Position‐independent, high‐level, and correct regional expression of the rat aldolase C gene in the central nervous system of transgenic mice

Abstract

Aldolase C is mainly expressed in the central nervous system (CNS). To clarify the regulatory mechanisms for the CNS-specific expression, transgenic mice were created using two constructs of the rat aldolase C gene. A fusion gene comprising the 5' regulatory region of the aldolase C gene was expressed in a CNS-specific manner. However, the expression levels and the cellular localization of the gene varied among transgenic mice. The other construct, including both 5' and 3' regulatory regions of the gene, showed position-independent and high-level expression as well as the correct regional distribution in the CNS. These results indicate that the 13-kb sequence of the rat aldolase C gene contains sufficient information for faithful expression of the gene.Tissue-specific expression of genomic information mainly occurs through transcriptional regulation. In eukaryotes, however, DNA is complexed with histone to form compact chromatin structures and the regulatory mechanism of gene expression is complex. The structures of chromosomes are important not only in the compaction of the chromatin fiber, but also in the utilization of genomic information (Mirkovitch et al., 1984). Therefore, it is a requisite for understanding the regulatory mechanisms of gene expression to elucidate how to open chromatin structure. To solve this problem, a number of genes have been used to create transgenic mice. In transgenic animals, however, those genes were frequently affected by the site of the integration (Palmiter and Brinster,

Genomic sequences of aldolase C (Zebrin II) direct lacZ expression exclusively in non-neuronal cells of transgenic mice

“…The exact cellular location of aldolase C is controversial. Studies of mRNA by Northern blot analysis, in situ hybridization, or transgene expression studies indicate that the gene is transcribed mostly in neurons (8,14,18). On the other hand, earlier studies using isozyme-specific antibodies report its location in gray matter astrocytes and cells of the pia mater (16,19).…”

“…Several tissue-specific methylation sites have been identified in the immediate vicinity of the transcription unit (22). In transgenic mice (18,22) large rat genomic fragments (or fragments with short marker tags inserted) have been shown to direct central nervous system (CNS)-specific expression. Expression outside of the CNS is suppressed.…”

Diverse human aldolase C gene promoter regions are required to direct specific LacZ expression in the hippocampus and Purkinje cells of transgenic mice

“…Aldolase C gene expression has been investigated in both in vivo and in vitro models. The proximal region of the rat promoter, spanning about 115 bp upstream from the major transcriptional start site, is able to direct CAT-reporter gene expression, albeit at low levels, in the brain of transgenic mice [10][11][12]. The upstream region binds Pax-6 transcriptional factor and is involved in the activation of rat aldolase C gene expression in the brain of transgenic mice [13].…”

Visualization of β-Galactosidase by Enzyme and Immunohistochemistry in the Olfactory Bulb of Transgenic Mice Carrying the LacZ Transgene

“…Some of the transgenic mouse lines express ␤ -galactosidase in the OB (Banerjee et al 1992;Smeyne et al 1992;Morita et al 1993;Arai et al 1994;Hoyle et al 1994;Masters et al 1994;Ponte et al 1994;RinconLimas et al 1994;Vanselow et al 1994;Erickson et al 1995;Morgan et al 1996), but in none of these cases was the intracellular distribution of ␤ -galactosidase determined.…”

“…Targeting of bacterial ␤ -galactosidase as a marker for CNS neurons can be achieved by using promoters of neuron-specific genes such as neuron-specific enolase (Forss-Petter et al 1990), ␤ -amyloid precursor protein (Wirak et al 1991), aldolase C (Arai et al 1994), GAP-43 (Vanselow et al 1994), and neurofilament light chain (Charron et al 1995). ␤ -Galactosidase expression can also be restricted to a defined subpopulation of neuronal cells dependent on the specificity of the promoter (Hoyle et al 1994;Huh et al 1994;Min et al 1994;Rincon-Limas et al 1994;Bessis et al 1995;Morgan et al 1996).…”