Physical mapping of the human hprt chromosomal region (Xq26).

The human hprt chromosomal region (Xq26) was physical-mapped using pulsed field gel electrophoresis (PFGE). This work involved: (i) the recovery of three new genomic DNA markers (DXS1327, DXS1328, and DXS1329), (ii) the ordering of new markers relative to 11 previously available hprt-linked markers by deletion mapping, and (iii) the completion of human T-lymphocyte PFGE Southern blots using the 14 Xq26 markers. A contiguous 1.5-Mb physical map of the region telomeric to hprt was determined. As this map identifies clusters of in vivo unmethylated rare-cutter restriction sites, potential CpG islands are revealed.