Several collections of mutated mouse embryonic stem cell lines are available.
The objective of the joint IRBM-TIGEM TRAP-FLIP project is to demonstrate the feasibility of constructing a library of ES cell clones in which each expressed gene is tagged with cassette exchange sites.
Our system is based on a novel types of gene trap vectors containing two heterospecific FRT sites, and on exchange vectors designed to exchange the trapped cassette with any gene of interest.
The availability of a tagged genome makes possible the insertion, in a controlled manner at each locus of interest, of multiple alternative trangenes that will be expressed with the same pattern of the endogenous gene.
We believe that this method may facilitate large-scale genomic studies of ES developmental biology or large-scale generation of mouse models of human disease.
Our sequence tags can be downloaded from NCBI dbGSS.