The role of kin-recognition in social evolution

描述(申请人提供)：社会性的进化很难解释，因为社会制度涉及合作的无私行为，这似乎与自然选择不一致，但亲属选择理论解释了自然选择将 当关联度超过成本效益比时，支持合作。该领域的一些悬而未决的问题是，生物如何识别彼此为亲属，亲属识别是如何进化的，以及亲属识别是否真的是促进社会性进化的机制。在一个基因可控的系统中回答这些问题在该领域是一个相当大的挑战。我们已经发现了一种亲缘识别机制，这种机制是由一对多态的细胞-细胞黏附蛋白介导的，这种黏附蛋白是由盘状网囊阿米巴中的一对多态细胞黏附蛋白介导的。我们还发现了数十个通过各种分子机制作弊的突变体。在这里，我们建议研究亲属识别在防止作弊中的作用，以及允许亲属识别本身进化的机制。我们将首先测试这样一个假设，即亲属识别可以保护社会性免受各种作弊者的伤害(目标1)。然后，我们将测试等位基因复制和多样化是否可能是允许亲属识别进化的机制的一部分(目标2)，以及它是否可以解释罕见的社交线索如何进化和确立(目标3)。越来越明显的是，细菌、酵母和阿米巴等微生物的发病机制受到微生物社会行为的影响。此外，对微生物的自然抗药性机制，如免疫系统，以及医疗干预，如抗生素治疗，对微生物病原体的社会性进化有深远的影响。因此，研究微生物社会性的进化对于理解和治疗微生物的发病机制是至关重要的。 与公共卫生相关：越来越明显的是，细菌、酵母和阿米巴等微生物的致病机制受到微生物社会行为的影响。此外，对微生物的自然抗药性机制，如免疫系统，以及医疗干预，如抗生素治疗，对微生物病原体的社会性进化有深远的影响。因此，研究微生物社会性的进化是理解和治疗微生物发病机制的核心，因此它对公共卫生具有重要意义。

DESCRIPTION (provided by applicant): The evolution of sociality is difficult to explain because social systems involve cooperative selfless behaviors, which are seemingly inconsistent with natural selection, but kin selection theory explains that natural selection would favor cooperation when relatedness exceeds the cost to benefit ratio. Some of the outstanding questions in the field are how organisms recognize each other as kin, how does kin-recognition evolve, and whether kin-recognition is indeed a mechanism that facilitates the evolution of sociality. Answering these questions in a genetically tractable system is a considerable challenge in the field. We have discovered a kin-recognition mechanism, which is mediated by a pair of polymorphic cell-cell adhesion proteins in the social amoeba Dictyostelium discoideum. We have also discovered dozens of mutants that cheat through various molecular mechanisms. Here we propose to study the role of kin-recognition in protection against cheating and the mechanisms that allow kin-recognition itself to evolve. We will first test the hypothesis that kin-recognition can protect sociality against various cheaters (Aim 1). We will then test whether allele duplication and diversification could be part of a mechanism that allows kin-recognition to evolve (Aim 2) and whether it may explain how rare social cues evolve and become established (Aim 3). It is becoming increasingly evident that pathogenesis of microbes, such as bacteria, yeast and amoebae, is affected by microbial social behavior. Moreover, natural mechanisms of resistance to microbes, such as the immune system, and medical interventions, such as antibiotic treatment, have profound effects on the evolution of sociality in microbial pathogens. Studying the evolution of microbial sociality is therefore central to understanding and treating microbial pathogenesis. PUBLIC HEALTH RELEVANCE: It is becoming increasingly evident that pathogenesis of microbes, such as bacteria, yeast and amoebae, is affected by microbial social behavior. Moreover, natural mechanisms of resistance to microbes, such as the immune system, and medical interventions, such as antibiotic treatment, have profound effects on the evolution of sociality in microbial pathogens. Studying the evolution of microbial sociality is therefore centra to understanding and treating microbial pathogenesis, hence its importance to public health.