Short-Term Effects of Thermal Stress on the Responses of Branchial Protein Quality Control and Osmoregulation in a Reef-Associated Fish, ＂Chromis Viridis

• Published in: Zoological Studies Vol. 53; no. 1; p. 21
• Main Authors: Tang, Cheng-Hao, Leu, Ming-Yih, Shao, Katrina, Hwang, Lie-Yueh, Chang, Wen-Been
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg 中央研究院生物多樣性研究中心 29.04.2014; Springer Berlin Heidelberg; BioMed Central Ltd
• Subjects: Biomedical and Life Sciences; Life Sciences; Research Article; Zoology; Thermal stress; Osmoregulation; Blue-green damselfish; Protein quality control
• ISSN: 1021-5506; 1810-522X; 1810-522X
• DOI: 10.1186/s40555-014-0021-7

Background Changes in ambient temperature seriously affect physiological regulation and biochemical reactions in ectotherms. However, transient elevation in oceanic temperature occurs naturally during the day. Short-term elevation in the ambient temperature affects different physiological responses in marine fish, including cellular protein stability and osmotic balance of the internal environment. Since fish gills are vital osmoregulatory organ which directly contacts external environment, activation of cytoprotective responses to maintain gill cell viability and biological function is essential for fish survival under challenging environmental conditions. The purpose of this study was to investigate the short-term effects of elevated temperature on physiological regulation in the gills of a marine teleost, blue green damselfish ( Chromis viridis ). Results As part of the stress response, plasma glucose levels were induced by short-term hyperthermic exposure (12 h). Furthermore, upregulation of the levels of gill heat shock proteins (HSPs) and ubiquitinated proteins was essential for preventing the accumulation of protein aggregations in branchial cells of C. viridis under hyperthermic stress. The specific activity of branchial Na + /K + -ATPase (NKA), however, significantly reduced while the amount of protein was similar between normal and high-temperature groups. Conclusions The present study provided the evidence to illustrate that activation of the branchial protein quality control mechanism to carry out cytoprotective response was involved in coping with thermal stress. However, plasma osmolality and muscle water content, respectively, that slightly but evidently increased and decreased might result from impaired osmoregulatory ability due to hyperthermia-decreased gill NKA activity.