A HIGH-RESOLUTION PAC AND BAC MAP OF THE SCA2 REGION

The spinocerebellar ataxia type 2 (SCA2) gene has been localized to ch romosome 12q24.1. To characterize this region and to aid in the identi fication of the SCA2 gene, we have constructed a 3.9-Mb physical map, which covers markers D12S1328 and D12S1329 known to flank the gene, Th e map comprises a contig of 84 overlapping yeast artificial chromosome s (YACs), P1 artificial chromosomes (PACs), and bacterial artificial c hromosomes (BACs) onto which we placed 82 PCR markers, We localized ei ght genes and expressed sequence tags on this map, many of which had n ot been precisely mapped before, In contrast to YACs, which showed a h igh degree of chimerism and deletions in this region, PACs and BACs we re stable, Only 1 in 65 PACs contained a small deletion, and 2 in 18 B ACs were chimeric, The high-resolution physical map, which was used in the identification of the SCA2 gene, will be useful for the positiona l cloning of ether disease genes mapped to this region. (C) 1997 Acade mic Press.