2.50
Hdl Handle:
http://hdl.handle.net/10033/19778
Title:
Dynamics of reductive genome evolution in mitochondria and obligate intracellular microbes.
Authors:
Khachane, Amit N; Timmis, Kenneth N; Martins dos Santos, Vítor A P
Abstract:
Reductive evolution in mitochondria and obligate intracellular microbes has led to a significant reduction in their genome size and guanine plus cytosine content (GC). We show that genome shrinkage during reductive evolution in prokaryotes follows an exponential decay pattern and provide a method to predict the extent of this decay on an evolutionary timescale. We validated predictions by comparison with estimated extents of genome reduction known to have occurred in mitochondria and Buchnera aphidicola, through comparative genomics and by drawing on available fossil evidences. The model shows how the mitochondrial ancestor would have quickly shed most of its genome, shortly after its incorporation into the protoeukaryotic cell and prior to codivergence subsequent to the split of eukaryotic lineages. It also predicts that the primary rickettsial parasitic event would have occurred between 180 and 425 million years ago (MYA), an event of relatively recent evolutionary origin considering the fact that Rickettsia and mitochondria evolved from a common alphaproteobacterial ancestor. This suggests that the symbiotic events of Rickettsia and mitochondria originated at different time points. Moreover, our model results predict that the ancestor of Wigglesworthia glossinidia brevipalpis, dated around the time of origin of its symbiotic association with the tsetse fly (50-100 MYA), was likely to have been an endosymbiont itself, thus supporting an earlier proposition that Wigglesworthia, which is currently a maternally inherited primary endosymbiont, evolved from a secondary endosymbiont.
Affiliation:
Department of Environmental Microbiology, Helmholtz Center for Infection Research, Braunschweig, Germany.
Citation:
Dynamics of reductive genome evolution in mitochondria and obligate intracellular microbes. 2007, 24 (2):449-56 Mol. Biol. Evol.
Journal:
Molecular biology and evolution
Issue Date:
Feb-2007
URI:
http://hdl.handle.net/10033/19778
DOI:
10.1093/molbev/msl174
PubMed ID:
17108184
Type:
Article
Language:
en
ISSN:
0737-4038
Appears in Collections:
Publications of RG Environmental Microbiology (UMW)

Full metadata record

DC FieldValue Language
dc.contributor.authorKhachane, Amit N-
dc.contributor.authorTimmis, Kenneth N-
dc.contributor.authorMartins dos Santos, Vítor A P-
dc.date.accessioned2008-03-05T13:40:54Z-
dc.date.available2008-03-05T13:40:54Z-
dc.date.issued2007-02-
dc.identifier.citationDynamics of reductive genome evolution in mitochondria and obligate intracellular microbes. 2007, 24 (2):449-56 Mol. Biol. Evol.en
dc.identifier.issn0737-4038-
dc.identifier.pmid17108184-
dc.identifier.doi10.1093/molbev/msl174-
dc.identifier.urihttp://hdl.handle.net/10033/19778-
dc.description.abstractReductive evolution in mitochondria and obligate intracellular microbes has led to a significant reduction in their genome size and guanine plus cytosine content (GC). We show that genome shrinkage during reductive evolution in prokaryotes follows an exponential decay pattern and provide a method to predict the extent of this decay on an evolutionary timescale. We validated predictions by comparison with estimated extents of genome reduction known to have occurred in mitochondria and Buchnera aphidicola, through comparative genomics and by drawing on available fossil evidences. The model shows how the mitochondrial ancestor would have quickly shed most of its genome, shortly after its incorporation into the protoeukaryotic cell and prior to codivergence subsequent to the split of eukaryotic lineages. It also predicts that the primary rickettsial parasitic event would have occurred between 180 and 425 million years ago (MYA), an event of relatively recent evolutionary origin considering the fact that Rickettsia and mitochondria evolved from a common alphaproteobacterial ancestor. This suggests that the symbiotic events of Rickettsia and mitochondria originated at different time points. Moreover, our model results predict that the ancestor of Wigglesworthia glossinidia brevipalpis, dated around the time of origin of its symbiotic association with the tsetse fly (50-100 MYA), was likely to have been an endosymbiont itself, thus supporting an earlier proposition that Wigglesworthia, which is currently a maternally inherited primary endosymbiont, evolved from a secondary endosymbiont.en
dc.language.isoenen
dc.subject.meshBase Compositionen
dc.subject.meshBuchneraen
dc.subject.meshDNA, Mitochondrialen
dc.subject.meshDNA, Ribosomalen
dc.subject.meshEvolutionen
dc.subject.meshEvolution, Molecularen
dc.subject.meshExtrachromosomal Inheritanceen
dc.subject.meshGenomeen
dc.subject.meshGenome, Bacterialen
dc.subject.meshMitochondriaen
dc.subject.meshModels, Geneticen
dc.subject.meshPhylogenyen
dc.subject.meshRNA, Ribosomal, 16Sen
dc.subject.meshSymbiosisen
dc.titleDynamics of reductive genome evolution in mitochondria and obligate intracellular microbes.en
dc.typeArticleen
dc.contributor.departmentDepartment of Environmental Microbiology, Helmholtz Center for Infection Research, Braunschweig, Germany.en
dc.identifier.journalMolecular biology and evolutionen

Related articles on PubMed

This item is licensed under a Creative Commons License
Creative Commons
All Items in HZI are protected by copyright, with all rights reserved, unless otherwise indicated.