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Martchenko D, Shafer ABA. Contrasting whole-genome and reduced representation sequencing for population demographic and adaptive inference: an alpine mammal case study. Heredity (Edinb) 2023; 131:273-281. [PMID: 37532838 PMCID: PMC10539292 DOI: 10.1038/s41437-023-00643-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 07/22/2023] [Accepted: 07/22/2023] [Indexed: 08/04/2023] Open
Abstract
Genomes capture the adaptive and demographic history of a species, but the choice of sequencing strategy and sample size can impact such inferences. We compared whole genome and reduced representation sequencing approaches to study the population demographic and adaptive signals of the North American mountain goat (Oreamnos americanus). We applied the restriction site-associated DNA sequencing (RADseq) approach to 254 individuals and whole genome resequencing (WGS) approach to 35 individuals across the species range at mid-level coverage (9X) and to 5 individuals at high coverage (30X). We used ANGSD to estimate the genotype likelihoods and estimated the effective population size (Ne), population structure, and explicitly modelled the demographic history with δaδi and MSMC2. The data sets were overall concordant in supporting a glacial induced vicariance and extremely low Ne in mountain goats. We evaluated a set of climatic variables and geographic location as predictors of genetic diversity using redundancy analysis. A moderate proportion of total variance (36% for WGS and 21% for RADseq data sets) was explained by geography and climate variables; both data sets support a large impact of drift and some degree of local adaptation. The empirical similarities of WGS and RADseq presented herein reassuringly suggest that both approaches will recover large demographic and adaptive signals in a population; however, WGS offers several advantages over RADseq, such as inferring adaptive processes and calculating runs-of-homozygosity estimates. Considering the predicted climate-induced changes in alpine environments and the genetically depauperate mountain goat, the long-term adaptive capabilities of this enigmatic species are questionable.
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Affiliation(s)
- Daria Martchenko
- Environmental and Life Sciences Graduate Program, Trent University, 2140 East Bank Drive, Peterborough, ON, K9J 7B8, Canada.
| | - Aaron B A Shafer
- Environmental and Life Sciences Graduate Program, Trent University, 2140 East Bank Drive, Peterborough, ON, K9J 7B8, Canada
- Department of Forensics & Environmental and Life Sciences Graduate Program, Trent University, 2140 East Bank Drive, Peterborough, ON, K9J 7B8, Canada
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2
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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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3
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Batley KC, Sandoval-Castillo J, Kemper CM, Zanardo N, Tomo I, Beheregaray LB, Möller LM. Whole genomes reveal multiple candidate genes and pathways involved in the immune response of dolphins to a highly infectious virus. Mol Ecol 2021; 30:6434-6448. [PMID: 33675577 DOI: 10.1111/mec.15873] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 02/11/2021] [Accepted: 02/22/2021] [Indexed: 01/02/2023]
Abstract
Wildlife species are challenged by various infectious diseases that act as important demographic drivers of populations and have become a great conservation concern particularly under growing environmental changes. The new era of whole genome sequencing provides new opportunities and avenues to explore the role of genetic variants in the plasticity of immune responses, particularly in non-model systems. Cetacean morbillivirus (CeMV) has emerged as a major viral threat to cetacean populations worldwide, contributing to the death of thousands of individuals of multiple dolphin and whale species. To understand the genomic basis of immune responses to CeMV, we generated and analysed whole genomes of 53 Indo-Pacific bottlenose dolphins (Tursiops aduncus) exposed to Australia's largest known CeMV-related mortality event that killed at least 50 dolphins from three different species. The genomic data set consisted of 10,168,981 SNPs anchored onto 23 chromosome-length scaffolds and 77 short scaffolds. Whole genome analysis indicated that levels of inbreeding in the dolphin population did not influence the outcome of an individual. Allele frequency estimates between survivors and nonsurvivors of the outbreak revealed 15,769 candidate SNPs, of which 689 were annotated to 295 protein coding genes. These included 50 genes with functions related to innate and adaptive immune responses, and cytokine signalling pathways and genes thought to be involved in immune responses to other morbilliviruses. Our study characterised genomic regions and pathways that may contribute to CeMV immune responses in dolphins. This represents a stride towards clarifying the complex interactions of the cetacean immune system and emphasises the value of whole genome data sets in understanding genetic elements that are essential for species conservation, including disease susceptibility and adaptation.
