Four-kilobase sequence of the mouse CNP gene directs spatial and temporal expression of lacZ in transgenic mice

The gene encoding 2′,3′-cyclic nucleotide 3′-phosphodiesterase (CNP) is one of the earliest myelin genes to be expressed in the brain. It is expressed at basal levels in some non-neural tissues but at much higher levels in the nervous system, and its relevance and mechanism are unknown. Using transgenic mice, we examined the expression pattern conferred by a 4-kilobase (-kb) 5′-flanking sequence of the mouse CNP gene coupled to the bacterial lacZ reporter gene. Here we report that this 4-kb fragment contains sufficient information to direct expression of the transgene to the tissue and/or cell type, in which CNP is normally expressed. In the central nervous system (CNS), CNP-lacZ expression was regulated in a temporal manner, consistent with endogenous CNP expression. Transgene expression was detected in embryonic brain and spinal cord in immature oligodendrocytes, and it significantly increased with age. In adult mice, β-galactosidase activity (which appeared to be oligodendrocyte specific) was found essentially in white matter areas of the CNS. Moreover, the transgene was expressed in peripheral nervous system, testis, and thymus—tissues that normally express CNP. Taken together, our results provide strong evidence that cis-acting regulatory elements, necessary to direct spatial and temporal expression of the transgene in oligodendrocytes, are located within the 4-kb 5′-flanking sequence of the mouse CNP gene. This promoter could be a valuable tool to target specific expression of other transgenes to oligodendrocytes, and may provide important new insights into myelination or dysmyelination. J. Neurosci. Res. 53:393–404, 1998. © 1998 Wiley-Liss, Inc.     

The 5'-flanking region of the mouse adenylyl cyclase type VIII gene imparts tissue-specific expression in transgenic mice.

The calcium-stimulated adenylyl cyclases (ACs) play a central role in stimulus-dependent modification of synaptic function. The type VIII AC (AC8) is one of three mammalian calcium-stimulated isoforms, each of which is expressed in a region-specific manner in the CNS. To delineate the DNA sequences responsible for appropriate targeting of AC8 expression, we report here the complete structure of the AC8 gene and define the pattern of expression of the full-length cDNA and its splice variants. In addition to expression within the brain, robust expression of AC8 was also found in the lung. By in situ hybridization, we have found the highest expression of AC8 mRNA within the olfactory bulb, thalamus, habenula, cerebral cortex, and hypothalamic supraoptic and paraventricular nuclei. By generating transgenic mice whose expression of beta-galactosidase is controlled by the AC8 5'-flanking DNA sequences, we demonstrate that the DNA sequences within the 10 kb preceding exon 1 are critical for establishment of this region-specific pattern. This spectrum of sites of production is unique to AC8 among the calcium-stimulated adenylyl cyclases and suggests nonredundant functions with other adenylyl cyclases in neuroendocrine regulation and/or behavior.     

Neuron-specific expression of reporter gene in transgenic mice carrying the 5'-upstream region of mouse P/Q-type Ca2+ channel alpha 1A subunit gene fused to E. coli lacZ reporter gene

To dissect the molecular mechanisms underlying the neuron-specific expression of the P/Q type calcium channel alpha 1A subunit gene, transgenic mice carrying a 0.5-kb, 1.5-kb, 3.0-kb or 6.3-kb 5'-upstream region of the gene fused to Escherichia coli lacZ reporter gene were produced. In transgenic mice carrying the 1.5-kb, 3.0-kb or 6.3-kb 5'-upstream region, the reporter gene was exclusively expressed in the nervous system, although those with the 0.5-kb 5'-upstream region failed to show reporter expression. Histological examinations showed that the three 5'-upstream regions induced distinct expression patterns of the reporter gene in the CNS and adrenal medulla. The 1.5-kb 5'-upstream region drove reporter gene expression in the olfactory bulb, dorsal cortex and hippocampus, while the regulatory element for the expression in the amygdaloid nucleus, septum, habenula medial nucleus, choroid plexus, substantia nigra, inferior colliculus, pontine nucleus and cerebellum was located in the 5'-upstream sequence between 1.5 kb and 6.3 kb. In the cerebellum, the expression of the reporter gene was induced by the 3.0-kb region in granule cells, whereas it was induced by the 6.3-kb region in Purkinje cells. The expression of the reporter gene in chromaffin cells in the adrenal medulla was induced only by the 6.3-kb 5'-upstream region. These results suggest that the expression of the mouse P/Q-type Ca2+ channel alpha 1A subunit gene is regulated in a complex fashion by both positive and negative cis-regulatory elements.     

