Characterization of 23-bp and 12-bp insertion/deletion polymorphisms in the prion protein gene (PRNP) of Jeju Black cattle

Host genetic factors are known to influence susceptibility to prion diseases. The prion protein gene (PRNP) contains polymorphisms associated with susceptibility across various host species. In cattle, a 23-bp insertion/deletion polymorphism (indel) in the promoter region and a 12-bp indel in intron 1 have been associated with susceptibility to bovine spongiform encephalopathy (BSE). This study aimed to investigate the distribution of these two indels in 100 Jeju Black cattle, a rare Korean native breed, and to compare genotype, allele, and haplotype frequencies with those previously reported in cattle populations from other countries and Korean cattle breeds. Significant differences in the 23-bp genotype frequencies were found across all breeds when comparing healthy and BSE-affected cattle from Korea and other countries, whereas differences in the 12-bp genotype frequencies were observed only in some breeds. The most frequent haplotype was 23del-12del (58.9%), which was comparable to that in healthy cattle. Compared to various global breeds, Jeju Black cattle exhibited higher deletion allele frequencies for both indels than the mean across all breeds examined. These findings provide baseline data for monitoring BSE susceptibility-associated polymorphisms and highlight the genetic characteristics of Korean native breeds in a global context.