Gene flow is maintained by polyandry and male dispersal in the army ant Eciton burchellii
Gene flow is maintained by polyandry and male dispersal in the army ant Eciton burchellii
复制标题
行军蚁 Eciton burchellii 的基因流是通过一妻多夫制和雄性扩散来维持的
作者：
R. Jaffé;R. Moritz;F. B. Kraus
单倍二倍体、互补性决定和真社会性的结合对社会性膜翅目昆虫的有效种群规模（Ne）的限制远远超过任何其他昆虫类群。 Ne 的额外限制出现在行军蚁中，因为它们有无翅蚁后和蚁群分裂，这两者都是导致母体基因流受限和种群粘性高的因素。因此，带翅膀的雄性行军蚁对于确保传播、促进基因流动和避免近亲繁殖具有特殊的意义。基于微卫星标记的群体遗传分析，我们研究了新热带行军蚁 Eciton burchellii 群体，发现杂合度高，群体分化弱，没有近亲繁殖的证据。此外，通过使用同胞关系重建分析，我们量化了蜂王配偶样本中雄性贡献群体的实际数量，证明通过极端的多重交配，蜂王能够从最多十个不同的群体（通常位于大约 1 公里半径内）中采集雄性基因的样本。最后，我们将每个雄性贡献群体的个体交配成功率与个体雄性的相对繁殖成功率相关联，并发现了一个显着的依赖于群体的雄性适应性成分。我们的结果表明，这些行军蚁的分散和交配系统似乎增强了基因流动，并最大限度地减少了与有效种群规模较小相关的有害影响。
The combination of haplodiploidy, complementary sex determination and eusociality constrains the effective population size (Ne) of social Hymenoptera far more than in any other insect group. Additional limitations on Ne occur in army ants since they have wingless queens and colony fission, both of which are factors causing restricted maternal gene flow and high population viscosity. Therefore, winged army ant males gain a particular significance to ensure dispersal, facilitate gene flow and avoid inbreeding. Based on population genetic analyses with microsatellite markers, we studied a population of the Neotropical army ant Eciton burchellii, finding a high level of heterozygosity, weak population differentiation and no evidence for inbreeding. Moreover, by using sibship reconstruction analyses, we quantified the actual number of male contributing colonies represented in a queen’s mate sample, demonstrating that, through extreme multiple mating, the queens are able to sample the genes of males from up to ten different colonies, usually located within an approximate radius of 1 km. We finally correlated the individual mating success of each male contributing colony with the relative siring success of individual males and found a significant colony-dependent male fitness component. Our results imply that the dispersal and mating system of these army ants seem to enhance gene flow and minimise the deleterious effects associated with small effective population size.