*Department of Microbiology, University of Illinois at Urbana-Champaign, 601 S. Goodwin Avenue, Urbana, IL 61801, U.S.A.
Biochem Soc Trans. 2013 Dec;41(6):1431-6. doi: 10.1042/BST20130243.
Host-pathogen co-evolution is a significant force which shapes the ecology and evolution of all types of organisms, and such interactions are driven by resistance and immunity mechanisms of the host. Diversity of resistance and immunity can affect the co-evolutionary trajectory of both host and pathogen. The microbial CRISPR (clustered regularly interspaced short palindromic repeats)-Cas (CRISPR-associated) system is one host immunity mechanism which offers a tractable model for examining the dynamics of diversity in an immune system. In the present article, we review CRISPR variation observed in a variety of natural populations, examine the forces which can push CRISPRs towards high or low diversity, and investigate the consequences of various levels of diversity on microbial populations.
宿主-病原体共同进化是一种重要的力量，它塑造了所有类型生物的生态和进化，而这种相互作用是由宿主的抗性和免疫机制驱动的。抗性和免疫的多样性会影响宿主和病原体的共同进化轨迹。微生物 CRISPR（成簇规律间隔短回文重复）-Cas（CRISPR 相关）系统是一种宿主免疫机制，为研究免疫系统多样性的动态提供了一个可行的模型。在本文中，我们回顾了在各种自然群体中观察到的 CRISPR 变异，研究了推动 CRISPR 向高或低多样性发展的力量，并研究了不同多样性水平对微生物群体的影响。
