Bilateral BBSRC-FAPESP: A genome wide view of the evolutionary processes shaping genetic variation in natural populations

双边 BBSRC-FAPESP：影响自然群体遗传变异的进化过程的全基因组视角

• 批准号: BB/M01035X/1
• 负责人: Jason Wolf
• 金额: $ 48.33万
• 依托单位: University of Bath
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2015
• 资助国家: 英国
• 起止时间: 2015 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FM01035X%2F1
• 关键词: Bilateral; BBSRC; FAPESP; genome; wide

The Darwinian idea of 'survival of the fittest' is central to our understanding of the diversity of life on this planet. However, if only the fittest survive and reproduce, then why do we see so much variation among individuals in traits that are tied to fitness? This problem is especially striking in social systems where cooperating individuals perform some sort of costly act that helps others. Cooperative behaviour therefore has important effects on the fitness of individuals and those that they interact with (often their relatives). Furthermore, cooperating individuals run the risk of invasion by disruptive cheaters that reap the benefits of cooperative behaviours, but do not pay their fair share of the cost. In such situations, we would expect the 'best' strategy to emerge: either cheating or cooperating. Surprisingly, however, studies of natural populations often reveal variation in the degree to which individuals appear to cooperate and cheat. If either cheating or cooperating is the better strategy, then why is there variation along a cooperator-cheater continuum? To better understand this problem, we believe that it is important to not only describe the nature of the variation that is actually present in populations, but also the genes that generate this variation and the processes shaping their variation. This is because, although evolutionary theory may suggest the best strategy, the genetic changes required may not be possible. For example, some strategies may not exist because any gains may be offset by other fitness costs. Alternatively, cooperative traits may be expressed rarely, or there may be limited opportunities to cheat, and as a result the action of Darwinian selection may simply be too inefficient to mould variation to achieve the optimal or favoured strategy.We propose to address this fundamental question using a simple system for the study of cooperative behaviour, the soil dwelling social amoeba Dictyostelium discoideum. Under favourable conditions, D. discoideum amoebae exist as single celled individuals that grow and divide by feeding on bacteria. Upon starvation, however, up to 100,000 amoebae aggregate and cooperate to make a multicellular fruiting body consisting of hardy spores supported by dead stalk cells. Stalk cells thus sacrifice themselves to help the dispersal of spores. Such sacrifices can be favoured because they typically help relatives, but when non-relatives interact, the sacrifices of an individual may help non-relatives. Crucially, like other systems, we have discovered that D. discoideum show enormous diversity in a wide array of traits, including the degree to which different individuals cooperate, thus providing us with a simple system to investigate why such variation exists. To achieve this goal, we will employ a novel combination of approaches in D. discoideum that allow the genetics and evolution of cooperative behaviour and other traits to be analysed with great power. We will use a large panel of naturally occurring strains to identify natural variation in genes that account for the diversity in the traits we observe. We will characterize the types of genes that produce natural diversity in social traits and ask whether those genes also affect other types of non-social traits, which could suggest that they are constrained or shaped by non-social processes. We will be able to determine the types of evolutionary processes that appear to be responsible for the maintenance or persistence of variation in populations. Finally, we will integrate these results with models of evolution to develop a better theoretical understanding of how genetic diversity is maintained and evolutionary outcomes constrained. This work will therefore lead to a fundamental advance in our understanding of the types of variation underlying phenotypic diversity in natural populations and the evolutionary processes shaping that variation.

