title: Quantitative approaches for assessing chromosome loss in Saccharomyces cerevisiae: general methods for analyzing downturns in dose response.
abstract: Statistical methods are considered for analysis of data arising from a mitotic chromosome loss assay in Saccharomyces cerevisiae strain D61.M. The methods make use of reproducibility trial data from the assay (presented herein) and previous data, which suggest a unimodal, 'umbrella-patterned' dose response. Computer simulations are employed to illustrate the operating characteristics of the umbrella response methods. These methods are generally applicable to any toxicity assay that exhibits a downturn in dose response. Experimental design considerations are also discussed. These include applications of 2-stage sampling rules to first gauge the dose window of peak response, then test if the response deviates significantly from untreated levels.
authors.affiliation: National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709.
authors.forename: W W
authors.initials: WW
authors.lastname: Piegorsch
authors.forename: F K
authors.initials: FK
authors.lastname: Zimmermann
authors.forename: S
authors.initials: S
authors.lastname: Fogel
authors.forename: S G
authors.initials: SG
authors.lastname: Whittaker
authors.forename: M A
authors.initials: MA
authors.lastname: Resnick
mesh_terms: D000483:Alleles; D000782:Aneuploidy; D002872:Chromosome Deletion; D003198:Computer Simulation; D004305:Dose-Response Relationship, Drug; D008433:Mathematics; D009154:Mutation; D012441:Saccharomyces cerevisiae / Q000235:genetics*