Roelofs Wendell L, Rooney Alejandro P
New York State Agricultural Experiment Station, Cornell University, Geneva, NY 14456, USA.
Proc Natl Acad Sci U S A. 2003 Aug 5;100(16):9179-84. doi: 10.1073/pnas.1233767100a. Epub 2003 Jul 22.
A great diversity of pheromone structures are used by moth species (Insecta: Lepidoptera) for long-distance mating signals. The signal/response channel seems to be narrow for each species, and a major conundrum is how signal divergence has occurred in the face of strong selection pressures against small changes in the signal. Observations of various closely related and morphologically similar species that use pheromone components biosynthesized by different enzymes and biosynthetic routes underscore the question as to how major jumps in the biosynthetic routes could have evolved with a mate recognition system that is based on responses to a specific blend of chemicals. Research on the desaturases used in the pheromone biosynthetic pathway for various moth species has revealed that one way to make a major shift in the pheromone blend is by activation of a different desaturase from mRNA that already exists in the pheromone gland. Data will be presented to support the hypothesis that this process was used in the evolution of the Asian corn borer, Ostrinia furnacalis species. In that context, moth sex-pheromone desaturase genes seem to be evolving under a birth-and-death process. According to this model of multigene family evolution, some genes are maintained in the genome for long periods of time, whereas others become deleted or lose their functionality, and new genes are created through gene duplication. This mode of evolution seems to play a role in moth speciation, as exemplified by the case of the Asian corn borer and European corn borer, Ostrinia nubilalis species.
蛾类物种（昆虫纲：鳞翅目）利用多种多样的信息素结构进行远距离交配信号传递。每个物种的信号/反应通道似乎都很狭窄，一个主要难题是，面对针对信号微小变化的强大选择压力，信号是如何发生分化的。对各种亲缘关系密切且形态相似的物种进行观察，这些物种使用由不同酶和生物合成途径生物合成的信息素成分，这突出了一个问题：在基于对特定化学混合物反应的配偶识别系统中，生物合成途径的重大跳跃是如何进化的。对各种蛾类物种信息素生物合成途径中使用的去饱和酶的研究表明，使信息素混合物发生重大转变的一种方法是激活信息素腺体内已存在的信使核糖核酸中的不同去饱和酶。将展示数据以支持这一假说，即该过程在亚洲玉米螟（Ostrinia furnacalis物种）的进化中被使用。在这种情况下，蛾类性信息素去饱和酶基因似乎是在生死过程中进化的。根据这种多基因家族进化模型，一些基因在基因组中长时间保留，而其他基因则被删除或失去功能，新基因通过基因复制产生。这种进化模式似乎在蛾类物种形成中发挥作用，亚洲玉米螟和欧洲玉米螟（Ostrinia nubilalis物种）的例子就说明了这一点。
