ISSN:
1617-4623
Keywords:
Key words DNA loop domains
;
Human hprt gene
;
Topoisomerase II
;
Nuclear matrix
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract We have mapped the positions in a ∼1.4-Mb region of genomic DNA around the human hprt gene which are accessible in vivo to cleavage by topoisomerase II associated with the nuclear matrix. These positions, which are interpreted as the boundaries of DNA loop domains, were mapped in K562 cells by examining the truncation of rare-cutter restriction fragments separated by pulsed field gel electrophoresis after topoisomerase II-mediated cleavage, using seven linked markers mapped in this region as probes for indirect end-labeling. Eleven cleavage positions were detected and were interpreted as defining ten loop domains of lengths between 70 and 210 kb (average ∼135 kb); the hprt gene resides in a 150-kb loop domain. Loop domain boundaries coincided with three of the fifteen deletion breakpoints mapped in a 600-kb sector of this region in human lymphocytes, within the limits of resolution of pulsed field gel electrophoresis; this correlation was not statistically significant.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s004380050911
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