Evolution of Unique Desaturases in Insect Glands

昆虫的性信息素系统受到了相当大的关注，因为用于吸引配偶的物种特异性引诱化学物质可以用于监测和昆虫管理策略。此外，这些信号在维持物种完整性方面的关键作用支持了特定信号的进化直接参与物种形成过程的观点。虽然我们现在对雌性飞蛾信息素腺中化学信号的生物合成已经了解很多，但是这些化学通讯系统是如何进化到在相关飞蛾物种中使用不同的混合物和化学成分的，仍然存在许多问题。PI发现，蛾子信息素腺中进化出了一种独特的酶家族，可以产生在其他动物中通常找不到的具有双键的不饱和化合物。PI假设这些独特的“去饱和酶”是从所有动物中发现的常见的(9)去饱和酶进化而来的，这些去饱和酶可以产生油酸（碳9不饱和）等化合物。一些独特的去饱和酶基因的表征将提供进行从原始和高级物种的去饱和酶基因与常见的(9)去饱和酶基因的比较，以更好地了解物种形成过程的可能性。这些新型的去饱和酶也将为研究这些去饱和酶如何在不同位置产生具有双键的不同化合物以及它们如何制造这些同分异构体的特定混合物提供重要的酶类资源。了解飞蛾腺体中独特的去饱和酶以及它们如何插入双键，除了对这些酶和物种形成过程的基础知识做出巨大贡献外，还可能导致商业过程的发展，为制药、食品或化学工业生产有价值的原材料。＊＊＊

9514211 Roelofs Sex pheromone systems in insects have had considerable attention because the species-specific attractant chemicals used for attracting mates can be exploited for monitoring and insect management strategies. Also, the critical use of these signals in maintaining the integrity of a species supports the idea that the evolution of the specific signals is directly involved in the speciation process. Although much is now known about how the chemical signals are biosynthesized in the pheromone gland of female moths, there remain many questions about how these chemical communication systems have evolved to use different blends and chemical compositions in related moth species. The PI has found that a family of unique enzymes have evolved in the moth pheromone gland to produce unsaturated compounds possessing double bonds in locations not normally found in other animals. The PI hypothesizes that these unique "desaturases" evolved from the common (9 desaturase that is found in all animals to make compounds such as oleic acid (unsaturation at carbon 9). The characterization of the genes for some of the unique desaturases would provide the possibility of conducting a comparison of desaturase genes from primitive and advanced species to the common (9 desaturase gene to better understand the speciation process. These novel desaturases also would provide an important resource of enzymes not available from other sources to study in general how these desaturases function to produce different compounds with double bonds in various positions and how they can make specific mixtures of these isomers. An understanding of the unique desaturases from moth glands and how they insert double bonds, in addition to its huge contribution to the fundamental knowledge about these enzymes and to the speciation process, could lead to the development of commercial processes for producing valuable raw materials for the pharmaceuticals, food or chemical industries. ***