Bioenergetic Constraints on the Evolution of Complex Life
Bioenergetic Constraints on the Evolution of Complex Life
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DOI：
10.1101/cshperspect.a015982
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发表时间：
2014-05-01
影响因子：
7.2
通讯作者：
Lane, Nick
中科院分区：
文献类型：
--
作者：
Lane, Nick
地球上所有形态复杂的生命，超过蓝藻的水平，都是真核生物。所有真核生物都有一个共同的祖先，那就是一个复杂的细胞。尽管原核生物具有高超的生化技能，但它们几乎没有进化出真核生物特征或大基因组的倾向。在这里，我认为原核生物受到其膜生物能量学的限制，这是与生命起源有关的基本原因。真核生物起源于两种原核生物之间罕见的内共生，这种内共生打破了原核生物的能量限制，产生了线粒体。几乎所有线粒体基因的丢失产生了极端的基因组不对称，在这种情况下，微小的线粒体基因组在能量上支持着巨大的核基因组，给真核生物每个基因比原核生物多3到5个数量级的能量。对内共生的要求从根本上改变了真核生物的选择，可能解释了独特特征的进化，包括细胞核、性别、两性、物种形成和衰老。
All morphologically complex life on Earth, beyond the level of cyanobacteria, is eukaryotic. All eukaryotes share a common ancestor that was already a complex cell. Despite their biochemical virtuosity, prokaryotes show little tendency to evolve eukaryotic traits or large genomes. Here I argue that prokaryotes are constrained by their membrane bioenergetics, for fundamental reasons relating to the origin of life. Eukaryotes arose in a rare endosymbiosis between two prokaryotes, which broke the energetic constraints on prokaryotes and gave rise to mitochondria. Loss of almost all mitochondrial genes produced an extreme genomic asymmetry, in which tiny mitochondrial genomes support, energetically, a massive nuclear genome, giving eukaryotes three to five orders of magnitude more energy per gene than prokaryotes. The requirement for endosymbiosis radically altered selection on eukaryotes, potentially explaining the evolution of unique traits, including the nucleus, sex, two sexes, speciation, and aging.