Juvenile hormone (JH) esterase activity but not JH epoxide hydrolase activity is downregulated in larval Adoxophyes honmai following nucleopolyhedroviruses infection

• Published in: Journal of insect physiology 2015-09, Vol.80, p.71-80
• Main Authors: Saito, Yasumasa, Kamita, Shizuo G., Hammock, Bruce D., Kunimi, Yasuhisa, Inoue, Maki N., Nakai, Madoka
• Format: Article
• Language: English
• Subjects: Adoxophyes honmai; Amino Acid Sequence; Animals; Baculovirus; Base Sequence; Carboxylic Ester Hydrolases - genetics; Carboxylic Ester Hydrolases - metabolism; Down-Regulation; Epoxide Hydrolases - genetics; Epoxide Hydrolases - metabolism; Female; Gene Expression Regulation, Enzymologic; Insect Proteins - genetics; Insect Proteins - metabolism; JH epoxide hydrolase (JHEH); Juvenile hormone esterase (JHE); Larva - enzymology; Larva - genetics; Larva - growth & development; Larva - virology; Lepidoptera; Male; Molecular Sequence Data; Moths - enzymology; Moths - genetics; Moths - growth & development; Moths - virology; Nuclear polyhedrosis virus; Nucleopolyhedrovirus; Nucleopolyhedrovirus - physiology; Phylogeny; qRT-PCR; Tortricidae
• ISSN: 0022-1910; 1879-1611
• DOI: 10.1016/j.jinsphys.2015.02.005

[Display omitted] •NPV infection downregulated JHE but not JHEH activity in larval Adoxophyes honmai.•A JHE-encoding gene of A. honmai (ahjhe) was cloned and characterized.•Downregulation of JHE activity resulted from knock down of ahjhe gene expression. Juvenile hormones (JHs) and ecdysteroids are critical insect developmental hormones. JH esterase (JHE) and JH epoxide hydrolase (JHEH) are JH-selective enzymes that metabolize JH and thus regulate the titer of JH. Baculoviruses are known to alter host endocrine regulation. The nucleopolyhedroviruses, AdhoNPV and AdorNPV, are known to have slow and fast killing activity against Adoxophyes honmai (Lepidoptera: Tortricidae), respectively. Here we found that when penultimate (4th) instar A. honmai are inoculated with AdhoNPV or AdorNPV, the mean survival time is 9.7 and 8.2days, respectively. The larvae molted once but did not pupate. The AdhoNPV- or AdorNPV-infected larvae did not show a dramatic increase in JHE activity as was found in mock-infected larvae, instead they showed a marked decrease in JHE activity. In contrast, both viral infections had no effect on JHEH activity. In order to further characterize the JHE activity, the JHE-coding sequence of A. honmai (ahjhe) was cloned and confirmed to encode a biologically active JHE. Quantitative real-time PCR analysis of ahjhe expression in 4th and 5th instar A. honmai revealed that AdhoNPV and AdorNPV are able to reduce ahjhe expression levels.