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Affiliation(s)
- Kimberley C Batley
- Molecular Ecology Laboratory, College of Science and Engineering, Flinders University, Adelaide, South Australia, Australia.,Cetacean Ecology, Behaviour, and Evolution Laboratory, College of Science and Engineering, Flinders University, Adelaide, South Australia, Australia
| | - Jonathan Sandoval-Castillo
- Molecular Ecology Laboratory, College of Science and Engineering, Flinders University, Adelaide, South Australia, Australia
| | | | - Nikki Zanardo
- Molecular Ecology Laboratory, College of Science and Engineering, Flinders University, Adelaide, South Australia, Australia.,Cetacean Ecology, Behaviour, and Evolution Laboratory, College of Science and Engineering, Flinders University, Adelaide, South Australia, Australia
| | - Ikuko Tomo
- South Australian Museum, Adelaide, South Australia, Australia
| | - Luciano B Beheregaray
- Molecular Ecology Laboratory, College of Science and Engineering, Flinders University, Adelaide, South Australia, Australia
| | - Luciana M Möller
- Molecular Ecology Laboratory, College of Science and Engineering, Flinders University, Adelaide, South Australia, Australia.,Cetacean Ecology, Behaviour, and Evolution Laboratory, College of Science and Engineering, Flinders University, Adelaide, South Australia, Australia
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4
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E GX, Chen LP, Zhou DK, Yang BG, Zhang JH, Zhao YJ, Hong QH, Ma YH, Chu MX, Zhang LP, Basang WD, Zhu YB, Han YG, Na RS, Zeng Y, Zhao ZQ, Huang YF, Han JL. Evolutionary relationship and population structure of domestic Bovidae animals based on MHC-linked and neutral autosomal microsatellite markers. Mol Immunol 2020; 124:83-90. [PMID: 32544655 DOI: 10.1016/j.molimm.2020.05.005] [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: 12/30/2019] [Revised: 04/21/2020] [Accepted: 05/07/2020] [Indexed: 11/26/2022]
Abstract
Major histocompatibility complex (MHC) genes are critical for disease resistance or susceptibility responsible for host-pathogen interactions determined mainly by extensive polymorphisms in the MHC genes. Here, we examined the diversity and phylogenetic pattern of MHC haplotypes reconstructed using three MHC-linked microsatellite markers in 55 populations of five Bovidae species and compared them with those based on neutral autosomal microsatellite markers (NAMs). Three-hundred-and-forty MHC haplotypes were identified in 1453 Bovidae individuals, suggesting significantly higher polymorphism and heterozygosity compared with those based on NAMs. The ambitious boundaries in population differentiation (phylogenetic network, pairwise FST and STRUCTURE analyses) within and between species assessed using the MHC haplotypes were different from those revealed by NAMs associated closely with speciation, geographical distribution, domestication and management histories. In addition, the mean FST was significantly correlated negatively with the number of observed alleles (NA), observed (HO) and expected (HE) heterozygosity and polymorphism information content (PIC) (P < 0.05) in the MHC haplotype dataset while there was no correction of the mean FST estimates (P> 0.05) between the MHC haplotype and NAMs datasets. Analysis of molecular variance (AMOVA) revealed a lower percentage of total variance (PTV) between species/groups based on the MHC-linked microsatellites than NAMs. Therefore, it was inferred that individuals within populations accumulated as many MHC variants as possible to increase their heterozygosity and thus the survival rate of their affiliated populations and species, which eventually reduced population differentiation and thereby complicated their classification and phylogenetic relationship inference. In summary, host-pathogen coevolution and heterozygote advantage, rather than demographic history, act as key driving forces shaping the MHC diversity within the populations and determining the interspecific MHC diversity.
