pJW168 Vector

In vivo genetics using Cre/lox

Lucigen's pJW168 Vector (Figure 1) is extremely useful for in vivo insertion/removal of a DNA sequence through cre-lox site-specific recombination (1). The vector contains the cre recombinase gene under the control of the IPTG-inducible lacUV5 promoter, as well as restriction sites for cloning.

The pJW168 vector can be eliminated by growing cells at 42°C. Its replication is based on the temperature-sensitive replicon from pSC101. This vector avoids the need for purified, expensive Cre or Flp recombinase enzymes for in vitro recombination. pJW168 also offers advantages over other in vivo insertion/removal systems, such as Flp/FRT-mediated recombination, as E. coli is a natural host for the Cre/loxP system of phage P1. Cre/loxP also has a smaller target (34 bp) than the resolvases/res sites (120-140 bp). With this system, DNA fragments are integrated and can be completely removed from the bacterial chromosome (2-4). Following recombination, growth of transformed bacterial cultures at 42°C efficiently eliminates pJW168, and the production of cre recombinase ceases.