1
|
Vasoya D, Connelley T, Tzelos T, Todd H, Ballingall KT. Large scale transcriptional analysis of MHC class I haplotype diversity in sheep. HLA 2024; 103:e15356. [PMID: 38304958 DOI: 10.1111/tan.15356] [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: 10/25/2023] [Revised: 12/15/2023] [Accepted: 01/09/2024] [Indexed: 02/03/2024]
Abstract
Domestic sheep (Ovis aries) have been an important component of livestock agricultural production for thousands of years. Preserving genetic diversity within livestock populations maintains a capacity to respond to changing environments and rapidly evolving pathogens. MHC genetic diversity can influence immune functionality at individual and population levels. Here, we focus on defining functional MHC class I haplotype diversity in a large cohort of Scottish Blackface sheep pre-selected for high levels of MHC class II DRB1 diversity. Using high-throughput amplicon sequencing with three independent sets of barcoded primers we identified 134 MHC class I transcripts within 38 haplotypes. Haplotypes were identified with between two and six MHC class I genes, plus variable numbers of conserved sequences with very low read frequencies. One or two highly transcribed transcripts dominate each haplotype indicative of two highly polymorphic, classical MHC class I genes. Additional clusters of medium, low, and very low expressed transcripts are described, indicative of lower transcribed classical, non-classical and genes whose function remains to be determined.
Collapse
Affiliation(s)
- Deepali Vasoya
- Division of Infection and Immunity, The Roslin Institute, The University of Edinburgh, Scotland, UK
| | - Timothy Connelley
- Division of Infection and Immunity, The Roslin Institute, The University of Edinburgh, Scotland, UK
| | - Thomas Tzelos
- Division of Infection and Immunity, The Roslin Institute, The University of Edinburgh, Scotland, UK
- Moredun Research Institute, Pentlands Science Park, Scotland, UK
| | - Helen Todd
- Moredun Research Institute, Pentlands Science Park, Scotland, UK
| | | |
Collapse
|
2
|
Gowane GR, Sharma P, Kumar R, Misra SS, Alex R, Vohra V, Chhotaray S, Sharma N, Chopra A, Kandalkar Y, Choudhary A, Magotra A. Population-wide genetic analysis of Ovar-DQA1 and DQA2 loci across sheep breeds in India revealed their evolutionary importance and fitness of sheep in a tropical climate. Anim Biotechnol 2023; 34:4645-4657. [PMID: 36847639 DOI: 10.1080/10495398.2023.2180010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
Genetic variability at the major histocompatibility complex (MHC) is important in any species due to significant role played by MHC for antigen presentation. DQA locus has not been studied for its genetic variability across sheep population in India. In the present study, MHC of sheep at DQA1 and DQA2 loci were evaluated across 17 Indian sheep breeds. Results revealed high degree of heterozygosity (10.34% to 100% for DQA1 and 37.39 to 100% for DQA2). 18 DQA1 alleles and 22 DQA2 alleles were isolated in different breeds. Nucleotide content for DQA region revealed richness of AT content (54.85% for DQA1 and 53.89% for DQA2). DQA1 and DQA2 sequences clustered independently. We could see evidence of divergence of DQA as DQA1 and DQA2 across sheep breeds. Wu-Kabat variability index revealed vast genetic variation across DQA1 and DQA2, specifically at peptide binding sites (PBS) that consisted 21 residues for DQA1 and 17 residues for DQA2. Evolutionary analysis revealed the presence of positive and balancing selection for DQA1 locus, however DQA2 was under purifying selection across sheep breeds. Higher heterozygosity and large diversity at both loci especially at PBS indicated the fitness of the sheep population for evading pathogens and adapt to the harsh tropical climate.
