THE FIRST INTRON OF THE MYELIN PROTEOLIPID PROTEIN GENE CONFERS CELL-TYPE-SPECIFIC EXPRESSION BY A TRANSCRIPTIONAL REPRESSION MECHANISM IN NON-EXPRESSING CELL-TYPES

Chimeric genes containing portions of the mouse myelin proteolipid pro tein (PLP) gene fused to the lacZ reporter gene were used to detect th e effect of PLP intron 1 sequences on cell type-specific expression. A transfected fusion gene containing PLP intron 1 sequences was express ed in an oligodendrocyte cell line but not in a liver cell line, consi stent with endogenous PLP gene expression. However, an analogous fusio n gene missing the first intron was expressed in either oligodendrocyt e or liver transfected cells. These studies suggest that transcription al repressor element(s) located in PLP intron 1 are important in extin guishing expression in non-glial cell types and that the promoter alon e functions in an indiscriminate manner. This moderately large intron (> 8 kb) was sequenced to aid in future fine mapping of these cell-spe cific regulatory element(s). (C) 1997 Elsevier Science B.V.