Tissue-specific expression and functional role of keratin 1 in sheep horn development

作者：Qiao Mei, Hao Li, Guoqing Zhang, Meng Zhu, Shiwen Zhang, Fei Liu, Zhangyuan Pan, Jie Yang · 发表于：Frontiers in Veterinary Science · 年份：2025 · DOI：10.3389/fvets.2025.1703700 · 被引用次数：1 · 研究领域：Skin and Cellular Biology Research、Hair Growth and Disorders、Wnt/β-catenin signaling in development and cancer

Introduction Sheep horn development has significant implications for animal welfare and farm management, yet its molecular mechanisms remain incompletely understood. Keratin 1 (KRT1), a key structural protein in epidermal keratinization, has been implicated in horn formation. This study systematically investigates the expression patterns, genetic variations, and functional role of KRT1 in sheep horn development. Methods We integrated RNA sequencing (RNA-seq) and whole-genome sequencing (WGS) data from Tibetan sheep and public databases. Multi-tissue expression profiling of KRT1 was performed across sheep, cattle, pigs, and humans. Phylogenetic and protein structural analyses identified conserved amino acid sites. Allele-specific expression (ASE) loci and functional SNPs were screened using population genetics approaches. Association analysis linked genotypes with horn length in Small Tail Han sheep. Results KRT1 expression was significantly higher in scurred (small-horned) sheep compared to SHE (large-horned) sheep ( p = 0.024), and exhibited tissue-specific enrichment in horn, skin, and periosteum. Cross-species analysis confirmed high KRT1 expression in horn and skin tissues. We identified 11 horned-artiodactyl-specific amino acid sites, including K312, which forms a hydrogen bond with E262 of KRT10; mutations at this site disrupted the interaction. Four ASE loci showed strong bias toward reference alleles in horned phenotypes. Thirty-two functional SNPs were prioritized, a...