Collapse
Affiliation(s)
- G R Gowane
- Animal Genetics and Breeding Division, ICAR-National Dairy Research Institute, Karnal, India
| | - Priya Sharma
- Animal Genetics and Breeding Division, ICAR-National Dairy Research Institute, Karnal, India
| | - Rajiv Kumar
- Animal Genetics and Breeding Division, ICAR-Central Sheep and Wool Research Institute, Avikanagar
| | - S S Misra
- Animal Genetics and Breeding Division, ICAR-Central Sheep and Wool Research Institute, Avikanagar
| | - Rani Alex
- Animal Genetics and Breeding Division, ICAR-National Dairy Research Institute, Karnal, India
| | - V Vohra
- Animal Genetics and Breeding Division, ICAR-National Dairy Research Institute, Karnal, India
| | - S Chhotaray
- Animal Genetics and Breeding Division, ICAR-National Dairy Research Institute, Karnal, India
| | - Nikita Sharma
- Animal Health Section, ICAR-Central Institute for Research on Goats, Makhdoom, India
| | - Ashish Chopra
- Animal Genetics and Breeding Division, ICAR-Arid Region Campus, Central Sheep and Wool Research Institute, Bikaner, India
| | - Yogesh Kandalkar
- Deccani Sheep Breeding Unit, NWPSI at Mahatma Phule Krishi Vidyapith, Rahuri, India
| | | | - Ankit Magotra
- Animal Genetics and Breeding Division, Chaudhary Charan Singh Haryana Agricultural University, Hisar, India
| |
Collapse
|
3
|
Gowane GR, Sharma P, Kumar R, Misra SS, Alex R, Vohra V, Chhotaray S, Dass G, Chopra A, Kandalkar Y, Vijay V, Choudhary A, Magotra A, Rajendran R. Cross-population genetic analysis revealed genetic variation and selection in the Ovar-DRB1 gene of Indian sheep breeds. Anim Biotechnol 2023; 34:2928-2939. [PMID: 36153754 DOI: 10.1080/10495398.2022.2125404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
In sheep, MHC variability is studied widely to explore disease association. The aim of the current study was to explore the genetic diversity of Ovar-DRB diversity across sheep breeds of India. Here, Ovar-DRB1 locus was studied across 20 sheep breeds. DRB1 was amplified (301 bp) and sequenced using a PCR-sequence-based typing approach. Results revealed a high degree of heterozygosity across breeds (mean: 73.99%). Overall mean distance for DRB1 was highest in Sangamneri (0.18) and lowest in Madgyal sheep (0.10). There was a higher rate of transition, across breeds. Further, 39 alleles were isolated in different breeds, out of which 10 were new. To allow easy access and use of the immune-polymorphic database, an online database management system was launched (http://www.mhcdbms.in/). Nucleotide content across breeds for the DRB1 region revealed the richness of GC content (59.26%). Wu-Kabat index revealed vast genetic variation across peptide binding sites (PBS) of DRB1. Residues 6, 66, 69, 52, and 81, were polymorphic showing utility for antigen presentation. All breeds were under positive selection for DRB1 locus (dN > dS). Study revealed the importance of DRB locus diversity for beta chain specifically at PBS across sheep breeds of the Indian subcontinent and presented evidence of positive selection for DRB owing to its evolutionary significance.
Collapse
Affiliation(s)
- G R Gowane
- Animal Genetics & Breeding Division, ICAR-National Dairy Research Institute, Karnal, India
| | - Priya Sharma
- Animal Genetics & Breeding Division, ICAR-National Dairy Research Institute, Karnal, India
| | - Rajiv Kumar
- Animal Genetics & Breeding Division, ICAR-Central Sheep & Wool Research Institute, Avikanagar, India
| | - S S Misra
- Animal Genetics & Breeding Division, ICAR-Central Sheep & Wool Research Institute, Avikanagar, India
| | - Rani Alex
- Animal Genetics & Breeding Division, ICAR-National Dairy Research Institute, Karnal, India
| | - V Vohra
- Animal Genetics & Breeding Division, ICAR-National Dairy Research Institute, Karnal, India
| | - S Chhotaray
- Animal Genetics & Breeding Division, ICAR-National Dairy Research Institute, Karnal, India
| | - Gopal Dass
- Animal Genetics & Breeding Division, ICAR-Central Institute for Research on Goats, Makhdoom, India
| | - Ashish Chopra
- Animal Genetics & Breeding Division, ICAR-Arid Region Campus, Central Sheep & Wool Research Institute Bikaner, Avikanagar, India
| | - Yogesh Kandalkar
