On testing the role of genetic asymmetries created by haplodiploidy in the evolution of eusociality in the Hymenoptera
On testing the role of genetic asymmetries created by haplodiploidy in the evolution of eusociality in the Hymenoptera
复制标题
测试单倍二倍体造成的遗传不对称在膜翅目真社会性进化中的作用
DOI：
10.1007/bf02923575
复制
发表时间：
1991
影响因子：
1.5
通讯作者：
R. Gadagkar
中科院分区：
文献类型：
--
作者：
R. Gadagkar
在所有的水翅目中发现的单倍二倍体遗传系统造成了遗传相关性的不对称，因此全姐妹之间的关系比母亲与女儿之间的关系更密切。因此，与养育后代的个体相比，养育兄弟姐妹的海蛛工人可以获得更高的包容性适应度。然而，一妻多夫制和一夫多妻制减少了工人和他们的姐妹篇之间的相关性，从而打破了单倍性造成的遗传不对称。自从酶位点变异的电泳分析出现以来，已经发表了几个关于Hytera群体内遗传相关性的估计。为了检验单倍二倍性所造成的遗传不对称性在真社会性进化中的作用，我假设工人有能力投资于他们的兄弟姐妹篇与他们的亲缘关系。然后，我计算一个单倍性阈值，这是阈值相关姐妹篇的工人需要获得一个加权平均相关性为0.5的兄弟姐妹，从而打破甚至与孤独的foundresses姐妹。当工蚁在远交种群中饲养兄弟姐妹篇的混合物时，该阈值为0.604。185个姐妹篇之间的平均遗传相关性的估计值的分布在Hyopteran殖民地的检查表明，该值远低于预期的0.75为全姐妹篇，无论是在higly eusocial以及在resistively eusocial物种，虽然在后者的相关值高于前者。在177个具有标准误差的估计值中，49个显著低于单倍性阈值，22个显著高于单倍性阈值。在研究的35个物种中，只有6个物种的一个或多个估计值显著高于单倍性阈值。对于超过一半的估计，相关性值高于单倍性阈值的概率小于0.5。使用0.5作为阈值对这些数据进行重新分析并没有显著改变这些结论。我的结论是，在大多数情况下，单倍性二倍体造成的遗传不对称性本身不足以促进真社会性的起源或维持高度的真社会性状态。
The haplodiploid genetic system found in all Hymenopterans creates an asymmetry in genetic relatedness so that full-sisters are more closely related to each other than a mother is to her daughters. Thus Hymenopteran workers who rear siblings can obtain higher inclusive fitness compared to individuals who rear offspring. However, polyandry and polygyny reduce relatedness between workers and their sisters and thus tend to break down the genetic asymmetry created by haplodiploidy. Since the advent of electrophoretic analysis of variability at enzyme loci, several estimates of intra-colony genetic relatedness in the Hymenoptera have been published. To test the role of the genetic asymmetry created by haplodiploidy in the evolution of eusociality, I assume that workers are capable of investing in their brothers and sisters in their ratio of relatedness to them. I then compute ahaplodiploidy threshold, which is the threshold relatedness to sisters required for workers to obtain a weighted mean relatedness of 0.5 to siblings and thus break even with solitary foundresses. When workers rear mixtures of sisters and brothers in an outbred population, the value of this threshold is 0.604. An examination of the distribution of 185 estimates of mean genetic relatedness between sisters in Hymenopteran colonies shows that the values are well below the expected 0.75 for full sisters, both in higly eusocial as well as in primitively eusocial species although relatedness values in the latter are higher than in the former. Of the 177 estimates with standard error, 49 are significantly lower than the haplodiploidy threshold and 22 are significantly higher. Of the 35 species studied only 6 have one or more estimates that are significantly higher than the haplodiploidy threshold. For more than half the estimates, the probability of the relatedness value being above the haplodiploidy threshold is less than 0.5. Reanalysis of these data using 0.5 as the threshold does not drastically alter these conclusions. I conclude that the genetic asymmetry created by haplodiploidy is, in most cases, insufficient by itself either topromote the origin of eusocialityor tomaintain the highly eusocial state.