Efficient production of Cre-mediated site-directed recombinants through the utilization of the puromycin resistance gene, pac: a transient gene-integration marker for ES cells

Nucleic Acids Res. 1998 Jan 15;26(2):679-80. doi: 10.1093/nar/26.2.679.


Gene targeting in embryonic stem (ES) cells is a powerful tool for generating mice carrying specifically designed mutations in the germline. Puromycin can completely kill ES cells within 24 to 48 h whereas G418 and hygromycin cannot. We have, therefore, proposed that the puromycin N-acetyltransferase ( pac ) gene, may be utilized as a transient gene-integration marker. Using a circular expression vector of cre and pac genes, Cre-mediated mutant cells were effectively enriched by pulse treatment of puromycin without stable integration of their genes. We have thus demonstrated the first application of pac as a transient gene-integration marker for ES cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetyltransferases / genetics*
  • Animals
  • Cells, Cultured
  • Embryo, Mammalian
  • Gene Expression
  • Gene Targeting
  • Genetic Markers*
  • Integrases / genetics
  • Integrases / metabolism*
  • Mice
  • Puromycin / pharmacology
  • Recombination, Genetic*
  • Stem Cells / metabolism*
  • Viral Proteins*


  • Genetic Markers
  • Viral Proteins
  • Puromycin
  • Acetyltransferases
  • puromycin N-acetyltransferase
  • Cre recombinase
  • Integrases