Koutroumpa Fotini A, Groot Astrid T, Dekker Teun, Heckel David G
Institute for Biodiversity and Ecosystems Dynamics, University of Amsterdam, 1098 XH Amsterdam, The Netherlands; Department of Entomology, Max Planck Institute for Chemical Ecology, D-07745 Jena, Germany;
Institute for Biodiversity and Ecosystems Dynamics, University of Amsterdam, 1098 XH Amsterdam, The Netherlands; Department of Entomology, Max Planck Institute for Chemical Ecology, D-07745 Jena, Germany.
Proc Natl Acad Sci U S A. 2016 Oct 18;113(42):E6401-E6408. doi: 10.1073/pnas.1610515113. Epub 2016 Oct 3.
The sexual pheromone communication system of moths is a model system for studies of the evolution of reproductive isolation. Females emit a blend of volatile components that males detect at a distance. Species differences in female pheromone composition and male response directly reinforce reproductive isolation in nature, because even slight variations in the species-specific pheromone blend are usually rejected by the male. The mechanisms by which a new pheromone signal-response system could evolve are enigmatic, because any deviation from the optimally attractive blend should be selected against. Here we investigate the genetic mechanisms enabling a switch in male response. We used a quantitative trait locus-mapping approach to identify the genetic basis of male response in the two pheromone races of the European corn borer, Ostrinia nubilalis Male response to a 99:1 vs. a 3:97 ratio of the E and Z isomers of the female pheromone is governed by a single, sex-linked locus. We found that the chromosomal region most tightly linked to this locus contains genes involved in neurogenesis but, in accordance with an earlier study, does not contain the odorant receptors expressed in the male antenna that detect the pheromone. This finding implies that differences in the development of neuronal pathways conveying information from the antenna, not differences in pheromone detection by the odorant receptors, are primarily responsible for the behavioral response differences among the males in this system. Comparison with other moth species reveals a previously unexplored mechanism by which male pheromone response can change in evolution.
蛾类的性信息素通讯系统是研究生殖隔离进化的一个模式系统。雌蛾释放出一种挥发性成分的混合物，雄蛾能在一定距离外检测到。雌蛾性信息素组成和雄蛾反应的物种差异在自然界中直接强化了生殖隔离，因为即使是物种特异性信息素混合物的细微变化通常也会被雄蛾拒绝。新的信息素信号 - 反应系统可能进化的机制尚不清楚，因为任何偏离最优吸引混合物的情况都应被淘汰。在这里，我们研究了使雄蛾反应发生转变的遗传机制。我们使用数量性状基因座定位方法来确定欧洲玉米螟两种性信息素类型中雄蛾反应的遗传基础。雄蛾对雌蛾性信息素E型和Z型异构体99:1与3:97比例的反应由一个单一的性连锁基因座控制。我们发现与该基因座紧密连锁的染色体区域包含参与神经发生的基因，但与早期研究一致，该区域不包含在雄蛾触角中表达的用于检测性信息素的气味受体。这一发现意味着，在这个系统中，传递来自触角信息的神经元通路发育差异，而非气味受体对性信息素检测的差异，是造成雄蛾行为反应差异的主要原因。与其他蛾类物种的比较揭示了一种以前未被探索的雄蛾性信息素反应在进化中可能发生变化的机制。
