Codon‐improved Cre recombinase (iCre) expression in the mouse

DR Shimshek, J Kim, MR Hübner, DJ Spergel… - genesis, 2002 - Wiley Online Library
DR Shimshek, J Kim, MR Hübner, DJ Spergel, F Buchholz, E Casanova, AF Stewart
genesis, 2002Wiley Online Library
By applying the mammalian codon usage to Cre recombinase, we improved Cre expression,
as determined by immunoblot and functional analysis, in three different mammalian cell
lines. The improved Cre (iCre) gene was also designed to reduce the high CpG content of
the prokaryotic coding sequence, thereby reducing the chances of epigenetic silencing in
mammals. Transgenic iCre expressing mice were obtained with good frequency, and in
these mice loxP‐mediated DNA recombination was observed in all cells expressing iCre …
Abstract
Summary: By applying the mammalian codon usage to Cre recombinase, we improved Cre expression, as determined by immunoblot and functional analysis, in three different mammalian cell lines. The improved Cre (iCre) gene was also designed to reduce the high CpG content of the prokaryotic coding sequence, thereby reducing the chances of epigenetic silencing in mammals. Transgenic iCre expressing mice were obtained with good frequency, and in these mice loxP‐mediated DNA recombination was observed in all cells expressing iCre. Moreover, iCre fused to two estrogen receptor hormone binding domains for temporal control of Cre activity could also be expressed in transgenic mice. However, Cre induction after administration of tamoxifen yielded only low Cre activity. Thus, whereas efficient activation of Cre fusion proteins in the brain needs further improvements, our studies indicate that iCre should facilitate genetic experiments in the mouse. genesis 32:19–26, 2002. © 2002 Wiley‐Liss, Inc.
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