Wang Shanhe, Wu Tianyi, Sun Jingyi, Li Yue, Yuan Zehu, Sun Wei
College of Animal Science and Technology, Yangzhou University, Yangzhou, China.
College of Veterinary Medicine, Yangzhou University, Yangzhou, China.
Front Cell Dev Biol. 2021 Dec 21;9:800157. doi: 10.3389/fcell.2021.800157. eCollection 2021.
Wool is the critical textile raw material which is produced by the hair follicle of sheep. Therefore, it has important implications to investigate the molecular mechanism governing hair follicle development. Due to high cellular heterogeneity as well as the insufficient cellular, molecular, and spatial characterization of hair follicles on sheep, the molecular mechanisms involved in hair follicle development and wool curvature of sheep remains largely unknown. Single-cell RNA sequencing (scRNA-seq) technologies have made it possible to comprehensively dissect the cellular composition of complex skin tissues and unveil the differentiation and spatial signatures of epidermal and hair follicle development. However, such studies are lacking so far in sheep. Here, single-cell suspensions from the curly wool and straight wool lambskins were prepared for unbiased scRNA-seq. Based on UAMP dimension reduction analysis, we identified 19 distinct cell populations from 15,830 single-cell transcriptomes and characterized their cellular identity according to specific gene expression profiles. Furthermore, novel marker gene was applied in identifying dermal papilla cells isolated . By using pseudotime ordering analysis, we constructed the matrix cell lineage differentiation trajectory and revealed the dynamic gene expression profiles of matrix progenitors' commitment to the hair shaft and inner root sheath (IRS) cells. Meanwhile, intercellular communication between mesenchymal and epithelial cells was inferred based on CellChat and the prior knowledge of ligand-receptor pairs. As a result, strong intercellular communication and associated signaling pathways were revealed. Besides, to clarify the molecular mechanism of wool curvature, differentially expressed genes in specific cells between straight wool and curly wool were identified and analyzed. Our findings here provided an unbiased and systematic view of the molecular anatomy of sheep hair follicle comprising 19 clusters; revealed the differentiation, spatial signatures, and intercellular communication underlying sheep hair follicle development; and at the same time revealed the potential molecular mechanism of wool curvature, which will give important new insights into the biology of the sheep hair follicle and has implications for sheep breeding.
羊毛是由绵羊毛囊产生的关键纺织原料。因此，研究毛囊发育的分子机制具有重要意义。由于绵羊毛囊存在高度的细胞异质性，以及细胞、分子和空间特征描述不足，绵羊毛囊发育和羊毛弯曲度所涉及的分子机制仍 largely 未知。单细胞 RNA 测序（scRNA-seq）技术使全面剖析复杂皮肤组织的细胞组成以及揭示表皮和毛囊发育的分化和空间特征成为可能。然而，目前在绵羊中缺乏此类研究。在此，制备了来自卷毛和直毛羔羊皮肤的单细胞悬液用于无偏倚的 scRNA-seq。基于 UAMP 降维分析，我们从 15,830 个单细胞转录组中鉴定出 19 个不同的细胞群，并根据特定基因表达谱对它们的细胞身份进行了表征。此外，新型标记基因被用于鉴定分离的真皮乳头细胞。通过使用伪时间排序分析，我们构建了基质细胞谱系分化轨迹，并揭示了基质祖细胞向毛干和内根鞘（IRS）细胞分化过程中的动态基因表达谱。同时，基于 CellChat 和配体 - 受体对的先验知识推断了间充质细胞和上皮细胞之间的细胞间通讯。结果，揭示了强烈的细胞间通讯和相关信号通路。此外，为阐明羊毛弯曲度的分子机制，鉴定并分析了直毛和卷毛特定细胞中的差异表达基因。我们在此的发现提供了一个包含 19 个簇的绵羊毛囊分子解剖的无偏倚且系统的视图；揭示了绵羊毛囊发育背后的分化、空间特征和细胞间通讯；同时揭示了羊毛弯曲度的潜在分子机制，这将为绵羊毛囊生物学提供重要的新见解，并对绵羊育种具有启示意义。
