H NMR-based metabolomic analysis of hypersalinity-induced oviparity in brine shrimp.

This study investigated the mechanisms by which high salinity conditions stimulate adult Artemia females to produce diapaused cysts. We used a H NMR-based metabolomic approach to elucidate the metabolic regulation between ovoviviparity and oviparity in Artemia exposed to different salinities. At a salinity of 80 ppt, 100 % of females produced diapaused cysts, compared to 20 % at 50 ppt. Metabolic profiling revealed significant alterations in a range of metabolites, including 5,6-dihydrouracil, betaine, and malate, in females undergoing oviparity at 80 ppt compared to ovoviviparity at 30 ppt. Multivariate statistical analyses indicated clear separation between the two reproductive strategies. The up-regulated metabolites in oviparity were involved in significant metabolic pathways, such as β-alanine metabolism and the citrate cycle, highlighting substantial metabolic differences between the two reproductive strategies. These identified metabolic pathways might play crucial roles in the maternal response to high salinity, facilitating embryo protection and enhancing the survival and reproductive success of brine shrimp. These findings provide a basis for further research into the molecular mechanisms underlying Artemia adaptation to high salinity environments.