AUTHOR=Sun Lili , Liu Peng , Zhang Chenshu , Du Hui , Wang Zhiying , Moural Timothy W. , Zhu Fang , Cao Chuanwang 

TITLE=Ocular Albinism Type 1 Regulates Deltamethrin Tolerance in Lymantria dispar and Drosophila melanogaster

JOURNAL=Frontiers in Physiology

VOLUME=10

YEAR=2019

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2019.00766

DOI=10.3389/fphys.2019.00766

ISSN=1664-042X

ABSTRACT=<p>The ocular albinism type 1 (OA1), a pigment cell-specific integral membrane glycoprotein, is a member of the G-protein-coupled receptor (GPCR) superfamily that binds to heterotrimeric G proteins in mammalian cells. We aimed to characterize the physiological functions an insect OA1 from <italic>Lymantria dispar</italic> (<italic>LdOA1</italic>) employs in the regulation of insecticide tolerance. In the present study, we investigated the roles of <italic>LdOA1</italic> in response to deltamethrin exposure in both <italic>L. dispar</italic> and <italic>Drosophila melanogaster</italic>. <italic>LdOA1</italic> was expressed at the lowest level during the 4<sup>th</sup> instar stage, while <italic>LdOA1</italic> was significantly upregulated in the 5<sup>th</sup> instar and male stages. Knockdown of <italic>LdOA1</italic> by injecting dsRNA of <italic>LdOA1</italic> into gypsy moth larvae caused a 4.80-fold higher mortality than in control larvae microinjected with dsRNA of <italic>GFP</italic> under deltamethrin stress. Nine out of 11 <italic>L. dispar CYP</italic> genes were significantly downregulated under deltamethrin stress in <italic>LdOA1</italic> silenced larvae as compared to control larvae. Moreover, the <italic>LdOA1</italic> gene was successfully overexpressed in <italic>D. melanogaster</italic> using transgenic technique. The deltamethrin contact assay showed that the <italic>LdOA1</italic> overexpression in flies significantly enhanced the tolerance to deltamethrin compared to the control flies. Furthermore, the downstream <italic>Drosophila</italic> CYP genes were upregulated in the <italic>LdOA1</italic> overexpression flies, suggesting <italic>LdOA1</italic> may play a master switch role in P450-mediated metabolic detoxification. This study is the first report of an insect OA1 gene regulating insecticide tolerance and potentially playing a role in the regulation of downstream cytochrome P450 expression. These results contribute to the future development of novel insecticides targeting insect GPCRs.</p>