Origins of Mitochondria

Carol A. Allen, Mark van der Giezen and John F. Allen 

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Cavaher-Smith T. 1987. The simultaneous symbiotic origin of mitochondria, chloro-plasts, and microbodies. Ann NY Acad Sci 503 55-71. 

Current concepts relating to the origin of mitochondria are most readily understood before the backdrop of how these concepts arose. Since about 1967,... 

The 1980 view assumed that the prokaryote-to-eukaryote transition occurred via gradualist mechanisms such as point mutation and hence did not involve symbiosis at all (van Valen and Maiorana 1980 Doolittle 1980) and culminated with a cell that possessed a nucleus, but lacked mitochondria. This is what Doolittle (1998) has called the standard model . In this view, mitochondria are interpreted as a small tack-on to, and mechanistically unrelated to, the process that made eukaryotic cells nucleated and complex (Cavalier-Smith 2002). In the standard model, mitochondria (and chloro-plasts) are descended from endosymbionts, but the nuts-and-bolts of the prokaryote-to-eukaryote transition (the origin of eukaryote-specific traits) was seen as having occurred independently from, and prior to, the origin of mitochondria. The paper by van Valen and Maiorana (1980) expresses this view in clear physiological terms the host was assumed to be an amoeboid, anaerobic, fermenting cell related to archaebacteria, the advantage of the mitochondrial endosymbiont was to supply ATP. 

Andersson SGE, Kurland CG (1999) Origins of mitochondria and hydrogenosomes. Curr Opin Microbiol 2 535-541... 

Emelyanov VV (2007) Constantin Merezhkowsky and the endokaryotic hypothesis. In Martin W, Muller M (eds) Origin of Mitochondria and Hydrogenosomes. Springer, Berlin Heidelberg New York, pp 201-238... 

Altschul SF et al. (1997) Gapped BLAST and PSI-BLAST a new generation of protein database search programs. Nucleic Acids Res 25 3389-3402 Andersson SG et al. (1998) The genome sequence of Rickettsia prowazekii and the origin of mitochondria. Nature 396 133-140... 

The machinery mediating this process was shown to be of an ISC type. Phylogenetic analyses indicate that the mitochondrial ISC machinery was inherited from the proteobacterial endosymbiont, which is consistent with the proposed origin of mitochondria (Tachezy et al. 2001). Components of the SUF system were found in plastids and in the apicoplast of apicomplexan such as P. falciparum (Wilson et al. 2003). The SUF machinery was most likely inherited from cyanobacteria, the ancestors of plastids (Tachezy et al. 2001). Entamoebids and related protists are the only eukaryotes which acquired components of the NIF system ( et al. 2004 van der Giezen et al. 

The existence of mitochondrial DNA, ribosomes, and tRNAs supports the hypothesis of the endosymbiotic origin of mitochondria (see Fig. 1-36), which holds that the first organisms capable of aerobic metabolism, including respiration-linked ATP production, were prokaryotes. Primitive eukaryotes that lived anaerobically (by fermentation) acquired the ability to carry out oxidative phosphorylation when they established a symbiotic relationship with bacteria living in their cytosol. After much evolution and the movement of many bacterial genes into the nucleus of the host eukaryote, the endosymbiotic bacteria eventually became mitochondria. 

What are the possible origins of mitochondria and chloroplasts What evidence can you cite to support your answer ... 

Roise, D and Maduke, M. (1994) Import of a Mitochondrial Presequence into P. Denitrificans, FEBS Letters, 337, 9-13 Cavalier-Smith, T. (1987) The Simultaneous Symbiotic Origin of Mitochondria, Chloroplasts and Microbodies, Annals of the New York Academy of Science, 503, 55-71 Cavalier-Smith, T. (1992) The Number of Symbiotic Origins of Organelles, BioSystems, 28, 91-106 Hartl, F Ostermann, J., Guiard, B and Neupert, W. (1987) Successive Translocation into and out of the Mitochondrial Matrix Targeting of Proteins to the Inner Membrane Space by a Bipartite Signal Peptide, Cell, 51,1027-1037. 

Origin of Mitochondria and Hydrogenosomes (ed. by William F. Martin and Miklds Muller) Springer-Verlag Berlin Heidelberg 2007... 

Whatley et al. (1979) in an overview of the origins of mitochondria and chloroplasts raised the possibility that hydrogenosomes arose through an independent endosymbiotic event. This idea agreed well with our thinking at the time and I embraced it wholeheartedly. In my review of 1980 I discussed this problem as follows ... 

Andersson SG, Karlberg O, Canback B, Kurland CG (2003) On the origin of mitochondria a genomics perspective. Philos Trans R Soc Lond B Biol Sci 358 165-177... 

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