# Weighted Single-Step Genome-Wide Association Study Identifies Candidate Genes for Carcass Traits and Primal Cut Yields in Hanwoo Cattle

## TL;DR

This study finds genetic regions linked to carcass traits and meat yield in Hanwoo cattle, which could help improve breeding strategies.

## Contribution

The study identifies candidate genes and pleiotropic genomic regions for carcass traits and primal cut yields in Hanwoo cattle using WssGWAS.

## Key findings

- Candidate genes for carcass weight include XKR4 and COBL, while LCORL and TGFBR2 are linked to eye muscle area.
- The chromosome 6 region containing WDR1 is commonly associated with multiple primal cut yield traits, suggesting pleiotropy.
- The chromosome 28 region containing SIRT1 explains the highest genetic variance for striploin yield.

## Abstract

The economic value of Hanwoo carcasses is determined not only by marbling score but also by primal cut yields. However, the genetic basis of primal cut yields remains largely unknown. This study identified genomic regions associated with carcass traits and primal cut yields. For carcass traits, candidate genes were identified for carcass weight (XKR4, COBL), eye muscle area (LCORL, TGFBR2), backfat thickness (ATG7, MYPN), and marbling score (TWIST2, BMP4). For primal cut yields, the chromosome 6 region containing WDR1 was commonly identified across six traits and the chromosome 4 region containing CACNA2D1 across five traits, suggesting pleiotropic effects. These findings provide candidate genomic regions that may inform future breeding strategies aimed at improving both carcass quality and meat yield, pending validation in independent populations.

This study identified genomic regions associated with carcass traits and primal cut yields in Hanwoo cattle using weighted single-step genome-wide association study (WssGWAS). A total of 50,227 carcass records and genomic data from 23,573 animals with 45,057 single-nucleotide polymorphisms were analyzed. Heritability estimates were 0.24 for carcass weight, 0.22 for eye muscle area, 0.31 for backfat thickness, and 0.36 for marbling score, while those for primal cut yields ranged from 0.02 to 0.26. For carcass traits, candidate genes were identified for carcass weight (XKR4 2.35%, COBL 1.26%), eye muscle area (LCORL 1.56%, TGFBR2 1.49%), backfat thickness (ATG7 1.27%, MYPN 1.33%), and marbling score (TWIST2 1.16%, BMP4 1.14%). For primal cut yields, the chromosome 6 region containing WDR1 was commonly identified across six traits and the chromosome 4 region containing CACNA2D1 across five traits; the chromosome 28 region containing SIRT1 explained the highest genetic variance (6.46%) for striploin. These pleiotropic regions are potential targets for genomic selection to improve production efficiency and carcass value in Hanwoo.