Faculty Profile

John Roth
Distinguished Professor
Microbiology (College of Biological Sciences)
314 Briggs Hall
Office 752.6679
Lab
jrroth@ucdavis.edu
[Picture of John Roth]

Degrees:
1965 - PhD - Johns Hopkins University - Biology (Genetics)
1961 - BA - Harvard College - Biochemical Sciences

Awards:
1974-5 Guggenheim Fellow, Cold Spring Harbor Laboratory
1986 University of Utah Distinguished Research Award
1987 First Governor's Medal for Science and Technology for the State of Utah
1988 Member, National Academy of Sciences
1990 Rosenblatt Prize, University of Utah
1990-2002 Distinguished Professor, University of Utah
1996 Recipient of the James E. Talmage Presidential Endowed Chair in Biology, U. of Utah
1997 Fellow, American Academy of Microbiology
1997 Honorary Doctorate, Umeå University, Umeå, Sweden
1998 Sackler Fellow at Tel Aviv University, Tel Aviv, Israel
2000-1 Leverhulme Fellow, Oxford University, Oxford, England

Department and Center Affiliations:
Section of Microbiology

Professional Societies:
American Society for Microbiology
Genetics Society of America
Society for General Microbiology

Grad Group Affiliations and Specialties:
Genetics
Microbiology

Publications:
One pathway can incorporate either adenine or dimethylbenzimidazole as alpha-axial ligand of B12 cofactors in Salmonella enterica (2007-8) Anderson, P. J., Lango, J., Carkeet, C., Britten, A., Kräutler, B., Hammock, B.D., and John R. Roth. J. Bacteriol.

Ohno’s Dilemma: Evolution of new genes under continuous selection. (2007) Bergthorsson, U., Andersson, D. I. and John. R. Roth Proc Natl Acad Sci (US) 104:17004-9

Multiple pathways of selected gene amplification during adaptive mutation. (2006) Kugelberg, E., Kofoid. E., Reams, A.B., Andersson, D.I. and J.R. Roth Proc. Natl Acad. Sci 103:17319-24.

Origins of Mutations Under Selection: The Adaptive Mutation Controversy Roth, J.R. (2006) Kugelberg, E., Reams, A.B., Kofoid, E. and D.I. Andersson. Ann Rev Microbiol 60:477-501.

Conserving a volatile metabolite: a role for carboxysomes in Salmonella enterica. (2006) Penrod, J. T. and J.R. Roth J. Bacteriol. 188: 2865-74

Evidence that feedback inhibition of NAD kinase controls responses to oxidative stress. (2006) Grose, J. H., Joss, L., Velick, S. and J.R. Roth Proc Natl Acad. Sci (US) 103:7601-7606

Research Interests:
While natural selection is simple to define, it is difficult to follow in natural settings since common small-effect mutations dictate the sequence of events. This process seems to underlie the enhanced frequency with which favored variants appear during growth under selection. We are trying to dissect in detail one system that is often cited as evidence for stress-induced mutagenesis (adaptive mutation). We think we can convince you that it's all about growth under selection and has nothing to do with mutagenesis.

All Salmonellae invest 1% of their genome in synthesis of cobalamin (B12), which must contribute heavily to their fitness in a natural setting. Yet, in the laboratory, it is difficult to demonstrate an important role of B12 in wild type bacteria. The main uses of B12 are in supporting degradation of ethanolamine and propanediol, both of which are degraded by enzymes enclosed in a carboxysome-like micro-compartment. We’re trying to determine how this works and how it benefits Salmonella in the wild.

While genetic recombination is generally studied using crosses the process in bacteria is used internally, primarily for DNA repair and replication fork restarting. We study formation of chromosome rearrangments in Salmonella to learn about recombination mechanisms. Most recently we've found (to our surprise) that gene duplications arise by a mechanism that does not always require recombination. Many duplications are not simple tandem repeats but have repeats that flank a central fragment inverse order (inversion duplications). We're testing a model by which inversion duplications form following a series of events initiated by short palindromes in the parent sequence.

Laboratory Personnel:
Briggs 316, 318 - Associates: Eric Kofoid, Sophie Maisnier-Patin Post-docs: Andrew Reams, Cristina Tun-Garrido Grad Students: Semarhy Quinones-Soto, Emiko Sano, Douglas Huseby Support staff: Shery Roth, Natalie Duleba
http://rothlab.ucdavis.edu/

Teaching Interests:


Origins of Life

Genetics of bacteria