%0 Journal Article
%T Conservation in the face of diversity: multistrain analysis of an intracellular bacterium
%A Michael J Dark
%A David R Herndon
%A Lowell S Kappmeyer
%A Mikel P Gonzales
%A Elizabeth Nordeen
%A Guy H Palmer
%A Donald P Knowles
%A Kelly A Brayton
%J BMC Genomics
%D 2009
%I BioMed Central
%R 10.1186/1471-2164-10-16
%X These comparisons revealed that A. marginale has a closed-core genome with few highly plastic regions, which include the msp2 and msp3 genes, as well as the aaap locus. Comparison of the Florida and St. Maries genome sequences found that SNPs comprise 0.8% of the longer Florida genome, with 33.5% of the total SNPs between all five strains present in at least two strains and 3.0% of SNPs present in all strains except Florida. Comparison of genomes from three strains of Mycobacterium tuberculosis, Bacillus anthracis, and Nessieria meningiditis, as well as four Chlamydophila pneumoniae strains found that 98.8%¨C100% of SNPs are unique to each strain, suggesting A. marginale, with 76.0%, has an intermediate level of strain-specific SNPs. Comparison of genomes from other organisms revealed variation in diversity that did not segregate with the environmental niche the bacterium occupies, ranging from 0.00% to 8.00% of the larger pairwise-compared genome.Analysis of multiple A. marginale strains suggests intracellular bacteria have more variable SNP retention rates than previously reported, and may have closed-core genomes in response to the host organism environment and/or reductive evolution.While the recent boom in genome sequencing projects has provided a wealth of information about bacterial metabolism and evolution, we know little about interstrain variation. A firm understanding of the rates and sites of variation is useful in determining genotypic differences associated with phenotypic traits and in formulating control strategies for a number of pathogens. Further, knowledge about the pan-genome of organisms will aid in determining the core genomic requirements, as well as shed more light on events that occur in the various environmental niches bacteria occupy.Most studies of bacterial diversity to date have either utilized specific genomic loci [1,2] or have examined metagenomics of specific environmental niches [3,4]. While these types of studies help elucidate th
%U http://www.biomedcentral.com/1471-2164/10/16