IDENTICAL-BY-DESCENT FRAGMENT ENRICHMENT

摘要

Methods of identifying DNA fragments comprising DNA that is identical by descent for two individuals are disclosed. The methods comprise obtaining a sample of genomic DNA from each of two individuals; contacting the samples o f genomic DNA with a restriction endonuclease; methylating one of the DNA samples; mixing the methylated DNA sample and the unmethylated DNA sample, a nd incubating the DNA sample mixture under denaturing conditions; further incubating the DNA sample mixture under conditions which allow re-annealing of the DNA samples to form a mixture comprising homohybrid DNA fragments and heterohybrid DNA fragments; contacting the mixture with restriction endonuclease(s) which digest homohybrid DNA fragments; contacting the mixtur e with an endonuclease(s) which cleaves both strands of a mismatch-containing heterohybrid DNA fragment, to form a DNA sample mixture comprising perfectly - matched heterohybrid DNA fragments which are enriched in DNA fragments that are identical by descent for the two individuals.