SoxC and MmpReg promote blastema formation in whole-body regeneration of fragmenting potworms Enchytraeus japonensis

Regeneration in many animals involves the formation of a blastema, which differentiates and organizes into the appropriate missing body parts. Although the mechanisms underlying blastema formation are often fundamental to regeneration biology, information on the cellular and molecular basis of blastema formation remains limited. Here, we focus on a fragmenting potworm ( Enchytraeus japonensis ), which can regenerate its whole body from small fragments. We find soxC and mmpReg as upregulated genes in the blastema. RNAi of soxC and mmpReg reduce the number of blastema cells, indicating that soxC and mmpReg promote blastema formation. Expression analyses show that soxC -expressing cells appear to gradually accumulate in blastema and constitute a large part of the blastema. Additionally, similar expression dynamics of SoxC orthologue genes in frog ( Xenopus laevis ) are found in the regeneration blastema of tadpole tail. Our findings provide insights into the cellular and molecular mechanisms underlying blastema formation across species. Blastema formation is a critical early step during regeneration, but how it is initially formed is still unclear. Here, they find soxC and mmpReg promote blastema formation in fragmenting potworms, and identify similar expression dynamics in tadpole tail, suggesting a conserved mechanism.