, ul. Umultowska 89, 61-614, Poznań, Poland
| | - Jacek Radwan
- Evolutionary Biology Group, Faculty of Biology, Adam Mickiewicz University in Poznań, ul. Umultowska 89, 61-614, Poznań, Poland
| | - Tadeusz Zając
- Institute of Nature Conservation, Polish Academy of Sciences, Al. Mickiewicza 33, 31-120, Kraków, Poland
| | - Wojciech Bielański
- Institute of Nature Conservation, Polish Academy of Sciences, Al. Mickiewicza 33, 31-120, Kraków, Poland
| | - Wojciech Solarz
- Institute of Nature Conservation, Polish Academy of Sciences, Al. Mickiewicza 33, 31-120, Kraków, Poland
| | - Adam Ćmiel
- Institute of Nature Conservation, Polish Academy of Sciences, Al. Mickiewicza 33, 31-120, Kraków, Poland
| | - Helena Westerdahl
- Molecular Ecology and Evolution Lab, Department of Biology, Lund University, Ecology Building, Sölvegatan 37, 223 62, Lund, Sweden
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34
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Drews A, Strandh M, Råberg L, Westerdahl H. Expression and phylogenetic analyses reveal paralogous lineages of putatively classical and non-classical MHC-I genes in three sparrow species (Passer). BMC Evol Biol 2017. [PMID: 28651571 PMCID: PMC5485651 DOI: 10.1186/s12862-017-0970-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The Major Histocompatibility Complex (MHC) plays a central role in immunity and has been given considerable attention by evolutionary ecologists due to its associations with fitness-related traits. Songbirds have unusually high numbers of MHC class I (MHC-I) genes, but it is not known whether all are expressed and equally important for immune function. Classical MHC-I genes are highly expressed, polymorphic and present peptides to T-cells whereas non-classical MHC-I genes have lower expression, are more monomorphic and do not present peptides to T-cells. To get a better understanding of the highly duplicated MHC genes in songbirds, we studied gene expression in a phylogenetic framework in three species of sparrows (house sparrow, tree sparrow and Spanish sparrow), using high-throughput sequencing. We hypothesize that sparrows could have classical and non-classical genes, as previously indicated though never tested using gene expression. RESULTS The phylogenetic analyses reveal two distinct types of MHC-I alleles among the three sparrow species, one with high and one with low level of polymorphism, thus resembling classical and non-classical genes, respectively. All individuals had both types of alleles, but there was copy number variation both within and among the sparrow species. However, the number of highly polymorphic alleles that were expressed did not vary between species, suggesting that the structural genomic variation is counterbalanced by conserved gene expression. Overall, 50% of the MHC-I alleles were expressed in sparrows. Expression of the highly polymorphic alleles was very variable, whereas the alleles with low polymorphism had uniformly low expression. Interestingly, within an individual only one or two alleles from the polymorphic genes were highly expressed, indicating that only a single copy of these is highly expressed. CONCLUSIONS Taken together, the phylogenetic reconstruction and the analyses of expression suggest that sparrows have both classical and non-classical MHC-I genes, and that the evolutionary origin of these genes predate the split of the three investigated sparrow species 7 million years ago. Because only the classical MHC-I genes are involved in antigen presentation, the function of different MHC-I genes should be considered in future ecological and evolutionary studies of MHC-I in sparrows and other songbirds.
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Affiliation(s)
- Anna Drews
- Department of Biology, Lund University, Ecology Building, 223 62, Lund, Sweden.
