Spatial and temporal distribution of ribosomes in single cells reveals aging differences between old and new daughters of Escherichia coli
- Department of Ecology, Behavior and Evolution, School of Biological Sciences, University of California San Diego, United States
Figures
Figure 1 with 1 supplement
Cell division and polarity in E. coli.
(A) Assignment of old (red) and new (blue) poles and daughters. The starting cell is white because it was randomly picked to start the experiment and its polarity was unknown. Because the division …
Figure 1—figure supplement 1
Fluorescence profile along new and old daughter pairs’ cell lengths at birth.
The fluorescence and length values were normalized (n = 89 pairs). Color designation is as in Figure 1A for old (red) and new (blue) poles and daughters. Error bars show standard error of the mean …
Figure 2
Ratios of ribosome density and elongation rates within and between cells.
Because ratios are a form of normalization, their values were derived from non-normalized data. Asterisks in figures indicate levels of significance from comparison between ratios of new (blue bar) …
Figure 3
Variation in ribosome density and elongation rate in old and new daughters from old and new mothers.
The measurements were made from the same cells in Figure 2C. All density and elongation values were normalized for this analysis. Means, variances, and other parameters extracted from these data are …
Figure 4
Correlation between normalized elongation rate and ribosome density of old and new daughters from old and new mothers.
Because the old and new daughter values were jointly normalized, they were not independent and their combination into a single plot could not be assessed by statistical models assuming independence. …
Figure 5
Ratio of ribosome density in old and new mothers over quartile time from birth to division.
Ratios correspond to density in the new pole half divided by density in the old pole half (Figure 1C) of the mothers. Regression slopes were significantly greater than zero for old (slope = 0.0177, …
Figure 6
Spatial and temporal distribution of ribosome density in old and new mothers.
(A) Density in length quartiles over time quartiles. Lines presented are from regressions of ribosome densities for one length quartile that were binned by the four time quartiles. All length …
Tables
Table 1
Variance components of ribosome density and elongation rates.
Total (VT), stochastic (VE), and deterministic (D2/4) components of variances estimated from Figure 3 (see ‘Materials and methods’). The deterministic proportion of total variance VT was h2 = (D2/4)/…
| (A) Ribosomal density | |||||||
|---|---|---|---|---|---|---|---|
| Vr | D | D2/4 | h2 | ||||
| Old mothers | 0.00634 | 0.101 *** | 0.00253 | 0.399 | |||
| New mothers | 0.00347 | 0.0184 * | 0.00008 | 0.024 | |||
| (B) Elongation rates | |||||||
| Vr | D | D2/4 | h2 | ||||
| Old mothers | 0.00913 | 0.0821 *** | 0.00168 | 0.185 | |||
| New mothers | 0.00581 | 0.0533 *** | 0.00071 | 0.122 | |||
| (C) VE estimates | |||||||
| Old mothers | New mothers | p-value1 | |||||
| Elongation rates | 0.00744 | 0.0051 | 0.0073** | ||||
| Ribosome density | 0.00381 | 0.00338 | 0.40 n.s. | ||||
| p-value2 | 0.000001*** | 0.0041** | |||||
