Serial Endosymbiosis

Cellular evolution from microbes to eukaryotes.

Reviews SET

Mitochondrial genome evolution and the origin of eukaryotes.:
Recent results from ancestral (minimally derived) protists testify to the tremendous diversity of the mitochondrial genome in various eukaryotic lineages, but also reinforce the view that mitochondria, descendants of an endosymbiotic alpha-Proteobacterium, arose only once in evolution. The serial endosymbiosis theory, currently the most popular hypothesis to explain the origin of mitochondria, postulates the capture of an alpha-proteobacterial endosymbiont by a nucleus-containing eukaryotic host resembling extant amitochondriate protists. New sequence data have challenged this scenario, instead raising the possibility that the origin of the mitochondrion was coincident with, and contributed substantially to, the origin of the nuclear genome of the eukaryotic cell. Defining more precisely the alpha-proteobacterial ancestry of the mitochondrial genome, and the contribution of the endosymbiotic event to the nuclear genome, will be essential for a full understanding of the origin and evolution of the eukaryotic cell as a whole.
Lang BF, Gray MW, Burger G. Mitochondrial genome evolution and the origin of eukaryotes. Annu Rev Genet. 1999;33:351-97.


Mitochondrial evolution. [Science. 1999] PMID: 10066161
[Evolution of mitochondria] [Tsitol Genet. 2002] PMID: 12442548
On the origin of mitochondria: a genomics perspective. [Philos Trans R Soc Lond B Biol Sci. 2003] PMID: 12594925
Fungal evolution: the case of the vanishing mitochondrion. [Curr Opin Microbiol. 2005] PMID: 15993645
A comparative genomics approach to the evolution of eukaryotes and their mitochondria. [J Eukaryot Microbiol. 1999] PMID: 10461380
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Mitochondrial evolution. :
The serial endosymbiosis theory is a favored model for explaining the origin of mitochondria, a defining event in the evolution of eukaryotic cells. As usually described, this theory posits that mitochondria are the direct descendants of a bacterial endosymbiont that became established at an early stage in a nucleus-containing (but amitochondriate) host cell. Gene sequence data strongly support a monophyletic origin of the mitochondrion from a eubacterial ancestor shared with a subgroup of the alpha-Proteobacteria. However, recent studies of unicellular eukaryotes (protists), some of them little known, have provided insights that challenge the traditional serial endosymbiosis-based view of how the eukaryotic cell and its mitochondrion came to be. These data indicate that the mitochondrion arose in a common ancestor of all extant eukaryotes and raise the possibility that this organelle originated at essentially the same time as the nuclear component of the eukaryotic cell rather than in a separate, subsequent event.
Gray MW, Burger G, Lang BF. Mitochondrial evolution. Science. 1999 Mar 5;283(5407):1476-81.


[Evolution of mitochondria] [Tsitol Genet. 2002] PMID: 12442548
Mitochondrial genome evolution and the origin of eukaryotes. [Annu Rev Genet. 1999] PMID: 10690412
Single eubacterial origin of eukaryotic sulfide:quinone oxidoreductase, a mitochondrial enzyme conserved from the early evolution of eukaryotes during anoxic and sulfidic times. [Mol Biol Evol. 2003] PMID: 12832624
On the origin of mitochondria: a genomics perspective. [Philos Trans R Soc Lond B Biol Sci. 2003] PMID: 12594925
Mitochondria of protists. [Annu Rev Genet. 2004] PMID: 15568984
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. . . endosymbiotic union began 10/06/06