Screening of Protein Related to Wool Development and Fineness in Gansu Alpine Fine-Wool Sheep

Fiber fineness is a critical determinant of wool quality and is of great significance in enhancing the overall quality of wool. The aim of this research was to pinpoint the key proteins that participate in the regulation of wool fineness. To achieve this, we utilized Astral-DIA proteomics technology to examine the disparities in proteins, pathways, and GO terms among the wool tissues of Gansu alpine fine-wool sheep with varying mean fiber diameters (MFD). The experiment was divided into two groups: coarse (group C, MFD = 22.36 ± 0.75 μm, n = 4) and fine (group F, MFD = 16.89 ± 0.36 μm, n = 4). The results indicated that 67 differentially expressed proteins (DEPs) were identified from the wool tissues of Gansu alpine fine-wool sheep in groups C and F. Functional enrichment analysis demonstrated that several key differential proteins, including MGST3, KRT26, KRT72, KRT74, KRT71, etc., were mainly enriched in multiple functional pathways. These pathways included glutathione metabolism, oxidative phosphorylation, the degradation of valine, leucine, and isoleucine, intermediate filaments, serine protease activity, and cysteine protease activity (p < 0.05). Furthermore, protein-protein interaction (PPI) network analysis suggested that type II keratin and type I keratin (such as CTSF, PSAP, TMEM106B, LYPD3, KRT71, KRT72), along with glutathione metabolism (MGST3, W5QDB7), are closely related to hair follicle development and the regulation of wool fineness. In summary, this study enriches the existing sheep proteinome database and offers novel perspectives on the regulatory mechanisms of wool fineness.