Massive horizontal transfer of mitochondrial genes from diverse land plant donors to the basal angiosperm Amborella
Massive horizontal transfer of mitochondrial genes from diverse land plant donors to the basal angiosperm Amborella
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DOI：
10.1073/pnas.0408336102
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发表时间：
2004-12-21
影响因子：
11.1
通讯作者：
Palmer, JD
中科院分区：
文献类型：
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作者：
Bergthorsson, U;Richardson, AO;Palmer, JD
已知有几种植物通过水平基因转移（HGT）获得了单个线粒体基因，但这些或任何其他植物是否获得了许多外源基因还完全不清楚。为了解决这个问题，我们把重点放在了Amborella dappoda上，因为已经知道它拥有一个水平获得的基因，而且在初步分析中发现它含有更多的基因。我们对Amborella的线粒体蛋白基因组进行了全面测序，对其他28种不同陆地植物的线粒体基因进行了可变数量的测序，并对这些序列以及已经获得的序列进行了系统发育分析，包括五个测序的被子植物线粒体基因组。结果表明，Amborella从其他陆生植物中获得了31个已知线粒体蛋白基因中的20个的一个或多个拷贝，总共26个外源基因，而在5个测序的基因组中没有发现HGT的证据。大多数Amborella转移来自其他被子植物（特别是真双子叶植物），而其他则来自非被子植物，包括六个引人注目的转移案例（至少三个不同的）苔藓供体。大多数转移的基因是完整的，与转移的功能性和/或新近性一致。Amborella mtDNA比任何其他真核生物，甚至可能是原核生物，基因组中的HGT比例更高。
Several plants are known to have acquired a single mitochondrial gene by horizontal gene transfer (HGT), but whether these or any other plants have acquired many foreign genes is entirely unclear. To address this question, we focused on Amborella trichopoda, because it was already known to possess one horizontally acquired gene and because it was found in preliminary analyses to contain several more. We comprehensively sequenced the mitochonchrial protein gene set of Amborella, sequenced a variable number of mitochondrial genes from 28 other diverse land plants, and conducted phylogenetic analyses of these sequences plus those already available, including the five sequenced mitochondrial genomes of angiosperms. Results indicate that Amborella has acquired one or more copies of 20 of its 31 known mitochonchrial protein genes from other land plants, for a total of 26 foreign genes, whereas no evidence for HGT was found in the five sequenced genomes. Most of the Amborella transfers are from other angiosperms (especially eudicots), whereas others are from nonangiosperms, including six striking cases of transfer from (at least three different) moss donors. Most of the transferred genes are intact, consistent with functionality and/or recency of transfer. Amborella mtDNA has sustained proportionately more HGT than any other eukaryotic, or perhaps even prokaryotic, genome yet examined.