ESCHERICHIA COLI CONTAINING UNNATURAL PYRIMIDINES IN ITS DEOXYRIBONUCLEIC ACID

Abstract
Study of E. coli containing 5-bromouracil in its deoxyribonucleic acid (DNA) suggests that the organism is capable of reproduction and contains an unchanged amount of DNA. Replacement of thymine by 5-bromouracil and vice versa need not be accompanied by changes in phenotypeor by typical mutations. However, these and other adverse conditions may produce modifications (greatly elongated cells poor in DNA, pinpoint colonies) which persist on normal media and as yet defy classification.