Department of Genetics, Heinrich Heine University, Duesseldorf, Germany.
PLoS One. 2012;7(2):e31653. doi: 10.1371/journal.pone.0031653. Epub 2012 Feb 14.
Division of labor in social insects has made the evolution of collective traits possible that cannot be achieved by individuals alone. Differences in behavioral responses produce variation in engagement in behavioral tasks, which as a consequence, generates a division of labor. We still have little understanding of the genetic components influencing these behaviors, although several candidate genomic regions and genes influencing individual behavior have been identified. Here, we report that mixing of worker honeybees with different genotypes influences the expression of individual worker behaviors and the transcription of genes in the neuronal substrate. These indirect genetic effects arise in a colony because numerous interactions between workers produce interacting phenotypes and genotypes across organisms. We studied hygienic behavior of honeybee workers, which involves the cleaning of diseased brood cells in the colony. We mixed ∼500 newly emerged honeybee workers with genotypes of preferred Low (L) and High (H) hygienic behaviors. The L/H genotypic mixing affected the behavioral engagement of L worker bees in a hygienic task, the cooperation among workers in uncapping single brood cells, and switching between hygienic tasks. We found no evidence that recruiting and task-related stimuli are the primary source of the indirect genetic effects on behavior. We suggested that behavioral responsiveness of L bees was affected by genotypic mixing and found evidence for changes in the brain in terms of 943 differently expressed genes. The functional categories of cell adhesion, cellular component organization, anatomical structure development, protein localization, developmental growth and cell morphogenesis were overrepresented in this set of 943 genes, suggesting that indirect genetic effects can play a role in modulating and modifying the neuronal substrate. Our results suggest that genotypes of social partners affect the behavioral responsiveness and the neuronal substrate of individual workers, indicating a complex genetic architecture underlying the expression of behavior.
社会昆虫的分工使得集体特征的进化成为可能，而这些特征单凭个体是无法实现的。行为反应的差异产生了行为任务参与的差异，进而产生了分工。尽管已经确定了几个影响个体行为的候选基因组区域和基因，但我们对影响这些行为的遗传成分仍然知之甚少。在这里，我们报告说，不同基因型的工蜂混合会影响个体工蜂行为的表达和神经元基质中基因的转录。这些间接遗传效应是在一个群体中产生的，因为工蜂之间的大量相互作用会在生物体之间产生相互作用的表型和基因型。我们研究了蜜蜂工蜂的卫生行为，它涉及到清理群体中患病的幼虫细胞。我们将约 500 只新出现的蜜蜂工蜂与偏好低（L）和高（H）卫生行为的基因型混合。L/H 基因型混合影响了 L 工蜂从事卫生任务的行为参与度、工蜂间在单个幼虫细胞上开顶的合作度，以及在卫生任务之间的切换。我们没有证据表明招募和与任务相关的刺激是对行为产生间接遗传效应的主要来源。我们认为，L 蜜蜂的行为反应能力受到基因型混合的影响，并发现了证据表明大脑在 943 个表达不同的基因方面发生了变化。细胞粘附、细胞成分组织、解剖结构发育、蛋白质定位、发育生长和细胞形态发生的功能类别在这 943 个基因中过表达，这表明间接遗传效应可以在调节和修饰神经元基质方面发挥作用。我们的研究结果表明，社会伙伴的基因型会影响个体工蜂的行为反应能力和神经元基质，这表明行为表达的背后存在复杂的遗传结构。
