Gene assignments

From a review of the literature, 19 genes were newly assigned or reassigned to the short arm of chromosome 1 since the previous chromosome 1 workshop (Table 2). Of note, two genes termed RERE/DNB1 and DNB5 (Deletion in Neuroblastoma) were identified by direct selection using two large-insert clones derived from a translocation/duplication breakpoint at 1p36.1-p36.2 in the neuroblastoma cell line NGP (Amler et al., 2000). These are positional candidate genes for this common form of cancer. Also, Gruber and coworkers mapped two new members of a family of calcium-activated chloride channels, CLCA2 and CLCA3, to 1p22-p31. They previously mapped CLCA1 to this same region (Gruber and Pauli, 1999), suggesting a new gene cluster on 1p. This literature survey is certainly an underestimate of genes that have been mapped to 1p, as most recently identified genes are as yet only documented in the various online databases described above. Two genes were mapped to positions that show discrepancy with previous mapping data. SCYA5 (Nomiyama et al., 1999) was initially mapped to 17q, and PAGA was mapped to chromosome 9. The correct map positions of these genes will be definitively assigned as the human genome sequencing project is completed.

Physical mapping

A BAC contig covering nearly all of 1p35-p36 was reported at this workshop (Chen et al., this workshop), and is now available at http://www.ncc.go.jp/research/1p-genome/. Some contigs were also constructed in the studies of the disease-associated genes; e.g., non-overlapping 500 kb (Ohira et al., 2000) and 5 Mb regions (Spieker et al., 2000) in 1p36 in association with neuroblastoma (Table 3). The Sanger Centre is constructing contigs and sequencing the entire chromosome 1 as discussed above.