牛津大學(xué)的研究人員Michiel Vos發(fā)現(xiàn),，土壤中的噬菌體能夠根據(jù)其周?chē)?xì)菌的類(lèi)型而不斷改進(jìn)他們感染細(xì)菌的能力,，因此，噬菌體的這種進(jìn)化方式能夠重構(gòu)其生存的小范圍內(nèi)的生態(tài)系統(tǒng),。這篇研究報(bào)告發(fā)表在Science雜志上,。
Michiel Vos在一塊土地上選取5個(gè)點(diǎn)為土壤樣本，每個(gè)樣本土壤面積為25cm×25cm,。然后從各個(gè)樣本中分離出Stenotrophomas細(xì)菌及其相關(guān)的噬菌體,。噬菌體對(duì)細(xì)菌進(jìn)行感染，增殖,，并導(dǎo)致細(xì)菌細(xì)胞破裂,，然后噬菌體從一個(gè)細(xì)菌繼續(xù)感染另一個(gè)細(xì)菌。研究人員發(fā)現(xiàn),，超過(guò)1/3的細(xì)菌對(duì)來(lái)自同一塊土壤的噬菌體非常敏感,，很容易被噬菌體感染。因而,，噬菌體能夠很快控制土壤細(xì)菌的種類(lèi),。
在進(jìn)一步的研究中Vos發(fā)現(xiàn)，噬菌體更容易感染來(lái)自同一塊土壤的細(xì)菌,，而對(duì)來(lái)自其他土壤樣本中的細(xì)菌感染力相對(duì)較弱,。進(jìn)化生態(tài)學(xué)家稱(chēng)這是噬菌體的“局部適應(yīng)性(locally adapted)”。
Vos及其同事的這項(xiàng)研究表明,，即使在只有幾平方厘米的小范圍內(nèi),，微生物種群的分布也不是隨機(jī)的。噬菌體通常都分布在最易被它們感染的細(xì)菌的周?chē)?。這項(xiàng)研究還證實(shí),，土壤中各種不同類(lèi)型的微生物間的相互作用在構(gòu)成生物多樣性上有非常重要的意義。（生物谷Bioon.com）
生物谷推薦原始出處：
Science 14 August 2009:DOI: 10.1126/science.1174173
Local Adaptation of Bacteriophages to Their Bacterial Hosts in Soil
Michiel Vos,1,*, Philip J. Birkett,1 Elizabeth Birch,1 Robert I. Griffiths,2 Angus Buckling1
Microbes are incredibly abundant and diverse and are key to ecosystem functioning, yet relatively little is known about the ecological and evolutionary mechanisms that shape their distributions. Bacteriophages, viral parasites that lyse their bacterial hosts, exert intense and spatially varying selection pressures on bacteria and vice versa. We measured local adaptation of bacteria and their associated phages in a centimeter-scale soil population. We first demonstrate that a large proportion of bacteria is sensitive to locally occurring phages. We then show that sympatric phages (isolated from the same 2-gram soil samples as the bacteria) are more infective than are phages from samples some distance away. This study demonstrates the importance of biotic interactions for the small-scale spatial structuring of microbial genetic diversity in soil.
1 Department of Zoology, University of Oxford, Oxford OX1 3PS, UK.
2 Centre for Ecology and Hydrology, Oxford OX1 35R, UK.
