A conditional Knockout (cKO) is
usually generated through the Cre-LoxP/Flp-Frtrecombination systems. The
candidate fragment that will be knocked out is flanked by LoxP or Frtelements. The floxed(flanked by LoxP or Frt)
mice are bred with tissue-specific Cre (or Flp) mice, so that the flanked sequence will
be removed from the offsprings’ genome in a tissue-specific pattern.
For the conditional knockout generation, theloxPfragments are usually inserted into the introns downstream of the ATG-containingexon, and
removal of the flanked exon (s)
will result in a frame-shift that disrupts protein expression.