| | - Maria Strandh
- Department of Biology, Lund University, Ecology Building, 223 62, Lund, Sweden
| | - Lars Råberg
- Department of Biology, Lund University, Ecology Building, 223 62, Lund, Sweden
| | - Helena Westerdahl
- Department of Biology, Lund University, Ecology Building, 223 62, Lund, Sweden
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Roved J, Westerdahl H, Hasselquist D. Sex differences in immune responses: Hormonal effects, antagonistic selection, and evolutionary consequences. Horm Behav 2017; 88:95-105. [PMID: 27956226 DOI: 10.1016/j.yhbeh.2016.11.017] [Citation(s) in RCA: 179] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 11/29/2016] [Accepted: 11/30/2016] [Indexed: 12/20/2022]
Abstract
Males and females differ in both parasite load and the strength of immune responses and these effects have been verified in humans and other vertebrates. Sex hormones act as important modulators of immune responses; the male sex hormone testosterone is generally immunosuppressive while the female sex hormone estrogen tends to be immunoenhancing. Different sets of T-helper cells (Th) have important roles in adaptive immunity, e.g. Th1 cells trigger type 1 responses which are primarily cell-mediated, and Th2 cells trigger type 2 responses which are primarily humoral responses. In our review of the literature, we find that estrogen and progesterone enhance type 2 and suppress type 1 responses in females, whereas testosterone suppresses type 2 responses and shows an inconsistent pattern for type 1 responses in males. When we combine these patterns of generally immunosuppressive and immunoenhancing effects of the sex hormones, our results imply that the sex differences in immune responses should be particularly strong in immune functions associated with type 2 responses, and less pronounced with type 1 responses. In general the hormone-mediated sex differences in immune responses may lead to genetic sexual conflicts on immunity. Thus, we propose the novel hypothesis that sexually antagonistic selection may act on immune genes shared by the sexes, and that the strength of this sexually antagonistic selection should be stronger for type 2- as compared with type 1-associated immune genes. Finally, we put the consequences of sex hormone-induced effects on immune responses into behavioral and ecological contexts, considering social mating system, sexual selection, geographical distribution of hosts, and parasite abundance.
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Affiliation(s)
- Jacob Roved
- Department of Biology, Lund University, Ecology Building, 223 62 Lund, Sweden.
| | - Helena Westerdahl
- Department of Biology, Lund University, Ecology Building, 223 62 Lund, Sweden
| | - Dennis Hasselquist
- Department of Biology, Lund University, Ecology Building, 223 62 Lund, Sweden
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Biedrzycka A, Sebastian A, Migalska M, Westerdahl H, Radwan J. Testing genotyping strategies for ultra-deep sequencing of a co-amplifying gene family: MHC class I in a passerine bird. Mol Ecol Resour 2016; 17:642-655. [DOI: 10.1111/1755-0998.12612] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Revised: 02/10/2016] [Accepted: 08/23/2016] [Indexed: 12/15/2022]
Affiliation(s)
- Aleksandra Biedrzycka
- Institute of Nature Conservation; Polish Academy of Sciences; Al. Mickiewicza 33 31-120 Kraków Poland
| | - Alvaro Sebastian
- Evolutionary Biology Group; Faculty of Biology; Adam Mickiewicz University; ul. Umultowska 89 61-614 Poznań Poland
| | - Magdalena Migalska
- Evolutionary Biology Group; Faculty of Biology; Adam Mickiewicz University; ul. Umultowska 89 61-614 Poznań Poland
| | - Helena Westerdahl
- Department of Biology; Lund University; Ecology Building, Sölvegatan 37 223 62 Lund Sweden
| | - Jacek Radwan
- Evolutionary Biology Group; Faculty of Biology; Adam Mickiewicz University; ul. Umultowska 89 61-614 Poznań Poland
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Salmier A, de Thoisy B, Crouau-Roy B, Lacoste V, Lavergne A. Spatial pattern of genetic diversity and selection in the MHC class II DRB of three Neotropical bat species. BMC Evol Biol 2016; 16:229. [PMID: 27782798 PMCID: PMC5080761 DOI: 10.1186/s12862-016-0802-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 10/14/2016] [Indexed: 11/10/2022] Open
Abstract
