Boyle John H, Martins Dino J, Pelaez Julianne, Musili Paul M, Kibet Staline, Ndung'u S Kimani, Kenfack David, Pierce Naomi E
Department of Organismic and Evolutionary Biology, and Museum of Comparative Zoology Harvard University Cambridge MA USA.
Department of Biology The College of William and Mary Williamsburg VA USA.
Ecol Evol. 2017 Dec 27;8(3):1441-1450. doi: 10.1002/ece3.3752. eCollection 2018 Feb.
The (also known as ) ant-plant symbiosis is considered a classic case of species coexistence, in which four species of tree-defending ants compete for nesting space in a single host tree species. Coexistence in this system has been explained by trade-offs in the ability of the ant associates to compete with each other for occupied trees versus the ability to colonize unoccupied trees. We seek to understand the proximal reasons for how and why the ant species vary in competitive or colonizing abilities, which are largely unknown. In this study, we use RADseq-derived SNPs to identify relatedness of workers in colonies to test the hypothesis that competitively dominant ants reach large colony sizes due to polygyny, that is, the presence of multiple egg-laying queens in a single colony. We find that variation in polygyny is not associated with competitive ability; in fact, the most dominant species, unexpectedly, showed little evidence of polygyny. We also use these markers to investigate variation in mating behavior among the ant species and find that different species vary in the number of males fathering the offspring of each colony. Finally, we show that the nature of polygyny varies between the two commonly polygynous species, and : in , queens in the same colony are often related, while this is not the case for . These results shed light on factors influencing the evolution of species coexistence in an ant-plant mutualism, as well as demonstrating the effectiveness of RADseq-derived SNPs for parentage analysis.
（也称为 ）蚁 - 植物共生被认为是物种共存的经典案例，在这种共生关系中，四种保护树木的蚂蚁物种在单一宿主树种中争夺筑巢空间。该系统中的共存现象已通过蚁类伙伴在争夺已被占据树木的竞争能力与在未被占据树木上定殖的能力之间的权衡来解释。我们试图了解蚁类物种在竞争或定殖能力方面如何以及为何存在差异的直接原因，而这些原因在很大程度上尚不清楚。在本研究中，我们使用基于RADseq的单核苷酸多态性（SNP）来确定蚁群中工蚁的亲缘关系，以检验以下假设：具有竞争优势的蚂蚁由于一夫多妻制（即单个蚁群中存在多个产卵蚁后）而达到较大的蚁群规模。我们发现一夫多妻制的差异与竞争能力无关；事实上，最具优势的物种出人意料地几乎没有一夫多妻制的迹象。我们还使用这些标记来研究蚁类物种之间交配行为的差异，发现不同物种在每个蚁群后代的父本数量上存在差异。最后，我们表明，在两种常见的一夫多妻制物种 和 中，一夫多妻制的性质有所不同：在 中，同一蚁群中的蚁后通常具有亲缘关系，而在 中情况并非如此。这些结果揭示了影响蚁 - 植物共生中物种共存进化的因素，同时也证明了基于RADseq的SNP在亲权分析中的有效性。
