Cyclization recombination enzyme (Cre) is a member of the extensive family of recombinases and recognizes a 34 bp sequence motif from PI bacteriophage referred to as LoxP. The Cre enzyme works to cleanly excise an intervening DNA fragment that is flanked by two LoxP sites. The LoxP sites must be present in the same orientation. The excised segment is later degraded to leave only a single LoxP site copy in the starting target molecule. As Cre was first developed in the late 1980's and heavily used to artificially manipulate gene expression in many systems, there are comprehensive reviews of the Cre/lox system in the literature (1). Additionally, because the Cre/Lox system is very compatible in terms of versatility, it can be applied to a wide variety of cell types, such that there are numerous stable bacterial, plant, and animal stocks containing a Cre gene copy controlled under an assortment of useful promoters - ubiquitous, tissue-specific, inducible promoters, etc. Welsbie’s group at Hopkins employed the Cre antibody in immunohistochemistry and immunofluorescence for their functional genomic screenings to identify retinal ganglion death mediators and help define the key signaling pathways in glaucoma and blindness (2).
Immunohistochemistry: Cre Antibody
Magenheim, et al. used the Cre antibody in their stem cell studies on pancreas development specifically focusing on the endocrine and exocrine cell compartments (3). Their group identified a novel regulatory pathway, as well as revealed a Notch-dependent coordination between endocrine and ductal progenitor cell groups. To develop a novel, pan-neuronal Cre-transgenic line, researchers relied upon the Cre antibody to allow the controlled and conditional deletion of specific target genes in neurons, CNS, and their progenitors (4). This fine-tuned gene ablation allowed them to generate a valuable transgenic line. Cre antibody was used to characterize myeloid-cell specific hypoxia inducible factor (HIF) knockout mice key to studies assessing the utility of HIF as a therapeutic target for chronic liver fibrosis and disease (5). Novus Biologicals offers several Cre antibodies for your research needs.
