A Limited Number of Globin Genes in Human DNA
- Department of Medicine, Columbia University, College of Physicians and Surgeons, New York, N.Y. 10032
- Department of Human Genetics and Development, Columbia University, College of Physicians and Surgeons, New York, N.Y. 10032
- Institute for Cancer Research, Columbia University, College of Physicians and Surgeons, New York, N.Y. 10032
Abstract
The number of globin genes in human cells was determined by hybridizing DNA from human spleens to 3H-labeled DNA complementary to human globin mRNA. Assuming the rates of reannealing of complementary DNA and cellular DNA are similar, the extent of hybridization of complementary DNA at various ratios of cellular DNA to complementary DNA indicate that there are fewer than 10 globin gene copies per haploid human genome. An alternative analysis of the data, which introduces no assumptions concerning the relative rates of reaction of complementary DNA and cellular DNA, indicates fewer than 20 globin gene copies are present. DNA isolated from the spleen of a patient with β+ thalassemia contained a number of globin gene copies similar to that of normal DNA.
