Mice homozygous for this dopamine transporter IRES-cre (DAT^IREScre or DAT-cre) mutant allele are viable and fertile. Cre recombinase activity is observed as early as embryonic day 15, and co-localizes with endogenous gene expression in adult dopaminergic cell groups (substantia nigra (SN) and ventral tegmental area (VTA), as well as in the retrorubral field). Lower Cre recombinase activity is detected in adult olfactory bulb glomeruli, mimicking the known lower Slc6a3 (or DAT) expression in this tissue. Although the pattern and intensity of DAT immunostaining in the SN, VTA and striatum do not differ between wildtype and mutant mice, striatum DAT protein levels are moderately reduced (17%) in heterozygotes and significantly reduced (47%) in homozygotes. This decrease in DAT protein levels in homozygous mutant striatum is associated with significantly increased neuropeptide PDyn (but not D1, D2, or PPE) mRNA levels compared to wildtype. Increases in these mRNA levels are not observed in heterozygotes. When these mice are bred with mice containing a loxP-flanked ("floxed") sequence of interest, cre-mediated recombination will result in deletion of the flanked genome in dopaminergic neurons in the cre-positive, homozygous floxed offspring. These mutant mice may facilitate gene function analysis in dopaminergic neurons in neurological studies of, for example, drug addiction or Parkinson's disease.