Adulte interfollicular epidermis (IFE) renewal is likely orchestrated by physiological demands of its complex tissue architecture comprising spatial and cellular heterogeneity. Mouse tail and back skin display two kinds of basal IFE spatial domains that regenerate at different rates. Here, we elucidate the molecular and cellular states of basal IFE domains by marker expression and single-cell transcriptomics in mouse and human skin. We uncover two paths of basal cell differentiation that in part reflect the IFE spatial domain organization. We unravel previously unrecognized similarities between mouse tail IFE basal domains defined as scales and interscales versus human rete ridges and inter-ridges, respectively. Furthermore, our basal IFE transcriptomics and gene targeting in mice provide evidence supporting a physiological role of IFE domains in adaptation to differential UV exposure. We identify Sox6 as a novel UV-induced and interscale/inter-ridge preferred basal IFE-domain transcription factor, important for IFE proliferation and survival. The spatial, cellular, and molecular organization of IFE basal domains underscores skin adaptation to environmental exposure and its unusual robustness in adult homeostasis.

中文翻译：

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表皮基底域的二元组织突出了对环境暴露的稳健性

成人滤泡间表皮（IFE）更新可能是由其复杂的组织结构（包括空间和细胞异质性）的生理需求精心策划的。小鼠尾部和背部皮肤显示出两种以不同速率再生的基础 IFE 空间域。在这里，我们通过小鼠和人类皮肤中的标记表达和单细胞转录组学阐明了基础 IFE 结构域的分子和细胞状态。我们发现了基底细胞分化的两条路径，部分反映了 IFE 空间域组织。我们揭示了小鼠尾 IFE 基底域（分别定义为鳞片和鳞间）与人类视网膜脊和脊间间之前未被认识到的相似性。此外，我们在小鼠中的基础 IFE 转录组学和基因靶向提供了支持 IFE 域在适应不同的紫外线照射中的生理作用的证据。我们将 Sox6 确定为一种新型 UV 诱导的、鳞间/脊间首选的基础 IFE 结构域转录因子，对于 IFE 增殖和存活很重要。IFE 基底域的空间、细胞和分子组织强调了皮肤对环境暴露的适应及其在成人稳态中异常的稳健性。