Loss of phenotypic plasticity generates genotype-caste association in harvester ants
Loss of phenotypic plasticity generates genotype-caste association in harvester ants
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DOI：
10.1016/j.cub.2004.12.027
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发表时间：
2004-12-29
期刊：
影响因子：
9.2
通讯作者：
Keller, L
中科院分区：
文献类型：
--
作者：
Cahan, SH;Julian, GE;Keller, L
种姓分化和生殖分工是昆虫社会的标志[1]。在蚂蚁和其他社会性的水翅目中，雌性幼虫发育成蚁后或工蚁通常是由环境诱导的基因表达差异引起的[2-4]。然而，在蜜蜂[5]和蚂蚁[6-9]中描述了某些基因组合可能决定生殖状态的几种情况。我们的实验研究是否基因型直接影响种姓决定在两个种群的Pogonomyrmex收获蚁的基因型种姓协会已被观察到。每个种群包含两个遗传谱系[10]。蚁后是一妻多夫的[11，12]，并与两个谱系的雄性交配[6，7]，但在成熟的殖民地，超过95%的女儿蚁后具有纯谱系基因组，而所有的工人都是F1谱系间的祖先[6-8]。我们发现，这种模式是保持在整个殖民地的生命周期，即使只有一个种姓正在生产。通过控制杂交，我们证明，即使不存在谱系间育雏，纯谱系卵子也无法发育成工蜂。因此，在这些人的环境种姓决定似乎已经失去了有利于硬连线遗传机制。我们的研究结果表明，生殖命运的遗传控制可以持续不丧失的真社会种姓结构。
Caste differentiation and reproductive division of labor are the hallmarks of insect societies [1]. In ants and other social Hymenoptera, development of female larvae into queens or workers generally results from environmentally induced differences in gene expression [2-4]. However, several cases in which certain gene combinations may determine reproductive status have been described in bees [5] and ants [6-9]. We investigated experimentally whether genotype directly influences caste determination in two populations of Pogonomyrmex harvester ants in which genotype-caste associations have been observed. Each population contains two genetic lineages [10]. Queens are polyandrous [11, 12] and mate with males of both lineages [6, 7], but in mature colonies, over 95% of daughter queens have a pure-lineage genome, whereas all workers are of F1 interlineage ancestry [6-8]. We found that this pattern is maintained throughout the colony life cycle, even when only a single caste is being produced. Through controlled crosses, we demonstrate that pure-lineage eggs fail to develop into workers even when interlineage brood are not present. Thus, environmental caste determination in these individuals appears to have been lost in favor of a hardwired genetic mechanism. Our results reveal that genetic control of reproductive fate can persist without loss of the eusocial caste structure.