Sequence organization of the human chromosome 2q telomere

The terminal 240 kb of a human 2q telomere region was clonedin two overlapping yeast artificial-chromosomes (YACs). ThisDNA contains a region of low-copy subtelomeric repeats (within50 kb of the 2q telomere), a segment of DNA duplicated on distal8p23 (100 kb from the 2q telomere), and a region of single-copyDNA (230 kb from the 2q telomere). Two CpG islands are presentin the DNA segment duplicated on distal 8p23. RecA-assistedrestriction endonuclease cleavage of genomic DNA samples revealeda potential 55 kb chromosome length polymorphism at the 2q telomere.This work provides telomeric closure of maps for human chromosome2q, demonstrates a novel, subtelomere-specific DNA duplication,and will permit detailed molecular and cytological studies ofthis human telomere region.