Kooij Pepijn W, Poulsen Michael, Schiøtt Morten, Boomsma Jacobus J
Centre for Social Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark.
Fungal Ecol. 2015 Dec;18:10-17. doi: 10.1016/j.funeco.2015.08.003.
Obligate mutualistic symbioses rely on mechanisms that secure host-symbiont commitments to maximize host benefits and prevent symbiont cheating. Previous studies showed that somatic incompatibilities correlate with neutral-marker-based genetic distances between fungal symbionts of Panamanian leaf-cutting ants, but the extent to which this relationship applies more generally remained unclear. Here we showed that genetic distances accurately predicted somatic incompatibility for symbionts irrespective of whether neutral microsatellites or AFLP markers were used, but that such correlations were weaker or absent in sympatric colonies. Further analysis showed that the symbiont clades maintained by and were likely to represent separate gene pools, so that neutral markers were unlikely to be similarly correlated with incompatibility loci that have experienced different selection regimes. We suggest that evolutionarily derived claustral colony founding by queens may have removed selection for strong incompatibility in fungi, as this condition makes the likelihood of symbiont swaps much lower than in , where incipient nests stay open because queens have to forage until the first workers emerge.
专性互利共生依赖于确保宿主 - 共生体承诺的机制，以最大化宿主利益并防止共生体作弊。先前的研究表明，体细胞不相容性与巴拿马切叶蚁真菌共生体之间基于中性标记的遗传距离相关，但这种关系在更广泛范围内的适用程度仍不清楚。在这里，我们表明，无论使用中性微卫星还是AFLP标记，遗传距离都能准确预测共生体的体细胞不相容性，但在同域菌落中这种相关性较弱或不存在。进一步分析表明，由……维持的共生体分支可能代表不同的基因库，因此中性标记不太可能与经历不同选择机制的不相容位点有类似的相关性。我们认为，……蚁后进化出的闭巢建巢方式可能消除了对……真菌中强烈不相容性的选择，因为这种情况使共生体交换的可能性远低于……，在……中，初始巢穴保持开放，因为蚁后必须觅食直到第一批工蚁出现。