Background Although bats are natural reservoirs of many pathogens, few studies have been conducted on the genetic variation and detection of selection in major histocompatibility complex (MHC) genes. These genes are critical for resistance and susceptibility to diseases, and host–pathogen interactions are major determinants of their extensive polymorphism. Here we examined spatial patterns of diversity of the expressed MHC class II DRB gene of three sympatric Neotropical bats, Carollia perspicillata and Desmodus rotundus (Phyllostomidae), and Molossus molossus (Molossidae), all of which use the same environments (e.g., forests, edge habitats, urban areas). Comparison with neutral marker (mtDNA D-loop) diversity was performed at the same time. Results Twenty-three DRB alleles were identified in 19 C. perspicillata, 30 alleles in 35 D. rotundus and 20 alleles in 28 M. molossus. The occurrence of multiple DRB loci was found for the two Phyllostomidae species. The DRB polymorphism was high in all sampling sites and different signatures of positive selection were detected depending on the environment. The patterns of DRB diversity were similar to those of neutral markers for C. perspicillata and M. molossus. In contrast, these patterns were different for D. rotundus for which a geographical structure was highlighted. A heterozygote advantage was also identified for this species. No recombination or gene conversion event was found and phylogenetic relationships showed a trans-species mode of evolution in the Phyllostomids. Conclusions This study of MHC diversity demonstrated the strength of the environment and contrasting pathogen pressures in shaping DRB diversity. Differences between positively selected sites identified in bat species highlighted the potential role of gut microbiota in shaping immune responses. Furthermore, multiple geographic origins and/or population admixtures observed in C. perspicillata and M. molossus populations acted as an additional force in shaping DRB diversity. In contrast, DRB diversity of D. rotundus was shaped by environment rather than demographic history. Electronic supplementary material The online version of this article (doi:10.1186/s12862-016-0802-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Arielle Salmier
- Laboratoire des Interactions Virus-Hôtes, Institut Pasteur de la Guyane, 23 avenue Pasteur, BP 6010, 97306, Cayenne, Cedex, French Guiana
| | - Benoit de Thoisy
- Laboratoire des Interactions Virus-Hôtes, Institut Pasteur de la Guyane, 23 avenue Pasteur, BP 6010, 97306, Cayenne, Cedex, French Guiana
| | - Brigitte Crouau-Roy
- CNRS, Université Toulouse 3 UPS, ENFA, UMR 5174 EDB (Laboratoire Évolution et Diversité Biologique), 118 Route de Narbonne, 31062, Toulouse, France
| | - Vincent Lacoste
- Laboratoire des Interactions Virus-Hôtes, Institut Pasteur de la Guyane, 23 avenue Pasteur, BP 6010, 97306, Cayenne, Cedex, French Guiana
| | - Anne Lavergne
- Laboratoire des Interactions Virus-Hôtes, Institut Pasteur de la Guyane, 23 avenue Pasteur, BP 6010, 97306, Cayenne, Cedex, French Guiana.
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38
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Migalska M, Sebastian A, Konczal M, Kotlík P, Radwan J. De novo transcriptome assembly facilitates characterisation of fast-evolving gene families, MHC class I in the bank vole (Myodes glareolus). Heredity (Edinb) 2016; 118:348-357. [PMID: 27782121 DOI: 10.1038/hdy.2016.105] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 09/20/2016] [Indexed: 02/07/2023] Open
Abstract
The major histocompatibility complex (MHC) plays a central role in the adaptive immune response and is the most polymorphic gene family in vertebrates. Although high-throughput sequencing has increasingly been used for genotyping families of co-amplifying MHC genes, its potential to facilitate early steps in the characterisation of MHC variation in nonmodel organism has not been fully explored. In this study we evaluated the usefulness of de novo transcriptome assembly in characterisation of MHC sequence diversity. We found that although de novo transcriptome assembly of MHC I genes does not reconstruct sequences of individual alleles, it does allow the identification of conserved regions for PCR primer design. Using the newly designed primers, we characterised MHC I sequences in the bank vole. Phylogenetic analysis of the partial MHC I coding sequence (2-4 exons) of the bank vole revealed a lack of orthology to MHC I of other Cricetidae, consistent with the high gene turnover of this region. The diversity of expressed alleles was characterised using ultra-deep sequencing of the third exon that codes for the peptide-binding region of the MHC molecule. High allelic diversity was demonstrated, with 72 alleles found in 29 individuals. Interindividual variation in the number of expressed loci was found, with the number of alleles per individual ranging from 5 to 14. Strong signatures of positive selection were found for 8 amino acid sites, most of which are inferred to bind antigens in human MHC, indicating conservation of structure despite rapid sequence evolution.
