A tyrosine hydroxylase-yellow fluorescent protein knock-in reporter system labeling dopaminergic neurons reveals potential regulatory role for the first intron of the rodent tyrosine hydroxylase gene.

Published

Journal Article

Degeneration of the dopaminergic neurons of the substantia nigra is a hallmark of Parkinson's disease. To facilitate the study of the differentiation and maintenance of this population of dopaminergic neurons both in vivo and in vitro, we generated a knock-in reporter line in which the yellow fluorescent protein (YFP) replaced the first exon and the first intron of the tyrosine hydroxylase (TH) gene in one allele by homologous recombination. Expression of YFP under the direct control of the entire endogenous 5' upstream region of the TH gene was predicted to closely match expression of TH from the wild type allele, thus marking functional dopaminergic neurons. We found that YFP was expressed in dopaminergic neurons differentiated in vitro from the knock-in mouse embryonic stem cell line and in dopaminergic brain regions in knock-in mice. Surprisingly, however, YFP expression did not overlap completely with TH expression, and the degree of overlap varied in different TH-expressing brain regions. Thus, the reporter gene did not identify functional TH-expressing cells with complete accuracy. A DNaseI hypersensitivity assay revealed a cluster of hypersensitivity sites in the first intron of the TH gene, which was deleted by insertion of the reporter gene, suggesting that this region may contain cis-acting regulatory sequences. Our results suggest that the first intron of the rodent TH gene may be important for accurate expression of TH.

Full Text

Duke Authors

Cited Authors

  • Kelly, BB; Hedlund, E; Kim, C; Ishiguro, H; Isacson, O; Chikaraishi, DM; Kim, K-S; Feng, G

Published Date

  • October 2006

Published In

Volume / Issue

  • 142 / 2

Start / End Page

  • 343 - 354

PubMed ID

  • 16876957

Pubmed Central ID

  • 16876957

Electronic International Standard Serial Number (EISSN)

  • 1873-7544

International Standard Serial Number (ISSN)

  • 0306-4522

Digital Object Identifier (DOI)

  • 10.1016/j.neuroscience.2006.06.032

Language

  • eng