Quantitive variation of male and female-specific compounds in 99 drosophilid flies

Variation in sex pheromones is regarded as one of the causes of reproductive isolation and speciation. We recently identified 51 male- and female-specific compounds – many of which function as sex pheromones – in 99 drosophilid species1. Here, we report that despite many of these compounds being shared between species, their quantities differ significantly. For example, although 34 drosophilid species share the male-specific compound cis-vaccenyl acetate (cVA), which plays a critical role in regulating various social and sexual behaviors, the amount of cVA can differ by up to 600-fold between different species. Additionally, we found 7-tricosene, the cuticular hydrocarbon pheromone, present in 35 Drosophila species. Our findings indicate that 7-tricosene is equally present in both sexes of 14 species, more abundant in males of 14 species, and more abundant in females of 7 species. We provide raw data on the concentration of potential pheromone components in the 99 drosophilids, which can provide important insights for further research on the behavior and evolution of these species. Quantitative variations highlight species-specific patterns, suggesting an additional mechanism for reproductive isolation built on specific combinations of compounds at set concentrations.

性别信息素的变异被视为生殖隔离和物种分化的成因之一。近期，我们已在99种果蝇属物种中识别出51种雄性和雌性特异性化合物——其中许多化合物作为性别信息素发挥作用。在此，我们报道，尽管许多这些化合物在物种间存在共享，但它们的含量存在显著差异。例如，尽管34种果蝇属物种共享了具有调节多种社会和性行为关键作用的雄性特异性化合物顺式-香茅基乙酸（cVA），但cVA在不同物种间的含量可能相差高达600倍。此外，我们还发现了一种存在于35种果蝇属物种中的切割烷烃性信息素——7-三十烷。我们的研究结果表明，7-三十烷在14种物种中在雌雄两性中含量相等，在14种物种的雄性中含量更为丰富，在7种物种的雌性中含量更为丰富。我们提供了99种果蝇属中潜在信息素成分浓度的原始数据，这些数据可为进一步研究这些物种的行为与进化提供重要洞见。定量变异凸显了物种特有的模式，并暗示了一种基于特定化合物在设定浓度下特定组合的附加生殖隔离机制。