Abstract
ABSTRACTNovel genetically engineered mouse models using the Cre-loxP or the Flp-FRT systems have generated useful reagents to manipulate the mouse genome in a temporally-regulated and tissue-specific manner. By incorporating a constitutive Cre driver line into a mouse model in which FRT-regulated genes in other cell types are regulated by Flp-FRT recombinase, gene expression can be manipulated simultaneously in separate tissue compartments. This application of dual recombinase technology can be used to dissect the role of stromal cells in tumor development and cancer therapy. Generating mice in which Cre-ERT2 is expressed under Flp-FRT-mediated regulation would enable step-wise manipulation of the mouse genome using dual recombinase technology. Such next-generation mouse models would enable sequential mutagenesis to better model cancer and define genes required for tumor maintenance. Here, we generated novel genetically engineered mice that activate or delete Cre-ERT2 in response to Flp recombinase. To potentially utilize the large number of Cre-loxP-regulated transgenic alleles that have already been targeted into the Rosa26 locus, such as different reporters and mutant genes, we targeted the two novel Cre-ERT2 alleles into the endogenous Col1a1 locus for ubiquitous expression. In the Col1a1FRT-Cre-ER-T2-FRT mice, Flp deletes Cre-ERT2, so that Cre-ERT2 is only expressed in cells that have never expressed Flp. In contrast, in the Col1a1FRT-STOP-FRT-Cre-ER-T2 mice, Flp removes the STOP cassette to allow Cre-ERT2 expression so that Cre-ERT2 is only expressed in cells that previously expressed Flp. These two new novel mouse strains will be complementary to each other and will enable the exploration of complex biological questions in development, normal tissue homeostasis and cancer.
Highlights
Engineered mouse models are ideal for studying complex mammalian biological processes in vivo
Cre-ERT2 was inserted into the endogenous Col1a1 locus to generate Col1a1FRT-Cre-ER-T2-FRT and Col1a1FRT-STOP-FRT-Cre-ER-T2 mice
The primary mouse model is an important tool to study biological processes in vivo; novel mouse strains and mouse models provide an opportunity for scientific advancement
Summary
Engineered mouse models are ideal for studying complex mammalian biological processes in vivo. Cre recombinase expressed from endogenous promoters enables tissue-specific deletion of DNA flanked by loxP sites to alter gene expression. In addition to small cell lung tumors, this method generated lung adenocarcinomas as well as medullary thyroid carcinomas both in mice that developed small cell lung tumors and in mice that did not. This drawback to using viral vectors, in cancer biology, is due to the fact that many cell types can be infected by the adenovirus. The Cre-loxP and, more recently, the Flp-FRT recombinase systems are widely used to generate transgenic mouse models to study a variety of human diseases, including cancer. Multiple recombinase systems can be combined to better temporally and spatially restrict gene mutations in in vivo models
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
