INRA, UMR CBGP (INRA/IRD/Cirad/Montpellier SupAgro), Campus international de Baillarguet, Montferrier-sur-Lez, France.
Heredity (Edinb). 2010 Aug;105(2):205-12. doi: 10.1038/hdy.2009.169. Epub 2009 Nov 25.
Previous studies indicate that some populations of the little fire ant, Wasmannia auropunctata, display an unusual reproduction system polymorphism. Although some populations have a classical haplodiploid reproduction system, in other populations queens are produced by thelytokous parthenogenesis, males are produced by a male clonality system and workers are produced sexually. An atypical genetic caste determination system was also suggested. However, these conclusions were indirectly inferred from genetic studies on field population samples. Here we set up experimental laboratory nests that allow the control of the parental relationships between individuals. The queens heading those nests originated from either putatively clonal or sexual populations. We characterized the male, queen and worker offspring they produced at 12 microsatellite loci. Our results unambiguously confirm the unique reproduction system polymorphism mentioned above and that male clonality is strictly associated with thelytokous parthenogenesis. We also observed direct evidence of the rare production of sexual gynes and arrhenotokous males in clonal populations. Finally, we obtained evidence of a genetic basis for caste determination. The evolutionary significance of the reproduction system polymorphism and genetic caste determination as well as future research opportunities are discussed.
先前的研究表明，一些小黄家蚁（Wasmannia auropunctata）种群表现出一种不寻常的繁殖系统多态性。尽管一些种群具有经典的单倍二倍体繁殖系统，但在其他种群中，蚁后通过孤雌生殖产生，雄蚁通过雄性克隆系统产生，工蚁则通过有性生殖产生。还提出了一种非典型的遗传等级决定系统。然而，这些结论是从对野外种群样本的遗传研究中间接推断出来的。在这里，我们建立了实验性的实验室巢穴，可以控制个体之间的亲子关系。领导这些巢穴的蚁后来自于假定的克隆或有性种群。我们在 12 个微卫星基因座上对它们所产生的雄蚁、蚁后和工蚁后代进行了特征描述。我们的结果明确证实了上述独特的繁殖系统多态性，以及雄性克隆性与孤雌生殖严格相关。我们还观察到了在克隆种群中罕见的有性雌蚁和孤雌雄蚁的直接证据。最后，我们获得了等级决定的遗传基础的证据。讨论了繁殖系统多态性和遗传等级决定的进化意义以及未来的研究机会。
