Stylophora pistillata cell atlas illuminates stony coral symbiosis, calcification and immunity

Stony corals are colonial cnidarians that sustain the most biodiverse marine ecosystems on Earth: coral reefs. Despite their ecological importance, little is known about the cell types and molecular pathways that underpin the biology of reef-building corals. Using single-cell RNA sequencing, here we define over 40 cell types across the life cycle of Stylophora pistillata. We discover specialized immune cells, and we uncover the developmental gene expression dynamics of calcium-carbonate skeleton formation. By simultaneously measuring the transcriptomes of coral cells and the algae within them, we characterize the metabolic programs involved in symbiosis in both partners. We also trace the evolution of these coral cell specializations by phylogenetic integration of multiple cnidarian cell type atlases. Overall, this study reveals the molecular and cellular basis of stony coral biology.

石珊瑚是群居刺胞动物，维系着全球生物多样性最为丰富的海洋生态系统——珊瑚礁。尽管其生态价值举足轻重，但学界对造礁珊瑚生物学背后的细胞类型与分子调控通路仍知之甚少。本研究通过单细胞RNA测序（single-cell RNA sequencing），对指形鹿角珊瑚（Stylophora pistillata）整个生命周期内的40余种细胞类型进行了系统定义；我们发现了一类特化的免疫细胞，并揭示了碳酸钙骨骼形成过程中的发育性基因表达动态变化。通过同时测定珊瑚细胞及其胞内藻类的转录组，我们对共生双方参与共生过程的代谢程序进行了系统解析。此外，我们还通过整合多个刺胞动物细胞类型图谱的系统发育数据，追溯了这些珊瑚细胞特化的演化历程。综上，本研究揭示了石珊瑚生物学的分子与细胞基础。