A blastema in sea star larvae integrates wound signaling to drive regeneration-specific and developmental gene expression patterns [snRNA-Seq]

Here, we investigate these processes in regenerating larvae of the sea star Patiria miniata, a deuterostome with robust regenerative capacity. By integrating single-nucleus transcriptomics with chromatin accessibility profiling across development and regeneration, we identify a regeneration-induced blastema cell state that is molecularly distinct from pre-existing larval populations and serves as the source of regenerated tissues.

We show that regeneration is associated with distinct classes of regeneration-responsive enhancers, including those reused from development as well as those predicted to be active during regeneration but not embryogenesis, which link wounding signals to gene regulatory network (GRN) activation. These enhancer classes converge on regulatory programs associated with the transcription factor Runx, positioning Runx as a central node within the inferred regeneration GRN.