一项新研究指出,细菌能从威胁它们的病毒上借遗传序列并将其结合到自己的基因组中,从而试图躲避病毒未来的进攻。这种独特的防御涉及名为CRISPR的重复遗传序列,该序列遍布细菌的基因组。CRISPR片段在重复段之间有与威胁细菌的病毒序列类似的“间隔区”序列。Rodolphe Barrangou和同事现在展示,对乳制品生产很重要的嗜热链球菌能从进攻它们的病毒上获得新的间隔区序列。一段时间后,这些新的间隔区序列使细菌对病毒有免疫,可能是通过沉默病毒基因的表达。研究人员提出,其它与CRISPR有关的基因也参与这个抵抗机制。
部分英文原文:
Science 23 March 2007:
Vol. 315. no. 5819, pp. 1709 - 1712
DOI: 10.1126/science.1138140
Reports
CRISPR Provides Acquired Resistance Against Viruses in Prokaryotes
Rodolphe Barrangou,1 Christophe Fremaux,2 Hélène Deveau,3 Melissa Richards,1 Patrick Boyaval,2 Sylvain Moineau,3 Dennis A. Romero,1 Philippe Horvath2*
Clustered regularly interspaced short palindromic repeats (CRISPR) are a distinctive feature of the genomes of most Bacteria and Archaea and are thought to be involved in resistance to bacteriophages. We found that, after viral challenge, bacteria integrated new spacers derived from phage genomic sequences. Removal or addition of particular spacers modified the phage-resistance phenotype of the cell. Thus, CRISPR, together with associated cas genes, provided resistance against phages, and resistance specificity is determined by spacer-phage sequence similarity.
1 Danisco USA Inc., 3329 Agriculture Drive, Madison, WI 53716, USA.
2 Danisco France SAS, Boîte Postale 10, F-86220 Dangé-Saint-Romain, France.
3 Département de Biochimie et de Microbiologie, Faculté des Sciences et de Génie, Groupe de Recherche en Ecologie Buccale, Faculté de Médecine Dentaire, Félix d'Hérelle Reference Center for Bacterial Viruses, Université Laval, G1K 7P4 Québec, Canada.
* To whom correspondence should be addressed. E-mail: philippe.horvath@danisco.com