达尔文的“适者生存”思想是我们理解地球上生命多样性的核心。然而，如果只有适者生存和繁殖，那么为什么我们看到个体之间在与健康有关的特征上存在如此大的差异？这个问题在社会制度中尤为突出，在这种制度下，合作的个人会做出某种代价高昂的帮助他人的行为。因此，合作行为对个人和与他们互动的人(通常是他们的亲属)的健康状况有重要影响。此外，合作的个体面临着被破坏性的作弊者入侵的风险，他们从合作行为中获益，但没有支付他们公平分担的成本。在这种情况下，我们预计最好的策略会出现：要么作弊，要么合作。然而，令人惊讶的是，对自然种群的研究往往揭示出个体合作和欺骗的程度存在差异。如果作弊或合作是更好的策略，那么为什么在合作者-作弊者连续体中会有变化？为了更好地理解这个问题，我们认为重要的是不仅要描述种群中实际存在的变异的性质，而且还要描述产生这种变异的基因及其形成变异的过程。这是因为，尽管进化论可能提出了最好的策略，但所需的基因变化可能是不可能的。例如，一些策略可能不存在，因为任何收益都可能被其他健身成本所抵消。或者，合作特征可能很少表现出来，或者作弊的机会可能有限，因此达尔文式的选择行为可能太过低效，无法塑造变异来实现最优或受青睐的策略。我们建议使用一个研究合作行为的简单系统来解决这个基本问题，即土壤栖息的社会盘基网生阿米巴。在有利的条件下，盘阿米巴变形虫以单细胞个体的形式存在，通过摄食细菌进行生长和分裂。然而，饥饿后，多达100,000个阿米巴聚集在一起，共同形成一个多细胞子实体，由死亡的茎细胞支撑的耐寒孢子组成。因此，柄细胞牺牲自己来帮助孢子的扩散。这种牺牲可以受到青睐，因为它们通常有助于亲属，但当非亲属互动时，个人的牺牲可能会帮助非亲属。至关重要的是，像其他系统一样，我们发现盘藻在一系列特征上表现出巨大的多样性，包括不同个体合作的程度，从而为我们提供了一个简单的系统来研究这种变异存在的原因。为了实现这一目标，我们将在圆盘芽孢杆菌中采用一种新的方法组合，允许以强大的力量分析合作行为和其他特征的遗传和进化。我们将使用一大批自然产生的菌株来识别基因的自然变异，这些基因解释了我们观察到的特征的多样性。我们将描述在社会特征中产生自然多样性的基因的类型，并询问这些基因是否也影响其他类型的非社会特征，这可能表明它们受到非社会过程的制约或塑造。我们将能够确定似乎负责维持或维持种群变异的进化过程的类型。最后，我们将把这些结果与进化模型相结合，以更好地从理论上理解遗传多样性是如何维持的，以及进化结果是如何受到限制的。因此，这项工作将从根本上促进我们对自然种群表型多样性背后的变异类型以及形成这种变异的进化过程的理解。

项目成果

Inferring Adaptive Codon Preference to Understand Sources of Selection Shaping Codon Usage Bias.

• DOI: 10.1093/molbev/msab099
• 发表时间: 2021-07-29
• 期刊: Molecular biology and evolution
• 影响因子: 10.7
• 作者: de Oliveira JL;Morales AC;Hurst LD;Urrutia AO;Thompson CRL;Wolf JB
• 通讯作者: Wolf JB

Evolutionary robustness of killer meiotic drives.

• DOI: 10.1002/evl3.255
• 发表时间: 2021-10
• 期刊: Evolution letters
• 影响因子: 5
• 作者: Madgwick PG;Wolf JB
• 通讯作者: Wolf JB

A polychromatic 'greenbeard' locus determines patterns of cooperation in a social amoeba.

• DOI: 10.1038/ncomms14171
• 发表时间: 2017-01-25
• 期刊: Nature communications
• 影响因子: 16.6
• 作者: Gruenheit N;Parkinson K;Stewart B;Howie JA;Wolf JB;Thompson CR
• 通讯作者: Thompson CR

Direct Determination of the Mutation Rate in the Bumblebee Reveals Evidence for Weak Recombination-Associated Mutation and an Approximate Rate Constancy in Insects.

直接测定大黄蜂的突变率揭示了昆虫中弱重组相关突变和近似速率恒定性的证据

• DOI: 10.1093/molbev/msw226
• 发表时间: 2017-01
• 期刊: Molecular biology and evolution
• 影响因子: 10.7
• 作者: Liu H;Jia Y;Sun X;Tian D;Hurst LD;Yang S
• 通讯作者: Yang S

Strategic investment explains patterns of cooperation and cheating in a microbe

• DOI: 10.1073/pnas.1716087115
• 发表时间: 2018-05-22
• 期刊: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• 影响因子: 11.1
• 作者: Madgwick, Philip G.;Stewart, Balint;Wolf, Jason B.
• 通讯作者: Wolf, Jason B.