Irradiation hybrids for human chromosome 11: characterization and use for generating region-specific markers in 11q14-q23.

High-dose irradiation hybrids containing fragments of chromosome 11 have been generated, with a view to isolating new region-specific markers. Forty-seven lines were scored for 34 markers: average retention was 6%. Fourteen lines contain markers from 11q14 to 11q23. One of these, Jo12, has 11q markers extending from tyrosinase (q14-q21) to PBGD (q23.3) plus one marker (TYRL, p11.2) from 11p. In situ hybridization using Alu PCR products from Jo12 as probe confirmed that the human DNA is derived from two regions, one in proximal 11p and a second, larger region in 11q23. Plasmid libraries of Alu PCR products from this and three other hybrids have been made. Six of eight recombinants identified as having single-copy inserts were mapped back to the regions of 11q22-q23 detected in the originating hybrid; only one mapped to a region not originally detected, and one was of hamster origin. These six clones provide new markers in 11q22-q23 that can be used directly for polymorphism studies. This series of hybrids is therefore a valuable resource for the rapid generation of markers from specific, defined regions of chromosome 11.