Acquisition of New Capsular Type by Pneumococcus, a Multifactor Transformation1
This extract was created in the absence of an abstract.
Excerpt
Transformation of noncapsulated or of partially capsulated mutants of pneumococcus type III with the desoxyribonucleates (DNA) of pneumococcus type I is followed by the appearance of two phenotypes: type I cells and doubly capsulated type I–III cells (Austrian and Bernheimer, 1955). The formation of type III polysaccharide by the I–III phenotype suggests that the noncapsulated mutant of pneumococcus type III retains its capsular polymerizing system but may be unable to carry out a preliminary biochemical step essential to the formation of a component of the polysaccharide. In the absence of any evidence that type I pneumococci can synthesize type III polysaccharide, this hypothesis seems to be a tenable one. The restitution of the synthesis of a normal amount of type III capsular material in the I–III phenotype may result from one of two possibilities. Transformation of the mutant type III strain with DNA from type I cells may be followed...
- 1
↵1 This investigation was supported in part by research grant E-1018(C2) from the Institute of Allergy and Infectious Diseases, United States Public Health Service, by Lederle Laboratories Division, American Cyanamid Company and by a research grant from the Medical Research Council and the Rankin Fund of the University of Glasgow.
