Genetic Polymorphism Reveals FAT3 Gene Associations with Wool Traits in Subo Merino Sheep

In this study, 944 Subo Merino sheep, a high-quality fine wool breed, were selected as research subjects. The SNP typing of the <i>FAT3</i> gene was performed using the Fluidigm BiomarkTM HD system, and 11 missense mutation sites were identified. The analysis of population polymorphism of single-nucleotide polymorphisms was conducted. It is noteworthy that a substantial strong linkage disequilibrium was identified between SNP 5 and SNP 6 (<i>r</i>² > 0.8). The association between SNPs of the <i>FAT3</i> gene and wool traits showed that multiple SNPs were significantly correlated with several different wool traits (<i>p</i> < 0.05). Furthermore, the investigation delved into the impact of the <i>FAT3</i> gene on wool fiber through the utilization of quantitative polymerase chain reaction (qPCR), which yielded findings that this gene was notably expressed in fine wool fiber (FW) (<i>p</i> < 0.001). To predict the subcellular localization and protein transmembrane structure of FAT3, we employed the PSORT II Prediction and TMHMM online software. It was determined that the protein contains a transmembrane domain. This study provides molecular markers for the improvement of the selection and breeding of ultrafine-wool sheep and offers experimental evidence for accelerating the genetic breeding of sheep.