Transcriptomic Response of the Liver Tissue in Trachinotus ovatus to Acute Heat Stress

Abstract

Trachinotus ovatus is a major economically important cultured marine fish in the South China Sea. However, extreme weather and increased culture density result in uncontrollable problems, such as increases in water temperature and a decline in dissolved oxygen (DO), hindering the high-quality development of aquaculture. In this study, liver transcriptional profiles of T. ovatus were investigated under acute high-temperature stress (31 °C and 34 °C) and normal water temperature (27 °C) using RNA sequencing (RNA-Seq) technology. Differential expression analysis and STEM analysis showed that 1347 differentially expressed genes (DEGs) and four significant profiles (profiles 0, 3, 4, and 7) were screened, respectively. Of these DEGs, some genes involved in heat shock protein (HSPs), hypoxic adaptation, and glycolysis were up-regulated, while some genes involved in the ubiquitin-proteasome system (UPS) and fatty acid metabolism were down-regulated. Our results suggest that protein dynamic balance and function, hypoxia adaptation, and energy metabolism transformation are crucial in response to acute high-temperature stress. Our findings contribute to understanding the molecular response mechanism of T. ovatus under acute heat stress, which may provide some reference for studying the molecular mechanisms of other fish in response to heat stress.

Acclimation to warm temperatures modulates lactate and malate dehydrogenase isozymes in juvenile Horabagrus brachysoma (Günther)

“…The biochemical mechanism for temperature adaptations in fish involves modulations in the activities of metabolic enzymes, the lipid composition of cellular membranes, quantitative changes in total or specific protein in different organs, and the manifestation of isozymes that allow for continuous functions under altered temperature conditions (Seddon 1997;Morgan et al 2022). Most enzymes that play an important role in adaptive response in fish are linked to energy-producing pathways, such as glycolysis, gluconeogenesis, pentose phosphate pathway, Kreb's cycle, respiratory chain, digestion, and protein metabolism (Guillen et al 2019;Volkoff and Rønnestad 2020;Li et al 2023). Organisms often produce isozymes that allow them to adapt and function at altered environmental temperatures (Tattersall et al 2012;Sejian et al 2018).…”