Role of nucleotide sequences of loxP spacer region in Cre-mediated recombination

Analysis of spacer regions derived from intramolecular recombination between heterologous loxP sites

“…The resulting recombinant products become to have the bases different from the parental spacers at position 4 0 and 4. Sequence homology within 6 bp cores is required for efficient strand exchange but it does not seem to be strict requisition because the productive recombination events were actually observed between loxP sites with heterologous spacers in a variety of degree [3,[5][6][7].…”

“…The mutant loxP sites with the altered spacer have been extensively studied to elucidate the role of nucleotide sequence of spacer region or to identify the one that undergoes recombination with the same mutant loxP but not other mutant loxP or wild type loxP site (wt loxP) [5,6,8]. These studies have examined intramolecular recombination efficiency between mutant loxPs bearing altered spacers as well as between wt loxP and mutant loxP, without any analyses for spacer sequence left in individual products after recombination.…”

“…The resulting recombinant products become to have the bases different from the parental spacers at position 4 0 and 4. Sequence homology within 6 bp cores is required for efficient strand exchange but it does not seem to be strict requisition because the productive recombination events were actually observed between loxP sites with heterologous spacers in a variety of degree [3,[5][6][7].The mutant loxP sites with the altered spacer have been extensively studied to elucidate the role of nucleotide sequence of spacer region or to identify the one that undergoes recombination with the same mutant loxP but not other mutant loxP or wild type loxP site (wt loxP) [5,6,8]. These studies have examined intramolecular recombination efficiency between mutant loxPs bearing altered spacers as well as between wt loxP and mutant loxP, without any analyses for spacer sequence left in individual products after recombination.…”

Targeted genetic modification of cell lines for recombinant protein production

“…In order to overcome this, two main approaches can be used. Firstly, Cre has been shown to catalyse recombination between a wild-type LoxP site and a mutant site with one or more base changes (Abremski et al 1986;Lee and Saito 1998). However the resulting pair of mutant LoxP sites cannot recombine, preventing immediate removal of the inserted sequence.…”

Recombinatorial Cloning Using Heterologous Lox Sites

“…Recombination between two compatible loxP sites will excise or invert the intervening DNA in the case of an intramolecular reaction or transfer suitably flanked loxP DNA in an intermolecular double cross-over recombination event. The Cre/loxP system does not require accessory factors to carry out recombination in vivo or in vitro, and studies have identified several hetero-specific loxP sequences that exclusively recombine with themselves, but not with wild-type lox (Hoess et al 1986;Sauer 1992;Lee and Saito 1998;Siegel et al 2001). The combination of WT loxP and 511 loxP has been successfully used for a double reciprocal cross-over reaction to transfer a DNA segment or gene to a predetermined target site (Bethke and Sauer 1997;Feng et al 1999;Trinh and Morrison 2000), and this has proved to be an important tool for the in vivo manipulation of eukaryotic genomes, including gene activation and deactivation studies in both mammalian cells and transgenic mice.…”