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Diversity and locus specificity of chicken MHC B class I sequences
Author(s) -
Livant E. J.,
Brigati J. R.,
Ewald S. J.
Publication year - 2004
Publication title -
animal genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.756
H-Index - 81
eISSN - 1365-2052
pISSN - 0268-9146
DOI - 10.1111/j.1365-2052.2003.01078.x
Subject(s) - biology , genetics , locus (genetics) , haplotype , allele , major histocompatibility complex , coding region , phylogenetic tree , sequence analysis , nucleotide diversity , exon , gene
Summary The major histocompatibility complex B ( MHC B ) region in a standard haplotype of Leghorn chickens contains two closely linked class I loci, B‐FI and B‐FIV . Few sequences of B‐FI alleles are available, and therefore alleles of the two loci have not been compared with regard to sequence diversity or locus specificity. Here, we report eight new B‐F α 1/ α 2‐coding sequences from broiler chicken MHC B haplotypes, and a unique recombinant between the two B‐F loci. The new sequences were combined with existing B‐F sequences from Leghorn and broiler haplotypes for analysis. On the basis of phylogenetic analysis and conserved sequence motifs, B‐F sequences separated into two groups (Groups A and B), corresponding to B‐FIV and B‐FI locus, respectively. Every broiler haplotype had one B‐F sequence in Group A and the second B‐F sequence, if it existed, clustered in Group B. Group B (presumptive B‐FI locus) sequences identified in broiler haplotypes resembled the human MHC class I HLA‐C locus in their distinctive pattern of allelic polymorphism. Compared with B‐FIV, B‐FI alleles were less polymorphic and possessed a conserved locus‐specific motif in the α 1 helix, but nevertheless demonstrated evidence of diversifying selection. One B‐FI α 1/ α 2‐coding nucleotide sequence was completely conserved in four different broiler haplotypes, but each allele differed in the exon encoding the α 3 domain.