Inhibitors of genetic recombination in pneumococci.
Treatment of transformable pneumococci with DNA-intercalating agents shortly after the uptake of DNA molecules inhibited the appearance of genetic transformants. The same drug treatments applied 20 min after DNA uptake were ineffective. Ethidium bromide, proflavin, daunomycin, actinomycin D, and platinum red were found to be effective inhibitors. Donor DNA molecules reisolated from the drug-treated bacteria appeared to be associated with the resident DNA in an abnormal manner, and they had only poor transforming activity.
Inhibitors of genetic recombination in pneumococci. Treatment of transformable pneumococci with DNA-intercalating agents shortly after the uptake of DNA molecules inhibited the appearance of genetic transformants. The same drug treatments applied 20 min after DNA uptake were ineffective. Ethidium bromide, proflavin, daunomycin, actinomycin D, and platinum red were found to be effective inhibitors. Donor DNA molecules reisolated from the drug-treated bacteria appeared to be associated with the resident DNA in an abnormal manner, and they had only poor transforming activity.