These transgenic mice express Cre recombinase under the control of the rat growth hormone gene, Gh1. Mice homozygous for the transgenic insert are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities. Cre recombinase gene product (mRNA) is detected in the pituitary and, at lower levels, in the testis by RT-PCR of tissues from 8-10 week old mice. Cre recombinase expression is also detected by RT-PCR analysis of cephalic extracts from hemizygous embryos aged embryonic day 17. Recombination is detected in the anterior pituitary gland, in the somatotrope cells and a subset of the lactotrope cells. Cre recombinase expression is not detected in the ovary, hypothalamus, cortex, cerebelum, heart, lung, liver, spleen, kidney, adrenal, pancreas, stomach, adipose or uterus.
