skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Asynchrony in the growth and motility responses to environmental changes by individual bacterial cells

Abstract

Knowing how individual cells respond to environmental changes helps one understand phenotypic diversity in a bacterial cell population, so we simultaneously monitored the growth and motility of isolated motile Escherichia coli cells over several generations by using a method called on-chip single-cell cultivation. Starved cells quickly stopped growing but remained motile for several hours before gradually becoming immotile. When nutrients were restored the cells soon resumed their growth and proliferation but remained immotile for up to six generations. A flagella visualization assay suggested that deflagellation underlies the observed loss of motility. This set of results demonstrates that single-cell transgenerational study under well-characterized environmental conditions can provide information that will help us understand distinct functions within individual cells.

Authors:
 [1];  [2];  [1];  [3]
  1. Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo (Japan)
  2. Department of Biomedical Information, Division of Biosystems, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (Japan)
  3. Department of Biomedical Information, Division of Biosystems, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (Japan). E-mail: yasuda.bmi@tmd.ac.jp
Publication Date:
OSTI Identifier:
20991325
Resource Type:
Journal Article
Resource Relation:
Journal Name: Biochemical and Biophysical Research Communications; Journal Volume: 356; Journal Issue: 2; Other Information: DOI: 10.1016/j.bbrc.2007.03.001; PII: S0006-291X(07)00462-7; Copyright (c) 2007 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; CELL CULTURES; CELL PROLIFERATION; CULTIVATION; ESCHERICHIA COLI; GROWTH; NUTRIENTS