- Deccani Sheep Breeding Unit, NWPSI at Mahatma Phule Krishi Vidyapith, Rahuri, India
| | - V Vijay
- Sonadi Seep Breeding Unit, NWPSI at Navaniya Maharana Pratap University of Agriculture and Technology, Udaipur, India
| | | | - Ankit Magotra
- Animal Genetics & Breeding Division, Chaudhary Charan Singh Haryana Agricultural University, Hisar, India
| | - R Rajendran
- Veterinary College and Research Institute, Tamil Nadu Veterinary and Animal Sciences University, Theni, India
| |
Collapse
|
4
|
Vahedi SM, Salek Ardetani S, Brito LF, Karimi K, Pahlavan Afshari K, Banabazi MH. Expanding the application of haplotype-based genomic predictions to the wild: A case of antibody response against Teladorsagia circumcincta in Soay sheep. BMC Genomics 2023; 24:335. [PMID: 37330501 DOI: 10.1186/s12864-023-09407-0] [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: 12/08/2022] [Accepted: 05/24/2023] [Indexed: 06/19/2023] Open
Abstract
BACKGROUND Genomic prediction of breeding values (GP) has been adopted in evolutionary genomic studies to uncover microevolutionary processes of wild populations or improve captive breeding strategies. While recent evolutionary studies applied GP with individual single nucleotide polymorphism (SNP), haplotype-based GP could outperform individual SNP predictions through better capturing the linkage disequilibrium (LD) between the SNP and quantitative trait loci (QTL). This study aimed to evaluate the accuracy and bias of haplotype-based GP of immunoglobulin (Ig) A (IgA), IgE, and IgG against Teladorsagia circumcincta in lambs of an unmanaged sheep population (Soay breed) based on Genomic Best Linear Unbiased Prediction (GBLUP) and five Bayesian [BayesA, BayesB, BayesCπ, Bayesian Lasso (BayesL), and BayesR] methods. RESULTS The accuracy and bias of GPs using SNP, haplotypic pseudo-SNP from blocks with different LD thresholds (0.15, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, and 1.00), or the combinations of pseudo-SNPs and non-LD clustered SNPs were obtained. Across methods and marker sets, higher ranges of genomic estimated breeding values (GEBV) accuracies were observed for IgA (0.20 to 0.49), followed by IgE (0.08 to 0.20) and IgG (0.05 to 0.14). Considering the methods evaluated, up to 8% gains in GP accuracy of IgG were achieved using pseudo-SNPs compared to SNPs. Up to 3% gain in GP accuracy for IgA was also obtained using the combinations of the pseudo-SNPs with non-clustered SNPs in comparison to fitting individual SNP. No improvement in GP accuracy of IgE was observed using haplotypic pseudo-SNPs or their combination with non-clustered SNPs compared to individual SNP. Bayesian methods outperformed GBLUP for all traits. Most scenarios yielded lower accuracies for all traits with an increased LD threshold. GP models using haplotypic pseudo-SNPs predicted less-biased GEBVs mainly for IgG. For this trait, lower bias was observed with higher LD thresholds, whereas no distinct trend was observed for other traits with changes in LD. CONCLUSIONS Haplotype information improves GP performance of anti-helminthic antibody traits of IgA and IgG compared to fitting individual SNP. The observed gains in the predictive performances indicate that haplotype-based methods could benefit GP of some traits in wild animal populations.
Collapse
Affiliation(s)
- Seyed Milad Vahedi
- Department of Animal Science and Aquaculture, Dalhousie University, Truro, NS, B2N5E3, Canada
| | | | - Luiz F Brito
- Department of Animal Sciences, Purdue University, West Lafayette, IN, 47907, USA
| | - Karim Karimi
- Molecular Diagnostics Program, Verspeeten Clinical Genome Centre, London Health Sciences Centre, London, ON, N6A 5W9, Canada
| | - Kian Pahlavan Afshari
- Department of Animal Sciences, Islamic Azad University, Varamin, Varamin-Pishva Branch3381774895, Iran
| | - Mohammad Hossein Banabazi
- Department of Animal Breeding and Genetics (HGEN), Centre for Veterinary Medicine and Animal Science (VHC), Swedish University of Agricultural Sciences (SLU), 75007, Uppsala, Sweden.
- Department of Biotechnology, Animal Science Research Institute of IRAN (ASRI), Agricultural Research, Education & Extension Organization (AREEO), Karaj, 3146618361, Iran.
