Significant differences in overall survival were determined using the Generalized Wilcoxon test

gesting that a size-based or a mixed regulatory mechanism is employed. Chromosome Segregation Impacts on Cell Growth in C. glutamicum Mutation of the C. glutamicum chromosome segregation Neuromedin N biological activity machinery induce a plethora of phenotypes, including altered growth rates and cell lengths, anucleate cells, guillotined chromosomes and perturbed chromosome organization. These phenotypic consequences led us to speculate that chromosome segregation and/or organization might be coupled to division site selection and cell growth. With this in mind, the growth characteristics of parA and parB mutants were analyzed using live cell imaging. Therefore, a divIVA-mCherry fusion was introduced into markerless parA or parB deletion background strains. In cells 23831757 lacking parA or parB, elongation rates varied from the DivIVA-mCherry strain. In the absence of parA, the elongation rate is reduced, while more variability is observed for the parB mutant, ranging from 0.25 mm/h to greater than 5 mm/h. Variation in the elongation rate might be due to deviating cell lengths at birth. Shorter cells at birth would require more time to reach a threshold size, while longer cells would require less time. Therefore, the association between birth length and elongation length was measured. In the absence of parA or parB, both birth lengths and elongation lengths are more variable. However, birth and elongation lengths remain negatively correlated. Taken together, mutation of parA or parB not only alters chromosome organization, but also gives rise to a population of cells that is extremely heterogeneous both in birth size and 11478874 elongation rate. Chromosome Segregation Influences Division Site Selection in C. glutamicum The inconsistency of cell lengths at birth between wild type or DivIVA-mCherry and par mutant cells would suggest that the placement of the division septum is more variable in the absence of functional chromosome segregation machinery. As C. glutamicum lacks recognisable homologues of the conventional division site regulatory systems and no other positive or negative regulation of cell division are presently known, we speculated that chromosome segregation or the subcellular organization of the nucleoid might influence division site selection. On a single cell level, the placement of the division site in C. glutamicum cells was spatially and temporally assessed. Division symmetry was assessed by measuring the distance between the division septum and the nearest cell pole divided by the length of the cell, with 0.5 corresponding to the exact midcell. We found that the placement of the division site is not always precisely at midcell in wild type or DivIVA-mCherry cells; but some regulatory mechanism must exist because the division septum is sited in the region between the 1/3 and 2/3 positions of the cell. In the DivIVA-mCherry strain, we observed polar divisions occurring in a low percentage of the cells . As DivIVA has been proposed to anchor the oriC at the cell poles through interaction with ParB, the low frequency of polar divisions is likely a consequence of the mCherry fusion which results in a mild chromosome segregation defect. However, in the absence of parA or parB, the placement of the division site is significantly more variable Distribution of elongation rates of wild type, DivIVA-mCherry, DparA DivIVA-mCherry and DparB DivIVA-mCherry mutant cells.. Association of birth lengths and elongation lengths in DivIVA-mCherry, DparA DivIVA-mCherry and DparB DivIVA