Deciphering the molecular regulatory mechanism underlying behavioral disorders and cardiac damage in Eriocheir sinensis under saline-alkaline environment.

With the exacerbation of global warming, the salinization of both land and water resource is becoming increasingly severe. As a widely distributed economic crustacean, investigating the impact mechanism of saline-alkaline environment on Chinese mitten crab (Eriocheir sinensis) holds significant importance. Behavioral, histological, and molecular regulatory mechanism are crucial for elucidating the pathological injury in organisms. The heart, being a core organ involved in lifespan regulation, plays a pivotal role in this context. In this study, we employed behavioral, cellular/ultrastructural morphological analysis, along with integrative omics approach, to uncover the pathological injury mechanism in the heart of E. sinensis under saline-alkaline stress. The present research demonstrated that saline-alkaline stress induced behavioral disorder and histological damage, including adipocyte infiltration and subcellular injury such as ruptured mitochondrial cristae, enlarged endoplasmic reticulum, and dilated Golgi apparatus. An integrative analysis of the top 10 KEGG and GSEA pathways revealed significant downregulation in "Glyoxylate and dicarboxylate metabolism", "Propanoate metabolism", and "Fatty acid degradation", all of which were associated with energy metabolism and cardiac function. These metabolic changes collectively contributed to cardiac damage in E. sinensis under saline-alkaline stress. This study, for the first time, elucidated the mechanism of heart damage in E. sinensis under saline-alkaline condition from multiple perspectives. It provides critical insights into the comprehensive damage mechanism of E. sinensis in such environment, offers a theoretical reference for developing the E. sinensis breeding industry under saline-alkaline condition, and contributes to understanding the impact of climate change on crustaceans. Moreover, the utilization of the high-throughput histopathological analysis tool CellProfiler can significantly enhance research into pathological damage in E. sinensis as well as in other crustacean species.