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Affiliation(s)
- M Migalska
- Evolutionary Biology Group, Faculty of Biology, Adam Mickiewicz University, Poznan, Poland
| | - A Sebastian
- Evolutionary Biology Group, Faculty of Biology, Adam Mickiewicz University, Poznan, Poland
| | - M Konczal
- Evolutionary Biology Group, Faculty of Biology, Adam Mickiewicz University, Poznan, Poland
| | - P Kotlík
- Laboratory of Molecular Ecology, Institute of Animal Physiology and Genetics, The Czech Academy of Sciences, Liběchov, Czech Republic
| | - J Radwan
- Evolutionary Biology Group, Faculty of Biology, Adam Mickiewicz University, Poznan, Poland
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Bateson ZW, Hammerly SC, Johnson JA, Morrow ME, Whittingham LA, Dunn PO. Specific alleles at immune genes, rather than genome‐wide heterozygosity, are related to immunity and survival in the critically endangered Attwater's prairie‐chicken. Mol Ecol 2016; 25:4730-44. [DOI: 10.1111/mec.13793] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 07/17/2016] [Accepted: 07/19/2016] [Indexed: 12/20/2022]
Affiliation(s)
- Zachary W. Bateson
- Behavioral and Molecular Ecology Group Department of Biological Sciences University of Wisconsin‐Milwaukee PO Box 413 Milwaukee WI 53201 USA
| | - Susan C. Hammerly
- Department of Biological Sciences Institute of Applied Sciences University of North Texas 1155 Union Circle Denton TX 76203 USA
| | - Jeff A. Johnson
- Department of Biological Sciences Institute of Applied Sciences University of North Texas 1155 Union Circle Denton TX 76203 USA
| | - Michael E. Morrow
- Attwater Prairie Chicken National Wildlife Refuge PO Box 519 Eagle Lake TX 77434 USA
| | - Linda A. Whittingham
- Behavioral and Molecular Ecology Group Department of Biological Sciences University of Wisconsin‐Milwaukee PO Box 413 Milwaukee WI 53201 USA
| | - Peter O. Dunn
- Behavioral and Molecular Ecology Group Department of Biological Sciences University of Wisconsin‐Milwaukee PO Box 413 Milwaukee WI 53201 USA
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40
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Gonzalez-Quevedo C, Davies RG, Phillips KP, Spurgin LG, Richardson DS. Landscape-scale variation in an anthropogenic factor shapes immune gene variation within a wild population. Mol Ecol 2016; 25:4234-46. [PMID: 27411090 DOI: 10.1111/mec.13759] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 06/23/2016] [Accepted: 07/05/2016] [Indexed: 02/03/2023]
Abstract
Understanding the spatial scale at which selection acts upon adaptive genetic variation in natural populations is fundamental to our understanding of evolutionary ecology, and has important ramifications for conservation. The environmental factors to which individuals of a population are exposed can vary at fine spatial scales, potentially generating localized patterns of adaptation. Here, we compared patterns of neutral and major histocompatibility complex (MHC) variation within an island population of Berthelot's pipit (Anthus berthelotii) to assess whether landscape-level differences in pathogen-mediated selection generate fine-scale spatial structuring in these immune genes. Specifically, we tested for spatial associations between the distribution of avian malaria, and the factors previously shown to influence that distribution, and MHC variation within resident individuals. Although we found no overall genetic structure across the population for either neutral or MHC loci, we did find localized associations between environmental factors and MHC variation. One MHC class I allele (ANBE48) was directly associated with malaria infection risk, while the presence of the ANBE48 and ANBE38 alleles within individuals correlated (positively and negatively, respectively) with distance to the nearest poultry farm, an anthropogenic factor previously shown to be an important determinant of disease distribution in the study population. Our findings highlight the importance of considering small spatial scales when studying the patterns and processes involved in evolution at adaptive loci.
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Affiliation(s)
- Catalina Gonzalez-Quevedo
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.,Grupo Ecología y Evolución de Vertebrados, Instituto de Biología, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia, Calle 70 No. 52-21, Medellín, Colombia
| | - Richard G Davies
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Karl P Phillips
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.,Evolutionary Biology Group, Institute of Environmental Biology, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
| | - Lewis G Spurgin
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - David S Richardson
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
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41
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Biedrzycka A, Kloch A. Development of novel associations between MHC alleles and susceptibility to parasitic infections in an isolated population of an endangered mammal. INFECTION GENETICS AND EVOLUTION 2016; 44:210-217. [PMID: 27423515 DOI: 10.1016/j.meegid.2016.07.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 07/11/2016] [Accepted: 07/12/2016] [Indexed: 10/21/2022]
Abstract
The role of pathogens in dynamics of endangered species is not fully understood, and the effect of infection often interacts with other processes affecting those species, such as fragmentation and isolation or loss of genetic variation. Small, isolated populations are prone to losing functional alleles due to demographic processes and genetic drift, which may diminish their ability to resist infection if immune genes are affected. Demographic processes may also alter the selective pressure exerted by a parasite, as they influence the rate of parasite transmission between individuals. In the present paper we studied changes in parasite infection levels and genetic variability in an isolated population of spotted suslik (Spermophillus suslicus). Over a three-year period (approx. three generations), when the population size remained relatively stable, we observed a considerable increase in parasite prevalence and infection intensity, followed by the development of novel associations between MHC DRB alleles and parasite burden. Contrary to expectations, the change in MHC allele frequency over time was not consistent with the effect of the allele - for instance, Spsu-DRB*07, associated with higher intensity of infection with a nematode Capillaria sp., increased in frequency from 11.8 to 20.2%. Yet, we found no signatures of selection in the studied loci. Our results show that an isolated, stable population may experience a sudden increase in parasitic infections, resulting in a development of novel associations between MHC alleles and parasite susceptibility/resistance, even though no signatures of selection can be found.
