Structural, biochemical, transcriptomic, and metabolomic changes in the body wall of sea cucumber (Stichopus monotuberculatus) across different stages of autolysis.

Stichopus monotuberculatus is a highly prized marine delicacy that undergoes post-harvest autolysis at a rate exceptionally faster than common species like Apostichopus japonicus. Driven by this pronounced phenotypic difference, we hypothesized that the autolysis of S. monotuberculatus is governed by an exceptionally accelerated cascade of oxidative and lipid disruptions, which rapidly overwhelms the classical protease and apoptosis mechanisms. To test this hypothesis, a trauma induced degradation model was established by incision and air exposure, and body-wall samples across seven time points were examined using histological, biochemical, metabolomic, and transcriptomic analyses. The autolytic process featured four distinct morphological and molecular stages, with temporal changes in Cathepsin B content and glycosaminoglycan solubilization accompanying progressive tissue disintegration. Integrated multi-omics strongly suggested that oxidative stress and lipid metabolism disruption are central events highly associated with the autolytic cascade. While oxidative injury is a ubiquitous cellular stress response, the rapid early molecular changes observed in this species appear to differ from patterns previously reported for A. japonicus, although direct interspecific comparisons under identical experimental conditions are still required. Overall, these findings support our hypothesis. By identifying oxidative stress and lipid metabolic disruption as the prominent biochemical processes associated with autolysis, this study provides a basis for future functional studies to determine whether modulation of these processes can influence post-harvest degradation.