Godde James S, Bickerton Amanda
Department of Biology, Monmouth College, Monmouth, IL 61462, USA.
J Mol Evol. 2006 Jun;62(6):718-29. doi: 10.1007/s00239-005-0223-z. Epub 2006 Apr 11.
We have found direct DNA repeats 21-47 bp in length interspersed with nonrepetitive sequences of similar length, or clustered regularly interspaced short palindromic repeats (CRISPRs) in a wide range of diverse prokaryotes, including many Archaeal and Eubacterial species. A number of cas, CRISPR-associated genes have also been characterized in many of the same organisms. Phylogenetic analysis of these cas genes suggests that the CRISPR loci have been propagated via HGT, horizontal gene transfer. We suggest a mechanism by which this HGT has occurred, namely, that the CRISPR loci can be carried between cells on megaplasmids > or = 40 kb in length.
我们在多种不同的原核生物中发现了长度为21 - 47 bp的直接DNA重复序列，这些序列穿插着相似长度的非重复序列，即成簇规律间隔短回文重复序列（CRISPRs），其中包括许多古细菌和真细菌物种。在许多相同的生物体中，还鉴定出了一些与CRISPR相关的cas基因。对这些cas基因的系统发育分析表明，CRISPR基因座是通过水平基因转移（HGT）传播的。我们提出了一种这种水平基因转移发生的机制，即CRISPR基因座可以在长度大于或等于40 kb的大质粒上在细胞间携带。
