Isolation and chromosomal localization of unique DNA sequences from a human genomic library.

Abstract

Recombinant bacteriophage .lambda. from a human genomic library were screened to identify human DNA inserts having only unique sequences. Unique human inserts were found in .apprx. 1% of the phase screened. One recombinant phage, P3-2, was studied in detail. It contains a human insert of 14.7 kilobases with 4 internal ECoRI cleavage sites. A restriction map was constructed for EcoRI and BamHI sites. Hybridization of the 32P-labeled P3-2 probe to a Southern blot to EcoRI-digested total human DNA yielded distinct bands at positions corresponding to the human insert fragments contained in P3-2. By using a series of human-Chinese hamster somatic cell hybrids containing unique combinations of human chromosomes, the human DNA segment in phage P3-2 was assigned to human chromosome 22 by blot hybridization and synteny analysis. Another human DNA segment, 11.4 kilobases, in phase P3-10 was assigned to human chromosome 10 by similar procedures. With this approach, more unique DNA sequences can be isolated, assigned to specific human chromosomes and used as genetic markers for gene mapping and linkage, polymorphism and other genetic studies in the human genome.