PHYSICAL AND TRANSCRIPTIONAL MAPPING OF DXS56-PGK1 1-MB REGION - IDENTIFICATION OF 3 NEW TRANSCRIPTS

Several new techniques for insolation expressed sequences have been re cently described considerably speeding up the identification of unknow n genes. Here we present a transcriptional map of the 1 Mb DXS56-PGK1 region in Xq13.3. Rare cutter restriction site mapping, direct cDNA se lection on membrane discs and probing of Northern blots with total YAC DNA, were the methods explored in order to achieve this goal. In addi tion to three known genes from this region which have been recloned, t wo new cDNA clones corresponding to two new genes were isolated, mappe d and characterized. Moreover one more transcript, highly expressed in placenta, has been detected in the region with a total YAC as a probe . In summary there are at least six genes known to reside in the DXS56 -PGK1 region. As several human disease gene loci (i.e. SCID, CMTX1, WW S, MRX, XDP, ASB) were tightly linked to the markers from the region ( PGK, CA repeats), the three new transcripts may be considered as their potential candidate genes.