Endosymbiont or host: who drove mitochondrial and plastid evolution?
Department of Ecology, Evolution and Natural Resources, and Institute of Marine and Coastal Sciences, Rutgers, The State University of New Jersey, Foran Hall 102, New Brunswick, NJ 08901, USA
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Biology Direct 2011, 6:12doi:10.1186/1745-6150-6-12
The electronic version of this article is the complete one and can be found online at:
Received: 4 October 2010
Accepted: 19 February 2011
Published: 19 February 2011
© 2011 Gross and Bhattacharya; licensee BioMed Central Ltd.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
The recognition that mitochondria and plastids are derived from alphaproteobacterial and cyanobacterial endosymbionts, respectively, was one of the greatest advances in modern evolutionary biology. Researchers have yet however to provide detailed cell biological descriptions of how these once free-living prokaryotes were transformed into intracellular organelles. A key area of study in this realm is elucidating the evolution of the molecular machines that control organelle protein topogenesis. Alcock et al. (Science 2010, 327 :649-650) suggest that evolutionary innovations that established the mitochondrial protein sorting system were driven by the alphaproteobacterial endosymbiont (an "insiders' perspective"). In contrast, here we argue that evolution of mitochondrial and plastid topogenesis may better be understood as an outcome of selective pressures acting on host cell chromosomes (the "outsiders' view").
This manuscript was reviewed by Gáspár Jékely, Martijn Huynen, and Purificación López-García.