Correlation Analysis of BLTP1 (KIAA1109) and KIF27 Gene Polymorphisms with Wool Traits in Subo Merino Sheep

Background/Objectives: The Subo Merino sheep is a high-quality fine-wool breed developed through progressive hybridization, characterized by high wool yield and excellent wool quality. This study is designed to investigate the effects of two gene polymorphisms in Subo Merino sheep on wool traits, thereby providing critical theoretical and technical support for the breeding of high-quality fine-wool sheep. Methods: In this study, 944 one-year-old Subo Merino sheep were genotyped for coding regions of the BLTP1 and KIF27 genes using the Fluidigm BioMark™ HD system. Association between SNP loci and wool traits was analyzed via the least squares means method in SAS 9.4. Protein–protein interaction networks were constructed using the STRING database, and protein structures before and after mutation were predicted with SOPMA and SWISS-MODEL. Results: The results revealed that BLTP1 gene identified a missense mutation site SNP1, which resulted in a nucleotide change c.812 (C > T) and an amino acid change p.Pro271Leu. KIF27 gene identified a missense mutation site SNP2, which resulted in a nucleotide change c.3896 (T > C) and an amino acid change p.Met1299Thr. Association analysis showed that SNP1 had a significant effect on wool crimp number (CN) and staple length (SL) (p < 0.05), while SNP2 significantly affected live weight after shearing (LWAS) (p < 0.05). Protein structure prediction showed that mutations at SNP1 and SNP2 primarily led to changes in α-helix, extended chain, and random coil structures. Conclusions: These results suggest that SNP1 in BLTP1 and SNP2 in KIF27 could serve as potential molecular markers for wool traits in Subo Merino sheep. This study provides theoretical support and candidate gene targets for molecular marker-assisted breeding, contributing to genetic improvement and efficient breeding of this fine-wool breed.