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Affiliation(s)
- Guang-Xin E
- College of Animal Science and Technology, Chongqing Key Laboratory of Forage & Herbivores, Chongqing Engineering Research Centre for Herbivore Resource Protection and Utilization, Southwest University, Chongqing 400716, China
| | - Li-Peng Chen
- College of Animal Science and Technology, Chongqing Key Laboratory of Forage & Herbivores, Chongqing Engineering Research Centre for Herbivore Resource Protection and Utilization, Southwest University, Chongqing 400716, China
| | - Dong-Ke Zhou
- College of Animal Science and Technology, Chongqing Key Laboratory of Forage & Herbivores, Chongqing Engineering Research Centre for Herbivore Resource Protection and Utilization, Southwest University, Chongqing 400716, China
| | - Bai-Gao Yang
- College of Animal Science and Technology, Chongqing Key Laboratory of Forage & Herbivores, Chongqing Engineering Research Centre for Herbivore Resource Protection and Utilization, Southwest University, Chongqing 400716, China
| | - Jia-Hua Zhang
- College of Animal Science and Technology, Chongqing Key Laboratory of Forage & Herbivores, Chongqing Engineering Research Centre for Herbivore Resource Protection and Utilization, Southwest University, Chongqing 400716, China
| | - Yong-Ju Zhao
- College of Animal Science and Technology, Chongqing Key Laboratory of Forage & Herbivores, Chongqing Engineering Research Centre for Herbivore Resource Protection and Utilization, Southwest University, Chongqing 400716, China
| | - Qiong-Hua Hong
- Yunnan Animal Science and Veterinary Institute, Kunming 650224, China
| | - Yue-Hui Ma
- Institute of Animal Science, Chinese Academy of Agricultural Sciences (CAAS), Beijing 100193, China
| | - Ming-Xing Chu
- Institute of Animal Science, Chinese Academy of Agricultural Sciences (CAAS), Beijing 100193, China
| | - Lu-Pei Zhang
- Institute of Animal Science, Chinese Academy of Agricultural Sciences (CAAS), Beijing 100193, China
| | - Wang-Dui Basang
- State Key Laboratory of Barley and Yak Germplasm Resources and Genetic Improvement (Tibet Academy of Agricultural and Animal Husbandry Science (TAAAS)), Lhasa 850002, China
| | - Yan-Bin Zhu
- State Key Laboratory of Barley and Yak Germplasm Resources and Genetic Improvement (Tibet Academy of Agricultural and Animal Husbandry Science (TAAAS)), Lhasa 850002, China
| | - Yan-Guo Han
- College of Animal Science and Technology, Chongqing Key Laboratory of Forage & Herbivores, Chongqing Engineering Research Centre for Herbivore Resource Protection and Utilization, Southwest University, Chongqing 400716, China
| | - Ri-Su Na
- College of Animal Science and Technology, Chongqing Key Laboratory of Forage & Herbivores, Chongqing Engineering Research Centre for Herbivore Resource Protection and Utilization, Southwest University, Chongqing 400716, China
| | - Yan Zeng
- College of Animal Science and Technology, Chongqing Key Laboratory of Forage & Herbivores, Chongqing Engineering Research Centre for Herbivore Resource Protection and Utilization, Southwest University, Chongqing 400716, China
| | - Zhong-Quan Zhao
- College of Animal Science and Technology, Chongqing Key Laboratory of Forage & Herbivores, Chongqing Engineering Research Centre for Herbivore Resource Protection and Utilization, Southwest University, Chongqing 400716, China
| | - Yong-Fu Huang
- College of Animal Science and Technology, Chongqing Key Laboratory of Forage & Herbivores, Chongqing Engineering Research Centre for Herbivore Resource Protection and Utilization, Southwest University, Chongqing 400716, China.
| | - Jian-Lin Han
- CAAS-ILRI Joint Laboratory on Livestock and Forage Genetic Resources Institute of Animal Science, Chinese Academy of Agricultural Sciences (CAAS), Beijing 100193, China; Livestock Genetics Program, International Livestock Research Institute (ILRI), Nairobi 00100, Kenya.
