ANUCLEATE CELL PRODUCTION BY ESCHERICHIA-COLI DELTA-HNS MUTANT LACKING A HISTONE-LIKE PROTEIN, H-NS

Normal-sized anucleate cells were observed in the cultures of a Delta hns mutant strain. Even in nucleate cells, some populations shelved ir regular intracellular localization of the nucleoids. The Delta hns mut ant showed reduced ploidy, although initiation of chromosome replicati on was essentially synchronous as defined by flow cytometric analysis. These results indicate that the Delta hns mutant is defective in the mechanisms of chromosome partitioning and chromosome replication.