Scheme of the GAP6 closing between two flanking clones on chromosome 19 by TAR cloning. Radial TAR cloning with a TAR vector containing a unique targeting sequence and an Alu repeat was used to close the gap between contigs AC020922 and AC008735.7. Yeast spheroplasts were transformed with genomic DNA containing human chromosome 19 along with a linearized TAR cloning vector (see Methods). Recombination between the sequences in the vector and genomic fragment containing the GAP6 sequence led to the establishment of circular YACs that extend from the unique sequence to various Alu positions. In the present scheme, only YACs that are positive by diagnostic primers for both contigs (DG1 and DG2) are shown. Orientation of contigs towards centromere and telomere are indicated.
