Restriction endonuclease sensitivity of DNA containing globin genes in different murine erythroleukemia cell lines

The arrangement of the globin structural genes has been examined in murine erythroleukemia cells, strain DS19, and several related inducer-resistant variant cell lines. One fragment larger than 20 kilobases and six globin gene-containing fragments between 10 and 1.9 kilobases in size are detected in EcoRI-cleaved purified DNA prepared from strain DS19. By comparison, when isolated nuclei are digested with EcoRI, only two globin gene-containing fragments are detected, one greater than 20 kilobases and the other 1.9 kilobases. Of seven cell lines derived from DS19 and resistant to inducers, six had similar patterns to DS19 of globin gene-containing EcoRI-generated DNA fragments from nuclei and from purified DNA. One cell line, DR10, a DMSo-resistant cell line, lacks the 1.9 kilobase fragment after digestion of either nuclei or purified DNA. The 1.9 kilobase fragment hybridizes with alpha-globin cDNA but not with the beta-globin cDNA, suggesting either rearrangement or deletion of an alpha-globin gene-like fragment in DR10 DNA.