Physiological functions of a methuselah-like G protein coupled receptor in Lymantria dispar Linnaeus

Abstract Insect G protein coupled receptors (GPCRs) have been identified as a highly attractive target for new generation insecticides discovery due to their critical physiological functions. However, few insect GPCRs have been functionally characterized. Here, we cloned the full length of a methuselah-like GPCR gene ( Ldmthl1 ) from the Asian gypsy moth, Lymantria dispar . We then characterized the secondary and tertiary structures of Ldmthl1. We also predicted the global structure for an insect GPCR protein (excludes odorant receptors) which includes three major domains. RNA interference of Ldmthl1 resulted in a reduction of gypsy moths' resistance to deltamethrin and suppressed the expression of downstream stress-associated genes, such as P450s, glutathione S transferases, and heat shock proteins. The function of methuselah-like GPCR Ldmthl1 was further investigated using transgenic lines of Drosophila melanogaster . Drosophila with overexpression of Ldmthl1 showed significantly longer lifespan than control flies. Taken together, our studies revealed that the physiological functions of Ldmthl1 in L. dispar are associated with longevity and resistance to insecticide stresses, which potentially can be used as a new target to manage of this notorious forest pest.