病原体宿主特异性的改变
了解细菌与动物之间的互利关系，对于包括病原微生物学在内的生物学的几个领域来说越来越重要。很多病原体对某一种宿主或组织具有特异性，但这种特异性的分 子基础基本上还不清楚。
现在，对名为Euprymna scolopes的乌贼与生物发光细菌Vibrio fischeri之间的互利关系中的宿主特异性所做的一项比较基因组研究表明，一个细菌基因（即调控基因rscS）的存在可改变宿主范围。当这个基因在该 细菌通常在日本松毬鱼身上寄生的菌种中表达时，它足以形成一个共生生物膜，这个膜是细菌在乌贼身上生存的关键。
这项工作提出一个可能性：为了治疗之目的， 也许可对人病原体的特异性进行类似操纵。
Nature 458 , 215-218 (12 March 2009) | doi :10.1038/nature07660 ; Received 18 August 2008; Accepted 20 November 2008; Published online 1 February 2009
A single regulatory gene is sufficient to alter bacterial host range
Mark J. Mandel 1 , Michael S. Wollenberg 1 , Eric V. Stabb 2 , Karen L. Visick 3 & Edward G. Ruby 1
1. Department of Medical Microbiology and Immunology, University of Wisconsin School of Medicine and Public Health, 1550 Linden Drive, Madison, Wisconsin 53706, USA
2. Department of Microbiology, University of Georgia, 828 Biological Sciences, Athens, Georgia 30602, USA
3. Department of Microbiology and Immunology, Loyola University Chicago, Maywood, Illinois 60153, USA
Microbial symbioses are essential for the normal development and growth of animals
Often, symbionts must be acquired from the environment during each generation, and identification of the relevant symbiotic partner against a myriad of unwanted relationships is a formidable task . Although examples of this specificity are well-documented, the genetic mechanisms governing it are poorly characterized . Here we show that the two-component sensor kinase RscS is necessary and sufficient for conferring efficient colonization of Euprymna scolopes squid by bioluminescent Vibrio fischeri from the North Pacific Ocean. In the squid symbiont V. fischeri ES114, RscS controls light-organ colonization by inducing the Syp exopolysaccharide, a mediator of biofilm formation during initial infection. A genome-level comparison revealed that rscS , although present in squid symbionts, is absent from the fish symbiont V. fischeri MJ11. We found that heterologous expression of RscS in strain MJ11 conferred the ability to colonize E. scolopes in a manner comparable to that of natural squid isolates. Furthermore, phylogenetic analyses support an important role for rscS in the evolution of the squid symbiosis. Our results demonstrate that a regulatory gene can alter the host range of animal-associated bacteria. We show that, by encoding a regulator and not an effector that interacts directly with the host, a single gene can contribute to the evolution of host specificity by switching 'on' pre-existing capabilities for interaction with animal tissue.
Full text ：http://www.nature.com/nature/journal/v458/n7235/full/nature07660.html
Download PDF ：http://www.nature.com/nature/journal/v458/n7235/pdf/nature07660.pdf
编辑: xiaoyan 作者:丁香园通讯员
以下网友留言只代表网友个人观点，不代表网站观点
