POLYMORPHIC DNA FRAGMENTS AND USES THEREOF

摘要

The invention provides methods and materials for generating a reference library of restriction fragments from pooled nucleic acids that contain a sequence polymorphism. Preferably, such a library is formed by digesting genomic DNA from a pool of individuals with a first and a second restriction endonuclease to form a population of restriction fragments; isolating restriction fragments of the population digested by both the first and second restriction endonucleases and forming a first single stranded fragment population therefrom; separately isolating restriction fragments from the population digested by the first restriction endonuclease but not the second restriction endonuclease and forming a second single stranded fragment population therefrom; hybridizing the first and second single stranded fragment populations to form a population of duplexes; and isolating the population of duplexes to form a reference library of restriction fragments that contain sequence polymorphism. An important aspect of the invention is the use of the reference population of restriction fragments to compare the frequencies of polymorphic sequences between different population pools. Such comparisons may be accomplished by competively hybridizing DNA from the respective pools which has been enriched for the presence of a restriction site polymorphism with DNA from the reference population. Preferably, such competitive hybridization reactions are carried out the reference library attached to one or more solid phase supports. Most preferably, members of the reference library are attached to individual microparticles so that each microparticle has a unique fragment attached. After competitive hybridization, the microparticles may be analyzed and sorted for identifying those microparticles carrying sequences for which the pools being compared exhibit different polymorphic frequencies.