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Affiliation(s)
- Aleksandra Biedrzycka
- Institute of Nature Conservation, Polish Academy of Sciences, al. A. Mickiewicza 33, 31-120 Kraków, Poland.
| | - Agnieszka Kloch
- Department of Ecology, Biological and Chemical Research Centre, Faculty of Biology, University of Warsaw, ul. Żwirki i Wigury 101, 02-089 Warszawa, Poland.
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42
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Setchell JM, Richards SA, Abbott KM, Knapp LA. Mate-guarding by male mandrills ( Mandrillus sphinx) is associated with female MHC genotype. Behav Ecol 2016. [DOI: 10.1093/beheco/arw106] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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43
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Lei W, Zhou X, Fang W, Lin Q, Chen X. Major histocompatibility complex class II DAB alleles associated with intestinal parasite load in the vulnerable Chinese egret (Egretta eulophotes). Ecol Evol 2016; 6:4421-34. [PMID: 27386085 PMCID: PMC4930990 DOI: 10.1002/ece3.2226] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 05/04/2016] [Accepted: 05/16/2016] [Indexed: 11/09/2022] Open
Abstract
The maintenance of major histocompatibility complex (MHC) polymorphism has been hypothesized to result from many mechanisms such as rare-allele advantage, heterozygote advantage, and allele counting. In the study reported herein, 224 vulnerable Chinese egrets (Egretta eulophotes) were used to examine these hypotheses as empirical results derived from bird studies are rare. Parasite survey showed that 147 (65.63%) individuals were infected with 1-3 helminths, and 82.31% of these infected individuals carried Ascaridia sp. Using asymmetric polymerase chain reaction technique, 10 DAB1, twelve DAB2, and three DAB3 exon 2 alleles were identified at each single locus. A significant association of the rare allele Egeu-DAB2*05 (allele frequency: 0.022) with helminth resistance was found for all helminths, as well as for the most abundant morphotype Ascaridia sp. in the separate analyses. Egeu-DAB2*05 occurred frequently in uninfected individuals, and individuals carrying Egeu-DAB2*05 had significantly lower helminth morphotypes per individual (HMI) (the number of HMI) and the fecal egg count values. Further, the parasite infection measurements were consistently lower in individuals with an intermediate number of different alleles in the duplicated DAB loci. Significantly, heterozygosity within each DAB locus was not correlated with any parasite infection measurements. These results indicate that the diversity in MHC Egeu-DAB gene is associated with intestinal parasite load and maintained by pathogen-driven selection that probably operate through both the rare-allele advantage and the allele counting strategy, and suggest that Egeu-DAB2*05 might be a valuable indicator of better resistance to helminth diseases in the vulnerable Chinese egret.
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Affiliation(s)
- Wei Lei
- Key Laboratory of Ministry of Education for Coast and Wetland EcosystemsCollege of the Environment and EcologyXiamen UniversityXiamen361102China
| | - Xiaoping Zhou
- Key Laboratory of Ministry of Education for Coast and Wetland EcosystemsCollege of the Environment and EcologyXiamen UniversityXiamen361102China
| | - Wenzhen Fang
- Key Laboratory of Ministry of Education for Coast and Wetland EcosystemsCollege of the Environment and EcologyXiamen UniversityXiamen361102China
| | - Qingxian Lin
- Key Laboratory of Ministry of Education for Coast and Wetland EcosystemsCollege of the Environment and EcologyXiamen UniversityXiamen361102China
| | - Xiaolin Chen
- Key Laboratory of Ministry of Education for Coast and Wetland EcosystemsCollege of the Environment and EcologyXiamen UniversityXiamen361102China
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44
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Ferrandiz-Rovira M, Allainé D, Callait-Cardinal MP, Cohas A. Mate choice for neutral and MHC genetic characteristics in Alpine marmots: different targets in different contexts? Ecol Evol 2016; 6:4243-57. [PMID: 27386072 PMCID: PMC4930977 DOI: 10.1002/ece3.2189] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 04/11/2016] [Accepted: 04/26/2016] [Indexed: 01/16/2023] Open
Abstract
Sexual selection through female mate choice for genetic characteristics has been suggested to be an important evolutionary force maintaining genetic variation in animal populations. However, the genetic targets of female mate choice are not clearly identified and whether female mate choice is based on neutral genetic characteristics or on particular functional loci remains an open question. Here, we investigated the genetic targets of female mate choice in Alpine marmots (Marmota marmota), a socially monogamous mammal where extra‐pair paternity (EPP) occurs. We used 16 microsatellites to describe neutral genetic characteristics and two MHC loci belonging to MHC class I and II as functional genetic characteristics. Our results reveal that (1) neutral and MHC genetic characteristics convey different information in this species, (2) social pairs show a higher MHC class II dissimilarity than expected under random mate choice, and (3) the occurrence of EPP increases when social pairs present a high neutral genetic similarity or dissimilarity but also when they present low MHC class II dissimilarity. Thus, female mate choice is based on both neutral and MHC genetic characteristics, and the genetic characteristics targeted seem to be context dependent (i.e., the genes involved in social mate choice and genetic mate choice differ). We emphasize the need for empirical studies of mate choice in the wild using both neutral and MHC genetic characteristics because whether neutral and functional genetic characteristics convey similar information is not universal.
