Fig. 1.

A single vector for dual-color marking of chromosomes. View of the linearized pCX-YNC vector showing the three independent expression cassettes for EYFP, neo, and ECFP. The EYFP and neo cassettes are flanked by loxP sites, and the ECFP cassette is flanked by FRT sites. CRE- and FLPe-mediated recombination generates single-color ECFP or EYFP expression as shown. The bacterial origin of replication (ori) and ampicillin resistance gene (amp) can be used for plasmid rescue of adjacent mouse genomic DNA. (S, SalI; B, BamHI).