Further Evidence Concerning the Configuration of Transforming Deoxyribonucleic Acid During Entry into Bacillus subtilis

Strauss, Norman (State University of New York at Buffalo, Buffalo, N.Y.). Further evidence concerning the configuration of transforming deoxyribonucleic acid during entry intoBacillus subtilis . J. Bacteriol91: 702–708. 1966.—The appearance of linked, unselected traits with selected markers was followed as a function of time after the exposure of competent cells to transforming deoxyribonucleic acid (DNA). It was found that the per cent cotransfer of a linked, unselected trait with a single selected trait increased sharply soon after the lag period characterizing the appearance of the selected trait. Similar results were obtained when cotransfer of a linked unselected trait with a pair of selected traits was examined. The results are taken as an unequivocal demonstration that the entry of transforming DNA into competentBacillus subtilis occurs in longitudinal fashion. The nature of the linkage betweentry2 andhis9 was characterized. It was found that, although these two traits had been found to be unlinked on the basis of recombination tests, the saturation curves showed these two traits to be present on the same fragment of DNA.