| |
Collapse
|
5
|
Huang W, Dicks KL, Hadfield JD, Johnston SE, Ballingall KT, Pemberton JM. Contemporary selection on MHC genes in a free-living ruminant population. Ecol Lett 2022; 25:828-838. [PMID: 35050541 PMCID: PMC9306867 DOI: 10.1111/ele.13957] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 10/21/2021] [Accepted: 12/08/2021] [Indexed: 11/27/2022]
Abstract
Genes within the major histocompatibility complex (MHC) are the most variable identified in vertebrates. Pathogen-mediated selection is believed to be the main force maintaining MHC diversity. However, relatively few studies have demonstrated contemporary selection on MHC genes. Here, we examine associations between MHC variation and several fitness measurements including total fitness and five fitness components, in 3400 wild Soay sheep (Ovis aries) monitored between 1989 and 2012. In terms of total fitness, measured as lifetime breeding success of all individuals born, we found haplotypes named C and D were associated with decreased and increased male total fitness respectively. In terms of fitness components, juvenile survival was associated with haplotype divergence while individual haplotypes (C, D and F) were associated with adult fitness components. Consistent with the increased male total fitness, the rarest haplotype D has increased in frequency throughout the study period more than expected under neutral expectations. Our results demonstrate contemporary natural selection is acting on MHC class II genes in Soay sheep and the mode of selection on specific fitness components can be different mode from selection on total fitness.
Collapse
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.,Royal Zoological Society of Scotland, Edinburgh, UK
| | - Jarrod D Hadfield
- 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
| | | | - Josephine M Pemberton
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| |
Collapse
|
6
|
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.
Collapse
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
| |
Collapse
|
7
|
Dicks KL, Pemberton JM, Ballingall KT, Johnston SE. MHC class IIa haplotypes derived by high-throughput SNP screening in an isolated sheep population. G3-GENES GENOMES GENETICS 2021; 11:6298591. [PMID: 34568908 PMCID: PMC8496268 DOI: 10.1093/g3journal/jkab200] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Accepted: 05/12/2021] [Indexed: 12/01/2022]
Abstract
Investigating the current evolutionary processes acting on a highly polymorphic gene region, such as the major histocompatibility complex (MHC), requires extensive population data for both genotypes and phenotypes. The MHC consists of several tightly linked loci with both allelic and gene content variation, making it challenging to genotype. Eight class IIa haplotypes have previously been identified in the Soay sheep (Ovis aries) of St. Kilda using Sanger sequencing and cloning, but no single locus is representative of all haplotypes. Here, we exploit the closed nature of the island population of Soay sheep and its limited haplotypic variation to identify a panel of SNPs that enable imputation of MHC haplotypes. We compared MHC class IIa haplotypes determined by Sanger sequence-based genotyping of 135 individuals to their SNP profiles generated using the Ovine Infinium HD BeadChip. A panel of 11 SNPs could reliably determine MHC diplotypes, and two additional SNPs within the DQA1 gene enabled detection of a recombinant haplotype affecting only the SNPs downstream of the expressed genes. The panel of 13 SNPs was genotyped in 5951 Soay sheep, of which 5349 passed quality control. Using the Soay sheep pedigree, we were able to trace the origin and inheritance of the recombinant SNP haplotype. This SNP-based method has enabled the rapid generation of locus-specific MHC genotypes for large numbers of Soay sheep. This volume of high-quality genotypes in a well-characterized population of free-living sheep will be valuable for investigating the mechanisms maintaining diversity at the MHC.
Collapse
Affiliation(s)
- Kara L Dicks
- School of Biological Sciences, Institute of Evolutionary Biology, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Josephine M Pemberton
- School of Biological Sciences, Institute of Evolutionary Biology, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Keith T Ballingall
- Moredun Research Institute, Pentlands Science Park, Edinburgh EH26 0PZ, UK
| | - Susan E Johnston
- School of Biological Sciences, Institute of Evolutionary Biology, University of Edinburgh, Edinburgh EH9 3FL, UK
| |
Collapse
|
8
|
Huang W, Pilkington JG, Pemberton JM. Patterns of MHC-dependent sexual selection in a free-living population of sheep. Mol Ecol 2021; 30:6733-6742. [PMID: 33960549 DOI: 10.1111/mec.15938] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 02/18/2021] [Accepted: 04/23/2021] [Indexed: 12/12/2022]
Abstract
The MHC is one of the most polymorphic gene clusters in vertebrates and play an essential role in adaptive immunity. Apart from pathogen-mediated selection, sexual selection can also contribute to the maintenance of MHC diversity. MHC-dependent sexual selection could occur via several mechanisms but at present there is no consensus as to which of these mechanisms are involved and their importance. Previous studies have often suffered from limited genetic and behavioural data and small sample size, and were rarely able to examine all the mechanisms together, determine whether signatures of MHC-based non-random mating are independent of genomic effects or differentiate whether MHC-dependent sexual selection takes place at the pre- or post-copulatory stage. In this study, we use Monte Carlo simulation to investigate evidence for non-random MHC-dependent mating patterns by all three mechanisms in a free-living population of Soay sheep. Using 1710 sheep diplotyped at the MHC class IIa region and genome-wide SNPs, together with field observations of consorts, we found sexual selection against a particular haplotype in males at the pre-copulatory stage and sexual selection against female MHC heterozygosity during the rut. We also found MHC-dependent disassortative mating at the post-copulatory stage, along with strong evidence of inbreeding avoidance at both stages. However, results from generalized linear mixed models suggest that the pattern of MHC-dependent disassortative mating could be a by-product of inbreeding avoidance. Our results therefore suggest that while multiple apparent mechanisms of non-random mating with respect to the MHC may occur, some of them have alternative explanations.
