Th-IRES-CreERT2 Mouse

Tyrosine hydroxylase (TH) gene encodes the rate-limiting enzyme in catecholamine biosynthesis, responsible for converting tyrosine to L-dopa, a critical step in the synthesis of dopamine, norepinephrine, and epinephrine. This gene is predominantly expressed in dopaminergic neurons of the substantia nigra and ventral tegmental area, as well as in adrenal chromaffin cells and sympathetic neurons. Its function is essential for neurotransmission, motor control, and stress responses, with abnormalities linked to Parkinson’s disease (degeneration of dopaminergic neurons), schizophrenia, and mood disorders. In immunohistochemical assays, TH serves as a key marker for identifying catecholaminergic neurons and neuroendocrine tumors (e.g., pheochromocytoma).

The Th-IRES-CreERT2 mice are generated via gene editing to integrate a tamoxifen-inducible CreERT2 recombinase expression cassette into the endogenous mouse Th gene. Without tamoxifen treatment, CreERT2 recombinase primarily localizes to the cytoplasm; nuclear translocation and recombination activity occur only upon tamoxifen stimulation. When Th-IRES-CreERT2 mice are crossed with mice containing loxP sites, tamoxifen induction is expected to drive Cre-mediated recombination between loxP sites in dopaminergic neurons of the nervous system in offspring mice.