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Affiliation(s)
- Mariona Ferrandiz-Rovira
- Laboratoire Biométrie et Biologie Evolutive Université de Lyon CNRS UMR 5558 Université Lyon 1 F-69622 Villeurbanne F-69000 Lyon France; Université of Lyon VetAgro Sup Campus Vet F-69280 Marcy-L'Étoile France; CREAF Cerdanyola del Vallès 08193 Catalonia Spain; Univ Autònoma de Barcelona Cerdanyola del Vallès 08193 Catalonia Spain
| | - Dominique Allainé
- Laboratoire Biométrie et Biologie Evolutive Université de Lyon CNRS UMR5558 Université Lyon 1 F-69622 Villeurbanne F-69000 Lyon France
| | - Marie-Pierre Callait-Cardinal
- Laboratoire Biométrie et Biologie Evolutive Université de Lyon CNRS UMR 5558 Université Lyon 1 F-69622 Villeurbanne F-69000 Lyon France; Université of Lyon VetAgro Sup Campus Vet F-69280 Marcy-L'Étoile France
| | - Aurélie Cohas
- Laboratoire Biométrie et Biologie Evolutive Université de Lyon CNRS UMR5558 Université Lyon 1 F-69622 Villeurbanne F-69000 Lyon France
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45
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Grogan KE, McGinnis GJ, Sauther ML, Cuozzo FP, Drea CM. Next-generation genotyping of hypervariable loci in many individuals of a non-model species: technical and theoretical implications. BMC Genomics 2016; 17:204. [PMID: 26957424 PMCID: PMC4782575 DOI: 10.1186/s12864-016-2503-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Accepted: 02/18/2016] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND Across species, diversity at the Major Histocompatibility Complex (MHC) is critical to disease resistance and population health; however, use of MHC diversity to quantify the genetic health of populations has been hampered by the extreme variation found in MHC genes. Next generation sequencing (NGS) technology generates sufficient data to genotype even the most diverse species, but workflows for distinguishing artifacts from alleles are still under development. We used NGS to evaluate the MHC diversity of over 300 captive and wild ring-tailed lemurs (Lemur catta: Primates: Mammalia). We modified a published workflow to address errors that arise from deep sequencing individuals and tested for evidence of selection at the most diverse MHC genes. RESULTS In addition to evaluating the accuracy of 454 Titanium and Ion Torrent PGM for genotyping large populations at hypervariable genes, we suggested modifications to improve current methods of allele calling. Using these modifications, we genotyped 302 out of 319 individuals, obtaining an average sequencing depth of over 1000 reads per amplicon. We identified 55 MHC-DRB alleles, 51 of which were previously undescribed, and provide the first sequences of five additional MHC genes: DOA, DOB, DPA, DQA, and DRA. The additional five MHC genes had one or two alleles each with little sequence variation; however, the 55 MHC-DRB alleles showed a high dN/dS ratio and trans-species polymorphism, indicating a history of positive selection. Because each individual possessed 1-7 MHC-DRB alleles, we suggest that ring-tailed lemurs have four, putatively functional, MHC-DRB copies. CONCLUSIONS In the future, accurate genotyping methods for NGS data will be critical to assessing genetic variation in non-model species. We recommend that future NGS studies increase the proportion of replicated samples, both within and across platforms, particularly for hypervariable genes like the MHC. Quantifying MHC diversity within non-model species is the first step to assessing the relationship of genetic diversity at functional loci to individual fitness and population viability. Owing to MHC-DRB diversity and copy number, ring-tailed lemurs may serve as an ideal model for estimating the interaction between genetic diversity, fitness, and environment, especially regarding endangered species.
