Transgenic zebrafish that express tyrosine hydroxylase promoter in inner retinal cells

Abstract

We have generated a transgenic zebrafish line [Tg(Th:GFP)] that expresses green fluorescence proteins (GFP) driven by rat tyrosine hydroxylase (TH) promoter. In zebrafish, the transgene was expressed as early as 16 hr postfertilization (hpf). The first transgene expression was detected in the midbrain. Within a few hours of development, the expression spread to the forebrain and hindbrain. In the retina, the first transgene expression was detected at approximately 40 hpf, at which time a single GFP-positive cell was seen in the ventral-nasal patch of the retina. In late development, GFP spread across the inner retina. GFP was found in retinal cells that expressed TH or phenylethanolamine N-methyl-transferase (PNMT), the first and last enzymes for synthesis of catecholamine, respectively. This suggests that the transgene is expressed in catecholaminergic neurons. Of interest, GFP was also detected in some retinal cells that release ␥-aminobutyric acid. These latter data suggest that the transgene may also be expressed in noncatecholaminergic cells. Developmental Dynamics 233:921-929, 2005.

Cloning and spatial and temporal expression of the zebrafish dopamine D1 receptor

“…Topographically, the patterns of drd1 expression are similar to the expression of dopamine transporters (Holzschuh et al, 2001), tyrosine hydroxylase (Guo et al, 1999(Guo et al, , 2000Holzschuh et al, 2001;Gao et al, 2005), and dopamine D2 receptors (Boehmler et al, 2004). However, the onset time of drd1 expression appeared to be delayed several hours compared with the expression of other dopaminergic system-specific genes.…”

“…Recently, the zebrafish (Danio rerio) has emerged as a model vertebrate for molecular and genetic studies of the dopaminergic system (Guo et al, 1999(Guo et al, , 2000Holzschuh et al, 2001;Ma and Lopez, 2003;Boehmler et al, 2004;Gao et al, 2005). By screening the F3 generation of chemically mutagenized zebrafish, for example, Guo et al (1999Guo et al ( , 2000 isolated a large number of gene mutations that disrupt the development or function of the dopaminergic system.…”

Green Fluorescent Protein Labeling of Dopaminergic Neurons in Zebrafish for the Study of Parkinson’s Diseases

“…In addition, we detected cells immunoreactive only for TH antibody mainly in adult brains, suggesting that our transgene is expressed, in other catecholaminergic cells not only in dopaminergic neurons. This fact is commonly seen in previous transgenic lines where the transgene is under regulation of regulatory elements from the tyrosine hydroxylase (th) gene [15,16]. D).…”

“…In zebrafish, the tyrosine hydroxylase promoter (from both rat and zebra fish) has been used to produce transgenic lines. However, these promoters have driven expression in retinal DA neurons [15,16]. We isolated an endogenous zebra fish th1 gene promoter to generate a transgenic zebra fish that expresses EGFP only in the brain.…”

“…Specifically, the first lines were generated with constructs containing TH promoter that could only drive GFP expression in retinal cells [15,16]. Despite the diverse role of DA cells in retinal functions, the understanding of DA cell function has been limited because they have a low density in the retina and cannot be identified in living retina by morphological characteristics.…”