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5
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E GX, Duan XH, Yang BG, Na RS, Han YG, Zeng Y. Genetic Diversity Pattern of the MHC-LEI0258 Locus across Asian Populations of Chickens. RUSS J GENET+ 2020. [DOI: 10.1134/s1022795420060058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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6
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Becker DJ, Albery GF, Kessler MK, Lunn TJ, Falvo CA, Czirják GÁ, Martin LB, Plowright RK. Macroimmunology: The drivers and consequences of spatial patterns in wildlife immune defence. J Anim Ecol 2020; 89:972-995. [PMID: 31856309 DOI: 10.1111/1365-2656.13166] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 11/06/2019] [Indexed: 01/26/2023]
Abstract
The prevalence and intensity of parasites in wild hosts varies across space and is a key determinant of infection risk in humans, domestic animals and threatened wildlife. Because the immune system serves as the primary barrier to infection, replication and transmission following exposure, we here consider the environmental drivers of immunity. Spatial variation in parasite pressure, abiotic and biotic conditions, and anthropogenic factors can all shape immunity across spatial scales. Identifying the most important spatial drivers of immunity could help pre-empt infectious disease risks, especially in the context of how large-scale factors such as urbanization affect defence by changing environmental conditions. We provide a synthesis of how to apply macroecological approaches to the study of ecoimmunology (i.e. macroimmunology). We first review spatial factors that could generate spatial variation in defence, highlighting the need for large-scale studies that can differentiate competing environmental predictors of immunity and detailing contexts where this approach might be favoured over small-scale experimental studies. We next conduct a systematic review of the literature to assess the frequency of spatial studies and to classify them according to taxa, immune measures, spatial replication and extent, and statistical methods. We review 210 ecoimmunology studies sampling multiple host populations. We show that whereas spatial approaches are relatively common, spatial replication is generally low and unlikely to provide sufficient environmental variation or power to differentiate competing spatial hypotheses. We also highlight statistical biases in macroimmunology, in that few studies characterize and account for spatial dependence statistically, potentially affecting inferences for the relationships between environmental conditions and immune defence. We use these findings to describe tools from geostatistics and spatial modelling that can improve inference about the associations between environmental and immunological variation. In particular, we emphasize exploratory tools that can guide spatial sampling and highlight the need for greater use of mixed-effects models that account for spatial variability while also allowing researchers to account for both individual- and habitat-level covariates. We finally discuss future research priorities for macroimmunology, including focusing on latitudinal gradients, range expansions and urbanization as being especially amenable to large-scale spatial approaches. Methodologically, we highlight critical opportunities posed by assessing spatial variation in host tolerance, using metagenomics to quantify spatial variation in parasite pressure, coupling large-scale field studies with small-scale field experiments and longitudinal approaches, and applying statistical tools from macroecology and meta-analysis to identify generalizable spatial patterns. Such work will facilitate scaling ecoimmunology from individual- to habitat-level insights about the drivers of immune defence and help predict where environmental change may most alter infectious disease risk.
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Affiliation(s)
- Daniel J Becker
- Department of Biology, Indiana University, Bloomington, IN, USA.,Center for the Ecology of Infectious Disease, University of Georgia, Athens, GA, USA
| | - Gregory F Albery
- Department of Biology, Georgetown University, Washington, DC, USA
| | | | - Tamika J Lunn
- Environmental Futures Research Institute, Griffith University, Nathan, Queensland, Australia
| | - Caylee A Falvo
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| | - Gábor Á Czirják
- Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany
| | - Lynn B Martin
- Department of Global and Planetary Health, University of South Florida, Tampa, FL, USA
| | - Raina K Plowright
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
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7
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Ilie DE, Kusza S, Sauer M, Gavojdian D. Genetic characterization of indigenous goat breeds in Romania and Hungary with a special focus on genetic resistance to mastitis and gastrointestinal parasitism based on 40 SNPs. PLoS One 2018; 13:e0197051. [PMID: 29742137 PMCID: PMC5942826 DOI: 10.1371/journal.pone.0197051] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 04/25/2018] [Indexed: 11/18/2022] Open
Abstract
Goat breeding has become an important sector in Eastern Europe, with Romania and Hungary being among the major producer countries. Given the limited number of research done up-to-date concerning genetic studies of indigenous goat breeds reared in Romania and Hungary, the current preliminary study aimed to analyze the variability of genes related to mastitis and gastrointestinal parasitism by using Kompetitive Allele Specific PCR (KASP™). We studied 52 single nucleotide polymorphisms (SNPs) belonging to 19 genes in indigenous breeds from both countries, namely Banat's White (n = 36), Carpatina (n = 35) from Romania and Hungarian Milking (n = 79) and identified 16 polymorphic SNPs among 10 genes (PTX3, IL6, CLEC4E, IL8, IL1RN, IL15RA, TNFSF13, SOCS3, TNF and TLR3) in 150 animals. Furthermore, the diversity of the studied breeds was investigated. The PIC values ranged from 0.042 to 0.691. The mean values of observed and expected heterozygosity were 0.235 and 0.246 respectively. The highest observed heterozygosity was obtained for IL15RA g.10343904C>T in Banat's White (0.464), IL15RA g.10354813C>T in Carpatina (0.577) and SOCS3 g.52626440T>G in Hungarian Milking (0.588). Pairwise FST values between the Romanian breeds and Romanian and Hungarian breeds were small (0.009 and 0.015), indicating the close relationship among the studied goat populations. From all the polymorphic SNPs identified, the Hungarian Milking breed showed the highest proportion of polymorphisms (100%), whereas the Carpatina breed had the lowest percentage (87.5%). The highest value of MAF was obtained for SOCS3 g.52626440T>G (0.46), IL15RA g.10343904C>T (0.47), IL15RA g.10344025C>T (0.45), and IL15RA g.10354813C>T (0.42). The 16 polymorphic SNPs identified in a panel of 150 unrelated individuals belonging to three Romanian and Hungarian indigenous goat breeds could be used in future genomic based breeding schemes as markers for genetic resistance to mastitis and gastrointestinal parasitism in goat breeds found in Eastern and Central Europe.
