|Multiple genetic switches spontaneously modulating bacterial mutability|
|Chen, Fang1,2; Liu, Wei-Qiao1,3; Eisenstark, Abraham4,5; Johnston, Randal N.6; Liu, Gui-Rong1; Liu, Shu-Lin1,2,3|
|刊名||BMC EVOLUTIONARY BIOLOGY|
|WOS标题词||Science & Technology|
|类目[WOS]||Evolutionary Biology ; Genetics & Heredity|
|研究领域[WOS]||Evolutionary Biology ; Genetics & Heredity|
|关键词[WOS]||DNA MISMATCH REPAIR ; ESCHERICHIA-COLI POPULATIONS ; STRESS-INDUCED MUTAGENESIS ; HIGH MUTATION-RATES ; SALMONELLA-TYPHIMURIUM ; ADAPTIVE EVOLUTION ; HIGH-FREQUENCY ; GENOME ; MUTL ; MECHANISMS|
Background: All life forms need both high genetic stability to survive as species and a degree of mutability to evolve for adaptation, but little is known about how the organisms balance the two seemingly conflicting aspects of life: genetic stability and mutability. The DNA mismatch repair (MMR) system is essential for maintaining genetic stability and defects in MMR lead to high mutability. Evolution is driven by genetic novelty, such as point mutation and lateral gene transfer, both of which require genetic mutability. However, normally a functional MMR system would strongly inhibit such genomic changes. Our previous work indicated that MMR gene allele conversion between functional and non-functional states through copy number changes of small tandem repeats could occur spontaneously via slipped-strand mis-pairing during DNA replication and therefore may play a role of genetic switches to modulate the bacterial mutability at the population level. The open question was: when the conversion from functional to defective MMR is prohibited, will bacteria still be able to evolve by accepting laterally transferred DNA or accumulating mutations?
Results: To prohibit allele conversion, we "locked" the MMR genes through nucleotide replacements. We then scored changes in bacterial mutability and found that Salmonella strains with MMR locked at the functional state had significantly decreased mutability. To determine the generalizability of this kind of mutability ′switching′ among a wider range of bacteria, we examined the distribution of tandem repeats within MMR genes in over 100 bacterial species and found that multiple genetic switches might exist in these bacteria and may spontaneously modulate bacterial mutability during evolution.
Conclusions: MMR allele conversion through repeats-mediated slipped-strand mis-pairing may function as a spontaneous mechanism to switch between high genetic stability and mutability during bacterial evolution.
|项目编号||NSFC30970078 ; NSFC30870098 ; 30970119 ; 81030029 ; 20092307110001|
|资助机构||Canadian Institutes of Health Research ; National Natural Science Foundation of China ; Natural Science Foundation of Heilongjiang Province of China ; Harbin Medical University ; Peking University Health Science Center ; Specialized Research Fund for the Doctoral Program of Higher Education (SRFDP)|
|作者单位||1.Canc Res Ctr, Columbia, MO USA|
2.Univ Calgary, Dept Microbiol & Infect Dis, Calgary, AB, Canada
3.Univ Missouri, Columbia, MO USA
4.Univ Calgary, Dept Biochem & Mol Biol, Calgary, AB, Canada
5.Harbin Med Coll, Genom Res Ctr, State Prov Key Labs Biomed Pharmaceut China, Harbin, Peoples R China
6.Peking Univ, Hlth Sci Ctr, Dept Microbiol, Beijing 100871, Peoples R China
|Chen, Fang,Liu, Wei-Qiao,Eisenstark, Abraham,et al. Multiple genetic switches spontaneously modulating bacterial mutability[J]. BMC EVOLUTIONARY BIOLOGY,2010,10(1).|
|APA||Chen, Fang,Liu, Wei-Qiao,Eisenstark, Abraham,Johnston, Randal N.,Liu, Gui-Rong,&Liu, Shu-Lin.(2010).Multiple genetic switches spontaneously modulating bacterial mutability.BMC EVOLUTIONARY BIOLOGY,10(1).|
|MLA||Chen, Fang,et al."Multiple genetic switches spontaneously modulating bacterial mutability".BMC EVOLUTIONARY BIOLOGY 10.1(2010).|
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