Differential genomic signatures of homozygosity and a haplotype sharing Extents across breeds associated with body size variation in Korean indigenous goats

Abstract

Korean indigenous goats are maintained as purebred lineages in geographically isolated populations such as Dangjin, Gyeongsang National University (GNU), Jangsu, and Tongyeong. However, their small population size and high rates of inbreeding have raised concerns regarding the preservation of genetic diversity. We generated SNP genotypes for 217 Korean indigenous goats using the GoatSNP50 BeadChip, and standardized body size measurements with complete metadata were available for 64 adult individuals. Principal component analysis (PCA) clearly separated the four lineages, with the GNU population showing particularly high values of inbreeding coefficient and proportion of runs of homozygosity, reflecting the impact of recent closed breeding. Genome-wide patterns of haplotype sharing revealed exploratory trends suggesting that introgression from global breeds tended to coincide with larger body size, whereas intensified inbreeding within the Korean population showed a general tendency toward reduced body size. Furthermore, cross-population extended haplotype homozygosity (XP-EHH) analysis revealed candidate genes, including ADGRL3, SP8, and ARL6IP5 that are likely involved in adaptation to seasonal environmental stress. Our findings highlight the global connectivity, functional relevance of body conformation traits, and selective signatures of Korean indigenous goats, providing a genomic foundation for preserving diversity and guiding future breeding.