在變化的環(huán)境中進(jìn)行細(xì)菌培養(yǎng),，有時(shí)會(huì)積累突變率增大的“轉(zhuǎn)座子”品系，可能會(huì)增強(qiáng)它們進(jìn)行適應(yīng)性演化的潛力,。這種情況經(jīng)常發(fā)生在臨床條件下,。如果“轉(zhuǎn)座子”要長(zhǎng)久存在，它們就需要一個(gè)一致變化的環(huán)境,。與寄生體(如病毒)共同演化是能夠提供這種環(huán)境的一個(gè)情形?，F(xiàn)在，用假單胞菌所作的實(shí)驗(yàn)表明,，與一種自然出現(xiàn)的噬菌體共同演化會(huì)明顯提高細(xì)菌突變率,，導(dǎo)致噬菌體絕滅概率增高。因此,，以噬菌體種群為控制目標(biāo)可能是在臨床感染環(huán)境中削弱對(duì)“轉(zhuǎn)座子”選擇性的一種辦法,。
原始出處:
Nature 450, 1079-1081 (13 December 2007) | doi:10.1038/nature06350; Received 9 July 2007; Accepted 4 October 2007; Published online 2 December 2007
Coevolution with viruses drives the evolution of bacterial mutation rates
Csaba Pal1,2, María D. Maciá3, Antonio Oliver3, Ira Schachar1 & Angus Buckling1
Department of Zoology, University of Oxford, Oxford OX1 3PS, UK
Institute of Biochemistry, Biological Research Center, Temesvári krt. 62. Szeged, H-6701, Hungary
Servicio de Microbiologia and Unidad de Investigación, Hospital Son Dureta, Instituto Universitario de Investigación en Ciencias de la Salud (IUNICS), 07014, Palma de Mallorca, Spain
Correspondence to: Csaba Pal1,2Angus Buckling1 Correspondence and requests for materials should be addressed to A.B. (Email: [email protected]) or C.P. (Email: [email protected]).
Abstract
Bacteria with greatly elevated mutation rates (mutators) are frequently found in natural1, 2, 3 and laboratory4, 5 populations, and are often associated with clinical infections6, 7. Although mutators may increase adaptability to novel environmental conditions, they are also prone to the accumulation of deleterious mutations. The long-term maintenance of high bacterial mutation rates is therefore likely to be driven by rapidly changing selection pressures8, 9, 10, 11, 12, 13, 14, in addition to the possible slow transition rate by point mutation from mutators to non-mutators15. One of the most likely causes of rapidly changing selection pressures is antagonistic coevolution with parasites16, 17. Here we show whether coevolution with viral parasites could drive the evolution of bacterial mutation rates in laboratory populations of the bacterium Pseudomonas fluorescens 18. After fewer than 200 bacterial generations, 25% of the populations coevolving with phages had evolved 10- to 100-fold increases in mutation rates owing to mutations in mismatch-repair genes; no populations evolving in the absence of phages showed any significant change in mutation rate. Furthermore, mutator populations had a higher probability of driving their phage populations extinct, strongly suggesting that mutators have an advantage against phages in the coevolutionary arms race. Given their ubiquity, bacteriophages may play an important role in the evolution of bacterial mutation rates.
