Paris Postdoc Seminar – Sophie Peron

Invited by the Institut Jacques Monod, Sophie Peron ( Institut Imagine, Team somatic mosaicism in neurodevelopment and disease, Paris) will present a Paris Postdoc seminar on the theme:

Coordination between cell cycle and differentiation in planarian stem cells

Abstract:

Planarians have extensive regenerative abilities fuelled by a population of adult stem cells. Those cells also constantly proliferate and differentiate into dozens of different cell types to maintain tissue homeostasis. However, how cell fate acquisition is coordinated with cell cycle progression remains poorly understood. We choose to address this question in Schmidtea mediterranea using single cell transcriptomics. We generated scRNA-seq datasets from cells enriched for 2C or 4C DNA content and from animals subjected to RNAi against the cell cycle regulators cdh1 and h2b. Our analyses show that progenitor populations across multiple lineages contain actively cycling cells and that lineage commitment occurs at different stages depending on the cell type. Comparative analyses reveal that Schmidtea possesses a simplified repertoire of canonical cell cycle regulators, consistent with a central role for cdh1 in controlling cell cycle exit. Functional perturbation of cdh1 demonstrates that cell cycle exit is needed for differentiation but not for lineage specification. Together, these findings provide new insights into how cell cycle regulation is coordinated with lineage commitment and differentiation in planarian stem cells.