Modeling Bacterial Evolution with Comparative-Genome-Based Marker Systems: Application to Mycobacterium tuberculosis Evolution and Pathogenesis Export

@article{citeulike:3214135, abstract = {The comparative-genomic sequencing of two Mycobacterium tuberculosis strains enabled us to identify single nucleotide polymorphism (SNP) markers for studies of evolution, pathogenesis, and epidemiology in clinical M. tuberculosis. Phylogenetic analysis using these "comparative-genome markers" (CGMs) produced a highly unusual phylogeny with a complete absence of secondary branches. To investigate CGM-based phylogenies, we devised computer models to simulate sequence evolution and calculate new phylogenies based on an SNP format. We found that CGMs represent a distinct class of phylogenetic markers that depend critically on the genetic distances between compared "reference strains." Properly distanced reference strains generate CGMs that accurately depict evolutionary relationships, distorted only by branch collapse. Improperly distanced reference strains generate CGMs that distort and reroot outgroups. Applying this understanding to the CGM-based phylogeny of M. tuberculosis, we found evidence to suggest that this species is highly clonal without detectable lateral gene exchange. We noted indications of evolutionary bottlenecks, including one at the level of the PHRI "C" strain previously associated with particular virulence characteristics. Our evidence also suggests that loss of IS6110 to fewer than seven elements per genome is uncommon. Finally, we present population-based evidence that KasA, an important component of mycolic acid biosynthesis, develops G312S polymorphisms under selective pressure. 10.1128/JB.185.11.3392-3399.2003}, address = {Department of Medicine, Center for Emerging Pathogens, New Jersey Medical School, Newark, New Jersey 07103, USA. allandda@umdnj.edu}, author = {Alland, David and Whittam, Thomas S. and Murray, Megan B. and Cave, M. Donald and Hazbon, Manzour H. and Dix, Kim and Kokoris, Mark and Duesterhoeft, Andreas and Eisen, Jonathan A. and Fraser, Claire M. and Fleischmann, Robert D.}, citeulike-article-id = {3214135}, citeulike-linkout-0 = {http://dx.doi.org/10.1128/JB.185.11.3392-3399.2003}, citeulike-linkout-1 = {http://jb.asm.org/cgi/content/abstract/185/11/3392}, citeulike-linkout-2 = {http://view.ncbi.nlm.nih.gov/pubmed/12754238}, citeulike-linkout-3 = {http://www.hubmed.org/display.cgi?uids=12754238}, day = {1}, doi = {10.1128/JB.185.11.3392-3399.2003}, issn = {0021-9193}, journal = {J. Bacteriol.}, keywords = {genomics, tuberculosis}, month = {June}, number = {11}, pages = {3392--3399}, posted-at = {2009-03-05 14:39:49}, priority = {2}, title = {Modeling Bacterial Evolution with Comparative-Genome-Based Marker Systems: Application to Mycobacterium tuberculosis Evolution and Pathogenesis}, url = {http://dx.doi.org/10.1128/JB.185.11.3392-3399.2003}, volume = {185}, year = {2003} }

TY - JOUR ID - citeulike:3214135 L3 - citeulike-article-id:3214135 N2 - The comparative-genomic sequencing of two Mycobacterium tuberculosis strains enabled us to identify single nucleotide polymorphism (SNP) markers for studies of evolution, pathogenesis, and epidemiology in clinical M. tuberculosis. Phylogenetic analysis using these "comparative-genome markers" (CGMs) produced a highly unusual phylogeny with a complete absence of secondary branches. To investigate CGM-based phylogenies, we devised computer models to simulate sequence evolution and calculate new phylogenies based on an SNP format. We found that CGMs represent a distinct class of phylogenetic markers that depend critically on the genetic distances between compared "reference strains." Properly distanced reference strains generate CGMs that accurately depict evolutionary relationships, distorted only by branch collapse. Improperly distanced reference strains generate CGMs that distort and reroot outgroups. Applying this understanding to the CGM-based phylogeny of M. tuberculosis, we found evidence to suggest that this species is highly clonal without detectable lateral gene exchange. We noted indications of evolutionary bottlenecks, including one at the level of the PHRI "C" strain previously associated with particular virulence characteristics. Our evidence also suggests that loss of IS6110 to fewer than seven elements per genome is uncommon. Finally, we present population-based evidence that KasA, an important component of mycolic acid biosynthesis, develops G312S polymorphisms under selective pressure. 10.1128/JB.185.11.3392-3399.2003 IS - 11 JF - J. Bacteriol. SN - 0021-9193 AD - Department of Medicine, Center for Emerging Pathogens, New Jersey Medical School, Newark, New Jersey 07103, USA. allandda@umdnj.edu EP - 3399 TI - Modeling Bacterial Evolution with Comparative-Genome-Based Marker Systems: Application to Mycobacterium tuberculosis Evolution and Pathogenesis VL - 185 SP - 3392 KW - genomics KW - tuberculosis AU - Alland, David AU - Whittam, Thomas AU - Murray, Megan AU - Cave, Donald AU - Hazbon, Manzour AU - Dix, Kim AU - Kokoris, Mark AU - Duesterhoeft, Andreas AU - Eisen, Jonathan AU - Fraser, Claire AU - Fleischmann, Robert PY - 2003/06/01/ UR - http://dx.doi.org/10.1128/JB.185.11.3392-3399.2003 ER -