DIRECT EVIDENCE FOR ACTIVE SEGREGATION OF ORIC REGIONS OF THE BACILLUS-SUBTILIS CHROMOSOME AND COLOCALIZATION WITH THE SPOOJ PARTITIONING PROTEIN

We have developed methods for labelling regions of the Bacillus subtil is chromosome with the nucleotide analogue 5-bromodeoxyuridine (BrdU) and for subcellular visualization of the labelled DNA. Examination of oriC-labelled chromosomes in outgrowing spores has provided direct evi dence for active segregation of sister chromosomes. Co-immunodetection of Spo0J and BrdU-labelled DNA has directly confirmed the expected cl ose association between this chromosome partitioning protein and the o riC region of the chromosome. The results provide further support for the notion that bacterial cells use an active mitotic-like mechanism t o segregate their chromosomes.