Roelofs Wendell L, Liu Weitian, Hao Guixia, Jiao Hongmei, Rooney Alejandro P, Linn Charles E
Department of Entomology, Cornell University, Geneva, NY 14456, USA.
Proc Natl Acad Sci U S A. 2002 Oct 15;99(21):13621-6. doi: 10.1073/pnas.152445399. Epub 2002 Sep 17.
Mate finding in most moth species involves long-distance signaling via female-emitted sex pheromones. There is a great diversity of pheromone structures used throughout the Lepidoptera, even among closely related species. The conundrum is how signal divergence has occurred. With strong normalizing selection pressure on blend composition and response preferences, it is improbable that shifts to pheromones of diverse structures occur through adaptive changes in small steps. Here, we present data supporting the hypothesis that a major shift in the pheromone of an Ostrinia species occurred by activation of a nonfunctional desaturase gene transcript present in the pheromone gland. We also demonstrate the existence of rare males that respond to the new pheromone blend. Their presence would allow for asymmetric tracking of male response to the new blend and, thus, evolution of an Ostrinia species with structurally different sex pheromone components.
大多数蛾类物种的配偶寻找过程涉及通过雌性释放的性信息素进行长距离信号传递。在整个鳞翅目昆虫中，所使用的信息素结构具有高度多样性，即使在亲缘关系密切的物种之间也是如此。难题在于信号差异是如何产生的。由于对混合成分和反应偏好存在强大的标准化选择压力，通过小步骤的适应性变化转向具有不同结构的信息素是不太可能的。在此，我们提供数据支持这样一种假说，即一种玉米螟物种的信息素发生重大转变是由于信息素腺中存在的一个无功能去饱和酶基因转录本被激活。我们还证明了存在对新信息素混合物有反应的罕见雄性个体。它们的存在将使得能够不对称地追踪雄性对新混合物的反应，从而使具有结构不同的性信息素成分的玉米螟物种得以进化。
