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Inflating bacterial cells by increased protein synthesis.

Basan M, Zhu M, Dai X, Warren M, Sévin D, Wang YP, Hwa T - Mol. Syst. Biol. (2015)

Bottom Line: In particular, synthesizing large amounts of "useless" proteins led to an inversion of the canonical, positive relation, with slow growing cells enlarged 7- to 8-fold compared to cells growing at similar rates under nutrient limitation.Strikingly, this increase in cell size was accompanied by a 3- to 4-fold increase in cellular DNA content at slow growth, reaching up to an amount equivalent to ~8 chromosomes per cell.Despite drastic changes in cell mass and macromolecular composition, cellular dry mass density remained constant.

View Article: PubMed Central - PubMed

Affiliation: Institute of Molecular Systems Biology, ETH Zürich, Zürich, Switzerland basan@imsb.biol.ethz.ch hwa@ucsd.edu.

No MeSH data available.


Related in: MedlinePlus

Cellular DNA content from DAPI stainingSymbols same as in Fig1.Cellular DNA content measured by DAPI staining and microscopy plotted against growth rate. The results confirm the data for cellular DNA content (Fig2F). Error bars represent the standard deviations of the measured distributions over the cell population (n = 20).Cellular DNA content determined from DAPI staining versus DNA content determined from biochemical assay (see Materials and Methods section). The two methods of determining cellular DNA content show good agreement.Microscopy images of DAPI-stained DNA and cells. Cellular DNA is localized at single nucleoid foci per cell. This suggests that even in large cells with high cellular DNA content resulting from LacZ OE, only one completely replicated chromosome per cell is present. Therefore, the high cellular DNA content likely results from multiple incomplete replication forks. Moreover, these images demonstrate that cell division proceeds normally in the large cells resulting from LacZ OE (e.g., right image, upper left corner) and the large cell size is not caused by inhibition of cell division as reported under other conditions, for example, by Zaritsky et al (2006).
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fig03ev: Cellular DNA content from DAPI stainingSymbols same as in Fig1.Cellular DNA content measured by DAPI staining and microscopy plotted against growth rate. The results confirm the data for cellular DNA content (Fig2F). Error bars represent the standard deviations of the measured distributions over the cell population (n = 20).Cellular DNA content determined from DAPI staining versus DNA content determined from biochemical assay (see Materials and Methods section). The two methods of determining cellular DNA content show good agreement.Microscopy images of DAPI-stained DNA and cells. Cellular DNA is localized at single nucleoid foci per cell. This suggests that even in large cells with high cellular DNA content resulting from LacZ OE, only one completely replicated chromosome per cell is present. Therefore, the high cellular DNA content likely results from multiple incomplete replication forks. Moreover, these images demonstrate that cell division proceeds normally in the large cells resulting from LacZ OE (e.g., right image, upper left corner) and the large cell size is not caused by inhibition of cell division as reported under other conditions, for example, by Zaritsky et al (2006).

Mentions: DNA content per cell. The trends in DNA content, as confirmed by DAPI staining (FigEV3), also closely follow the change in cell size shown in panel (C) (see FigEV1C for the correlation plot).


Inflating bacterial cells by increased protein synthesis.

Basan M, Zhu M, Dai X, Warren M, Sévin D, Wang YP, Hwa T - Mol. Syst. Biol. (2015)

Cellular DNA content from DAPI stainingSymbols same as in Fig1.Cellular DNA content measured by DAPI staining and microscopy plotted against growth rate. The results confirm the data for cellular DNA content (Fig2F). Error bars represent the standard deviations of the measured distributions over the cell population (n = 20).Cellular DNA content determined from DAPI staining versus DNA content determined from biochemical assay (see Materials and Methods section). The two methods of determining cellular DNA content show good agreement.Microscopy images of DAPI-stained DNA and cells. Cellular DNA is localized at single nucleoid foci per cell. This suggests that even in large cells with high cellular DNA content resulting from LacZ OE, only one completely replicated chromosome per cell is present. Therefore, the high cellular DNA content likely results from multiple incomplete replication forks. Moreover, these images demonstrate that cell division proceeds normally in the large cells resulting from LacZ OE (e.g., right image, upper left corner) and the large cell size is not caused by inhibition of cell division as reported under other conditions, for example, by Zaritsky et al (2006).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4631207&req=5

fig03ev: Cellular DNA content from DAPI stainingSymbols same as in Fig1.Cellular DNA content measured by DAPI staining and microscopy plotted against growth rate. The results confirm the data for cellular DNA content (Fig2F). Error bars represent the standard deviations of the measured distributions over the cell population (n = 20).Cellular DNA content determined from DAPI staining versus DNA content determined from biochemical assay (see Materials and Methods section). The two methods of determining cellular DNA content show good agreement.Microscopy images of DAPI-stained DNA and cells. Cellular DNA is localized at single nucleoid foci per cell. This suggests that even in large cells with high cellular DNA content resulting from LacZ OE, only one completely replicated chromosome per cell is present. Therefore, the high cellular DNA content likely results from multiple incomplete replication forks. Moreover, these images demonstrate that cell division proceeds normally in the large cells resulting from LacZ OE (e.g., right image, upper left corner) and the large cell size is not caused by inhibition of cell division as reported under other conditions, for example, by Zaritsky et al (2006).
Mentions: DNA content per cell. The trends in DNA content, as confirmed by DAPI staining (FigEV3), also closely follow the change in cell size shown in panel (C) (see FigEV1C for the correlation plot).

Bottom Line: In particular, synthesizing large amounts of "useless" proteins led to an inversion of the canonical, positive relation, with slow growing cells enlarged 7- to 8-fold compared to cells growing at similar rates under nutrient limitation.Strikingly, this increase in cell size was accompanied by a 3- to 4-fold increase in cellular DNA content at slow growth, reaching up to an amount equivalent to ~8 chromosomes per cell.Despite drastic changes in cell mass and macromolecular composition, cellular dry mass density remained constant.

View Article: PubMed Central - PubMed

Affiliation: Institute of Molecular Systems Biology, ETH Zürich, Zürich, Switzerland basan@imsb.biol.ethz.ch hwa@ucsd.edu.

No MeSH data available.


Related in: MedlinePlus