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Affiliation(s)
- Daniela Elena Ilie
- Department of Research, Research and Development Station for Sheep and Goats Caransebes, Academy for Agricultural and Forestry Sciences, Caransebes, Romania
- Department of Research, Research and Development Station for Bovine Arad, Academy for Agricultural and Forestry Sciences, Arad, Romania
- * E-mail:
| | - Szilvia Kusza
- Department of Research, Research and Development Station for Sheep and Goats Caransebes, Academy for Agricultural and Forestry Sciences, Caransebes, Romania
- Animal Genetics Laboratory, Institute of Animal Science, Biotechnology and Nature Conservation, University of Debrecen, Debrecen, Hungary
| | - Maria Sauer
- Department of Research, Research and Development Station for Sheep and Goats Caransebes, Academy for Agricultural and Forestry Sciences, Caransebes, Romania
| | - Dinu Gavojdian
- Department of Research, Research and Development Station for Sheep and Goats Caransebes, Academy for Agricultural and Forestry Sciences, Caransebes, Romania
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Angelone S, Jowers MJ, Molinar Min AR, Fandos P, Prieto P, Pasquetti M, Cano-Manuel FJ, Mentaberre G, Olvera JRL, Ráez-Bravo A, Espinosa J, Pérez JM, Soriguer RC, Rossi L, Granados JE. Hidden MHC genetic diversity in the Iberian ibex (Capra pyrenaica). BMC Genet 2018; 19:28. [PMID: 29739323 PMCID: PMC5941765 DOI: 10.1186/s12863-018-0616-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 04/30/2018] [Indexed: 01/09/2023] Open
Abstract
Background Defining hidden genetic diversity within species is of great significance when attempting to maintain the evolutionary potential of natural populations and conduct appropriate management. Our hypothesis is that isolated (and eventually small) wild animal populations hide unexpected genetic diversity due to their maintenance of ancient polymorphisms or introgressions. Results We tested this hypothesis using the Iberian ibex (Capra pyrenaica) as an example. Previous studies based on large sample sizes taken from its principal populations have revealed that the Iberian ibex has a remarkably small MHC DRB1 diversity (only six remnant alleles) as a result of recent population bottlenecks and a marked demographic decline that has led to the extinction of two recognized subspecies. Extending on the geographic range to include non-studied isolated Iberian ibex populations, we sequenced a new MHC DRB1 in what seemed three small isolated populations in Southern Spain (n = 132). The findings indicate a higher genetic diversity than previously reported in this important gene. The newly discovered allele, MHC DRB1*7, is identical to one reported in the domestic goat C. aegagrus hircus. Whether or not this is the result of ancient polymorphisms maintained by balancing selection or, alternatively, introgressions from domestic goats through hybridization needs to be clarified in future studies. However, hybridization between Iberian ibex and domestic goats has been reported in Spain and the fact that the newly discovered allele is only present in one of the small isolated populations and not in the others suggests introgression. The new discovered allele is not expected to increase fitness in C. pyrenaica since it generates the same protein as the existing MHC DRB1*6. Analysis of a microsatellite locus (OLADRB1) near the new MHC DRB1*7 gene reveals a linkage disequilibrium between these two loci. The allele OLADRB1, 187 bp in length, was unambiguously linked to the MHC DRB1*7 allele. This enabled us to perform a DRB-STR matching method for the recently discovered MHC allele. Conclusions This finding is critical for the conservation of the Iberian ibex since it directly affects the identification of the units of this species that should be managed and conserved separately (Evolutionarily Significant Units). Electronic supplementary material The online version of this article (10.1186/s12863-018-0616-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Samer Angelone
- Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas (CSIC), Avda. Américo Vespucio s/n, 41092, Sevilla, Spain. .,Institute of Evolutionary Biology and Environmental Studies (IEU), University of Zurich, Winterthurerstrasse 190, Zurich, Switzerland.
