Diversity and evolution of multiple orc/cdc6-adjacent replication origins in haloarchaea

BMC Genomics

Research Article

Hailong Liu¹  Zhenfang Wu¹  Jingfang Liu¹  Hua Xiang¹  Xiaoqing Liu¹ 

[1] State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, 100101, Beijing, China;

关键词: Replication Origin;    Genomic Content;    Autonomous Replication;    Extrachromosomal Element;    Main Chromosome;   

DOI  :  10.1186/1471-2164-13-478

 received in 2012-01-16, accepted in 2012-08-28,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundWhile multiple replication origins have been observed in archaea, considerably less is known about their evolutionary processes. Here, we performed a comparative analysis of the predicted (proved in part) orc/cdc6-associated replication origins in 15 completely sequenced haloarchaeal genomes to investigate the diversity and evolution of replication origins in halophilic Archaea.ResultsMultiple orc/cdc6-associated replication origins were predicted in all of the analyzed haloarchaeal genomes following the identification of putative ORBs (origin recognition boxes) that are associated with orc/cdc6 genes. Five of these predicted replication origins in Haloarcula hispanica were experimentally confirmed via autonomous replication activities. Strikingly, several predicted replication origins in H. hispanica and Haloarcula marismortui are located in the distinct regions of their highly homologous chromosomes, suggesting that these replication origins might have been introduced as parts of new genomic content. A comparison of the origin-associated Orc/Cdc6 homologs and the corresponding predicted ORB elements revealed that the replication origins in a given haloarchaeon are quite diverse, while different haloarchaea can share a few conserved origins. Phylogenetic and genomic context analyses suggested that there is an original replication origin (oriC1) that was inherited from the ancestor of archaea, and several other origins were likely evolved and/or translocated within the haloarchaeal species.ConclusionThis study provides detailed information about the diversity of multiple orc/cdc6-associated replication origins in haloarchaeal genomes, and provides novel insight into the evolution of multiple replication origins in Archaea.

【 授权许可】

Unknown   
© Wu et al.; licensee BioMed Central Ltd. 2012. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.