Physical analysis of the terminal 240 kb of DNA from human chromosome 7q.

DNA from a 240-kb human telomeric yeast artificial chromosome (HTY) clone was analyzed using physical mapping methods. Cosmid subclones of the YAC were fingerprinted using restriction enzyme digestion and human repeat sequence hybridization and then assembled into two contigs that together span 93% of the human insert. Data from restriction mapping and Bal31 exonuclease experiments indicate that, except for the truncation of distal genomic (T2AG3)n sequences, the molecular clone HTY 146 contains a contiguous, 230-kb telomere-terminal fragment from 7qter. Markers derived from this clone will allow telomeric closure of the physical and genetic linkage maps of human chromosome 7q.