Host-symbiont coevolution: Exploring the parasitism-mutualism continuum

宿主-共生体共同进化：探索寄生-互惠连续体

• 批准号: NE/H005250/1
• 负责人: Andrew Spiers
• 金额: $ 1.85万
• 依托单位: Abertay University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2010
• 资助国家: 英国
• 起止时间: 2010 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FH005250%2F1
• 关键词: Host; symbiont; coevolution; Exploring; parasitism

Intimate and prolonged associations between different organisms - symbioses - are widespread and important in the natural environment. Symbiotic associations can range from being parasitic, where one organism benefits at the expense of the other, to being mutualistic, where both organisms benefit from the association. Such symbiotic associations underpin the functioning of ecosystems: mutualism can allow pairs of organisms to survive where otherwise neither would and parasitism can limit the growth of host populations. These symbioses are particularly important in microbial communities but little is known about how these associations shape the evolution and diversity of microbial symbionts. Here we want to understand how the evolution of symbiotic organisms is different under conditions that range from parasitic to mutualistic. Our approach is to study the evolution of a bacterial-plasmid symbiosis where the nature of the association ranges from parasitic to mutualistic depending on the environment: in the presence of mercury the association is mutualistic because the plasmid has a gene for mercury resistance; and in the absence of mercury the association is parasitic because carrying the plasmid slows the growth of the bacteria. In nature carrying the plasmid allows bacteria to survive in otherwise toxic mercury contaminated soils. We will exploit the short generation times, and large population sizes of bacteria to observe evolution in action. We will discover and contrast the genetic changes that occur in the genomes of both the bacteria and the plasmid as they co-evolve on a continuum of environments that change the symbiosis from parasitic to mutualistic. - Our study is novel because we will, for the first time, study evolution across a parasitic-mutualistic symbiosis continuum using a single symbiotic association. - Our study is relevant to the natural environment because such bacterial-plasmid associations are widespread, but poorly understood, in microbial communities and are likely to play an important role in maintaining biodiversity and ecosystem function, particularly in response to heavy metal contamination of soils. - Our study is powerful because we will use an experimental approach to study evolution in action. - Our study is timely because we will exploit the latest technologies in DNA sequencing to directly observe evolution of genetic sequences in bacterial and plasmid genomes.

不同生物体之间密切且长期的联系——共生——在自然环境中广泛且重要。共生关联的范围可以从寄生（一种生物体以牺牲另一种生物体的利益为代价）到互利（两种生物体都从这种关联中受益）。这种共生关系支撑着生态系统的功能：互利共生可以让成对的生物体在其他情况下都无法生存的情况下生存，而寄生则可以限制宿主种群的增长。这些共生关系在微生物群落中特别重要，但人们对这些关联如何影响微生物共生体的进化和多样性知之甚少。在这里，我们想要了解共生生物的进化在从寄生到共生的条件下有何不同。我们的方法是研究细菌-质粒共生的进化，其中关联的性质从寄生到互利共生，具体取决于环境：在汞存在下，这种关联是互利的，因为质粒具有抗汞基因；在没有汞的情况下，这种结合是寄生的，因为携带质粒会减慢细菌的生长。在自然界中，携带质粒的细菌可以在有毒的汞污染土壤中生存。我们将利用细菌的短世代时间和大量种群来观察进化过程。我们将发现并对比细菌和质粒基因组中发生的遗传变化，因为它们在连续的环境中共同进化，将共生关系从寄生变为共生。 -我们的研究是新颖的，因为我们将首次使用单一共生关联来研究寄生-互惠共生连续体的进化。 -我们的研究与自然环境相关，因为这种细菌-质粒关联在微生物群落中广泛存在，但人们对此知之甚少，并且可能在维持生物多样性和生态系统功能方面发挥重要作用，特别是在应对土壤重金属污染方面。 - 我们的研究很强​​大，因为我们将使用实验方法来研究实际的进化。 - 我们的研究是及时的，因为我们将利用最新的DNA测序技术来直接观察细菌和质粒基因组中基因序列的进化。

项目成果

Rapid compensatory evolution promotes the survival of conjugative plasmids.

• DOI: 10.1080/2159256x.2016.1179074
• 发表时间: 2016-05
• 期刊: Mobile genetic elements
• 作者: Harrison E;Dytham C;Hall JP;Guymer D;Spiers AJ;Paterson S;Brockhurst MA
• 通讯作者: Brockhurst MA

Bacteriophages limit the existence conditions for conjugative plasmids.

• DOI: 10.1128/mbio.00586-15
• 发表时间: 2015-06-02
• 期刊: mBio
• 影响因子: 6.4
• 作者: Harrison E;Wood AJ;Dytham C;Pitchford JW;Truman J;Spiers A;Paterson S;Brockhurst MA
• 通讯作者: Brockhurst MA

Conflicting selection alters the trajectory of molecular evolution in a tripartite bacteria-plasmid-phage interaction.

• DOI: 10.1111/mec.14080
• 发表时间: 2017-05
• 期刊: Molecular ecology
• 影响因子: 4.9
• 作者: Harrison E;Hall JPJ;Paterson S;Spiers AJ;Brockhurst MA
• 通讯作者: Brockhurst MA

Environmentally co-occurring mercury resistance plasmids are genetically and phenotypically diverse and confer variable context-dependent fitness effects.

• DOI: 10.1111/1462-2920.12901
• 发表时间: 2015-12
• 期刊: Environmental microbiology
• 影响因子: 5.1
• 作者: Hall JP;Harrison E;Lilley AK;Paterson S;Spiers AJ;Brockhurst MA
• 通讯作者: Brockhurst MA