Zhang Ji-Pan, Xiao Min, Fang Jia-Bei, Huang De-Li, Zhao Yong-Ju
College of Animal Science and Technology, Southwest University, Chongqing 400715, China.
Chongqing Key Laboratory of Herbivore Science, Chongqing 400715, China.
Zool Res. 2025 Jul 18;46(4):825-840. doi: 10.24272/j.issn.2095-8137.2025.034.
The genetic regulation of hair density in animals remains poorly understood. The Dazu black goat, characterized by its black coarse hair and white skin, provides a unique model for dissecting coarse hair density (CHD). Using high-resolution micro-camera imaging, this study analyzed 905 skin images, 33 skin transcriptomes, 272 whole-genome sequences, and 182 downloaded transcriptomes. Morphological assessment from juvenile to adult stages revealed the thickening of hair shafts accompanied by a progressive decline in density, largely attributable to rapid surface expansion of the trunk skin. Transcriptomic comparison between high- and low-CHD individuals identified 572 differentially expressed genes (DEGs). A genome-wide association study detected 25 significant single nucleotide polymorphisms ( <9.07e-8) and mapped 48 annotated genes, with the most prominent association signal located near on chr9_15831585-18621011. Literature review and Venn analysis highlighted six genes ( , , , , , and ) with documented roles in skin and hair biology, and three genes ( , , and ) overlapped with DEGs. Multiple-tissue transcriptomic profiling, western blotting, immunohistochemical staining, and skin single-cell RNA sequencing confirmed that and were highly and specifically expressed in skin, particularly within hair follicles. Expression was localized predominantly to follicular stem cells and dermal papilla cells, suggesting a significant role in folliculogenesis and structural maintenance. Cross-validation using four public datasets further demonstrated positive correlations between and expression and hair follicle density. The innovative micro-camera application allowed the elucidation of spatiotemporal patterns and genes associated with CHD, thereby addressing a significant knowledge gap in animal hair density.
动物毛发密度的遗传调控仍知之甚少。大足黑山羊以其黑色粗毛和白色皮肤为特征，为剖析粗毛密度（CHD）提供了独特的模型。本研究使用高分辨率微相机成像分析了905张皮肤图像、33个皮肤转录组、272个全基因组序列和182个下载的转录组。从幼年到成年阶段的形态学评估显示，毛干变粗，同时密度逐渐下降，这主要归因于躯干皮肤的快速表面扩张。高CHD和低CHD个体之间的转录组比较确定了572个差异表达基因（DEG）。全基因组关联研究检测到25个显著的单核苷酸多态性（<9.07e-8），并定位了48个注释基因，最显著的关联信号位于chr9_15831585-18621011附近。文献综述和维恩分析突出了六个在皮肤和毛发生物学中有记录作用的基因（、、、、、和），以及三个与DEG重叠的基因（、和）。多组织转录组分析、蛋白质免疫印迹、免疫组织化学染色和皮肤单细胞RNA测序证实，和在皮肤中高度特异性表达，尤其是在毛囊内。表达主要定位于毛囊干细胞和真皮乳头细胞，表明在毛囊发生和结构维持中起重要作用。使用四个公共数据集进行的交叉验证进一步证明了和表达与毛囊密度之间的正相关。创新的微相机应用使得能够阐明与CHD相关的时空模式和基因，从而填补了动物毛发密度方面的重大知识空白。
