title: Papillation in Bacillus anthracis colonies: a tool for finding new mutators.
abstract: Colonies of Bacillus anthracis Sterne allow the growth of papillation after 6 days of incubation at 30°C on Luria-Bertani medium. The papillae are due to mutations that allow the cells to overcome the barriers to continued growth. Cells isolated from papillae display two distinct gross phenotypes (group A and group B). We determined that group A mutants have mutations in the nprR gene including frameshifts, deletions, duplications and base substitutions. We used papillation as a tool for finding new mutators as the mutators generate elevated levels of papillation. We discovered that disruption of yycJ or recJ leads to a spontaneous mutator phenotype. We defined the nprR/papillation system as a new mutational analysis system for B. anthracis. The mutational specificity of the new mutator yycJ is similar to that of mismatch repair-deficient strains (MMR⁻) such as those with mutations in mutL or mutS. Deficiency in recJ results in a unique specificity, generating only tandem duplications.
authors.affiliation: Department of Microbiology, Immunology, and Molecular Genetics, Molecular Biology Institute, University of California, David Geffen School of Medicine, Los Angeles, CA 90095, USA.
authors.forename: Hanjing
authors.initials: H
authors.lastname: Yang
authors.forename: Cameron
authors.initials: C
authors.lastname: Sikavi
authors.forename: Katherine
authors.initials: K
authors.lastname: Tran
authors.forename: Shauna M
authors.initials: SM
authors.lastname: McGillivray
authors.forename: Victor
authors.initials: V
authors.lastname: Nizet
authors.forename: Madeline
authors.initials: M
authors.lastname: Yung
authors.forename: Aileen
authors.initials: A
authors.lastname: Chang
authors.forename: Jeffrey H
authors.initials: JH
authors.lastname: Miller
mesh_terms: D001408:Bacillus anthracis / Q000235:genetics* / Q000254:growth & development*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D004252:DNA Mutational Analysis / Q000379:methods*; D009154:Mutation; D010641:Phenotype
chemical_list: D001426:Bacterial Proteins