4.5 kb of the rat tyrosine hydroxylase 5 ' flanking sequence directs tissue specific expression during development and contains consensus sites for multiple transcription factors
Jj. Schimmel et al., 4.5 kb of the rat tyrosine hydroxylase 5 ' flanking sequence directs tissue specific expression during development and contains consensus sites for multiple transcription factors, MOL BRAIN R, 74(1-2), 1999, pp. 1-14
To delineate DNA sequences responsible for developmentally correct expressi
on of the rat tyrosine hydroxylase (TH) gene, we analyzed a line of transge
nic mice expressing high levels of human placental alkaline phosphatase (AP
) under control of 4.5 kb of 5' flanking DNA from the rat TH gene in embryo
s and adults. Several regions, such as the accessory olfactory bulb, which
were not thought to synthesize TH protein or do so only transiently, were s
hown to express TH protein using an improved method of antigen retrieval fo
r TH immunohistochemistry. Many of these regions had been shown to express
TH-driven reporter genes in transgenic mice. In the central nervous system,
AP was detected in essentially all TH-expressing cell groups throughout de
velopment and in adults. In the peripheral nervous system, transgene expres
sion paralleled endogenous TH expression in the developing adrenal medulla
and sympathetic ganglia but not in transiently TH-positive cells in dorsal
root ganglia. Peripheral expression in the adult adrenal medulla was very w
eak and absent in sympathetic ganglia. The specificity with which the 4.5 k
b region directs transgene expression in embryos is comparable to that obse
rved with longer 5' flanking promoter regions, implying that this region co
ntains the control elements for appropriate expression during development.
Sequence analysis of the region demonstrates a GT dinucleotide repeat, an e
lement that resembles the neural restrictive silencer element (NRSE), which
restricts transcription of neuronal genes in non-neuronal cells, and conse
nsus sites for three families of transcription factors, Ptx1/3, Nurr1 and G
li1/2, which are required for the early differentiation of mesencephalic ne
urons. (C) 1999 Elsevier Science B.V. All rights reserved.