RUI: Genetic Dissection of the Reproductive Ground-Plan Hypothesis of Social Evolution

合作的动物社会非常成功，但它们的进化仍然没有得到很好的理解。新出现的生殖地面计划假说提供了一个理解社会进化的框架，它表明非社会祖先的生殖调节途径在进化过程中被增选来控制社会表型。根据这一假设，生殖基因网络应该控制着不同群体成员的复杂专业化，以保证社会的运作。该假说将生理和行为的调节机制与一个合理的进化情景联系起来，从而形成了一个统一的社会进化理论。最近的数学模拟模型和行为研究表明，社会性昆虫的基本特征（生殖分工和工人行为的合作专业化）确实来自祖先的生殖周期。该项目将利用这些令人鼓舞的成果，以蜜蜂为实验模型，在遗传水平上首次直接检验生殖基础计划假设。工蜂表现出一系列相关的行为、生活史和生理特征，包括感觉灵敏度、行为成熟度、生殖调节、觅食偏好和寿命。这种复杂的性状关联是由生殖地面计划假说预测的。已经确定了影响行为成熟率和对花蜜或花粉的觅食偏好的特定蜜蜂基因组区域。 两个育种系（选择高和低花粉囤积行为）和两个种族（非洲化和欧洲）的蜜蜂将被用来调查预测之间的联系生殖和社会行为的遗传结构。生殖将根据卵巢大小和卵巢活性进行测量。对于这两个繁殖性状，第一个目标是通过一系列的实验杂交来表征遗传模式。接下来，将研究这些性状的遗传控制是否与先前确定的影响社会行为的基因组区域有关，以及哪些其他区域具有影响力。最后，将从蜜蜂基因组序列中识别有影响的基因组区域中的所有潜在基因，以基于位置和功能标准产生优先的候选基因列表。将研究顶级候选基因的活性模式，并通过特定基因表达操作确定其功能。生殖特征和社会行为之间的遗传和功能基因重叠将支持社会进化的生殖基础计划假设，没有重叠将反驳它。因此，这个项目将严格测试社会性的主要统一解释，这是一个具有广泛科学意义和兴趣的奋进。这项研究的一个重要部分将涉及互动的学生研究，特别是在本科阶段。学生将获得尖端分子技术的一流研究经验。更广泛的影响还延伸到部门、机构和区域一级。

Cooperative animal societies are extremely successful but their evolution still is not well understood. A framework for understanding social evolution is offered by the emerging reproductive ground-plan hypothesis, which suggests that the reproductive regulatory pathways of non-social ancestors were co-opted during evolution to control social phenotypes. According to this hypothesis, reproductive gene-networks should govern the complex specialization of different colony members that guarantee the functioning of the societies. The hypothesis links regulatory mechanisms of physiology and behavior to a plausible evolutionary scenario, leading to a unified theory of social evolution. Recent mathematical simulation models and behavioral studies suggest that the fundamental characteristics of social insects (reproductive division of labor and co-operative specialization of worker behavior) indeed are derived from an ancestral reproductive cycle. This project will take advantage of these encouraging results and conduct the first direct test of the reproductive ground-plan hypothesis at the genetic level, using the honey bee as experimental model. Worker honey bees show a set of correlated behavioral, life-history, and physiological traits; including sensory sensitivity, behavioral maturation, reproductive tuning, foraging preference and length of life. Such complex trait-associations are predicted by the reproductive ground-plan hypothesis. Specific honey bee genomic regions have been identified that affect the rate of behavioral maturation and foraging preference for nectar or pollen. Two breeding lines (selected for high and low pollen-hoarding behavior) and two races (Africanized and European) of honey bees will be used to investigate the predicted link between the genetic architectures of reproduction and of social behavior. Reproduction will be measured as ovary size and ovary activity. For both reproductive traits, the first goal is to characterize the inheritance pattern through a series of experimental crosses. Next, it will be investigated whether the genetic control of these traits is tied to the previously identified genomic regions that influence social behavior, and which other regions are influential. Finally, all potential genes in the influential genomic regions will be identified from the honey bee genome sequence to produce a prioritized candidate gene list based on positional and functional criteria. The activity patterns of the top candidate genes will be studied, and their function will be determined by means of specific gene expression manipulations. Genetic and functional gene overlap between reproductive traits and social behavior will support the reproductive ground-plan hypothesis of social evolution, no overlap will refute it. Thus, this project will critically test a major unifying explanation of sociality, which is an endeavor of broad scientific implication and interest. A significant portion of this research will involve interactive student research, particularly at the undergraduate level. Students will get first-class research experiences in cutting-edge molecular techniques. Broader impacts also extend to the departmental, institutional, and regional level.