YAC contig and cell hybrid mapping of six expressed sequences encoded by human chromosome 21
- Univ. of Colorado Health Sciences Center, Denver, CO (United States); and others
The candidate gene approach for positional cloning requires a sufficient number of expressed gene sequences from the chromosomal region of interest. Trisomy for human chromosome 21 results in Down syndrome (DS). However, only a limited number of genes on chromosome 21 have been identified and cloned. We used 1,000 single-copy microclones from a microdissection library of chromosome 21 to screen various cDNA libraries and isolated 9 cDNA clones, of which 6 contain unique sequences: 21E-C1, C3, C4, C5, C7, C10. Using a refined regional mapping panel of chromosome 21 which comprised 24 cell hybrids and divided the chromosome into 33 subregions, we assigned 21E-C1 and C7 to subregion No. 22 (distal q22.1), 21E-C3 to No. 25 (proximal q22.2), 21E-C4 to No. 23 (very distal q22.1), 21E-C5 to No. 31 (proximal q22.3), and 21E-C10 to No. 28 (middle q22.2). In addition, we identified YAC clones corresponding to these cDNA clones using the complete YAC contig spanning the entire chromosome 21q. On the average, 10 positive YAC clones were identified for each cDNA. The mapping positions for the 6 cDNAs determined by the STSs in the YAC contig agree well with the cytogenetic map constructed by the hybrid panel. These cDNA clones with refined mapping positions on chromosome 21 should be useful as candidate genes for the specific component phenotypes of DS assigned to the region.
- OSTI ID:
- 134825
- Report Number(s):
- CONF-941009-; ISSN 0002-9297; TRN: 95:005313-1564
- Journal Information:
- American Journal of Human Genetics, Vol. 55, Issue Suppl.3; Conference: 44. annual meeting of the American Society of Human Genetics, Montreal (Canada), 18-22 Oct 1994; Other Information: PBD: Sep 1994
- Country of Publication:
- United States
- Language:
- English
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