Organ function relies on the spatial organization and functional coordination of numerous cell types. The Drosophila ovary is a widely used model system to study the cellular activities underlying organ function, including stem cell regulation, cell signaling and epithelial morphogenesis. However, the relative paucity of cell type–specific reagents hinders investigation of molecular functions at the appropriate cellular resolution. Here, we used single-cell RNA sequencing to characterize all cell types of the stem cell compartment and early follicles of the Drosophila ovary. We computed transcriptional signatures and identified specific markers for nine states of germ cell differentiation and 23 somatic cell types and subtypes. We uncovered an unanticipated diversity of escort cells, the somatic cells that directly interact with differentiating germline cysts. Three escort cell subtypes reside in discrete anatomical positions and express distinct sets of secreted and transmembrane proteins, suggesting that diverse micro-environments support the progressive differentiation of germ cells. Finally, we identified 17 follicle cell subtypes and characterized their transcriptional profiles. Altogether, we provide a comprehensive resource of gene expression, cell type–specific markers, spatial coordinates, and functional predictions for 34 ovarian cell types and subtypes.

中文翻译：

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单细胞图谱揭示了果蝇卵巢中意想不到的细胞类型复杂性

器官功能依赖于多种细胞类型的空间组织和功能协调。果蝇卵巢是一种广泛使用的模型系统，用于研究器官功能的细胞活动，包括干细胞调节、细胞信号传导和上皮形态发生。然而，细胞类型特异性试剂的相对缺乏阻碍了以适当的细胞分辨率研究分子功能。在这里，我们使用单细胞 RNA 测序来表征果蝇干细胞区室和早期卵泡的所有细胞类型子房。我们计算了转录特征并确定了九种生殖细胞分化状态和 23 种体细胞类型和亚型的特定标记。我们发现了出乎意料的护送细胞多样性，即直接与分化的种系囊肿相互作用的体细胞。三种护送细胞亚型位于离散的解剖位置，并表达不同的分泌和跨膜蛋白组，这表明不同的微环境支持生殖细胞的逐步分化。最后，我们确定了 17 种卵泡细胞亚型并表征了它们的转录谱。总之，我们为 34 种卵巢细胞类型和亚型提供基因表达、细胞类型特异性标记、空间坐标和功能预测的综合资源。