AUTHOR=Li Sheng , Guo Hui , Du Chun-Ying , Tao Yi-Xi , Feng Jing-Yun , Xu Hao , Pang Xu , Li Yun 

TITLE=Effect of temperature on exercise metabolism, hypoxia tolerance, and RNA-seq analysis in Sinilabeo rendahli from the Yangtze River, China

JOURNAL=Frontiers in Ecology and Evolution

VOLUME=11

YEAR=2023

URL=https://www.frontiersin.org/journals/ecology-and-evolution/articles/10.3389/fevo.2023.1159161

DOI=10.3389/fevo.2023.1159161

ISSN=2296-701X

ABSTRACT=<p>Temperature variation affects the growth performance of fish species due to growing constraints and trade-off on physiological functions. Here we experimentally investigated several metabolic and physiological parameters in <italic>Sinilabeo rendahli</italic>, an endemic fish species found in the Yangtze River in China. After a 14-day acclimation period, we measured routine metabolic rate (RMR), individual metabolic rate (<italic>MO</italic><sub>2</sub>), temperature quotient (Q<sub>10</sub>), loss of equilibrium (LOE), and critical oxygen tension (<italic>P</italic><sub>crit</sub>) at three different temperatures (15, 20, and 25°C). Moreover, we sampled the muscle tissue from juvenile <italic>S</italic>. <italic>rendahli</italic> under experimental conditions after 28 days of acclimation and performed transcriptome-RNA sequencing (RNA-seq). The <italic>P</italic><sub>crit</sub> of the fish at the above acclimation temperatures were determined to be 1.07, 1.28, and 1.33 mg·<italic>L</italic><sup>−1</sup>, respectively, and corresponded with increasing acclimation temperatures (15–25°C). RMR was positively correlated with <italic>P</italic><sub>crit</sub> (<italic>r</italic> = 0.4711, <italic>P</italic> = 0.0201), negatively correlated with LOE (<italic>r</italic> = −0.4284, <italic>P</italic> = 0.0367), and significantly positively correlated with MR<sub>crit</sub> (<italic>r</italic> = 0.8797, <italic>P</italic> &lt; 0.001) at temperatures ranging from 15 to 25°C. In addition, a total of 4,710 differentially expressed genes (DEGs) were identified. The results of DEG analysis and KEGG clustering analysis indicated that energy metabolism played a central role in thermal stress in <italic>S</italic>. <italic>rendahli</italic> for the major upregulated genes. This was followed by autophagy, mitophagy, cardiac muscle contraction, extracellular matrix (ECM)-receptor interaction, and protein digestion and absorption. This study is significant for understanding the adaptive response of <italic>S</italic>. <italic>rendahli</italic> to thermal stress. Even more importantly, this study demonstrates that <italic>S. rendahli</italic> is more suitable for cold-water life.</p>