Z/AP, a double reporter for cre-mediated recombination

Dev Biol. 1999 Apr 15;208(2):281-92. doi: 10.1006/dbio.1999.9209.


The Cre/loxP site-specific recombination system combined with embryonic stem cell-mediated technologies has greatly expanded our capability to address normal and disease development in mammals using genetic approaches. The success of this emerging technology hinges on the production of Cre-expressing transgenic lines that provide cell type-, tissue-, or developmental stage-specific recombination between loxP sites placed in the genome. Here we describe and characterize the production of a double-reporter mouse line that provides a convenient and reliable readout of Cre recombinase activity. Throughout all embryonic and adult stages, the transgenic animal expresses the lacZ reporter gene before Cre-mediated excision occurs. Cre excision, however, removes the lacZ gene, allowing expression of the second reporter, the human alkaline phosphatase gene. This double-reporter transgenic line is able to indicate the occurrence of Cre excision in an extremely widespread manner from early embryonic to adult lineages. It will be a valuable reagent for the increasing number of investigators taking advantage of the powerful tools provided by the Cre/loxP site-specific recombinase system.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkaline Phosphatase / genetics
  • Animals
  • Cell Aggregation
  • Embryo, Mammalian / cytology
  • Gene Expression
  • Genes, Reporter*
  • Genetic Vectors
  • Genotype
  • Histocytochemistry
  • Integrases / metabolism*
  • Lac Operon
  • Mice
  • Mice, Transgenic*
  • Ploidies
  • Recombination, Genetic*
  • Sequence Deletion
  • Stem Cells
  • Tissue Distribution
  • Transgenes
  • Viral Proteins*


  • Viral Proteins
  • Cre recombinase
  • Integrases
  • Alkaline Phosphatase