Environmentally co-occurring mercury resistance plasmids are genetically and phenotypically diverse and confer variable context-dependent fitness effects.
Environmentally co-occurring mercury resistance plasmids are genetically and phenotypically diverse and confer variable context-dependent fitness effects.
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DOI：
10.1111/1462-2920.12901
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发表时间：
2015-12
影响因子：
5.1
通讯作者：
Brockhurst MA
中科院分区：
文献类型：
--
作者：
Hall JP;Harrison E;Lilley AK;Paterson S;Spiers AJ;Brockhurst MA
质体是重要的移动的元件，可以促进微生物群落内的遗传交换和局部适应。我们比较了四种共存的pQBR家族环境汞抗性质粒的序列，并测量了它们对荧光假单胞菌SBW25宿主竞争适应性的影响，该宿主是在同一田间站点分离的。 健身效果的载体质粒之间的差异和强烈的上下文依赖性，不同的介质，竞争对手的质粒状态和环境汞水平。质粒的接合率和分离损失率也有很大差异。我们发现很少有质粒携带的辅助基因可以归因于功能，尽管我们确定了一个假定的趋化操纵子，一个IV型菌毛编码簇和一个编码假定的芳基硫酸酯酶的区域，这些基因在地理上遥远的分离株中是保守的。一种质粒pQBR 55赋予分解代谢蔗糖的能力。转座子，包括抗汞Tn5042，似乎已经获得了不同的pQBR质粒重组，水平基因转移在最近的pQBR质粒的进化中的重要作用。我们的研究结果表明，质粒群落的共存成员之间存在广泛的遗传和表型多样性，并表明环境异质性在维持质粒多样性中的作用。
Plasmids are important mobile elements that can facilitate genetic exchange and local adaptation within microbial communities. We compared the sequences of four co‐occurring pQBR family environmental mercury resistance plasmids and measured their effects on competitive fitness of a P seudomonas fluorescens SBW25 host, which was isolated at the same field site. Fitness effects of carriage differed between plasmids and were strongly context dependent, varying with medium, plasmid status of competitor and levels of environmental mercury. The plasmids also varied widely in their rates of conjugation and segregational loss. We found that few of the plasmid‐borne accessory genes could be ascribed functions, although we identified a putative chemotaxis operon, a type IV pilus‐encoding cluster and a region encoding putative arylsulfatase enzymes, which were conserved across geographically distant isolates. One plasmid, pQBR55, conferred the ability to catabolize sucrose. Transposons, including the mercury resistance Tn5042, appeared to have been acquired by different pQBR plasmids by recombination, indicating an important role for horizontal gene transfer in the recent evolution of pQBR plasmids. Our findings demonstrate extensive genetic and phenotypic diversity among co‐occurring members of a plasmid community and suggest a role for environmental heterogeneity in the maintenance of plasmid diversity.