Dataset Information

Spatial-temporal dynamics of collective chemosensing.

ABSTRACT: Although the process of chemosensing by individual cells is intrisically stochastic, multicellular organisms exhibit highly regulated responses to external stimulations. Two key elements to understand the deterministic features of chemosensing are intercellular communications and the role of pacemaker cells. To characterize the collective behavior induced by these two factors, we study the spatial-temporal calcium dynamics of fibroblast cells in response to ATP stimulation. We find that closely packed cell colonies exhibit faster, more synchronized, and highly correlated responses compared to isolated cells. In addition, we demonstrate for chemosensing the existence of pacemaker cells and how the presence of gap junctions impact the first step of the collective response. By further comparing these results with the calcium dynamics of cells embedded in thin hydrogel films, where intercellular communication is only possible via diffusing molecules, we conclude that gap junctions are required for synchronized and highly correlated responses among cells in high density colonies. In addition, in high density cell colonies, both communication channels lead to calcium oscillations following the stimulation by external ATP. While the calcium oscillations associated with cells directly exposed to external flows were transient, the oscillations of hydrogel trapped cells can persist with a fundamental frequency and higher harmonics. Our observations and measurements highlight the crucial role of intercellular signaling for generating regulated spatial and temporal dynamics in cell colonies and tissues.

SUBMITTER: Sun B

PROVIDER: S-EPMC3356672 | biostudies-literature | 2012 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Spatial-temporal dynamics of collective chemosensing.

Sun Bo B Lembong Josephine J Normand Valery V Rogers Matthew M Stone Howard A HA

Proceedings of the National Academy of Sciences of the United States of America 20120507 20

Although the process of chemosensing by individual cells is intrisically stochastic, multicellular organisms exhibit highly regulated responses to external stimulations. Two key elements to understand the deterministic features of chemosensing are intercellular communications and the role of pacemaker cells. To characterize the collective behavior induced by these two factors, we study the spatial-temporal calcium dynamics of fibroblast cells in response to ATP stimulation. We find that closely ...[more]

PMID: 22566661

Similar Datasets

Project description:BackgroundThe spatio-temporal patterns of infectious diseases that are environmentally driven reflect the combined effects of transmission dynamics and environmental heterogeneity. They contain important information on different routes of transmission, including the role of environmental reservoirs. Consideration of the spatial component in infectious disease dynamics has led to insights on the propagation of fronts at the level of counties in rabies in the US, and the metapopulation behavior at the level of cities in childhood diseases such as measles in the UK, both at relatively coarse scales. As epidemiological data on individual infections become available, spatio-temporal patterns can be examined at higher resolutions.MethodsThe extensive spatio-temporal data set for cholera in Matlab, Bangladesh, maps the individual location of cases from 1983 to 2003. This unique record allows us to examine the spatial structure of cholera outbreaks, to address the role of primary transmission, occurring from an aquatic reservoir to the human host, and that of secondary transmission, involving a feedback between current and past levels of infection. We use Ripley's K and L indices and bootstrapping methods to evaluate the occurrence of spatial clustering in the cases during outbreaks using different temporal windows. The spatial location of cases was also confronted against the spatial location of water sources.ResultsSpatial clustering of cholera cases was detected at different temporal and spatial scales. Cases relative to water sources also exhibit spatial clustering.ConclusionsThe clustering of cases supports an important role of secondary transmission in the dynamics of cholera epidemics in Matlab, Bangladesh. The spatial clustering of cases relative to water sources, and its timing, suggests an effective role of water reservoirs during the onset of cholera outbreaks. Once primary transmission has initiated an outbreak, secondary transmission takes over and plays a fundamental role in shaping the epidemics in this endemic area.

Project description:Steep Cone Geyser is a unique geothermal feature in Yellowstone National Park (YNP), Wyoming, actively gushing silicon-rich fluids along outflow channels possessing living and actively silicifying microbial biomats. To assess the geomicrobial dynamics occurring temporally and spatially at Steep Cone, samples were collected at discrete locations along one of Steep Cone's outflow channels for both microbial community composition and aqueous geochemistry analysis during field campaigns in 2010, 2018, 2019, and 2020. Geochemical analysis characterized Steep Cone as an oligotrophic, surface boiling, silicious, alkaline-chloride thermal feature with consistent dissolved inorganic carbon and total sulfur concentrations down the outflow channel ranging from 4.59 ± 0.11 to 4.26 ± 0.07 mM and 189.7 ± 7.2 to 204.7 ± 3.55 μM, respectively. Furthermore, geochemistry remained relatively stable temporally with consistently detectable analytes displaying a relative standard deviation <32%. A thermal gradient decrease of ~55°C was observed from the sampled hydrothermal source to the end of the sampled outflow transect (90.34°C ± 3.38 to 35.06°C ± 7.24). The thermal gradient led to temperature-driven divergence and stratification of the microbial community along the outflow channel. The hyperthermophile Thermocrinis dominates the hydrothermal source biofilm community, and the thermophiles Meiothermus and Leptococcus dominate along the outflow before finally giving way to more diverse and even microbial communities at the end of the transect. Beyond the hydrothermal source, phototrophic taxa such as Leptococcus, Chloroflexus, and Chloracidobacterium act as primary producers for the system, supporting heterotrophic growth of taxa such as Raineya, Tepidimonas, and Meiothermus. Community dynamics illustrate large changes yearly driven by abundance shifts of the dominant taxa in the system. Results indicate Steep Cone possesses dynamic outflow microbial communities despite stable geochemistry. These findings improve our understanding of thermal geomicrobiological dynamics and inform how we can interpret the silicified rock record.

Project description:Wild turkeys (Meleagris gallopavo; hereafter turkeys) are an important game animal whose popularity among hunters has increased in recent decades. Yet, the number of hunters pursuing turkeys appears to be in flux, patterns of hunter abundance have primarily been described at broad spatial scales, and the ability of management to impact hunter numbers in the post-restoration era of management through opportunity for quality hunting is unclear. We used county-scale estimates of turkey hunter numbers collected over a 14-year period (2001-2014) and time-series analyses to evaluate the spatial scales at which spring and fall turkey hunter populations fluctuate, and also used generalized linear mixed models to evaluate whether attributes related to quality turkey hunting explain recent patterns in hunter abundance. We found heterogeneity in turkey hunter population growth at finer spatial scales than has been previously described (i.e., counties and management units), and provide evidence for spatial structuring of hunter population dynamics among counties that did not always correspond with existing management units. Specifically, the directionality of hunter population change displays spatial structure along an east-west gradient in southern Michigan. We also found little evidence that factors providing opportunity for quality turkey hunting had meaningful impacts on recent spatial-temporal patterns of hunter numbers. Our results imply that providing quality turkey hunting opportunities alone may be insufficient for sustaining populations of turkey hunters in the future, and that modern determinants of hunter participation extend beyond the availability of abundant turkey populations. Moreover, our results demonstrate that interpretation of harvest data as indices of abundance for turkey populations is difficult in the absence of hunter effort data, as changes to turkey harvest are a function of potentially fine-scaled changes in populations of hunters, not simply changes to turkey populations.

Dataset Information

Spatial-temporal dynamics of collective chemosensing.

Publications

Spatial-temporal dynamics of collective chemosensing.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets