Positive-negative selection gene targeting with the diphtheria toxin A-chain gene in mouse embryonic stem cells

Transgenic Res. 1993 Jul;2(4):183-90. doi: 10.1007/BF01977348.


The diphtheria toxin A-chain gene was used in a positive-negative selection gene targeting vector to alter the CD4 gene which is transcriptionally silent in mouse embryonic stem cells. Expression of the toxin gene was driven by a constitutively active enhancer, yet the targeting construct exhibited only minimal transient toxicity while enriching for targeted clones 9- to 29-fold. Germline transmission of the stem cell-derived genome was obtained. These data suggest the usefulness of this diphtheria toxin A-chain cassette in replacement-type positive-negative selection vectors. Its potential for novel applications, particularly in the enrichment for 'hit-and-run' insertion-type vectors, is discussed.

Publication types

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

MeSH terms

  • Animals
  • CD4 Antigens / genetics
  • Cell Line
  • DNA
  • Diphtheria Toxin / genetics*
  • Embryo, Mammalian / cytology
  • Genetic Vectors*
  • Mice
  • Mutagenesis
  • Peptide Fragments / genetics*
  • Stem Cells


  • CD4 Antigens
  • Diphtheria Toxin
  • Peptide Fragments
  • diphtheria toxin fragment A
  • DNA