Conserved haplotype blocks within the sheep MHC and low SNP heterozygosity in the Class IIa subregion.

This report describes single nucleotide polymorphisms (SNPs) in the sheep MHC class II and class III regions and provides insights into the internal structure of this important genomic complex. MHC haplotypes were deduced from sheep family trios based on genotypes from 20 novel SNPs representative...

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Main Authors: Lee, C., Qin, J., Munyard, Kylie, Subramaniam, N., Wetherall, John, Stear, M., Groth, David
Format: Journal Article
Published: Wiley-Blackwell 2012
Subjects:
Online Access:http://hdl.handle.net/20.500.11937/9115
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author Lee, C.
Qin, J.
Munyard, Kylie
Subramaniam, N.
Wetherall, John
Stear, M.
Groth, David
author_facet Lee, C.
Qin, J.
Munyard, Kylie
Subramaniam, N.
Wetherall, John
Stear, M.
Groth, David
author_sort Lee, C.
building Curtin Institutional Repository
collection Online Access
description This report describes single nucleotide polymorphisms (SNPs) in the sheep MHC class II and class III regions and provides insights into the internal structure of this important genomic complex. MHC haplotypes were deduced from sheep family trios based on genotypes from 20 novel SNPs representative of the class II region and 10 previously described SNPs spanning the class III region. All 30 SNPs exhibited Hardy Weinberg proportions in the sheep population studied. Recombination within an extended sire haplotype was observed within the class II region for 4 of 20 sheep chromosomes, thereby supporting the presence of separated IIa and IIb subregions similar to those present in cattle. SNP heterozygosity varied across the class II and III regions. One segment of the class IIa subregion manifested very low heterozygosity for several SNPs spanning approximately 120 Kbp. This feature corresponds to a subregion within the human MHC class II region previously described as a ‘SNP desert’ due to its paucity of SNPs. Linkage disequilibrium (LD) was reduced at the junction separating the putative class IIb and IIa subregions and also between the class IIa and the class III subregions. The latter observation is consistent with either an unmapped physical separation at this location, or more likely a boundary characterised by more frequent recombination between two conserved subregions, each manifesting within-block high LD. These results identify internal blocks of loci in the sheep MHC, within which recombination is relatively rare.
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institution Curtin University Malaysia
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publishDate 2012
publisher Wiley-Blackwell
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spelling curtin-20.500.11937-91152017-09-13T16:06:10Z Conserved haplotype blocks within the sheep MHC and low SNP heterozygosity in the Class IIa subregion. Lee, C. Qin, J. Munyard, Kylie Subramaniam, N. Wetherall, John Stear, M. Groth, David Class II Linkage disequilibrium SNP Class III Sheep MHC This report describes single nucleotide polymorphisms (SNPs) in the sheep MHC class II and class III regions and provides insights into the internal structure of this important genomic complex. MHC haplotypes were deduced from sheep family trios based on genotypes from 20 novel SNPs representative of the class II region and 10 previously described SNPs spanning the class III region. All 30 SNPs exhibited Hardy Weinberg proportions in the sheep population studied. Recombination within an extended sire haplotype was observed within the class II region for 4 of 20 sheep chromosomes, thereby supporting the presence of separated IIa and IIb subregions similar to those present in cattle. SNP heterozygosity varied across the class II and III regions. One segment of the class IIa subregion manifested very low heterozygosity for several SNPs spanning approximately 120 Kbp. This feature corresponds to a subregion within the human MHC class II region previously described as a ‘SNP desert’ due to its paucity of SNPs. Linkage disequilibrium (LD) was reduced at the junction separating the putative class IIb and IIa subregions and also between the class IIa and the class III subregions. The latter observation is consistent with either an unmapped physical separation at this location, or more likely a boundary characterised by more frequent recombination between two conserved subregions, each manifesting within-block high LD. These results identify internal blocks of loci in the sheep MHC, within which recombination is relatively rare. 2012 Journal Article http://hdl.handle.net/20.500.11937/9115 10.1111/j.1365-2052.2011.02268.x Wiley-Blackwell restricted
spellingShingle Class II
Linkage disequilibrium
SNP
Class III
Sheep MHC
Lee, C.
Qin, J.
Munyard, Kylie
Subramaniam, N.
Wetherall, John
Stear, M.
Groth, David
Conserved haplotype blocks within the sheep MHC and low SNP heterozygosity in the Class IIa subregion.
title Conserved haplotype blocks within the sheep MHC and low SNP heterozygosity in the Class IIa subregion.
title_full Conserved haplotype blocks within the sheep MHC and low SNP heterozygosity in the Class IIa subregion.
title_fullStr Conserved haplotype blocks within the sheep MHC and low SNP heterozygosity in the Class IIa subregion.
title_full_unstemmed Conserved haplotype blocks within the sheep MHC and low SNP heterozygosity in the Class IIa subregion.
title_short Conserved haplotype blocks within the sheep MHC and low SNP heterozygosity in the Class IIa subregion.
title_sort conserved haplotype blocks within the sheep mhc and low snp heterozygosity in the class iia subregion.
topic Class II
Linkage disequilibrium
SNP
Class III
Sheep MHC
url http://hdl.handle.net/20.500.11937/9115