SEEDING OF YACS OVER REGIONS 1Q41-Q42.3 AND 11Q14.3-Q23 WITH MICRODISSECTION CLONES

We describe the use of pooled, region-specific hybridisation probes to screen high-density replica filters of a human genome YAC library. Th e probes were derived by microdissection of an approximately 30-Mbp re gion subtending the translocation breakpoint on a der(1)(1;11)(q42.1;q 14.3) chromosome. Of 70 microdissection clones used in pools of 4-10, 47 identified a total of 77 YAC recombinants, representing over 50% of the microdissected region, This strategy can easily be adapted to oth er poorly mapped subchromosomal regions of the human or other mammalia n genomes and will provide a solid framework for detailed contig map c onstructions.