Open AccessNuclease sensitivity of the mouse HPRT gene promoter region: differential sensitivity on the active and inactive X chromosomes.
Author(s) -
Thomas P. Yang,
C. Thomas Caskey
Publication year - 1987
Publication title -
molecular and cellular biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.14
H-Index - 327
eISSN - 1067-8824
pISSN - 0270-7306
DOI - 10.1128/mcb.7.8.2994
Subject(s) - hypersensitive site , biology , microbiology and biotechnology , dnase i hypersensitive site , chromatin , deoxyribonuclease i , nuclease , hypoxanthine guanine phosphoribosyltransferase , dna , promoter , gene , plasmid , genetics , gene expression , mutant , base sequence
We investigated the conformation of the X-linked mouse hypoxanthine-guanine phosphoribosyltransferase gene (HPRT) promoter region both in chromatin from the active and inactive X chromosomes with DNase I and in naked supercoiled DNA with S1 nuclease. A direct comparison of the chromatin structures of the active and inactive mouse HPRT promoter regions was performed by simultaneous DNase I treatment of the active and inactive X chromosomes in the nucleus of interspecies hybrid cells from Mus musculus and Mus caroli. Using a restriction fragment length polymorphism to distinguish between the active and inactive HPRT promoters, we found a small but very distinct difference in the DNase I sensitivity of active versus inactive chromatin. We also observed a single DNase I-hypersensitive site in the immediate area of the promoter which was present only on the active X chromosome. Analysis of the promoter region by S1 nuclease digestion of supercoiled plasmid DNA showed an S1-sensitive site which maps adjacent to or within the DNase I-hypersensitive site found in chromatin but upstream of the region minimally required for normal HPRT gene expression.