Fa-Ten Kao and Jingwei Yu
Eleanor Roosevelt Institute for Cancer Research, 1899 Gaylord Street, Denver, C0 80206, and Department of Biochemistry, Biophysics and Genetice, University of Colorado Health Sciences Center, Denver, CO
Since we developed the chromosome microdissection and MboI-linker adaptor microcloning techniques,[1] we have constructed and characterized 11 region-specific libraries for the entire human chromosome 2: 4 libraries for the short arm and 6 libraries for the long arm, plus a library for the centromere region.[2-8] Each library comprises hundreds of thousands of MboI-cleaved sequences, with a mean size of 200-250 bp. About half of the plasmid microclones contain unique sequences, and between 70 to 90% of the microclones were derived from the dissected region. In addition, we have isolated and characterized many unique sequence microclones from each library that can be readily sequenced as STSs, or in isolating other clones with large inserts for contig assembly. These libraries have been used successfully for high resolution physical and linkage mapping, and for positional cloning of disease-related genes assigned to these regions, e.g. the cloning of the gene for hereditary nonpolypsis colorectal cancer.[9,10] For each library, we have established a plasmid sub-library of at least 20,000 independent microclones. These sub-libraries have been deposited to the American Type Culture Collection (ATCC) for general distribution.
Comparing to human chromosomes like 3, 4, 5, 7, 11, 12, 13, 16, 19, 21, 22 and X, chr. 2 is one of the human chromosomes that are largely under-studied, with insufficient probes and mapping details. In order to accelerate whole genome sequencing and positional cloning particularly in under-exploited chromosomes, we are constructing additional region-specific libraries for these chromosome regions, including 40 libraries in 10 chromosomes: 3 libraries for chr. 20, 3 for chr. 18, 3 for chr. 17, 3 for chr. 15, 3 for chr. 14, 4 for chr. 10, 4 for chr. 9, 4 for chr. 8, 5 for chr. 6, and 8 for chr. 1. Progress has already been made in constructing libraries for chromosomes 17, 18 and 20. A complete set of region-specific libraries for the under-studied parts of the human genome should furnish valuable resources for the genome community. These libraries can be used to isolate more densely populated probes for high resolution physical mapping and contig assembly, and also for isolating region-specific cDNA clones as candidate genes in positional cloning.[11,12] Moreover, the microclones with short inserts are particularly suited for large scale sequencing projects in these under-mapped regions.
*Supported by a grant from DOE (DE-FG03-94ER41819).
[1] F.T.Kao and J.W.Yu, Proc. Natl. Acad. Sci. USA 88,1844-1848 (1991).
[2] J.Yu, et al., Genomics 14, 769-774 (1992).
[3] J.Yu, et al., Somat. Cell Mol. Genet. 20, 133-136 (1994).
[4] J.Yu, et al., Hum. Genet. 93, 557-562 (1994).
[5] J.Yu, et al., Somat. Cell Mol. Genet. 20, 353-357 (1994).
[6] F.T.Kao, et al., Cytogenet. Cell Genet. 68, 17-18 (1995).
[7] J.Yu, et al., Somat. Cell Mol. Genet. 21, 133-137 (1995).
[8] F.T.Kao, et al., submitted
[9] F.S.Leach, et al., Cell 75, 1215-1225 (1993).
[10] F.S.Leach, et al., Hum. Mol. Genet. 3, 2082 (1994).
[11] J.Yu, et al., Am. J. Hum. Genet. 51, 263-272 (1992).
[12] F.T.Kao, et al., Genomics 23, 700-703 (1994).