Collapse
Affiliation(s)
- Wei Huang
- Institute of Evolutionary Biology,School of Biological Science, University of Edinburgh, Edinburgh, UK
| | - Jill G Pilkington
- Institute of Evolutionary Biology,School of Biological Science, University of Edinburgh, Edinburgh, UK
| | - Josephine M Pemberton
- Institute of Evolutionary Biology,School of Biological Science, University of Edinburgh, Edinburgh, UK
| |
Collapse
|
9
|
Huang W, Pemberton JM. Within-trio tests provide little support for post-copulatory selection on major histocompatibility complex haplotypes in a free-living population. Proc Biol Sci 2021; 288:20202862. [PMID: 33622127 PMCID: PMC7934901 DOI: 10.1098/rspb.2020.2862] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 01/27/2021] [Indexed: 11/12/2022] Open
Abstract
Sexual selection has been proposed as a force that could help maintain the diversity of major histocompatibility complex (MHC) genes in vertebrates. Potential selective mechanisms can be divided into pre-copulatory and post-copulatory, and in both cases, the evidence for occurrence is mixed, especially in natural populations. In this study, we used a large number of parent-offspring trios that were diplotyped for MHC class II genes in a wild population of Soay sheep (Ovis aries) to examine whether there was within-trio post-copulatory selection on MHC class II genes at both the haplotype and diplotype levels. We found there was transmission ratio distortion of one of the eight MHC class II haplotypes (E) which was transmitted less than expected by fathers, and transmission ratio distortion of another haplotype (A) which was transmitted more than expected by chance to male offspring. However, in both cases, these deviations were not significant after correction for multiple tests. In addition, we did not find any evidence of post-copulatory selection at the diplotype level. These results imply that, given known parents, there is no strong post-copulatory selection on MHC class II genes in this population.
Collapse
Affiliation(s)
- W. Huang
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - J. M. Pemberton
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| |
Collapse
|
10
|
Polymorphism of Selected Regions of Ovar-MHC and the Health Status of the Ovine Mammary Gland. Animals (Basel) 2020; 10:ani10122325. [PMID: 33297470 PMCID: PMC7762418 DOI: 10.3390/ani10122325] [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: 11/12/2020] [Revised: 12/02/2020] [Accepted: 12/02/2020] [Indexed: 11/17/2022] Open
Abstract
Udder diseases (mastitis) are a serious cause of economic losses in sheep breeding as they have a negative impact on lamb rearing and the quality of dairy products. Thus far, progress in treatment and prevention of these diseases has been insufficient-giving ground for searching possibilities of using natural immunity to combat mastitis. This study aims to assess the relationship between the microsatellite polymorphism of selected Ovar-MHC genes and the health status of the mammary gland of sheep. The research is carried out on sheep of the Polish Heath and Polish Lowland breeds. In ovine milk, the SCC and the percentage of the lymphocyte subpopulation are assessed. Based on genomic DNA, molecular analysis of the Ovar-MHC gene fragments (OLADRB1, OLADRB2, OMHC1) polymorphism is performed. Significant differences are found in SCC level and the percentage of lymphocytes (CD4, CD8, CD19) in the milk depending on the alleles of the Ovar-MHC genes. Alleles of 488 bp (DRB1) and 284 bp (DRB2) are found more frequently in sheep, which milk contained <200 × 103/mL SCC, while in carriers of the 508 bp (DRB1) and 272 bp (DRB2) alleles, SCC level in milk is significantly higher (>200 × 103/mL). The obtained results justify the need for further research to better understand the genetic basis of mastitis, and to search for effective molecular markers that can be used in breeding practice.
Collapse
|