Sculfort Ombeline, de Castro Erika C P, Kozak Krzysztof M, Bak Søren, Elias Marianne, Nay Bastien, Llaurens Violaine
Institut de Systématique, Evolution, Biodiversité (ISYEB) Muséum National d'Histoire Naturelle CNRS Sorbonne-Université EPHE Université des Antilles Paris France.
Unité Molécules de Communication et Adaptations des Micro-organismes (MCAM) Muséum National d'Histoire Naturelle CNRS Paris France.
Ecol Evol. 2020 Feb 13;10(5):2677-2694. doi: 10.1002/ece3.6044. eCollection 2020 Mar.
Evolutionary convergence of color pattern in mimetic species is tightly linked with the evolution of chemical defenses. Yet, the evolutionary forces involved in natural variations of chemical defenses in aposematic species are still understudied. Herein, we focus on the evolution of chemical defenses in the butterfly tribe Heliconiini. These neotropical butterflies contain large concentrations of cyanogenic glucosides, cyanide-releasing compounds acting as predator deterrent. These compounds are either de novo synthesized or sequestered from their host plant, so that their concentrations may depend on host plant specialization and host plant availability. We sampled 375 wild Heliconiini butterflies across Central and South America, covering 43% species of this clade, and quantify individual variations in the different CGs using liquid chromatography coupled with tandem mass spectrometry. We detected new compounds and important variations in chemical defenses both within and among species. Based on the most recent and well-studied phylogeny of Heliconiini, we show that ecological factors such as mimetic interactions and host plant specialization have a significant association with chemical profiles, but these effects are largely explained by phylogenetic relationships. Our results therefore suggest that shared ancestries largely contribute to chemical defense variation, pointing out at the interaction between historical and ecological factors in the evolution of Müllerian mimicry.
拟态物种中颜色模式的进化趋同与化学防御的进化紧密相连。然而，有关警戒色物种化学防御自然变异所涉及的进化力量仍未得到充分研究。在此，我们聚焦于蝴蝶族赫利孔蝶亚族（Heliconiini）化学防御的进化。这些新热带蝴蝶含有高浓度的生氰糖苷，即释放氰化物的化合物，可作为捕食者的威慑物。这些化合物要么是从头合成，要么是从宿主植物中摄取，因此其浓度可能取决于宿主植物的专一性和宿主植物的可利用性。我们在中美洲和南美洲采集了375只野生赫利孔蝶亚族蝴蝶，涵盖了该分支43%的物种，并使用液相色谱-串联质谱法对不同生氰糖苷的个体差异进行了量化。我们检测到了新化合物以及物种内部和物种之间化学防御的重要差异。基于赫利孔蝶亚族最新且研究充分的系统发育，我们表明诸如拟态相互作用和宿主植物专一性等生态因素与化学特征存在显著关联，但这些影响在很大程度上可由系统发育关系来解释。因此，我们的结果表明共同祖先在很大程度上促成了化学防御的变异，指出了缪勒拟态进化中历史因素与生态因素之间的相互作用。