Citation Formats

Umehara, Senkei, Hattori, Akihiro, Inoue, Ippei, and Yasuda, Kenji. Asynchrony in the growth and motility responses to environmental changes by individual bacterial cells. United States: N. p., 2007. Web. doi:10.1016/j.bbrc.2007.03.001.
Umehara, Senkei, Hattori, Akihiro, Inoue, Ippei, & Yasuda, Kenji. Asynchrony in the growth and motility responses to environmental changes by individual bacterial cells. United States. doi:10.1016/j.bbrc.2007.03.001.
Umehara, Senkei, Hattori, Akihiro, Inoue, Ippei, and Yasuda, Kenji. Fri . "Asynchrony in the growth and motility responses to environmental changes by individual bacterial cells". United States. doi:10.1016/j.bbrc.2007.03.001.
@article{osti_20991325,
title = {Asynchrony in the growth and motility responses to environmental changes by individual bacterial cells},
author = {Umehara, Senkei and Hattori, Akihiro and Inoue, Ippei and Yasuda, Kenji},
abstractNote = {Knowing how individual cells respond to environmental changes helps one understand phenotypic diversity in a bacterial cell population, so we simultaneously monitored the growth and motility of isolated motile Escherichia coli cells over several generations by using a method called on-chip single-cell cultivation. Starved cells quickly stopped growing but remained motile for several hours before gradually becoming immotile. When nutrients were restored the cells soon resumed their growth and proliferation but remained immotile for up to six generations. A flagella visualization assay suggested that deflagellation underlies the observed loss of motility. This set of results demonstrates that single-cell transgenerational study under well-characterized environmental conditions can provide information that will help us understand distinct functions within individual cells.},
doi = {10.1016/j.bbrc.2007.03.001},
journal = {Biochemical and Biophysical Research Communications},
number = 2,
volume = 356,
place = {United States},
year = {Fri May 04 00:00:00 EDT 2007},
month = {Fri May 04 00:00:00 EDT 2007}
}
  • S100A4 protein belongs to the S100 subfamily, which has grown to be one of the large subfamilies of the EF-hand Ca{sup 2+}-binding proteins, and overexpression of S100A4 is suggested to associate with cell proliferation, invasion, and metastasis. We observed frequent overexpression of S100A4 in pancreatic cancer cell lines and further analyzed RNAi-mediated knockdown to address the possibility of its use as a therapeutic target for pancreatic cancer. The specific knockdown of S100A4 strongly suppressed cell growth, induced G2 arrest and eventual apoptosis, and decreased cell migration. Furthermore, microarray analyses revealed that knockdown of S100A4 induced expression of the tumor suppressormore » genes PRDM2 and VASH1. Our present results suggest the possibility that the inhibition of S100A4 can be utilized in antitumor applications for patients with pancreatic cancer.« less
  • Highlights: • We observed frequent overexpression of S100A4 in lung cancer cell lines. • Knockdown of S100A4 suppressed proliferation in lung cancer cells. • Forced expression of S100A4 accelerated cell motility in lung cancer cells. • PRDM2 was found to be one of the downstream suppressed genes of S100A4. - Abstract: S100A4, a small calcium-binding protein belonging to the S100 protein family, is commonly overexpressed in a variety of tumor types and is widely accepted to associate with metastasis by regulating the motility and invasiveness of cancer cells. However, its biological role in lung carcinogenesis is largely unknown. In thismore » study, we found that S100A4 was frequently overexpressed in lung cancer cells, irrespective of histological subtype. Then we performed knockdown and forced expression of S100A4 in lung cancer cell lines and found that specific knockdown of S100A4 effectively suppressed cell proliferation only in lung cancer cells with S100A4-overexpression; forced expression of S100A4 accelerated cell motility only in S100A4 low-expressing lung cancer cells. PRDM2 and VASH1, identified as novel upregulated genes by microarray after specific knockdown of S100A4 in pancreatic cancer, were also analyzed, and we found that PRDM2 was significantly upregulated after S100A4-knockdown in one of two analyzed S100A4-overexpressing lung cancer cells. Our present results suggest that S100A4 plays an important role in lung carcinogenesis by means of cell proliferation and motility by a pathway similar to that in pancreatic cancer.« less
  • Marked asynchronous hatching was observed in Tree Swallows (Iridoprocne bicolor), apparently because incubation started before the full clutch was laid. Asynchronous hatching resulted in pronounced size differences of nestlings. Immediately after hatching, the first-hatched nestling was, on average, 94% heavier than the last-hatched. Clearly, a weight hierarchy was established, with small late-hatched young at a disadvantage. Egg weight increased with laying order, and last-laid eggs tended to hatch last. Thus, egg-size differences did not enhance the weight hierarchy due to hatching asynchrony. Early hatchlings had longer nestling times than late hatchlings. The former also had a higher observed asymptotic weightmore » and longer primaries at fledging than the latter. Late-hatched young were less likely to fledge than early hatchlings. The number of young fledged increased with hatching asynchrony but so did brood size. Tree Swallows appear to use brood reduction to maximize reproductive output, but alternative hypotheses cannot be ruled out.« less
  • We link life history theory, environmental setting, and individual-based modeling to compare the responses of two fish species to environmental change. Life history theory provides the framework for selecting representative species, and in combination with information on important environmental characteristics, it provides the framework for predicting the results of model simulations. Individual-based modeling offers a promising tool for integrating and extrapolating our mechanistic understanding of reproduction, growth, and mortality at the individual level to population-level responses such as size-frequency distributions and indices of year-class strength. Based on the trade-offs between life history characteristics of striped bass Morone saxatilis and smallmouthmore » bass Micropterus dolomieu and differences in their respective environments, we predicted that young-of-year smallmouth bass are likely to demonstrate a greater compensatory change in growth and mortality than young-of-year striped bass in response to changes in density of early life stages and turnover rates of zooplankton prey. We tested this prediction with a simulation experiment. The pattern of model results was consistent with our expectations: by the end of the first growing season, compensatory changes in length and abundance of juveniles were more pronounced for smallmouth bass than for striped bass. The results also highlighted the dependence of model predictions on the interplay between density of larvae and juveniles and characteristics of their zooplankton prey.« less
  • Total culturable heterotrophic bacteria in a coal ash basin and drainage system were monitored over a period of two years. In the first year heavy (bottom) ash was sluiced to the basin resulting in a pH of 6.5. During the second year fly ash was precipitated and added to the sluice lowering the basin pH to 4.6. Sulfate concentrations during 1975 ranged from 16 to 73 ppM (mean 33) and in 1976 from 44 to 88 ppM (mean 72). Mean annual basin temperatures were 28.8 and 26.0/sup 0/C, respectively. Approximately 1500 m in the receiving swamp below the basin, meanmore » pH and temperature were 6.8 and 22.2/sup 0/C for the first year, and 5.4 and 22.1/sup 0/C for the second. Total culturable bacteria and diversity (colony types) were reduced at all sampling stations by 44 and 30%, respectively, whereas the percentage of the population comprised of chromagenic bacteria increased by 51% at the lower pH. Data indicated the pH had a greater effect than did water temperature when temperature was within the range of 15 to 25/sup 0/C. The predominant genera within the system in the first year were Bacillus, Sarcina, Achromobacter, Flavobacterium, and Pseudomonas. In the second year, at the lower pH, predominant genera were Pseudomonas, Flavobacterium, Chromobacterium, Bacillus, and Brevibacterium.« less