Serial Endosymbiosis

Cellular evolution from microbes to eukaryotes.

On the origin of mitochondria: a genomics perspective

On the origin of mitochondria: a genomics perspective. : Entrez PubMed:
The availability of complete genome sequence data from both bacteria and eukaryotes provides information about the contribution of bacterial genes to the origin and evolution of mitochondria. Phylogenetic analyses based on genes located in the mitochondrial genome indicate that these genes originated from within the alpha-proteobacteria. A number of ancestral bacterial genes have also been transferred from the mitochondrial to the nuclear genome, as evidenced by the presence of orthologous genes in the mitochondrial genome in some species and in the nuclear genome of other species. However, a multitude of mitochondrial proteins encoded in the nucleus display no homology to bacterial proteins, indicating that these originated within the eukaryotic cell subsequent to the acquisition of the endosymbiont. An analysis of the expression patterns of yeast nuclear genes coding for mitochondrial proteins has shown that genes predicted to be of eukaryotic origin are mainly translated on polysomes that are free in the cytosol whereas those of putative bacterial origin are translated on polysomes attached to the mitochondrion. The strong relationship with alpha-proteobacterial genes observed for some mitochondrial genes, combined with the lack of such a relationship for others, indicates that the modern mitochondrial proteome is the product of both reductive and expansive processes.
Andersson SG, Karlberg O, Canback B, Kurland CG. On the origin of mitochondria: a genomics perspective. Philos Trans R Soc Lond B Biol Sci. 2003 Jan 29;358(1429):165-77; discussion 177-9.

More:

Origin and evolution of the mitochondrial proteome. [Microbiol Mol Biol Rev. 2000] PMID: 11104819
Mitochondrial genome evolution and the origin of eukaryotes. [Annu Rev Genet. 1999] PMID: 10690412
Mitochondrial evolution. [Science. 1999] PMID: 10066161
The dual origin of the yeast mitochondrial proteome. [Yeast. 2000] PMID: 11025528
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
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. . . endosymbiotic union began 10/06/06