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Affiliation(s)
- Kathleen E Grogan
- University Program in Ecology, Duke University, Durham, NC, USA.
- Department of Evolutionary Anthropology, Duke University, Durham, NC, USA.
- Emory University, Room 2006 O. Wayne Rollins Research Center, 1510 Clifton Rd NE, Atlanta, GA, 30322, USA.
| | | | - Michelle L Sauther
- Department of Anthropology, University of Colorado-Boulder, Boulder, CO, USA
| | - Frank P Cuozzo
- Department of Anthropology, University of North Dakota, Grand Forks, ND, USA
| | - Christine M Drea
- University Program in Ecology, Duke University, Durham, NC, USA
- Department of Evolutionary Anthropology, Duke University, Durham, NC, USA
- Department of Biology, Duke University, Durham, USA
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46
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O'Connor EA, Strandh M, Hasselquist D, Nilsson JÅ, Westerdahl H. The evolution of highly variable immunity genes across a passerine bird radiation. Mol Ecol 2016; 25:977-89. [DOI: 10.1111/mec.13530] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Revised: 11/24/2015] [Accepted: 12/09/2015] [Indexed: 11/29/2022]
Affiliation(s)
- E. A. O'Connor
- Molecular Ecology and Evolution Lab; Lund University; Ecology building 223 62 Lund Sweden
| | - M. Strandh
- Molecular Ecology and Evolution Lab; Lund University; Ecology building 223 62 Lund Sweden
| | - D. Hasselquist
- Molecular Ecology and Evolution Lab; Lund University; Ecology building 223 62 Lund Sweden
| | - J.-Å. Nilsson
- Molecular Ecology and Evolution Lab; Lund University; Ecology building 223 62 Lund Sweden
| | - H. Westerdahl
- Molecular Ecology and Evolution Lab; Lund University; Ecology building 223 62 Lund Sweden
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Buczek M, Okarma H, Demiaszkiewicz AW, Radwan J. MHC, parasites and antler development in red deer: no support for the Hamilton & Zuk hypothesis. J Evol Biol 2016; 29:617-32. [PMID: 26687843 DOI: 10.1111/jeb.12811] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Revised: 12/08/2015] [Accepted: 12/11/2015] [Indexed: 12/28/2022]
Abstract
The Hamilton-Zuk hypothesis proposes that the genetic benefits of preferences for elaborated secondary sexual traits have their origins in the arms race between hosts and parasites, which maintains genetic variance in parasite resistance. Infection, in turn, can be reflected in the expression of costly sexual ornaments. However, the link between immune genes, infection and the expression of secondary sexual traits has rarely been investigated. Here, we explored whether the presence and identity of functional variants (supertypes) of the highly polymorphic major histocompatibility complex (MHC), which is responsible for the recognition of parasites, predict the load of lung and gut parasites and antler development in the red deer (Cervus elaphus). While we found MHC supertypes to be associated with infection by a number of parasite species, including debilitating lung nematodes, we did not find support for the Hamilton-Zuk hypothesis. On the contrary, we found that lung nematode load was positively associated with antler development. We also found that the supertypes that were associated with resistance to certain parasites at the same time cause susceptibility to others. Such trade-offs may undermine the potential genetic benefits of mate choice for resistant partners.
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Affiliation(s)
- M Buczek
- Institute of Environmental Sciences, Jagiellonian University, Krakow, Poland
| | - H Okarma
- Institute of Nature Conservation, Polish Academy of Sciences, Kraków, Poland
| | | | - J Radwan
- Institute of Environmental Sciences, Jagiellonian University, Krakow, Poland.,Institute of Environmental Biology, Adam Mickiewicz University, Poznań, Poland
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Long-term spatiotemporal stability and dynamic changes in helminth infracommunities of bank voles (Myodes glareolus) in NE Poland. Parasitology 2015; 142:1722-43. [PMID: 26442655 DOI: 10.1017/s0031182015001225] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Parasites are considered to be an important selective force in host evolution but ecological studies of host-parasite systems are usually short-term providing only snap-shots of what may be dynamic systems. We have conducted four surveys of helminths of bank voles at three ecologically similar woodland sites in NE Poland, spaced over a period of 11 years, to assess the relative importance of temporal and spatial effects on helminth infracommunities. Some measures of infracommunity structure maintained relative stability: the rank order of prevalence and abundance of Heligmosomum mixtum, Heligmosomoides glareoli and Mastophorus muris changed little between the four surveys. Other measures changed markedly: dynamic changes were evident in Syphacia petrusewiczi which declined to local extinction, while the capillariid Aonchotheca annulosa first appeared in 2002 and then increased in prevalence and abundance over the remaining three surveys. Some species are therefore dynamic and both introductions and extinctions can be expected in ecological time. At higher taxonomic levels and for derived measures, year and host-age effects and their interactions with site are important. Our surveys emphasize that the site of capture is the major determinant of the species contributing to helminth community structure, providing some predictability in these systems.
