Nucleic Acids Research Advance Access originally published online on September 24, 2007
Nucleic Acids Research 2007 35(19):e126; doi:10.1093/nar/gkm559
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Nucleic Acids Research, 2007, Vol. 35, No. 19 e126
© 2007 The Author(s)
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/2.0/uk/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Methods Online |
Cre reconstitution allows for DNA recombination selectively in dual-marker-expressing cells in transgenic mice
1Program in Developmental Biology and Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA, 2Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong and 3Center for AIDS Health Disparities Research, Meharry Medical College, Nashville, TN 37208, USA
*To whom correspondence should be addressed. Tel: +1 615 936 3634; Fax: +1 615 936 5673; Email: guoqiang.gu{at}vanderbilt.edu
Received May 2, 2007. Revised July 8, 2007. Accepted July 9, 2007.
Cre/LoxP-based DNA recombination has been used to introduce desired DNA rearrangements in various organisms, having for example, greatly assisted genetic analyses in mice. For most applications, single gene promoters are used to drive Cre production for conditional gene activation/inactivation or lineage-tracing experiments. Such a manipulation introduces Cre in all cells in which the utilized promoter is active. To overcome the limited selectivity of single promoters for cell-type-specific recombination, we have explored the ‘dual promoter combinatorial control’ of Cre activity, so that Cre activity could be restricted to cells that express dual protein markers. We efficiently reconstituted Cre activity from two modified, inactive Cre fragments. Cre re-association was greatly enhanced by fusing the Cre fragments separately to peptides that can form a tight antiparallel leucine zipper. The co-expressed Cre fusion fragments showed substantial activity in cultured cells. As proof of principle of the utility of this technique in vivo for manipulating genes specifically in dual-marker-positive cells, we expressed each inactive Cre fragments in transgenic mice via individual promoters. Result showed the effective reconstitution of Cre activates LoxP recombination in the co-expressing cells.