Temperature-sensitive mutants of Bacillus subtilis. I. Multiforked replication and sequential transfer of DNA by a temperature-sensitive mutant.

A temperature-sensitive mutant of Bacillus subtilis 168 was isolated. Its chromosome was found to undergo multiforked replication at normal temperature. The mutant cells then transferred chromosomes to recipient cells sequentially from the origin to the terminus of the chromosome at sublethal temperatures. Sequential transfer of the chromosome facilitated the determination of the relative positions of markers on the chromosome. Linkage between origin (adenine-16) and terminus (methionine) was demonstrated.