5-Fluoro-orotic acid induces chromosome alterations in Candida albicans

Yeast. 2005 Jan 15;22(1):57-70. doi: 10.1002/yea.1191.


Treatment of a prototrophic laboratory strain of Candida albicans with 5-fluoro-orotic acid (5-FOA) produced two major types of mutants with chromosomal alterations, 5-FOA-resistant (FoaR) and those remaining sensitive (FoaS). Both major types remained Ura+. FoaR mutants, produced after a long exposure, contained either a duplication of chromosome 4b or an inner enlargement of chromosome 5b. The average mutant frequency was approximately 1.0 x 10(-5). The reverse mutation of FoaR to FoaS also caused the loss of either the extra chromosome 4b or the enlarged chromosome 5b, revealing a causal relationship between the resistance and the specific chromosome constitution. The cells remained sensitive after a relatively short 24 h exposure to 5-FOA medium, but the treatment induced non-specific changes in lengths of various chromosomes. Furthermore, FoaR type mutants acquired a notable chromosomal and phenotypic instability. Our results indicate the necessity of electrokaryotyping of strains that have been exposed to 5-FOA, especially with studies of gene function and with DNA microarray assays.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Candida albicans / drug effects*
  • Candida albicans / genetics
  • Chromosome Aberrations*
  • Chromosomes, Fungal / drug effects*
  • Karyotyping
  • Mutation
  • Orotic Acid / analogs & derivatives*
  • Orotic Acid / pharmacology*
  • Phenotype


  • Orotic Acid
  • 5-fluoroorotic acid