Tg(MMTV-Prlr)3Eder

Mice with this transgene express the F3-short form of the rat prolactin receptor (F3-SPRLR) in mammary epithelium under control of the mouse mammary tumor virus (MMTV) enhancer/promoter. A 1.4-kb cDNA encoding the F3-SPRLR with a N-terminal FLAG tag was inserted into an expression vector containing the MMTV long terminal repeat (LTR) followed by the second exon, second intron, third exon and 3' untranslated sequence of the rabbit beta-globin gene; insertion occurred at the EcoRI site in the third exon. Northern blot analysis shows the transgene-encoded transcript to be present at high levels in the mammary glands of virgin, pregnant and postpartum transgenic female mice; it is also detected at low levels in epididymis, salivary gland and lungs and at very low levels in liver, seminal vesicle, ovary and uterus. In mid-gestation mammary glands, the level of transgene-derived mRNA is much greater than that of endogenous LPRLR. Western blot analysis using antibodies to the FLAG epitope tag demonstrates the presence of very high levels of the protein in 2-d postpartum mammary gland, but little or none in liver or uterus of transgenic mice of this line. (J:83682)