Functional Characterization of Allatostatin C (PISCF/AST) and Juvenile Hormone Acid O-Methyltransferase in Dendroctonus armandi

Allatostatin C (PISCF/AST) is a neuropeptide gene that affects juvenile hormone (JH) synthesis in the corpora allata. Juvenile hormone acid O-methyltransferase ( ) is a key gene in the JH biosynthetic pathway. In this study, two genes encoding and were cloned. Both and were expressed in the larvae, pupae and adults of Chinese white pine beetle ( ), and highly expressed in the head and the gut. The expression of the two genes was induced by JH analog (JHA) methoprene and the functions of the two genes were then investigated by RNAi. Considering the role of hormones in metamorphosis, JHA significantly induced and in the larval stage. knockdown in larvae, pupae and adults significantly increased the mRNA levels. Moreover, knockdown of instead of increased pupae mortality and the abnormal rate of emergence morphology and reduced emergence rates. However, knockdown of instead of significantly reduced frontalin biosynthesis in adult males. The results showed that acts as an allatostatin and inhibits JH biosynthesis, and that is a key regulatory enzyme for JH synthesis in the .