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Kloch A, Michalski A, Bajer A, Behnke J. Biased sex ratio among worms of the family Heligmosomidae--searching for a mechanism. Int J Parasitol 2015; 45:939-45. [PMID: 26385437 DOI: 10.1016/j.ijpara.2015.08.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 07/30/2015] [Accepted: 08/01/2015] [Indexed: 10/23/2022]
Abstract
According to Fisher's principle, an equal sex ratio is an evolutionary stable strategy. However, biased sex ratios have been reported in many metazoan parasite species, although the causes and mechanisms of the observed bias are still poorly understood. In the present study, we analysed sex ratios in long-term datasets from three populations of bank voles (Clethrionomys (=Myodes) glareolus) infected with Heligmosomum mixtum and Heligmosomoides glareoli. The overall sex ratios of both species were female-biased but in contrast to previous studies we did not find a relationship between the proportion of females and infection intensity. A higher female bias was observed in older hosts, suggesting that the sex ratio changes over time; the lifespan of nematodes in the family Heligmosomidae is known to be comparable with that of their hosts. We also compared the distributions of sexes in voles infected with two, three, four or five worms and we found significant differences from the expected values in both parasite species. In infections with four and five H. glareoli we observed more single-sex infections than expected, both female- and male-dominated, whereas in the case of H. mixtum female-dominated infections were more frequent.
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Affiliation(s)
- Agnieszka Kloch
- Department of Ecology, Faculty of Biology, Biological and Chemical Research Centre, University of Warsaw, ul. Zwirki i Wigury 101, 02-089 Warszawa, Poland.
| | - Aleksander Michalski
- perlism.org Data Analysis & Visualisation, ul. Przy Agorze 5a m. 98, 01-960 Warszawa, Poland
| | - Anna Bajer
- Department of Parasitology, Faculty of Biology, University of Warsaw, ul. Miecznikowa 1, 02-096 Warszawa, Poland
| | - Jerzy Behnke
- School of Life Sciences, University of Nottingham, Nottinghamshire NG7, UK
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50
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Hans JB, Haubner A, Arandjelovic M, Bergl RA, Fünfstück T, Gray M, Morgan DB, Robbins MM, Sanz C, Vigilant L. Characterization of MHC class II B polymorphism in multiple populations of wild gorillas using non-invasive samples and next-generation sequencing. Am J Primatol 2015; 77:1193-206. [PMID: 26283172 DOI: 10.1002/ajp.22458] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 07/08/2015] [Accepted: 08/03/2015] [Indexed: 01/03/2023]
Abstract
Genes encoded by the major histocompatibility complex (MHC) are crucial for the recognition and presentation of antigens to the immune system. In contrast to their closest relatives, chimpanzees and humans, much less is known about variation in gorillas at these loci. This study explored the exon 2 variation of -DPB1, -DQB1, and -DRB genes in 46 gorillas from four populations while simultaneously evaluating the feasibility of using fecal samples for high-throughput MHC genotyping. By applying strict similarity- and frequency-based analysis, we found, despite our modest sample size, a total of 18 alleles that have not been described previously, thereby illustrating the potential for efficient and highly accurate MHC genotyping from non-invasive DNA samples. We emphasize the importance of controlling for multiple potential sources of error when applying this massively parallel short-read sequencing technology to PCR products generated from low concentration DNA extracts. We observed pronounced differences in MHC variation between species, subspecies and populations that are consistent with both the ancient and recent demographic histories experienced by gorillas.
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Affiliation(s)
- Jörg B Hans
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Anne Haubner
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Mimi Arandjelovic
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Richard A Bergl
- North Carolina Zoological Park, Asheboro, North Carolina, USA
| | | | - Maryke Gray
- International Gorilla Conservation Program, Kigali, Rwanda
| | | | - Martha M Robbins
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | | | - Linda Vigilant
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
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