Single-cell molecular and cellular architecture of neurohypophyseal cell types in adult mouse

The neurohypophysis (NH), located at the posterior lobe of the pituitary, is a major neuroendocrine tissue, which mediates osmotic balance, blood pressure, reproduction, and lactation by means of releasing the neurohormones oxytocin and arginine-vasopressin from the brain into the peripheral blood circulation. The major cellular components of the NH are hypothalamic axonal termini, fenestrated endothelia and pituicytes, the resident astroglia. However, despite the physiological importance of the NH, the exact molecular signature defining neurohypophyseal cell types and in particular the pituicytes, remains unclear. Using single cell RNA sequencing, we captured seven distinct cell types in the NH and intermediate lobe (IL) of adult male mouse. We revealed novel pituicyte markers showing higher specificity than previously reported markers. Multiplexing single molecule in situ hybridization revealed spatial organization of the major cell types implying intercellular communications. We present a comprehensive molecular and cellular characterization of neurohypophyseal cell-types serving as a valuable resource for further functional research. 2 pools of 5 dissected neurohypophyses from 3-month-old male C57/BL6 mice were prepared for 10x Chromium single-cell RNA-Seq位于垂体后叶的神经垂体（neurohypophysis, NH）是一类关键的神经内分泌组织，其通过将脑内的神经激素催产素（oxytocin）与精氨酸加压素（arginine-vasopressin）释放至外周血液循环，介导渗透压平衡、血压调控、生殖与泌乳等生理过程。神经垂体的主要细胞组分包括下丘脑轴突终末、有孔内皮细胞以及常驻星形胶质细胞垂体细胞（pituicytes）。尽管神经垂体具有重要的生理功能，但目前仍未明确界定神经垂体各类细胞（尤其是垂体细胞）的确切分子特征。本研究利用单细胞RNA测序（single cell RNA sequencing）技术，在成年雄性小鼠的神经垂体与中间叶（intermediate lobe, IL）中鉴定出7种不同的细胞类型。我们发现了相较于既往报道标记物特异性更高的新型垂体细胞标记基因。多重单分子原位杂交实验揭示了主要细胞类型的空间组织模式，提示其间存在细胞间通讯。本研究完成了神经垂体细胞类型的全面分子与细胞学表征，可为后续功能研究提供宝贵的参考资源。本研究制备了2组样本，每组包含5个取自3月龄雄性C57/BL6小鼠的解剖分离神经垂体，用于10x Chromium单细胞RNA测序。