Functional specificity of sex pheromone receptors in the cotton bollworm Helicoverpa armigera.

Yang Liu,Chengcheng Liu,Kejian Lin,Guirong Wang

doi:10.1371/journal.pone.0062094

Yang Liu, Chengcheng Liu + Show 2 more

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https://doi.org/10.1371/journal.pone.0062094

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Abstract

Male moths can accurately perceive the sex pheromone emitted from conspecific females by their highly accurate and specific olfactory sensory system. Pheromone receptors are of special importance in moth pheromone reception because of their central role in chemosensory signal transduction processes that occur in olfactory receptor neurons in the male antennae. There are a number of pheromone receptor genes have been cloned, however, only a few have been functionally characterized. Here we cloned six full-length pheromone receptor genes from Helicoverpa armigera male antennae. Real-time PCR showing all genes exhibited male-biased expression in adult antennae. Functional analyses of the six pheromone receptor genes were then conducted in the heterologous expression system of Xenopus oocytes. HarmOR13 was found to be a specific receptor for the major sex pheromone component Z11-16:Ald. HarmOR6 was equally tuned to both of Z9-16: Ald and Z9-14: Ald. HarmOR16 was sensitively tuned to Z11-16: OH. HarmOR11, HarmOR14 and HarmOR15 failed to respond to the tested candidate pheromone compounds. Our experiments elucidated the functions of some pheromone receptor genes of H. armigera. These advances may provide remarkable evidence for intraspecific mating choice and speciation extension in moths at molecular level.

Highlights

Male moth can accurately find and recognize mates through detection of the sex pheromone at extremely low concentration emitted from conspecific females
Six cDNA sequences encoding H. armigera pheromone receptor genes were identified (GenBank accession number: KC538876KC538881) and three of these sequences including HarmOR11, HarmOR13 and HarmOR16 were verified as full-length openreading frames in previous reports [37,38]
Sex pheromone communication between male and female moths is believed to have contributed to successful intraspecific mating choice and interspecific isolation [46]

Summary

Introduction

Male moth can accurately find and recognize mates through detection of the sex pheromone at extremely low concentration emitted from conspecific females. With the development of DNA sequencing technology, more and more sex pheromone receptor genes have been cloned, only a few have been functionally characterized. The pheromone sensitive trichiod sensilla are in the majority amongst several different types of sensilla on male silkworm antennae [14,15]. Each trichiod sensilla houses two pheromone-sensitive neurons: one of which coexpresses BmOR1/BmOR2 that is activated by bombykol, the major pheromone that elicits the male mating behavior [16]. Most species, including European corn borers (ECB), in the genus Ostrinia use varying ratios of Z11- and E11tetradecenyl acetate (Z11- and E11-14:OAc) as the two main components of their pheromone blend. At least five different sex pheromone receptor candidates have recently been identified and functionally characterized in vitro using Xenopus oocytes system. Except that ECB(Z) OR6 responded almost exclusively to Z11, the primary pheromone produced by ECB(Z) females, other receptors responded broadly to sex pheromone components in general [17,18,19]

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