Accumulation of soxC-expressing cells facilitated by MMPreg is essential for blastema formation in annelids

Abstract

Abstract Regeneration in many organisms involves the formation of a blastema that differentiates and organises into appropriate missing tissues. Although the mechanisms involved in blastema formation have been an intriguing topic of study in regeneration biology, the cellular and molecular basis of blastema formation remains poorly understood. Here, we demonstrate that during regeneration in E. japonensis, which can regenerate all organs from small fragments, the Sry-related high-mobility group (HMG) box (Sox) C-expressing cells accumulate in the head blastema. In addition, using RNAi silencing, we showed that MMPreg, a member of the matrix metalloprotease (MMP) family involved in extracellular matrix remodelling, is necessary for the accumulation of soxC-expressing cells in the head blastema, suggesting that MMPreg facilitated soxC-expressing cell migration to the head blastema. These findings provide insight into the cellular and molecular mechanisms underlying blastema formation.