Evolution of small prokaryotic genomes
As revealed by genome sequencing, the biology of prokaryotes with reduced genomes is strikingly diverse. These include free-living prokaryotes with ~800 genes as well as endosymbiotic bacteria with as few as ~140 genes. Comparative genomics is revealing the evolutionary mechanisms that led to these...
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doaj-1abd6feba2994f69a80fc6ac60a6c5572020-11-25T00:11:26ZengFrontiers Media S.A.Frontiers in Microbiology1664-302X2015-01-01510.3389/fmicb.2014.00742122226Evolution of small prokaryotic genomesDavid José Martínez-Cano0Mariana eReyes-Prieto1Esperanza eMartinez-Romero2Laila Pamela Partida-Martinez3Amparo eLatorre4Andres eMoya5Luis eDelaye6Departamento de Ingeniería Genética, CINVESTAV Unidad IrapuatoInstitut Cavanilles de Biodiversitat i Biologia Evolutiva (ICBiBE), Universitat de Valencia,Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México,Departamento de Ingeniería Genética, CINVESTAV Unidad IrapuatoInstitut Cavanilles de Biodiversitat i Biologia Evolutiva (ICBiBE), Universitat de Valencia,Institut Cavanilles de Biodiversitat i Biologia Evolutiva (ICBiBE), Universitat de Valencia,Departamento de Ingeniería Genética, CINVESTAV Unidad IrapuatoAs revealed by genome sequencing, the biology of prokaryotes with reduced genomes is strikingly diverse. These include free-living prokaryotes with ~800 genes as well as endosymbiotic bacteria with as few as ~140 genes. Comparative genomics is revealing the evolutionary mechanisms that led to these small genomes. In the case of free-living prokaryotes, natural selection directly favored genome reduction, while in the case of endosymbiotic prokaryotes neutral processes played a more prominent role. However, new experimental data suggest that selective processes may be at operation as well for endosymbiotic prokaryotes at least during the first stages of genome reduction. Endosymbiotic prokaryotes have evolved diverse strategies for living with reduced gene sets inside a host-defined medium. These include utilization of host-encoded functions (some of them coded by genes acquired by gene transfer from the endosymbiont and/or other bacteria); metabolic complementation between co-symbionts; and forming consortiums with other bacteria within the host. Recent genome sequencing projects of intracellular mutualistic bacteria showed that previously believed universal evolutionary trends like reduced G+C content and conservation of genome synteny are not always present in highly reduced genomes. Finally, the simplified molecular machinery of some of these organisms with small genomes may be used to aid in the design of artificial minimal cells. Here we review recent genomic discoveries of the biology of prokaryotes endowed with small gene sets and discuss the evolutionary mechanisms that have been proposed to explain their peculiar nature.http://journal.frontiersin.org/Journal/10.3389/fmicb.2014.00742/fullendosymbiosisMuller’s ratchetBlack Queen Hypothesisreductive genome evolutionminimal genome sizestreamlining evolution |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
David José Martínez-Cano Mariana eReyes-Prieto Esperanza eMartinez-Romero Laila Pamela Partida-Martinez Amparo eLatorre Andres eMoya Luis eDelaye |
spellingShingle |
David José Martínez-Cano Mariana eReyes-Prieto Esperanza eMartinez-Romero Laila Pamela Partida-Martinez Amparo eLatorre Andres eMoya Luis eDelaye Evolution of small prokaryotic genomes Frontiers in Microbiology endosymbiosis Muller’s ratchet Black Queen Hypothesis reductive genome evolution minimal genome size streamlining evolution |
author_facet |
David José Martínez-Cano Mariana eReyes-Prieto Esperanza eMartinez-Romero Laila Pamela Partida-Martinez Amparo eLatorre Andres eMoya Luis eDelaye |
author_sort |
David José Martínez-Cano |
title |
Evolution of small prokaryotic genomes |
title_short |
Evolution of small prokaryotic genomes |
title_full |
Evolution of small prokaryotic genomes |
title_fullStr |
Evolution of small prokaryotic genomes |
title_full_unstemmed |
Evolution of small prokaryotic genomes |
title_sort |
evolution of small prokaryotic genomes |
publisher |
Frontiers Media S.A. |
series |
Frontiers in Microbiology |
issn |
1664-302X |
publishDate |
2015-01-01 |
description |
As revealed by genome sequencing, the biology of prokaryotes with reduced genomes is strikingly diverse. These include free-living prokaryotes with ~800 genes as well as endosymbiotic bacteria with as few as ~140 genes. Comparative genomics is revealing the evolutionary mechanisms that led to these small genomes. In the case of free-living prokaryotes, natural selection directly favored genome reduction, while in the case of endosymbiotic prokaryotes neutral processes played a more prominent role. However, new experimental data suggest that selective processes may be at operation as well for endosymbiotic prokaryotes at least during the first stages of genome reduction. Endosymbiotic prokaryotes have evolved diverse strategies for living with reduced gene sets inside a host-defined medium. These include utilization of host-encoded functions (some of them coded by genes acquired by gene transfer from the endosymbiont and/or other bacteria); metabolic complementation between co-symbionts; and forming consortiums with other bacteria within the host. Recent genome sequencing projects of intracellular mutualistic bacteria showed that previously believed universal evolutionary trends like reduced G+C content and conservation of genome synteny are not always present in highly reduced genomes. Finally, the simplified molecular machinery of some of these organisms with small genomes may be used to aid in the design of artificial minimal cells. Here we review recent genomic discoveries of the biology of prokaryotes endowed with small gene sets and discuss the evolutionary mechanisms that have been proposed to explain their peculiar nature. |
topic |
endosymbiosis Muller’s ratchet Black Queen Hypothesis reductive genome evolution minimal genome size streamlining evolution |
url |
http://journal.frontiersin.org/Journal/10.3389/fmicb.2014.00742/full |
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