Single mutation to a sex pheromone receptor provides adaptive specificity between closely related moth species
Single mutation to a sex pheromone receptor provides adaptive specificity between closely related moth species
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DOI：
10.1073/pnas.1204661109
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发表时间：
2012-08-28
影响因子：
11.1
通讯作者：
Wanner, Kevin W.
中科院分区：
文献类型：
--
作者：
Leary, Greg P.;Allen, Jean E.;Wanner, Kevin W.
性信息素的交流，作为一个前合子的交配障碍，被认为是促成了蛾和蝴蝶的物种形成在鳞翅目。在第一个蛾性信息素被发现的五十年后，人们对密切相关的物种之间信息素通信进化的分子机制知之甚少。虽然亚洲和欧洲的玉米螟（ACB和ECB）可以在实验室中杂交，但它们对性信息素异构体（E）-12-和（Z）-12-十四碳烯乙酸酯和（E）-11-和（Z）-11-十四碳烯乙酸酯（ACB：E12，Z12; ECB; E11，Z11）的反应与自然交配行为隔离。雄蛾的嗅觉系统对同种雌蛾产生的混合信息素有特异性反应。在离体条件下，雄性触角中表达的性信息素受体ECB（Z）气味受体3（OR 3）对E11有强烈的反应，但对Z11、E12和Z12信息素也有普遍的反应。相比之下，我们表明，ACB OR 3，一个基因，已受到积极的选择（ω = 2.9），优先响应ACB E12和Z12信息素。在鸵鸟属物种中，对应于OR 3的跨膜结构域3中的位置148的氨基酸残基是丙氨酸（A），除了ACB OR 3在该位置具有苏氨酸（T）。该残基从A突变为T改变了信息素识别模式，通过选择性地减少E11响应类似于14倍。这些结果表明，离散突变，缩小更广泛的响应性信息素受体的特异性，可能提供了一种机制，有助于物种形成。
Sex pheromone communication, acting as a prezygotic barrier to mating, is believed to have contributed to the speciation of moths and butterflies in the order Lepidoptera. Five decades after the discovery of the first moth sex pheromone, little is known about the molecular mechanisms that underlie the evolution of pheromone communication between closely related species. Although Asian and European corn borers (ACB and ECB) can be interbred in the laboratory, they are behaviorally isolated from mating naturally by their responses to subtly different sex pheromone isomers, (E)-12- and (Z)-12-tetradecenyl acetate and (E)-11- and (Z)-11-tetradecenyl acetate (ACB: E12, Z12; ECB; E11, Z11). Male moth olfactory systems respond specifically to the pheromone blend produced by their conspecific females. In vitro, ECB(Z) odorant receptor 3 (OR3), a sex pheromone receptor expressed in male antennae, responds strongly to E11 but also generally to the Z11, E12, and Z12 pheromones. In contrast, we show that ACB OR3, a gene that has been subjected to positive selection (omega = 2.9), responds preferentially to the ACB E12 and Z12 pheromones. In Ostrinia species the amino acid residue corresponding to position 148 in transmembrane domain 3 of OR3 is alanine (A), except for ACB OR3 that has a threonine (T) in this position. Mutation of this residue from A to T alters the pheromone recognition pattern by selectively reducing the E11 response similar to 14-fold. These results suggest that discrete mutations that narrow the specificity of more broadly responsive sex pheromone receptors may provide a mechanism that contributes to speciation.