Progress towards integrated physical and genetic maps of chromosome 22
- and others
Our immediate objective is to identify and characterize a set of overlapping YAC clones spanning the long arm of chromosome 22 by STS content mapping of the CEPH YAC libraries. STSs are assigned to bins defined by a 25 interval hybrid mapping panel and the YAC libraries are screened by amplification of hierarchical pools of yeast DNAs. Thus far, 382 probes and STSs have been assigned to bins and 251 probes and STSs have been used to identify a total 659 YACs, which is nearly 5X coverage of the chromosome. We have assembled more than twenty putative contigs using simulated annealing, split and merge, and backtracking optimization algorithms. The largest contig contains 82 STSs linked with 250 YACs, connects bin 12 to 15, and contains approximately one third of the long arm. The proximal region also contains two large contigs in bins 1-2 and bin 9, between them containing 26 STSs and 62 YACs. The DiGeorge (DGCR) region, encompassing bins 3-5, is currently 80% covered in a contig of cosmids. The distal portion (bins 17-22) is the least represented in YACs, due to a paucity of markers and a lower hit-rate of YACs per STS. We are targeting this region with new STSs from inter-Alu PCR plasmid libraries derived from radiation hybrid cell lines that retain relevant portions of the chromosome. A concurrent objective of the center is to construct a robust multi-point linkage map of the chromosome. STRPs (simple tandem repeat polymorphisms) were assembled into a 20-point skeletal map and a 29-point framework map; 15 of the markers in the skeletal map have been unequivocally assigned to single intervals in the hybrid panel with identical linkage and bin orders. This genetic map, combined with markers ordered by pulsed field gel maps covering large portions of the chromosome, provides a robust framework for ordering YACs within contigs and ordering contigs along the chromosome.
- OSTI ID:
- 134381
- Report Number(s):
- CONF-941009--
- Journal Information:
- American Journal of Human Genetics, Journal Name: American Journal of Human Genetics Journal Issue: Suppl.3 Vol. 55; ISSN AJHGAG; ISSN 0002-9297
- Country of Publication:
- United States
- Language:
- English
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