| | - Michael J Jowers
- CIBIO/ InBIO (Centro de Investigação em Biodiversidade e Recursos Genéticos), Universidade do Porto, Campus Agrario De Vairão, 4485-661, Vairão, Portugal
| | - Anna Rita Molinar Min
- Dipartimento di Scienze Veterinarie, Universita` degli Studi di Torino, Grugliasco, Italy
| | - Paulino Fandos
- Agencia de Medio Ambiente y Agua, E-41092, Sevilla, Isla de la Cartuja, Spain
| | - Paloma Prieto
- Parque Natural Sierras de Cazorla, Segura y Las Villas, Martínez Falero11, E-23470, Cazorla, Jaén, Spain
| | - Mario Pasquetti
- Dipartimento di Scienze Veterinarie, Universita` degli Studi di Torino, Grugliasco, Italy
| | | | - Gregorio Mentaberre
- Servei d'Ecopatologia de Fauna Salvatge (SEFAS), Departament de Medicina i Cirurgia Animals, Universitat Autònoma de Barcelona (UAB), E-08193 Bellaterra, Barcelona, Spain
| | - Jorge Ramón López Olvera
- Servei d'Ecopatologia de Fauna Salvatge (SEFAS), Departament de Medicina i Cirurgia Animals, Universitat Autònoma de Barcelona (UAB), E-08193 Bellaterra, Barcelona, Spain
| | - Arián Ráez-Bravo
- Servei d'Ecopatologia de Fauna Salvatge (SEFAS), Departament de Medicina i Cirurgia Animals, Universitat Autònoma de Barcelona (UAB), E-08193 Bellaterra, Barcelona, Spain
| | - José Espinosa
- Departamento de Biología Animal, Biología Vegetal y Ecología, Universidad de Jaén, Campus Las Lagunillas, s.n., E-23071, Jaén, Spain
| | - Jesús M Pérez
- Departamento de Biología Animal, Biología Vegetal y Ecología, Universidad de Jaén, Campus Las Lagunillas, s.n., E-23071, Jaén, Spain
| | - Ramón C Soriguer
- Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas (CSIC), Avda. Américo Vespucio s/n, 41092, Sevilla, Spain
| | - Luca Rossi
- Dipartimento di Scienze Veterinarie, Universita` degli Studi di Torino, Grugliasco, Italy
| | - José Enrique Granados
- Espacio Natural Sierra Nevada, Carretera Antigua de Sierra Nevada, Km 7, E-18071, Pinos Genil, Granada, Spain
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Schenekar T, Weiss S. Selection and genetic drift in captive versus wild populations: an assessment of neutral and adaptive (MHC-linked) genetic variation in wild and hatchery brown trout (Salmo trutta) populations. CONSERV GENET 2017. [DOI: 10.1007/s10592-017-0949-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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10
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11
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Rico Y, Ethier DM, Davy CM, Sayers J, Weir RD, Swanson BJ, Nocera JJ, Kyle CJ. Spatial patterns of immunogenetic and neutral variation underscore the conservation value of small, isolated American badger populations. Evol Appl 2016; 9:1271-1284. [PMID: 27877205 PMCID: PMC5108218 DOI: 10.1111/eva.12410] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 07/14/2016] [Indexed: 12/29/2022] Open
Abstract
Small and isolated populations often exhibit low genetic diversity due to drift and inbreeding, but may simultaneously harbour adaptive variation. We investigate spatial distributions of immunogenetic variation in American badger subspecies (Taxidea taxus), as a proxy for evaluating their evolutionary potential across the northern extent of the species' range. We compared genetic structure of 20 microsatellites and the major histocompatibility complex (MHC DRB exon 2) to evaluate whether small, isolated populations show low adaptive polymorphism relative to large and well-connected populations. Our results suggest that gene flow plays a prominent role in shaping MHC polymorphism across large spatial scales, while the interplay between gene flow and selection was stronger towards the northern peripheries. The similarity of MHC alleles within subspecies relative to their neutral genetic differentiation suggests that adaptive divergence among subspecies can be maintained despite ongoing gene flow along subspecies boundaries. Neutral genetic diversity was low in small relative to large populations, but MHC diversity within individuals was high in small populations. Despite reduced neutral genetic variation, small and isolated populations harbour functional variation that likely contribute to the species evolutionary potential at the northern range. Our findings suggest that conservation approaches should focus on managing adaptive variation across the species range rather than protecting subspecies per se.
