RNA-seq analysis identifies key genes and signaling pathways involved in androgen promotion of sebaceous gland proliferation in Hetian sheep.

Sebaceous glands (SGs), essential elements of the skin barrier in sheep, are tightly regulated by the androgen signaling pathway. This study investigated how androgens influence SGs hyperplasia in sheep by combining morphological assessments with transcriptomic analysis. Histological examination revealed a significant increase (P < 0.05) in both the number and average size of SGs in the testosterone-treated groups across four concentration gradients compared to the control group. Transcriptome sequencing was performed on fifteen skin samples, revealing that, compared to the control group, 371 genes were upregulated and 115 were downregulated across the four treatment groups. The upregulated genes were predominantly enriched in lipid metabolism pathways, while the downregulated genes were mainly associated with keratin filament structures. Protein-protein interaction (PPI) network analysis identified ten hub genes involved in mitochondrial β-oxidation and lipid synthesis. These findings were further supported by gene set enrichment analysis (GSEA), which indicated significant activation of fatty acid metabolic pathways (P < 0.05). The results of this study suggest that androgens may be involved in SGs hyperplasia in sheep by regulating mitochondrial lipid metabolism-related pathways.