Atzinger, A. and J.G. Lawrence (2020) Sele
Atzinger, A. and J.G. Lawrence (2020) Selection for ancient periodic motifs that do not impart DNA bending, PLoS Genetics In Press
Contact
Office: (412) 624-4350
A234 Langley Hall
4249 Fifth Avenue
Pittsburgh, PA 15260
Our research is directed toward elucidating the evolution of bacterial genomes, including their size, composition, variability and organization. In other words, why do genomes have the genes that they do? An understanding of the evolutionary process that leads to differences in genomes will shed light on how species themselves differentiate. We take computations, theoretical and experimental approaches to understanding how genomes evolve.
Speciation. Bacterial speciation - the process by which lineages become genetically and ecologically distinct from one another - is quite different from its eukaryotic counterpart. The differences arise from both the manner by which bacteria adapt (by gene acquisition, rather than gene modification) and the constraints on their gene exchange. Our work has supported a "fragmented" model of speciation, whereby lineages become genetically isolated on a gene-by-gene basis over a period of tens of millions of years.
Ecological adaptation. Which are the first genes to become genetically isolated in nascent species? Among the earliest diverging genes in the Salmonella chromosome are those that encode the O-antigen biosynthetic machinery. We have been investigating the role of protozoan predation in driving this diversification. Here, different antigens allow the newly-diverging Salmonella to escape protozoan predators in different environments.
Genomic architecture. The fate of a newly-arrived gene is the function of two factors. Its likelhood of retention increases as it provides an increasingly beneficial function. However, its insertion may also be detrimental in interfering with genome-wide patterns fo information required to successfully manipulate the massive DNA polymer duing growth and reproduction. We study the embdedd information - here termed architecture - which differs between organisms and controls the flow of genes between taxa.
Dr. Lawrence is seeking a graduate student or post-doctoral researcher with interests in computational biology and genome evolution.
- Castilleja Olmsted, Graduate Student
- Emily Schultz, Undergraduate Researcher
Hendrickson H.L., D. Barbeau, R. Ceschin, and J
Hendrickson H.L., D. Barbeau, R. Ceschin, and J.G. Lawrence (2018) Chromosome architecture constrains horizontal gene transfer in bacteria. PLoS Genet. 14(5):e1007421.
Xu M, J.G. Lawrence, and D. Durand (2018) Selec
Xu M, J.G. Lawrence, and D. Durand (2018) Selection, periodicity and potential function for Highly Iterative Palindrome-1 (HIP1) in cyanobacterial genomes. Nucleic Acids Res. 46(5):2265-2278.Xu M, J.G. Lawrence, and D. Durand (2018) Selection, periodicity and potential function for Highly Iterative Palindrome-1 (HIP1) in cyanobacterial genomes. Nucleic Acids Res. 46(5):2265-2278.
Mustapha MM, JW Marsh, MG Krauland, JO Fernande
Mustapha MM, JW Marsh, MG Krauland, JO Fernandez, AP de Lemos, JC Dunning Hotopp, X Wang, LW Mayer, JG Lawrence, NL Hiller, LH Harrison (2016) Genomic Investigation Reveals Highly Conserved, Mosaic, Recombination Events Associated with Capsular Switching among Invasive Neisseria meningitidis Serogroup W Sequence Type (ST)-11 Strains. Genome Biol Evol. 8(6):2065-75.
Lawrence, J.G., K. Butela, A. Atzinger (2013) A
Lawrence, J.G., K. Butela, A. Atzinger (2013) A likelihood approach to classifying fluorescent events collected by multicolor flow cytometry. J. Microbiol. Methods In Press.
Butela, K., and J.G. Lawrence (2012) Genetic ma
Butela, K., and J.G. Lawrence (2012) Genetic manipulation of pathogenicity loci in non-Typhimurium Salmonella. J. Microbiol. Methods 91(3):477-482
Retchless, A.C. and J.G. Lawrence (2012) Ecolog
Retchless, A.C. and J.G. Lawrence (2012) Ecological adaptation in bacteria: Speciation driven by codon selection. Mol Biol Evol 29:3669-3683
Retchless, A.C. and J.G. Lawrence (2011) Quanti
Retchless, A.C. and J.G. Lawrence (2011) Quantification of codon selection for comparative bacterial genomics. BMC Genomics 12:374
Ricotta, E.E., N. Wang, R. Cutler, J.G. Lawrence, and T.L. Humpries (2011) Rapid divergence of tw
Ricotta, E.E., N. Wang, R. Cutler, J.G. Lawrence, and T.L. Humpries (2011) Rapid divergence of two classes of Haemophilus ducreyi. J Bacteriol 193:2941-2947
Azad, R.K., and J.G. Lawrence (2011) Towards more robust methods of alien gene detection. Nuc
Azad, R.K., and J.G. Lawrence (2011) Towards more robust methods of alien gene detection. Nucleic Acids Res 39(9):e56
Retchless, A.C., and J.G. Lawrence (2010) Phylogenetic incongruence arising from fragmented speci
Retchless, A.C., and J.G. Lawrence (2010) Phylogenetic incongruence arising from fragmented speciation in enteric bacteria. Proc. Natl. Acad. Sci., USA 107:11453-11458
Lawrence, J.G., and A.C. Retchless (2010) The myth of bacterial species and speciation. Biol.
Lawrence, J.G., and A.C. Retchless (2010) The myth of bacterial species and speciation. Biol. Philos. 25:569-588
Dr. Lawrence received his Ph.D. in 1991 with Daniel L. Hartl at Washington University, St. Louis, working on the evolution of bacterial genes and bacterial transposons. He performed his postdoctoral studies with John Roth at the University of Utah studying the evolution of the coenzyme B12 (cobalamin) biosynthetic pathway. He joined the Department as an Assistant Professor in September 1996.