AUTHOR=Xu Kang-Kang , Yan Yi , Yan Shu-Yan , Xia Peng-Liang , Yang Wen-Jia , Li Can , Yang Hong 

TITLE=Disruption of the Serine/Threonine Kinase Akt Gene Affects Ovarian Development and Fecundity in the Cigarette Beetle, Lasioderma serricorne

JOURNAL=Frontiers in Physiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2021.765819

DOI=10.3389/fphys.2021.765819

ISSN=1664-042X

ABSTRACT=<p>Serine/threonine kinase Akt, an important component of the insulin signaling pathway, plays an essential role in many physiological processes. In this study, we identified and characterized an <italic>Akt</italic> gene (designated <italic>LsAkt</italic>) from the cigarette beetle, <italic>Lasioderma serricorne</italic>. <italic>LsAkt</italic> contains a 1614 bp open reading frame encoding a 537 amino acid protein that possesses a conserved pleckstrin homology domain and a serine/threonine kinase domain. The expression of <italic>LsAkt</italic> was high in pupal stages and peaked in day-4 female pupae. In adult tissues, <italic>LsAkt</italic> was highly expressed in the thorax, ovary, and midgut. The expression of <italic>LsAkt</italic> was induced by methoprene or bovine insulin <italic>in vivo</italic>, but significantly decreased by 20-hydroxyecdysone. RNA interference-mediated knockdown of <italic>LsAkt</italic> resulted in severely blocked ovarian development and reduced fecundity and hatchability. The vitellogenin (Vg) content and juvenile hormone (JH) titers of <italic>LsAkt</italic>-depletion beetles were decreased, and expressions of <italic>Vg</italic> and four JH signaling and biosynthetic genes were significantly decreased. Silencing of <italic>LsAkt</italic> reduced the amounts of glucose, glycogen, and trehalose in female adults and affected the expressions of seven key carbohydrate metabolic genes. Taken together, it is inferred that <italic>Akt</italic> implicates in <italic>L. serricorne</italic> reproduction by modification of Vg synthesis, juvenile hormone production and carbohydrate metabolism.</p>