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Affiliation(s)
- Yessica Rico
- Forensic Science DepartmentTrent UniversityPeterboroughONCanada
- Natural Resources DNA Profiling and Forensics CentreTrent UniversityPeterboroughONCanada
- Present address: CONACYTInstituto de Ecología A.C.Centro Regional del BajíoAvenida Lázaro Cárdenas 253PátzcuaroMichoacán61600México
| | - Danielle M. Ethier
- Ontario Badger ProjectGuelphONCanada
- Department of Integrative BiologyUniversity of GuelphGuelphONCanada
| | - Christina M. Davy
- Forensic Science DepartmentTrent UniversityPeterboroughONCanada
- Natural Resources DNA Profiling and Forensics CentreTrent UniversityPeterboroughONCanada
| | | | - Richard D. Weir
- Ecosystems Protection & Sustainability BranchMinistry of EnvironmentVictoriaBCCanada
| | | | - Joseph J. Nocera
- Wildlife Research and Monitoring SectionMinistry of Natural Resources & ForestryPeterboroughONCanada
| | - Christopher J. Kyle
- Forensic Science DepartmentTrent UniversityPeterboroughONCanada
- Natural Resources DNA Profiling and Forensics CentreTrent UniversityPeterboroughONCanada
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12
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A descriptive analysis of the climbing mechanics of a mountain goat (Oreamnos americanus). ZOOLOGY 2016; 119:541-546. [PMID: 27402383 DOI: 10.1016/j.zool.2016.06.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 02/01/2016] [Accepted: 06/01/2016] [Indexed: 11/22/2022]
Abstract
The mountain goat (Oreamnos americanus) is one of the most extraordinary mountaineers in the animal kingdom. While observational descriptions exist to indicate factors that may influence their climbing ability, these have never been assessed biomechanically. Here, we describe whole-body motion of a mountain goat during ascent of a 45° incline based on a video recording in the Canadian Rocky Mountains, and discuss the results in a mechanical context. During the push-off phase, the hindlimb extended and the forelimb was tucked close to the torso. During the pull-up phase, the hindlimb was raised near to the torso, while the forelimb humerus seemed to "lock" in a constant position relative to the torso, allowing the elbow to be held in close proximity to the whole-body center of mass. Extension of the elbow and carpal joints resulted in a vertical translation of the center of mass up the mountain slope. Based on the observations from this naturalistic study, hypotheses for future controlled studies of mountain goat climbing mechanics are proposed.
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13
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Cai R, Shafer ABA, Laguardia A, Lin Z, Liu S, Hu D. Recombination and selection in the major histocompatibility complex of the endangered forest musk deer (Moschus berezovskii). Sci Rep 2015; 5:17285. [PMID: 26603338 PMCID: PMC4658564 DOI: 10.1038/srep17285] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Accepted: 10/28/2015] [Indexed: 11/18/2022] Open
Abstract
The forest musk deer (Moschus berezovskii) is a high elevation species distributed across western China and northern Vietnam. Once abundant, habitat loss and poaching has led to a dramatic decrease in population numbers prompting the IUCN to list the species as endangered. Here, we characterized the genetic diversity of a Major Histocompatibility Complex (MHC) locus and teased apart driving factors shaping its variation. Seven DRB exon 2 alleles were identified among a group of randomly sampled forest musk deer from a captive population in the Sichuan province of China. Compared to other endangered or captive ungulates, forest musk deer have relatively low levels of MHC genetic diversity. Non-synonymous substitutions primarily occurred in the putative peptide-binding region (PBR), with analyses suggesting that recombination and selection has shaped the genetic diversity across the locus. Specifically, inter-allelic recombination generated novel allelic combinations, with evidence for both positive selection acting on the PBR and negative selection on the non-PBR. An improved understanding of functional genetic variability of the MHC will facilitate better design and management of captive breeding programs for this endangered species.
