Posso-Terranova Andrés, Andrés José Á
Department of Biology, University of Saskatchewan, 112 Science Pl, Saskatoon, SK, Canada.
Facultad de Ciencias Agropecuarias, Universidad Nacional de Colombia, Sede de Palmira, A.A. 237, Palmira, Colombia.
Evolution. 2017 Nov;71(11):2677-2692. doi: 10.1111/evo.13335. Epub 2017 Sep 20.
Aposematic signals represent one of the classical systems to study evolution and, as such, they have received considerable empirical and theoretical investigation. Despite the extensive literature on aposematic coloration, much uncertainty remains about genetic changes responsible for the repeated evolution of similar signals in multiple lineages. Here, we study the diversification and convergence of coloration among lineages of aposematic harlequin poison frogs (Oophaga histrionica complex). Our results suggest that different background phenotypes, showing different color and/or luminance contrast, have evolved independently at least twice in this group. We suggest that cellular arrangements are behind the striking diversity of color and patterns in this group and propose that differences in dorsal background color may be related to either or both, the presence/absence of xanthophores and the dispersion of melanosomes. Our genetic analyses support a role for the melanocortin receptor MC1R in melanosome aggregation, and we show evidence that two different mutations (∆433 and C432A) are responsible for the darker phenotypes that may display a more detectable, easier to learn, aposematic signal.
警戒信号是研究进化的经典系统之一，因此，它们受到了大量实证和理论研究。尽管关于警戒色的文献广泛，但对于多个谱系中相似信号反复进化所涉及的基因变化仍存在很多不确定性。在这里，我们研究了警戒性小丑毒蛙（Oophaga histrionica复合体）谱系之间颜色的多样化和趋同现象。我们的结果表明，在这个群体中，具有不同颜色和/或亮度对比度的不同背景表型至少独立进化了两次。我们认为细胞排列是该群体颜色和图案惊人多样性的背后原因，并提出背部背景颜色的差异可能与黄色素细胞的有无和黑素体的分散中的一个或两个有关。我们的基因分析支持黑皮质素受体MC1R在黑素体聚集过程中的作用，并且我们证明有证据表明两种不同的突变（∆433和C432A）导致了较深的表型，这些表型可能显示出更易察觉、更易学习的警戒信号。
