Construction of a 5.2-megabase physical map of the human X chromosome at Xq22 using pulsed-field gel electrophoresis and yeast artificial chromosomes.
Vetrie D., Bobrow M., Harris A.
Several genes involved in human genetic diseases map to the Xq22 band on the long arm of the human X chromosome. We have constructed a long-range restriction map of the most proximal part of Xq22. Initially, pulsed-field gel electrophoresis, in combination with rare-cutting restriction enzymes, was used to try and establish physical linkage of 11 polymorphic and nonpolymorphic DNA markers. This approach resulted in the construction of three long-range restriction maps around groups of physically linked Xq22 markers that spanned over 5.0 Mb of DNA. Yeast artificial chromosome clones were used to organize the three long-range maps onto a contiguous 5.2-Mb stretch of Xq22. The order of markers in this region was shown to be cen-GLA-DXS178-DXS101-DXS83-DXS24-DXS101-+ ++DXS54-PLP-DXS94-DXS147-DXS17-DXS87-tel . The results of this study suggest that the proximal part of Xq22 may be rich in genes. Construction of a physical map for this region will, therefore, facilitate the localization and subsequent isolation of novel genes.