Cytosine deaminase MX cassettes as positive/negative selectable markers in Saccharomyces cerevisiae.

Journal Article (Journal Article)

We describe positive/negative selectable cytosine deaminase MX cassettes for use in Saccharomyces cerevisiae. The basis of positive selection for cytosine deaminase (Fcy1) activity is that (a) fcy1 strains are unable to grow on medium containing cytosine as a sole nitrogen source and (b) fcy1 ura3 strains are unable to grow on medium containing cytosine as the sole pyrimidine source. Conversely, as 5-fluorocytosine (5FC) is toxic to cytosine deaminase-producing cells, fcy1 strains are resistant to 5FC. FCY1MX and FCA1MX cassettes, containing open reading frames (ORFs) of S. cerevisiae FCY1 and Candida albicans FCA1, respectively, were constructed and used to disrupt targeted genes in S. cerevisiae fcy1 strains. In addition, new direct repeat cassettes, kanPR, FCA1PR, FCY1PR and CaURA3PR, were developed to allow efficient deletion of target genes in cells containing MX3 repeats. Finally, the FCY1- and FCA1MX3 or PR direct repeat cassettes can be readily recycled after 5FC counter-selection on both synthetic and rich media.

Full Text

Duke Authors

Cited Authors

  • Hartzog, PE; Nicholson, BP; McCusker, JH

Published Date

  • July 30, 2005

Published In

Volume / Issue

  • 22 / 10

Start / End Page

  • 789 - 798

PubMed ID

  • 16088873

International Standard Serial Number (ISSN)

  • 0749-503X

Digital Object Identifier (DOI)

  • 10.1002/yea.1245


  • eng

Conference Location

  • England