[Some YAC contig construction and long range physical mapping at human X chromosome Xp11.3-21.3].

Human X chromosome short arm Xp11.3-p21.3 is an area, where several genetic disease gene loci are located. In this work, the YAC conting construction, long range physical mapping were done for this region. Some DNA probes and STS markers were used for YAC screening. Totally 77 YACs were obtained from the YAC libraries of CEPH, ICRF and ours. The size determination, 26 pairs of microsatelite STS analysis, single copy probe hybridization, Alu-PCR finger printing and long range physical mapping were conducted with these YACs. These results allowed us to map these YACs, and finally 6 YAC contigs were obtained in Xp11.3-21.3, covering about 15.3 Mb. This work will greatly facilitate the positional cloning of disease genes or the genome sequencing in this important region.