Construction and characterization of region-specific microdissection libraries and single-copy microclones for short arm of human chromosome 2.

The short arm of human chromosome 2, comprising approximately 93 million bp, has been divided into four regions to construct region-specific microdissection libraries to facilitate physical mapping and gene cloning. These four regions include 2p23-p25 (designated 2P1), 2p21-p23 (2P2), 2p14-p16 (2P3), and 2p11-p13 (2P4). Together with three previously constructed microdissection libraries of 2P1, 2P2 and 2P4, a fourth library for the region 2p14-p16 (2P3) has been constructed and characterized to complete all four region-specific libraries for the entire 2p. The 2P3 library is very large, potentially comprising 1,000,000 recombinant microclones with insert sizes ranging between 50 and 800 bp and a mean of 250 bp. Approximately 40% of the microclones contain unique sequences. Of the 77 single-copy microclones analyzed, 66 clones (86%) hybridized to both human and chromosome 2 DNAs, indicating that they were derived from human and are chromosome 2 specific. The hybridizing HindIII genomic fragments for the 66 microclones have also been determined.