Transcriptome Dynamics Reveal Stage-Specific and Melatonin-Triggered Gene Expression Patterns During the Cashmere Growth Cycle in Capra Hircus

In the study, RNA-sequencing was used to analyze hair follicles from six Inner Mongolian cashmere goats, three of which were treated with melatonin, to understand gene expression patterns throughout the cashmere growth cycle. The researchers identified 3559 seasonal changing genes (SCGs) in the control group and 988 SCGs in the melatonin-treated group. These genes were categorized into clusters corresponding to the anagen, catagen, and telogen stages of hair growth. Key pathways promoting cashmere growth were identified, including Wnt, TGF-beta, and Hippo signaling pathways, while various immune-related pathways were associated with the catagen and telogen stages. The transition from telogen to anagen was marked by genes involved in PI3K-Akt signaling, ECM-receptor interaction, and Focal adhesion, which may serve as biomarkers for this stage. Additionally, 941 monthly differentially expressed genes were found between the control and melatonin-treated groups, particularly from April to September, suggesting melatonin's role in regulating the anagen stage. Pathways such as Wnt, Hedgehog, ECM, Chemokines, and NF-kappa B signaling were implicated in the regulation of hair growth influenced by melatonin. This research provides insight into the molecular mechanisms of cashmere growth and could contribute to improving cashmere yield.