STOCK Wap^tm2(rtTA)Kuw/J

Stock number: 016116
Research areas: Cell Biology Research, Research Tools

Description

These mice contain a reverse tetracycline-controlled transactivator (rtTA) protein in the 5' untranslated region of the whey acidic protein gene. Theses Wap-rtTA mice are useful in regulating the expression of proteins (including oncoproteins) in mammary epithelium.

Detailed description

These mice contain a reverse tetracycline-controlled transactivator (rtTA) protein in the 5' untranslated region of the whey acidic protein (Wap) gene. Homozygous mice are viable, fertile, and normal in size. WAP, expressed late during pregnancy and during lactation in the mammary gland, is the principal whey protein found in rodent milk. When mated to a mutant strain carrying a gene of interest under the regulatory control of a tetracycline-responsive promoter element (TetO), the Wap-rtTA allele mediates expression of TetO-responder genes in the developing mammary gland upon administration of doxycycline (dox). Since expression of the endogenous WAP locus is elevated during pregnancy and lactation, the expression of TetO responder genes is particularly high during these stages of mammary gland development. The Wap-rtTA mice are useful to express exogenous proteins including teto-regulated oncogenes in the mammary epithelium.

Development

A targeting vector was designed to place a reverse tetracycline-controlled transactivator (rtTA) protein, followed by a loxP-flanked neomycin resistance (neo) cassette, in the 5' untranslated region of the whey acidic protein (Wap) gene. The construct was electroporated into 129X1/SvJ-derived RW-4 embryonic stem (ES) cells. Correctly targeted ES cells were injected into C57BL6NCrl blastocysts and the resulting chimeric males were bred to C57BL6NCrl females. Offspring were then crossed to STOCK-Tg(MMTV-Cre)1Mam/J transgenic mice (Stock No. 003551) to remove the neo cassette. The resulting double positive females were then bred to wildtype males to remove the Cre transgene. These mice were maintained on a mixed background. Upon arrival at The Jackson Laboratory, mice were bred to C57BL/6NJ (Stock No. 005304) for at least one generation to establish the colony.

Allele

Symbol: Wap^tm2(rtTA)Kuw
Name: targeted mutation 2, Kay Uwe Wagner
MGI accession ID: MGI:3799057
Generation method: Targeted
Attributes: Transactivator
Marker symbol: Wap
Marker name: whey acidic protein
Chromosome: 11
Strain of origin: 129X1/SvJ
Expressed genes: rtTA,reverse tetracycline-controlled transactivator,E. coli
Molecular note: The coding sequence for rtTA was inserted into the 5'-UTR along with a floxed neomycin selection cassette. The neo selection cassette was eliminated in founder line 7A3 by crossing properly targeted mice to Tg(MMTV-cre)1Mam transgenic animals. When mice were given doxycycline, transgene expression was restricted to mammary epithelial cells as determined by crosses with two different rtTA reporter strains.