Association analysis of GPRC5D and GJA1 gene polymorphisms with cashmere fiber diameter and production traits in Liaoning Cashmere Goats

Liaoning cashmere goats are renowned for high cashmere yield but often exhibit coarser fiber diameter, limiting commercial value. This study investigated the associations of GPRC5D (G protein-coupled receptor class C group 5 member D) (G2122T) and GJA1 (gap junction protein alpha 1, also known as Connexin 43) (G11298A) gene polymorphisms with fiber diameter and production traits in 1163 goats. Results showed distinct sexual dimorphism. For GPRC5D, the GT genotype in males was associated with 0.45 µm finer fiber (P = 0.001) and 10-percentage-point higher clean yield (p < 0.001) than GG; in females, GG produced 1.06-µm finer fiber (p < 0.001) and 13-percentage-point higher clean yield (p < 0.001) than GT, although GT conferred 8.14-mm longer cashmere (p < 0.001). For GJA1, the GG genotype in males was linked to 0.59-µm finer fiber (p < 0.001) and 5.67-mm longer cashmere (p < 0.001) than GA; in females, GG showed 10.93-mm longer cashmere (p < 0.001) but no significant difference in fiber diameter. Haplotype GGGT was associated with superior cashmere yield and fineness, while GGGG and GAGT were associated with larger body size in males and females, respectively. These findings provide candidate markers for breeding finer cashmere goats. The study supports genetic improvement programs in Liaoning cashmere goats.