A myogenic regulatory factor is required for myogenesis during limb regeneration in the Chinese mitten crab.

Myogenic regulatory factors (MRFs) are a group of transcription factors that regulate the activity of skeletal muscle cells during embryonic development and postnatal myogenesis in various vertebrate species. However, the role of MRFs in limb regeneration remains poorly understood in crustaceans. In this study, we identified a full-length cDNA encoding a myogenic regulatory factor from Eriocheir sinensis (EsMRF) and evaluated its mRNA expression profile during muscle development, growth, and regeneration. The expression of EsMRF was found to correlate with the onset of muscle formation during development and with the regeneration process following limb autotomy. To elucidate the function of MRF during limb regeneration in E. sinensis, we assessed regenerative efficiency using RNA interference (RNAi) targeting EsMRF. Our findings revealed that the blockade of MRF delayed limb regeneration by disrupting the proliferation and myogenesis of blastema cells at the basal growth stage. Furthermore, luciferase assays results demonstrated that EsMRF can transcriptionally activate target myogenic genes, either through direct binding to their promoters or by interacting with co-regulators such as EsHEB or EsMEF2. This study identifies a novel MRF in E. sinensis and elucidates its function during limb regeneration, thereby contributing to our understanding of muscle growth and regeneration mechanisms in crustaceans.