The Edn2 gene encodes a member of the vasoconstrictive peptides and growth-promoting endothelin protein family, and which is predominantly expressed in the intestines, ovary, and uterus. These transgenic mice express iCre recombinase under the control of the mouse endothelin 2 promoter. When crossed with a strain containing loxP site flanked sequence of interest, Cre-mediated recombination results in deletion of the floxed sequence in the cre expressing tissues and in the ovary after gonadotropin stimulation. After treatment with human chorionic gonadotropin (hCG) to induce ovulation, Cre recombinase expression is detected in the ovary 11 and 12 hours after injection. iCre recombinase expression mimics the endogenous Edn2 gene expression pattern. Cre recombinase activity is also detected in developing dermis of the embryo starting at E15.5 and persisting through puberty.
When bred to a reporter strain, the resulting mice exhibited strong Cre recombinase activity in the epidermis, ovary (capsule, stromal cells, corpora lutea, granulosa cells), testicular interstitium, coagulation gland (anterior prostate), preputial gland. Punctate Cre activity is detected in the oviduct epithelium, uterine smooth muscle, olfactory bulb, cerebral and cerebellar neurons, anterior and intermediate pituitary, cornea and retina of the eye, cardiac epicardium, scattered pneumocytes of the respiratory epithelium, salivary glands, liver parenchyma, pancreas, renal cortex corpuscles and tubules, adrenal, intestinal villi and tubular glands, and the detrusor muscle of the bladder. Mice that are homozygous for the transgene are viable and fertile.
