Suni Sevan S, Gignoux Christopher, Gordon Deborah M
Department of Biological Sciences, Stanford University, Stanford, CA 94305-5020, USA.
Mol Ecol. 2007 Dec;16(24):5149-55. doi: 10.1111/j.1365-294X.2007.03492.x.
We investigated the extent to which workers reproduce in a dependent-lineage population of the monogynous harvester ant Pogonomyrmex barbatus. Dependent-lineage populations contain two interbreeding, yet genetically distinct mitochondrial lineages, each associated with specific alleles at nuclear loci. Workers develop from matings between lineages, and queens develop from matings within lineages, so queens must mate with males of both lineages to produce daughter queens and workers. Males develop from unfertilized eggs and are haploid. Worker production of males could lead to male-mediated gene flow between the lineages if worker-produced males were reproductively capable. This could result in the loss of the dependent-lineage system, because its persistence depends on the maintenance of allelic differences between the lineages. To investigate the extent of worker reproduction in P. barbatus, we genotyped 19-20 males and workers from seven colonies, at seven microsatellite loci, and 1239 additional males at two microsatellite loci. Our methods were powerful enough to detect worker reproduction if workers produced more than 0.39% of males in the population. We detected no worker-produced males; all males appeared to be produced by queens. Thus, worker reproduction is sufficiently infrequent to have little impact on the dependent-lineage system. These results are consistent with predictions based on inclusive fitness theory because the effective queen mating frequency calculated from worker genotypes was 4.26, which is sufficiently high for workers to police those that attempt to reproduce.
我们研究了在单后制收获蚁巴氏收获蚁（Pogonomyrmex barbatus）的依赖谱系种群中工蚁进行繁殖的程度。依赖谱系种群包含两个相互杂交但线粒体谱系在基因上不同的谱系，每个谱系与核基因座上的特定等位基因相关联。工蚁由不同谱系之间的交配产生，蚁后由同一谱系内的交配产生，所以蚁后必须与两个谱系的雄蚁交配才能产生雌性后代蚁后和工蚁。雄蚁由未受精的卵发育而来，是单倍体。如果工蚁产生的雄蚁具有生殖能力，那么工蚁产生雄蚁可能会导致谱系间由雄蚁介导的基因流动。这可能会导致依赖谱系系统的丧失，因为其持续存在依赖于谱系间等位基因差异的维持。为了研究巴氏收获蚁中工蚁繁殖的程度，我们对来自七个蚁群的19 - 20只雄蚁和工蚁在七个微卫星基因座上进行了基因分型，并对另外1239只雄蚁在两个微卫星基因座上进行了基因分型。如果工蚁在种群中产生的雄蚁超过0.39%，我们的方法有足够的能力检测到工蚁繁殖。我们未检测到由工蚁产生的雄蚁；所有雄蚁似乎都是由蚁后产生的。因此，工蚁繁殖极少发生，对依赖谱系系统几乎没有影响。这些结果与基于广义适合度理论的预测一致，因为根据工蚁基因型计算出的有效蚁后交配频率为4.26，这足够高，使工蚁能够监督那些试图繁殖的个体。
