关键词: 蛾类, 嗅觉, 性信息素受体, 表达模式, 功能分析, 进化

Abstract:  As a vital element in male moth for reception of sex pheromone components emitted by the sex gland of the conspecific female moth, pheromone receptor (PR) determines the selectivity and specificity of male odorant receptor neuron (ORN) sensing sex pheromones. Since the first PR gene in moths was identified from Heliothis virescens, PR genes have been identified in more than 60 moth species with the development of high-throughput sequencing techniques combined with sequence homology analysis. Subsequent studies proved that unlike ordinary odorant receptor (OR) genes, PR genes in moths are relatively conserved in evolution, and they cluster into a unique group in the phylogenetic tree, forming the so-called traditional PR subfamily. The expression profile and in situ hybridization results demonstrate that PR genes are mainly specifically or biased expressed in male antennae, and in the studied moth species, PRs are restrictedly expressed in the long sensilla trichodea of male antennae. In recent years, the PRs of 30 moth species have been functionally characterized by using in vitro expression system, transgenic Drosophila and other methods. As an increasing number of PRs in moths have been identified and functionally studied, researchers found other PR clades separated with the traditional PR clade in moths, which also function to recognize moth pheromone components, giving us a new understanding of the evolutionary relationships of PRs in moths and the relationship between PR evolution and species differentiation. In this article, we reviewed the new research advances of PRs in moths from aspects including PR identification, expression patterns, functional characterization and evolution, and proposed the following important directions for further research: (1) Identifying and deorphanizing more PR genes in moths that do not use type I pheromone, to promote the understanding of the evolution of PR genes; (2) Characterizing the function of special PRs, to broaden our knowledge of the function of PRs; (3) Paying more attention to PRs in the new PR clades, especially for moth species whose PR genes belonging to the traditional PR clade have not been identified; (4) Studying the interactions between PR and other olfactory-related proteins, especially PBPs and SNMP1, to further understand how PR works; (5) Illuminating the structure of PR and Orco complex, to reveal the relationship between PR structure and function, and the relationship between the differentiation of PR function and the evolution of moth species; (6) Designing efficient and environmentally friendly measures to control moth pests based on the identified PRs.

Key words:  Moths, olfaction, pheromone receptor, expression pattern, functional characterization, evolution