A SET OF INTER-ALU PCR MARKERS FOR CHROMOSOME-21 GENERATED FROM PULSED-FIELD GEL-FRACTIONATED NOTI RESTRICTION FRAGMENTS

Genomic probes can be efficiently obtained for specific chromosomal re gions by PCR amplification of gel slices containing fractionated restr iction enzyme-cleaved DNA. Here, single-copy, human-specific DNA seque nces were amplified using inter-Alu PCR on gel slices containing a Not I digest of DNA from hybrid cell line WAV17. Rodent cell line WAV17 co ntains human chromosome 21. About 75% of the 0.15- to 3-kb inter-Alu P CR products could be regionally assigned, en masse, by hybridization e xperiments using inter-Alu PCR probes generated from cell lines contai ning portions of chromosome 21. This work produced 10 new chromosome 2 1 markers that came from regions of 21q containing few useful markers. These markers were needed to finish a NotI restriction map for 21q (W ang and Smith (1994) Genomics 20: 441). This approach provides markers needed to close map gaps and for top-down mapping approaches. (C) 199 5 Academic Press, Inc.