Effects of different temperature stress on gill apoptosis of medaka Oryzias latipes
HU Linghong, WANG Ying, WANG Huamin, CHEN Liangbiao
1. International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai 201306, China; 2. Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai 201306, China; 3. National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China
Abstract: In order to explore the effect of different temperature stress on gill apoptosis of medaka Oryziaslatipe, Japanese HdrR strain of medaka was exposed to 35 ℃ and 40 ℃ (2 high temperature groups), 10 ℃ and 4 ℃ (2 low temperature groups) and 26 ℃ (1 normal temperature group), at a rate of 1 ℃/h warming or cooling. Then the degree of apoptosis and ROS content in gill cells of the medaka exposed to different temperature stress for 12 h were determined by TUNEL staining and flow cytometry and the expression levels of pro-apoptotic genes caspase 3, caspase 9, p53 and anti-apoptotic genes caspase1 and bcl2 were detected by qPCR. The results showed that the apoptosis phenomenon was observed in medaka gill cells in 12 h at 35 ℃ and 12 h at 40 ℃ under high temperature stress compared with normal temperature (26 ℃) (P<0.05), with cell apoptosis rate of 21.78% and the most significant apoptosis in 40 ℃ for 12 h (P<0.01). The content of ROS was shown to be increased with temperature rising significantly (P<0.05), and the expression levels of the apoptosis promoting genes caspase3, caspase9 and p53 were significantly elevated with temperature rising (P<0.05), while the expression levels of the suppression of apoptosis gene caspase1 and bcl2 were significantly reduced accordingly (P<0.05). The gill cells of medaka also showed apoptosis under low temperature stress of 10 ℃ for 12 h and 4 ℃ for 12 h (P<0.05), with apoptotic rate of 24.79% at 4 ℃ for 12 h (P<0.01). The expression levels of the apoptosis promoting genes caspase3, caspase9 and p53 were not increased significantly at 10 ℃ for 12 h (P>0.05), while the expression levels of the apoptosis promoting genes were increased significantly at 4 ℃ for 12 h (P<0.01) compared with normal temperature (26 ℃) (P<0.05). The expression levels of anti-apoptotic genes caspase1 and bcl2 showed a trend of first decreasing and then increasing as the warming temperature. In conclusion, both high temperature and low temperature stresses can cause oxidative stress to some extent, produce a large amount of ROS, and induce the gill tissue apoptosis. The degree of cell apoptosis in the gill under extreme temperature stress affects the survival time of fish. The finding provides foundation for the research of the lethal mechanism of fish under extreme temperature stress.
胡玲红, 王映, 王化敏, 陈良标. 不同温度胁迫对青鳉鳃凋亡的影响[J]. 大连海洋大学学报, 2021, 36(6): 929-936.
HU Linghong, WANG Ying, WANG Huamin, CHEN Liangbiao. Effects of different temperature stress on gill apoptosis of medaka Oryzias latipes. Journal of Dalian Ocean University, 2021, 36(6): 929-936.
2021, Vol. 36 