Early postnatal chronic inflammation produces long-term changes in pain behavior and N-methyl-D-aspartate receptor subtype gene expression in the central nervous system of adult mice

The objective of this study was to test whether postnatal chronic inflammation resulted in altered reactivity to pain later in life when reexposed to the same inflammatory agent and whether this alteration correlated with brain-region-specific patterns of N-methyl-D-aspartate (NMDA) receptor subtype gene expression. Neonatal mouse pups received a single injection of complete Freund's adjuvant (CFA) or saline into the left hind paw on postnatal day 1 or 14. At 12 weeks of age, both neonatal CFA- and saline-treated animals received a unilateral injection of CFA in the left hind paw. Adult behavioral responsiveness of the left paw to a radiant heat source was determined in mice treated neonatally with saline or CFA before and after receiving CFA as adults. Twenty-four hours later, brains were dissected and NMDA receptor subunit gene expression was determined in four different brain areas by using an RNase protection assay. The results indicated that NMDA receptor subtype gene expression in adult mice exposed to persistent neonatal peripheral inflammation was brain region specific and that NMDA gene expression and pain reactivity differed according to the day of neonatal CFA exposure. Similarly, adult behavioral responsiveness to a noxious radiant heat source differed according to the age of neonatal exposure to CFA. The data suggest a possible molecular basis for the hypothesis that chronic persistent inflammation experienced early during development may permanently alter the future behavior and the sensitivity to pain later in life, especially in response to subsequent or recurrent inflammatory events.     

Neuron-specific expression of reporter gene in transgenic mice carrying the 5′-upstream region of mouse P/Q-type Ca channel α1A subunit gene fused to E. coli lacZ reporter gene

To dissect the molecular mechanisms underlying the neuron-specific expression of the P/Q type calcium channel α_1A subunit gene, transgenic mice carrying a 0.5-kb, 1.5-kb, 3.0-kb or 6.3-kb 5′-upstream region of the gene fused to Escherichia coli lacZ reporter gene were produced. In transgenic mice carrying the 1.5-kb, 3.0-kb or 6.3-kb 5′-upstream region, the reporter gene was exclusively expressed in the nervous system, although those with the 0.5-kb 5′-upstream region failed to show reporter expression. Histological examinations showed that the three 5′-upstream regions induced distinct expression patterns of the reporter gene in the CNS and adrenal medulla. The 1.5-kb 5′-upstream region drove reporter gene expression in the olfactory bulb, dorsal cortex and hippocampus, while the regulatory element for the expression in the amygdaloid nucleus, septum, habenula medial nucleus, choroid plexus, substantia nigra, inferior colliculus, pontine nucleus and cerebellum was located in the 5′-upstream sequence between 1.5 kb and 6.3 kb. In the cerebellum, the expression of the reporter gene was induced by the 3.0-kb region in granule cells, whereas it was induced by the 6.3-kb region in Purkinje cells. The expression of the reporter gene in chromaffin cells in the adrenal medulla was induced only by the 6.3-kb 5′-upstream region. These results suggest that the expression of the mouse P/Q-type Ca²⁺ channel α_1A subunit gene is regulated in a complex fashion by both positive and negative cis-regulatory elements.