B6;129S-Slc6a3^tm4.1(tTA)Xz/J

Stock number: 027178
Product name: DAT-PF-tTA
Research areas: Cell Biology Research, Neurobiology Research, Research Tools

Description

These DAT-PF-tTA mice conditionally express tetracycline responsive transactivator (tTA) in dopamine neurons from the mouse Slc6a3 (DAT) promoter. A “PF” (tetO-tTA) positive feedback cassette is incorporated in the construct to amplify tTA expression. Homozygotes have little or no endogenous SLC6A3/DAT expression and show growth retardation. These mice may be useful for studying gene function in dopaminergic neurons, such as drug addiction, Parkinson's disease and Attention Deficit-Hyperactivity Disorder (ADHD).

Detailed description

These DAT-PF-tTA mice express tetracycline responsive transactivator (tTA) in dopamine neurons from the mouse Slc6a3 (solute carrier family 6 (neurotransmitter transporter, dopamine), member 3; also called DAT) promoter. A downstream “PF” (tetO-tTA) positive feedback amplification cassette enhances tTA expression, but itself has no transcription activity due to an upstream "stop". Homozygotes have little or no endogenous SLC6A3/DAT expression and show growth retardation.

When these tTA mice are crossed with tetO-human α-synuclein A53T mutant animals (see Stock No. 012442), double mutant DA_SYN53 mice develop features of Parkinson’s disease. These animals do not have detectable transgenic α-synuclein protein expression at 1 week after birth, later than endogenous DAT expression (E15–E17), suggesting that the transgene amplification through “PF” may increase gradually. This pattern of expression can help avoid complications in phenotype interpretation due to early developmental effects. At 6 weeks, the DA_SYN53 mice have transgenic α-synuclein expression in more than 95% of dopamine neurons in the midbrain. The DA_SYN53 mice showed profound early-onset mitochondria abnormalities, characterized by macroautophagy marker-positive cytoplasmic inclusions containing mainly mitochondrial remnants, which precede the degeneration of dopamine neurons.

Development

The following were inserted, in order, between the promoter and coding sequences of the mouse Slc6a3 (DAT) gene: tTA-pA-STOP-“PF” [TetO-tTA] cassette-pA-loxP-Neo-loxP. The mutation was created through homologous recombination in Primogenix PRX-129/S6 embryonic stem (ES) cells. Resultant chimeric males were crossed with Meox2-cre germline deleter mice (see Stock No. 003755) to excise the PGK-neomycyin cassette. This strain was maintained on a mixed C57BL/6 and 129S genetic background by the donating laboratory.

Allele

Symbol: Slc6a3^tm4.1(tTA)Xz
Name: targeted mutation 4.1, Xiaoxi Zhuang
MGI accession ID: MGI:5619093
Generation method: Targeted
Attributes: Transactivator
Marker symbol: Slc6a3
Marker name: solute carrier family 6 (neurotransmitter transporter, dopamine), member 3
Chromosome: 13
Strain of origin: 129S6/SvEvTac
Site of expression: Tetracycline responsive transactivator (tTA) is expressed in dopamine neurons.
Molecular note: The following were inserted, in order, between the promoter and coding sequences of the endogenous gene: tTA-pA-STOP-"PF" [TetO-tTA] cassette-pA-loxP-Neo-loxP. The PF (positive feedback) amplification cassette enhances tTA expression following the removal of the STOP. Cre-mediated recombination removed the downstream floxed neo cassette. Transgene expression is eight-fold higher than endogenous alpha-synuclein expression in dopaminergic neurons.