AUTHOR=Wang Yuan-Yuan , Zhang Xin-Yu , Mu Xue-Rui , Li Xian , Zhou Min , Song Yue-Hua , Xu Kang-Kang , Li Can 

TITLE=Insulin-Like ILP2 Regulates Trehalose Metabolism to Tolerate Hypoxia/Hypercapnia in Tribolium castaneum

JOURNAL=Frontiers in Physiology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2022.857239

DOI=10.3389/fphys.2022.857239

ISSN=1664-042X

ABSTRACT=<p>RNAi was used to downregulate the expression of insulin-like peptides (<italic>ILP2</italic>), with air-modulation, and high-concentration CO<sub>2</sub> stress, in the larvae of <italic>Tribolium castaneum</italic>. We assessed the changes in carbohydrate-related content, trehalase activity, and the expression levels of trehalose pathway genes. And pupation, adult emergence, pupation rate, and mortality were assessed. There was a significant change in the expression of <italic>ILPs</italic> in <italic>T. castaneum</italic>, at a certain concentration of CO<sub>2</sub>. <italic>ILP2</italic> RNAi did not alter the trehalose content significantly, however, the glycogen and glucose content increased significantly. High-concentration CO<sub>2</sub> stress altered the trehalose content and reduced the glycogen and glucose content. The expression levels of <italic>TPS</italic> and <italic>TRE2</italic> were up-regulated by hypoxia/hypercapnia and <italic>dsILP2</italic> combination, with the increase of CO<sub>2</sub> concentration, other trehalase genes begin to respond successively. <italic>ILP2</italic> knockout raised the mortality and reduced the pupation rate and eclosion rate in CO<sub>2</sub>. Understanding the insulin pathway responses to hypoxic stress induced by a high concentration of CO<sub>2</sub> would further elucidate the mechanisms underlying trehalose metabolism in insects.</p>