Effects of Mechanical Shear on Genetic Activity of Bacillus Subtilis Dna

DNA molecules in solution can be fragmented by mechanical shearing forces.' Such fragmentation disrupts the linkage of genetic markers arrayed on the DNA molecule of the bacteriophage lambda.2 In Bacillus subtilis, the aromatic linkage group carries at least nine genes specifying structural enzymes for steps in aromatic acid biosynthesis and also a histidine marker.3 4 This situation affords an unusually favorable opportunity to relate the biological to the physical consequences of shearing forces of DNA in a transformation system. Materials and Methods.-Pertinent information on the strains carrying the linked mutants is given in Table 1 and linkage map, Figure 1. All loci, except for aro2 and aro3, were ordered on