한우 암소 번식형질 연관 유전체 영역 식별을 위한 Single-Step 전장유전체연관분석 연구

초록

Reproductive traits in Hanwoo cows are key economic traits directly linked to productivity, highlighting the importance of geneticimprovement. This study applied a single-step genome-wide association study (ssGWAS), integrating pedigree and genomic information,to identify genomic regions associated with reproductive traits in Hanwoo cows and to propose functionally candidate genes. Phenotypicrecords included age at first calving in primiparous cows and gestation length, days open, calving interval, and services per conceptionin multiparous cows, comprising 809 primiparous and 789 multiparous cows. In the ssGWAS results, most SNP markers explained lessthan 1% of the total additive genetic variance, whereas distinct peaks were observed on several chromosomes. SNP windows explaining≥1% of the total additive genetic variance were therefore selected, and adjacent windows were merged based on physical proximityto define peak intervals. Within each peak, the SNP with the highest percentage of variance explained was designated as the lead SNP. Candidate gene identification and functional annotation were subsequently performed, and overlap with previously reported QTL/associationregions for reproductive traits was assessed using the CattleQTLdb. Functional enrichment analysis highlighted terms related to proteolysis regulation involved in uterine–placental tissue remodeling, as well as functions associated with sperm performance and fertilization capacity,suggesting key biological pathways underlying reproduction. In addition, multiple novel candidate QTL regions that did not overlap withpreviously reported loci were detected, providing further clues to the genetic basis of reproductive traits. Overall, these findings providecandidate genomic regions and functional evidence for reproductive traits in Hanwoo cows, which may serve as foundational informationfor future genomic selection and improvement of reproductive performance.

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