Construction of highly extensive polymorphic DNA libraries by in-gel competitive reassociation procedure.

Differential genomic DNA libraries between two mouse strains and from two human individuals were constructed by means of the in-gel competitive reassociation (IGCR) procedure, a procedure developed for cloning altered anonymous restriction fragments. The libraries were highly enriched in RFLP fragments, approximately 60 and 40% for the mouse and human libraries, respectively, and, more importantly, maintained most of the original complexities of the RFLP fragments. Therefore, differential genomic DNA libraries constructed by the IGCR procedure, particularly for human genomic DNA, should offer highly extensive sources for polymorphic DNA sequences necessary for a variety of genome analyses, including studies on the origin and mechanism of biological diversity among the same species.