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, beta-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.
Department of Biochemistry, McGill University, Montreal, Quebec, Canada.
M
M
Gravel
A
A
Di Polo
P B
PB
Valera
P E
PE
Braun
D000375:Aging; D000818:Animals; D001921:Brain / Q000196:embryology / Q000254:growth & development / Q000378:metabolism*; D005314:Embryonic and Fetal Development; D005091:Exons; D015971:Gene Expression Regulation, Enzymologic; D017930:Genes, Reporter; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D020098:Natriuretic Peptide, C-Type / Q000096:biosynthesis / Q000235:genetics*; D009836:Oligodendroglia / Q000378:metabolism; D009928:Organ Specificity; D011993:Recombinant Fusion Proteins; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013116:Spinal Cord / Q000196:embryology / Q000254:growth & development / Q000378:metabolism*; D001616:beta-Galactosidase / Q000096:biosynthesis / Q000235:genetics
D011993:Recombinant Fusion Proteins; D020098:Natriuretic Peptide, C-Type; D001616:beta-Galactosidase