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Affiliation(s)
- Ruibo Cai
- College of Nature Conservation, Beijing Forestry University, China
| | | | - Alice Laguardia
- College of Nature Conservation, Beijing Forestry University, China
| | - Zhenzhen Lin
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Shuqiang Liu
- College of Nature Conservation, Beijing Forestry University, China
| | - Defu Hu
- College of Nature Conservation, Beijing Forestry University, China
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14
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Zemanová B, Hájková P, Hájek B, Martínková N, Mikulíček P, Zima J, Bryja J. Extremely low genetic variation in endangered Tatra chamois and evidence for hybridization with an introduced Alpine population. CONSERV GENET 2015. [DOI: 10.1007/s10592-015-0696-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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15
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Chen W, Bei Y, Li H. Genetic variation of the major histocompatibility complex (MHC class II B gene) in the threatened Hume's pheasant, Syrmaticus humiae. PLoS One 2015; 10:e0116499. [PMID: 25629763 PMCID: PMC4309451 DOI: 10.1371/journal.pone.0116499] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Accepted: 12/10/2014] [Indexed: 11/18/2022] Open
Abstract
Major histocompatibility complex (MHC) genes are the most polymorphic genes in vertebrates and encode molecules that play a crucial role in pathogen resistance. As a result of their diversity, they have received much attention in the fields of evolutionary and conservation biology. Here, we described the genetic variation of MHC class II B (MHCIIB) exon 2 in a wild population of Hume's pheasant (Syrmaticus humiae), which has suffered a dramatic decline in population over the last three decades across its ranges in the face of heavy exploitation and habitat loss. Twenty-four distinct alleles were found in 73 S. humiae specimens. We found seven shared alleles among four geographical groups as well as six rare MHCIIB alleles. Most individuals displayed between one to five alleles, suggesting that there are at least three MHCIIB loci of the Hume's pheasant. The dN ⁄ dS ratio at putative antigen-binding sites (ABS) was significantly greater than one, indicating balancing selection is acting on MHCIIB exon 2. Additionally, recombination and gene conversion contributed to generating MHCIIB diversity in the Hume's pheasant. One to three recombination events and seventy-five significant gene conversion events were observed within the Hume's pheasant MHCIIB loci. The phylogenetic tree and network analysis revealed that the Hume's pheasant alleles do not cluster together, but are scattered through the tree or network indicating a trans-species evolutionary mode. These findings revealed the evolution of the Hume's pheasant MHC after suffering extreme habitat fragmentation.
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Affiliation(s)
- Weicai Chen
- Natural History Museum of Guangxi, Nanning 530012, People’s Republic of China
| | - Yongjian Bei
- College of Life Science and Technology, Yulin Normal University, Yulin 537000, People’s Republic of China
| | - Hanhua Li
- Guangxi Key Laboratory of Rare and Endangered Animal Ecology, College of Life Sciences Guangxi Normal University, Guilin 541004, People’s Republic of China
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Drift rather than selection dominates MHC class II allelic diversity patterns at the biogeographical range scale in natterjack toads Bufo calamita. PLoS One 2014; 9:e100176. [PMID: 24937211 PMCID: PMC4061088 DOI: 10.1371/journal.pone.0100176] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Accepted: 05/23/2014] [Indexed: 12/31/2022] Open
Abstract
Study of major histocompatibility complex (MHC) loci has gained great popularity in recent years, partly due to their function in protecting vertebrates from infections. This is of particular interest in amphibians on account of major threats many species face from emergent diseases such as chytridiomycosis. In this study we compare levels of diversity in an expressed MHC class II locus with neutral genetic diversity at microsatellite loci in natterjack toad (Bufo (Epidalea) calamita) populations across the whole of the species' biogeographical range. Variation at both classes of loci was high in the glacial refugium areas (REF) and much lower in postglacial expansion areas (PGE), especially in range edge populations. Although there was clear evidence that the MHC locus was influenced by positive selection in the past, congruence with the neutral markers suggested that historical demographic events were the main force shaping MHC variation in the PGE area. Both neutral and adaptive genetic variation declined with distance from glacial refugia. Nevertheless, there were also some indications from differential isolation by distance and allele abundance patterns that weak effects of selection have been superimposed on the main drift effect in the PGE zone.
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