The duplicated human alpha globin genes lie close together in cellular DNA

Abstract

The organization of alpha globin genes in normal human DNA was examined by restriction endonuclease mapping, alpha globin-specific fragments in endonuclease digests of total cell DNA were identified after electrophoresis by hybridization with [32P]cDNA following the blotting procedure of Southern [(1975) J. Mol. Biol. 98, 503--517]. The data provide direct evidence for the duplication of alpha genes and further indicate that these loci are closely linked within a single restriction fragment. The HindIII sites (codons 90/91) of these duplicated genes lie approximately 3.7 kilobases apart in the physical map proposed for this region. This organization of alpha genes can be altered in DNA of individuals with alpha-thalassemia.