CONSTRUCTION OF A 1.5-MB BACTERIAL ARTIFICIAL CHROMOSOME CONTIG IN XP11.23, A REGION OF HIGH GENE CONTENT

To generate sequence-ready templates for the gene-rich Xp11.23 region, we have constructed a 1.5-Mb bacterial artificial chromosome (BAC) co ntig spanning the interval between the DNA markers OATL1 and DXS255. T he contig includes 28 BACs, ranging in size from 58 to 285 kb with an average size of 135 kb, which provide 2.5-Fold coverage of the region. The BAC contig was constructed based entirely on the content of 40 DN A markers from a previously established YAC contig and II new markers developed from BAG-end DNA sequences, 4 of which mere required to clos e gaps in the map. There was no evidence of rearrangement, instability , or chimerism in any of the BAG clones. The BAG cloning system appear s to provide robust and total physical coverage of this gene-rich regi on with clones that are suitable for DNA sequencing. (C) 1998 Academic Press.