Markedly different genome arrangements between serotype a strains and serotypes b or c strains of <it>Aggregatibacter actinomycetemcomitans</it>
<p>Abstract</p> <p>Background</p> <p>Bacterial phenotype may be profoundly affected by the physical arrangement of their genes in the genome. The Gram-negative species <it>Aggregatibacter actinomycetemcomitans </it>is a major etiologic agent of human periodo...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
BMC
2010-09-01
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| Series: | BMC Genomics |
| Online Access: | http://www.biomedcentral.com/1471-2164/11/489 |
| Summary: | <p>Abstract</p> <p>Background</p> <p>Bacterial phenotype may be profoundly affected by the physical arrangement of their genes in the genome. The Gram-negative species <it>Aggregatibacter actinomycetemcomitans </it>is a major etiologic agent of human periodontitis. Individual clonal types of <it>A. actinomycetemcomitans </it>may exhibit variable virulence and different patterns of disease association. This study examined the genome arrangement of <it>A. actinomycetemcomitans </it>using the genome sequences of serotypes a-c strains. The genome alignment and rearrangement were analyzed by the MAUVE and the GRIMM algorithms. The distribution patterns of genes along the leading/lagging strands were investigated. The occurrence and the location of repeat sequences relative to the genome rearrangement breakpoints were also determined.</p> <p>Results</p> <p>The genome arrangement of the serotype a strain D7S-1 is markedly different from the serotype b strain HK1651 or the serotype c strain D11S-1. Specific genome arrangements appear to be conserved among strains of the same serotypes. The reversal distance between D7S-1 and HK1651 by GRIMM analysis is also higher than the within-species comparisons of 7 randomly selected bacterial species. The locations of the orthologous genes are largely preserved between HK1651 and D11S-1 but not between D7S-1 and HK1651 (or D11S-1), irrespective of whether the genes are categorized as essential/nonessential or highly/nonhighly expressed. However, genome rearrangement did not disrupt the operons of the <it>A. actinomycetemcomitans </it>strains. A higher proportion of the genome in strain D7S-1 is occupied by repeat sequences than in strains HK1651 or D11S-1.</p> <p>Conclusion</p> <p>The results suggest a significant evolutionary divergence between serotype a strains and serotypes b/c strains of <it>A. actinomycetemcomitans</it>. The distinct patterns of genome arrangement may suggest phenotypic differences between serotype a and serotypes b/c strains.</p> |
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| ISSN: | 1471-2164 |