Label-Free Proteomics to Identify Keratins and Keratin-Associated Proteins and Their Effects on the Fleece Traits of Inner Mongolia Cashmere Goats

The study analyzed the protein composition and fleece traits of down hair (DH) and guard hair (GH) from Inner Mongolia Cashmere Goats. A total of 141 proteins were identified, with 116 in DH and 108 in GH, and 39 proteins differentially expressed between the two. The GH was found to have a significantly higher diameter (43.06 µm) and strength (50.03 cN/dtex) compared to DH (16.45 µm diameter and 6.9 cN/dtex strength). The differences in fleece traits between DH and GH may be influenced by specific proteins, such as KRT38 associated with the smaller diameter of DH and KRTAP8-1 with the greater strength of GH. These findings suggest that keratins and keratin-associated proteins play a crucial role in the structural differences and fleece quality of cashmere goats.