Integration of cytogenetic landmarks into the draft sequence of the human genome

We have placed 7,600 cytogenetically defined landmarks on the draft sequenc e of the human genome to help with the characterization of genes altered by gross chromosomal aberrations that cause human disease. The landmarks are large-insert clones mapped to chromosome bands by fluorescence in situ hybr idization. Each clone contains a sequence tag that is positioned on the gen omic sequence. This genome-wide set of sequence-anchored clones allows stru ctural and functional analyses of the genome. This resource represents the first comprehensive integration of cytogenetic, radiation hybrid, linkage a nd sequence maps of the human genome; provides an independent validation of the sequence map(1,2) and framework for contig order and orientation; surv eys the genome for large-scale duplications, which are likely to require sp ecial attention during sequence assembly; and allows a stringent assessment of sequence differences between the dark and light bands of chromosomes. I t also provides insight into large-scale chromatin structure and the evolut ion of chromosomes and gene families and will accelerate our understanding of the molecular bases of human disease and cancer.