Coyne J A, Wicker-Thomas C, Jallon J M
Department of Ecology and Evolution, University of Chicago, IL 60637, USA.
Genet Res. 1999 Jun;73(3):189-203. doi: 10.1017/s0016672398003723.
Drosophila melanogaster is polymorphic for the major cuticular hydrocarbon of females. In most populations this hydrocarbon is 7,11-heptacosadiene, but females from Africa and the Caribbean usually possess low levels of 7,11-heptacosadiene and high quantities of its position isomer 5,9-heptacosadiene. Genetic analysis shows that the difference between these two morphs is due to variation at a single segregating factor located on the right arm of chromosome 3 near map position 51.5 and cytological position 87C-D. This is precisely the position of a desaturase gene previously sequenced using primers derived from yeast and mouse, and localized by in situ hybridization to the polytene chromosomes of D. melanogaster. Alleles of this desaturase gene may therefore be responsible for producing the two hydrocarbon morphs. Mating tests following the transfer of these isomers between females of the two morphs show that, in contrast to previous studies, the hydrocarbon profiles have no detectable effect on mating behaviour or sexual isolation.
黑腹果蝇雌性的主要表皮碳氢化合物具有多态性。在大多数种群中，这种碳氢化合物是7,11 - 二十七碳二烯，但来自非洲和加勒比地区的雌性通常含有低水平的7,11 - 二十七碳二烯和大量其位置异构体5,9 - 二十七碳二烯。遗传分析表明，这两种形态之间的差异是由于位于3号染色体右臂靠近图谱位置51.5和细胞学位置87C - D处的单个分离因子的变异。这恰好是先前使用源自酵母和小鼠的引物进行测序，并通过原位杂交定位到黑腹果蝇多线染色体上的去饱和酶基因的位置。因此，这个去饱和酶基因的等位基因可能负责产生这两种碳氢化合物形态。在这两种形态的雌性之间转移这些异构体后进行的交配试验表明，与先前的研究相反，碳氢化合物谱对交配行为或性隔离没有可检测到的影响。
