Cargando…
Characterisation of major histocompatibility complex class IIa haplotypes in an island sheep population
The ovine MHC class IIa is known to consist of six to eight loci located in close proximity on chromosome 20, forming haplotypes that are typically inherited without recombination. Here, we characterise the class IIa haplotypes within the Soay sheep (Ovis aries) on St. Kilda to assess the diversity...
Autores principales: | , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Springer Berlin Heidelberg
2019
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6525122/ https://www.ncbi.nlm.nih.gov/pubmed/30796497 http://dx.doi.org/10.1007/s00251-019-01109-w |
_version_ | 1783419658700849152 |
---|---|
author | Dicks, Kara L. Pemberton, Josephine M. Ballingall, Keith T. |
author_facet | Dicks, Kara L. Pemberton, Josephine M. Ballingall, Keith T. |
author_sort | Dicks, Kara L. |
collection | PubMed |
description | The ovine MHC class IIa is known to consist of six to eight loci located in close proximity on chromosome 20, forming haplotypes that are typically inherited without recombination. Here, we characterise the class IIa haplotypes within the Soay sheep (Ovis aries) on St. Kilda to assess the diversity present within this unmanaged island population. We used a stepwise sequence-based genotyping strategy to identify alleles at seven polymorphic MHC class IIa loci in a sample of 118 Soay sheep from four cohorts spanning 15 years of the long-term study on St. Kilda. DRB1, the most polymorphic MHC class II locus, was characterised first in all 118 sheep and identified six alleles. Using DRB1 homozygous animals, the DQA (DQA1, DQA2 and DQA2-like) and DQB (DQB1, DQB2 and DQB2-like) loci were sequenced, revealing eight haplotypes. Both DQ1/DQ2 and DQ2/DQ2-like haplotype configurations were identified and a single haplotype carrying three DQB alleles. A test sample of 94 further individuals typed at the DRB1 and DQA loci found no exceptions to the eight identified haplotypes and a haplotype homozygosity of 21.3%. We found evidence of historic positive selection at DRB1, DQA and DQB. The limited variation at MHC class IIa loci in Soay sheep enabled haplotype characterisation but showed that no single locus could capture the full extent of the expressed variation in the region. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s00251-019-01109-w) contains supplementary material, which is available to authorized users. |
format | Online Article Text |
id | pubmed-6525122 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | Springer Berlin Heidelberg |
record_format | MEDLINE/PubMed |
spelling | pubmed-65251222019-06-05 Characterisation of major histocompatibility complex class IIa haplotypes in an island sheep population Dicks, Kara L. Pemberton, Josephine M. Ballingall, Keith T. Immunogenetics Original Article The ovine MHC class IIa is known to consist of six to eight loci located in close proximity on chromosome 20, forming haplotypes that are typically inherited without recombination. Here, we characterise the class IIa haplotypes within the Soay sheep (Ovis aries) on St. Kilda to assess the diversity present within this unmanaged island population. We used a stepwise sequence-based genotyping strategy to identify alleles at seven polymorphic MHC class IIa loci in a sample of 118 Soay sheep from four cohorts spanning 15 years of the long-term study on St. Kilda. DRB1, the most polymorphic MHC class II locus, was characterised first in all 118 sheep and identified six alleles. Using DRB1 homozygous animals, the DQA (DQA1, DQA2 and DQA2-like) and DQB (DQB1, DQB2 and DQB2-like) loci were sequenced, revealing eight haplotypes. Both DQ1/DQ2 and DQ2/DQ2-like haplotype configurations were identified and a single haplotype carrying three DQB alleles. A test sample of 94 further individuals typed at the DRB1 and DQA loci found no exceptions to the eight identified haplotypes and a haplotype homozygosity of 21.3%. We found evidence of historic positive selection at DRB1, DQA and DQB. The limited variation at MHC class IIa loci in Soay sheep enabled haplotype characterisation but showed that no single locus could capture the full extent of the expressed variation in the region. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s00251-019-01109-w) contains supplementary material, which is available to authorized users. Springer Berlin Heidelberg 2019-02-22 2019 /pmc/articles/PMC6525122/ /pubmed/30796497 http://dx.doi.org/10.1007/s00251-019-01109-w Text en © The Author(s) 2019 OpenAccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. |
spellingShingle | Original Article Dicks, Kara L. Pemberton, Josephine M. Ballingall, Keith T. Characterisation of major histocompatibility complex class IIa haplotypes in an island sheep population |
title | Characterisation of major histocompatibility complex class IIa haplotypes in an island sheep population |
title_full | Characterisation of major histocompatibility complex class IIa haplotypes in an island sheep population |
title_fullStr | Characterisation of major histocompatibility complex class IIa haplotypes in an island sheep population |
title_full_unstemmed | Characterisation of major histocompatibility complex class IIa haplotypes in an island sheep population |
title_short | Characterisation of major histocompatibility complex class IIa haplotypes in an island sheep population |
title_sort | characterisation of major histocompatibility complex class iia haplotypes in an island sheep population |
topic | Original Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6525122/ https://www.ncbi.nlm.nih.gov/pubmed/30796497 http://dx.doi.org/10.1007/s00251-019-01109-w |
work_keys_str_mv | AT dickskaral characterisationofmajorhistocompatibilitycomplexclassiiahaplotypesinanislandsheeppopulation AT pembertonjosephinem characterisationofmajorhistocompatibilitycomplexclassiiahaplotypesinanislandsheeppopulation AT ballingallkeitht characterisationofmajorhistocompatibilitycomplexclassiiahaplotypesinanislandsheeppopulation |