Meeting Abstract

P1-18  Saturday, Jan. 4  Single-cell profiling of acoel stem cell dynamics during development and regeneration LUO, YJ*; RICCI, L; HULETT, RE; SRIVASTAVA, M; Harvard University, Cambridge, MA; Harvard University, Cambridge, MA; Harvard University, Cambridge, MA; Harvard University, Cambridge, MA yjluo@fas.harvard.edu https://sites.google.com/view/yjluo/

Animals capable of whole-body regeneration carry a large population of pluripotent stem cells that are able to differentiate into any missing cell type. However, the molecular control of this cell type is poorly understood. Here we apply single-cell RNA sequencing to profile the cell transcriptional states of the acoel worm Hofstenia miamia during development and regeneration. We identify cell types shared across juvenile and adult stages, including neural, epidermal, muscle, digestive, and multipotent/pluripotent stem cells, reflecting major bilaterian cell types. Reconstruction of developmental single-cell trajectories reveals that juvenile and adult pluripotent stem cells have distinct cell states and population size. Single-cell profiling of regenerating worms shows that wound-induced genes are specifically expressed in muscle cells, suggesting a role for muscle in early regenerative responses. Furthermore, we find that germline stem cells are reduced around one-week post amputation, indicating a dichotomy for balancing soma and germline stem populations during regeneration. Together, our study uncovers juvenile and adult cell state dynamics and provides insights into the evolution of pluripotent stem cells.