Rouault Jacques-Deric, Marican Charlotte, Wicker-Thomas Claude, Jallon Jean-Marc
Laboratoire de Neurobiologie de l'Apprentissage, de la Memoire et de la Communication, CNRS UMR 8620, Universite Paris Sud, Batiment 446, F-91405 Orsay Cedex, France.
Genetica. 2004 Mar;120(1-3):195-212. doi: 10.1023/b:gene.0000017641.75820.49.
D. simulans and D. melanogaster present two types of polymorphism in their cuticular hydrocarbon (HC) composition. Especially both sexes of D. simulans, and D. melanogaster males display 7-tricosene (7T) as the major compound type [7T]s and [7T]m, or 7-pentacosene (7P) [7P]s and [7P]m. D. melanogaster females display 7,11-heptacosadiene (7,11HD) as the major compound: [7,11HD]m, or 5,9-heptacosadiene (5,9HD): [5,9HD]m. The [7P]s, [7P]m and [5,9HD]m are mainly present in central Africa. A significant correlation was found between latitude and the proportion of compounds with 23 and 25 carbon atoms, especially 7T and 7P in both sexes of D. melanogaster. [7P]m type of D. melanogaster, characterized with an excess of C25 compounds, presents a higher resistance against desiccation than [7T]m type, where C23 compounds are more abundant. These differences can be correlated with calculated HC fusion temperatures. Moreover, increasing the breeding temperature from 18 to 29 degrees C induces in D. melanogaster males an increase in 25C compounds and a decrease in 23C compounds, but the opposite effect in D. simulans. A mathematical model of biosynthesis, based on kinetics of elongation and decarboxylation enzymes, suggests that a simple variation of the efficiency of an elongation enzyme may account for the differences observed between the [7T]m and [7P]m types of D. melanogaster and [7T]s and [7P]s types D. simulans. Finally on the basis of the geographical distribution of the HC types of both Drosophila species, an evolutionary dispersal pathway is proposed and discussed in relation to the environment and reproductive behavior.
拟果蝇和黑腹果蝇在其表皮碳氢化合物（HC）组成上呈现出两种多态性。特别是拟果蝇的雌雄两性以及黑腹果蝇的雄性，均以7-二十三碳烯（7T）作为主要化合物类型，即[7T]s和[7T]m，或者7-二十五碳烯（7P），即[7P]s和[7P]m。黑腹果蝇的雌性则以7,11-二十七碳二烯（7,11HD）作为主要化合物：[7,11HD]m，或者5,9-二十七碳二烯（5,9HD）：[5,9HD]m。[7P]s、[7P]m和[5,9HD]m主要存在于中非地区。在黑腹果蝇的雌雄两性中，发现纬度与含有23和25个碳原子的化合物比例之间存在显著相关性，尤其是7T和7P。黑腹果蝇的[7P]m类型以C25化合物过量为特征，比C23化合物更为丰富的[7T]m类型具有更高的抗干燥能力。这些差异可能与计算得出的HC融合温度相关。此外，将饲养温度从18摄氏度提高到29摄氏度，会导致黑腹果蝇雄性中25碳化合物增加、23碳化合物减少，但在拟果蝇中则产生相反的效果。基于延长和脱羧酶动力学的生物合成数学模型表明，延长酶效率的简单变化可能解释了在黑腹果蝇的[7T]m和[7P]m类型以及拟果蝇的[7T]s和[7P]s类型之间观察到的差异。最后，根据这两种果蝇物种HC类型的地理分布，提出并讨论了与环境和生殖行为相关的进化扩散途径。
