B6;129S4-Npy^tm2Rpa/J

Stock number: 007585
Research areas: Neurobiology Research

Description

Mice homozygous for this tetracycline regulatory cassette knockin into the neuropeptide Y gene show a 3-fold increase over constitutive levels of expression. Treatment of mice with doxycycline blunts transcription and mRNA and protein levels fall to approximately 20% of wild-type levels. Overexpression of the gene decreased sensitivity to kainate-induced seizures but treatment with doxycycline increased sensitivity.

Detailed description

Mice homozygous for this tetracycline regulatory cassette knockin are viable and fertile and do not display any gross physical or behavioral abnormalities. The mice overexpress the gene 3-fold in all brain cells where it is normally expressed. Treatment of mice with doxycycline blunts transcription and mRNA and protein levels fall to approximately 20% of wild-type levels. It takes approximately a week for protein levels to subsequently fall to wild-type levels, and six weeks to fall to 20% that of wild-type mice. Treatment of adults with doxycycline has little effect on body weight or feeding. Overexpression of the gene decreased sensitivity to kainate-induced seizures but treatment with doxycycline increased sensitivity.

Development

A targeting vector was designed to introduce a doxycycline (Dox)-regulated cassette into exon 1, such that the gene is expressed until the mice are given Dox to block transcription. The cassette included a TK-Neo and Ura3 gene, flanked by a pair of loxP sites in addition to a tetracycline-controlled transcriptional activator (tTA) cassette. The vector was introduced to 129S4/SvJaeSor-derived AK18.1 embryonic stem (ES) cells. Mice carrying the mutation were bred with Mox2-Cre to delete the TK-Neo and Ura3 genes, and subsequently bred to remove Cre from the background. This line has been maintained on a mixed 129S4 and C57BL/6 background by the donating laboratory.

Allele

Symbol: Npy^tm2Rpa
Name: targeted mutation 2, Richard D Palmiter
MGI accession ID: MGI:3527174
Generation method: Targeted
Marker symbol: Npy
Marker name: neuropeptide Y
Chromosome: 6
Strain of origin: 129S4/SvJaeSor
Expressed genes: tTA,tetracycline-controlled transactivator,E. coli
Molecular note: Tetracycline activator and tet promoter targeted to first exon such that expression can be turned off with doxycycline. The TK-Neo and Ura3 genes from the tetracycline cassette were removed by breeding with Mox2-cre mice. In the absence of doxycyline, there is approximately 4-fold more mRNA and increased protein expression in the brain. Doxycycline treatment for 10 days reduces protein expression by about 50%.