Genetic insights into the major histocompatibility complex class I BF2 gene of Korean native chickens in relation to the LEI0258 microsatellite marker and the 90-SNP panel
摘要
The chicken major histocompatibility complex (MHC) represents a “minimal essential MHC” consisting of classical class I (BF) and class II (BL) molecules that present peptides to CD8+ cytotoxic and CD4+ helper T cells, respectively. Class I molecules, primarily encoded by the BF2 gene, are central to immune responses against pathogens. Moreover, these molecules show enormous genetic diversity driven by a molecular arms race with pathogens that determines peptide binding to the polymorphic α1 and α2 domains. Genotyping tools such as the 90-single nucleotide polymorphism (SNP) panel for the MHC-B region (BSNP) and the LEI0258 microsatellite marker have revealed MHC diversity in chickens but do not capture the variation within the α1 and α2 domains. In this study, six populations of Korean native chickens (KNC) were analyzed to assess BF2 gene diversity in individuals homozygous for both the BSNP panel and LEI0258 marker. Two standard BF2 alleles, B06 and B09, were identical while seven additional haplotypes showed high similarity to those found in KNC samples. A total of 30 novel SNPs were identified, with over half located in peptide-binding regions. Most variants overlapped with previously reported data from polymerase chain reaction (PCR) and next-generation sequencing (NGS), leading to the identification of four unique BF2 alleles in KNC. There was no clear relationship among BSNP, the LEI0258 marker, and the BF2 gene, but individuals homozygous for the first two markers also had a homozygous BF2 region. These findings provide insights into MHC diversity and immune potential in KNC populations, supporting conservation and breeding strategies for enhanced disease resistance.