scholarly journals Phenotypic variability in unicellular organisms: from calcium signalling to social behaviour

2015 ◽  
Vol 282 (1819) ◽  
pp. 20152322 ◽  
Author(s):  
David Vogel ◽  
Stamatios C. Nicolis ◽  
Alfonso Perez-Escudero ◽  
Vidyanand Nanjundiah ◽  
David J. T. Sumpter ◽  
...  
Keyword(s):  
Social Interactions ◽  
Phenotypic Variability ◽  
Cell Signalling ◽  
Calcium Signalling ◽  
Social Strategies ◽  
Unicellular Organism ◽  
Unicellular Organisms ◽  
Behavioural Phenotypes ◽  
The Mean ◽  
Living Organisms

Historically, research has focused on the mean and often neglected the variance. However, variability in nature is observable at all scales: among cells within an individual, among individuals within a population and among populations within a species. A fundamental quest in biology now is to find the mechanisms that underlie variability. Here, we investigated behavioural variability in a unique unicellular organism, Physarum polycephalum . We combined experiments and models to show that variability in cell signalling contributes to major differences in behaviour underpinning some aspects of social interactions. First, following thousands of cells under various contexts, we identified distinct behavioural phenotypes: ‘slow–regular–social’, ‘fast–regular–social’ and ‘fast–irregular–asocial’. Second, coupling chemical analysis and behavioural assays we found that calcium signalling is responsible for these behavioural phenotypes. Finally, we show that differences in signalling and behaviour led to alternative social strategies. Our results have considerable implications for our understanding of the emergence of variability in living organisms.

scholarly journals Phenotypic variability predicts decision accuracy in unicellular organisms

2019 ◽  
Vol 286 (1896) ◽  
pp. 20182825 ◽  
Author(s):  
Audrey Dussutour ◽  
Qi Ma ◽  
David Sumpter
Keyword(s):  
Phenotypic Variability ◽  
Sampling Time ◽  
Exploratory Behaviour ◽  
Food Sources ◽  
Food Cues ◽  
Unicellular Organism ◽  
Decision Accuracy ◽  
Slime Moulds ◽  
Behavioural Types ◽  
Unicellular Organisms

When deciding between different options, animals including humans face the dilemma that fast decisions tend to be erroneous, whereas accurate decisions tend to be relatively slow. Recently, it has been suggested that differences in the efficacy with which animals make a decision relate closely to individual behavioural differences. In this paper, we tested this hypothesis in a unique unicellular organism, the slime mould Physarum polycephalum . We first confirmed that slime moulds differed consistently in their exploratory behaviour from ‘fast’ to ‘slow’ explorers. Second, we showed that slow explorers made more accurate decisions than fast explorers. Third, we demonstrated that slime moulds integrated food cues in time and achieved higher accuracy when sampling time was longer. Lastly, we showed that in a competition context, fast explorers excelled when a single food source was offered, while slow explorers excelled when two food sources varying in quality were offered. Our results revealed that individual differences in accuracy were partly driven by differences in exploratory behaviour. These findings support the hypothesis that decision-making abilities are associated with behavioural types, even in unicellular organisms.

scholarly journals Novel hypergravity treatment enhances root phenotype and positively influences physio-biochemical parameters in bread wheat (Triticum aestivum L.)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Basavalingayya K. Swamy ◽  
Ravikumar Hosamani ◽  
Malarvizhi Sathasivam ◽  
S. S. Chandrashekhar ◽  
Uday G. Reddy ◽  
...  
Keyword(s):  
Bread Wheat ◽  
Vegetative Growth ◽  
Growth Parameters ◽  
Phenotypic Variability ◽  
Crop Improvement ◽  
Triticum Aestivum L ◽  
Hormonal Changes ◽  
Wheat Varieties ◽  
Living Organisms ◽  
Physiological Benefits

AbstractHypergravity—an evolutionarily novel environment has been exploited to comprehend the response of living organisms including plants in the context of extra-terrestrial applications. Recently, researchers have shown that hypergravity induces desired phenotypic variability in seedlings. In the present study, we tested the utility of hypergravity as a novel tool in inducing reliable phenotype/s for potential terrestrial crop improvement applications. To investigate, bread wheat seeds (UAS-375 genotype) were subjected to hypergravity treatment (10×g for 12, and 24 h), and evaluated for seedling vigor and plant growth parameters in both laboratory and greenhouse conditions. It was also attempted to elucidate the associated biochemical and hormonal changes at different stages of vegetative growth. Resultant data revealed that hypergravity treatment (10×g for 12 h) significantly enhanced root length, root volume, and root biomass in response to hypergravity. The robust seedling growth phenotype may be attributed to increased alpha-amylase and TDH enzyme activities observed in seeds treated with hypergravity. Elevated total chlorophyll content and Rubisco (55 kDa) protein expression across different stages of vegetative growth in response to hypergravity may impart physiological benefits to wheat growth. Further, hypergravity elicited robust endogenous phytohormones dynamics in root signifying altered phenotype/s. Collectively, this study for the first time describes the utility of hypergravity as a novel tool in inducing reliable root phenotype that could be potentially exploited for improving wheat varieties for better water usage management.

scholarly journals Amoebic Foraging Model of Metastatic Cancer Cells

Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1140
Author(s):  
Daiki Andoh ◽  
Yukio-Pegio Gunji
Keyword(s):  
Bayesian Inference ◽  
Cancer Cells ◽  
Metastatic Cancer ◽  
Gait Patterns ◽  
Lévy Walk ◽  
Levy Walk ◽  
Unicellular Organisms ◽  
Living Organisms ◽  
Walk Algorithm ◽  
Metastatic Cancer Cells

The Lévy walk is a pattern that is often seen in the movement of living organisms; it has both ballistic and random features and is a behavior that has been recognized in various animals and unicellular organisms, such as amoebae, in recent years. We proposed an amoeba locomotion model that implements Bayesian and inverse Bayesian inference as a Lévy walk algorithm that balances exploration and exploitation, and through a comparison with general random walks, we confirmed its effectiveness. While Bayesian inference is expressed only by P(h) = P(h|d), we introduce inverse Bayesian inference expressed as P(d|h) = P(d) in a symmetry fashion. That symmetry contributes to balancing contracting and expanding the probability space. Additionally, the conditions of various environments were set, and experimental results were obtained that corresponded to changes in gait patterns with respect to changes in the conditions of actual metastatic cancer cells.

scholarly journals Loneliness and social interaction dynamics: An ambulatory assessment study in a student population

2021 ◽  
Author(s):  
Timon Elmer ◽  
Gerine M. A. Lodder
Keyword(s):  
Social Interaction ◽  
Social Interactions ◽  
Social Relationships ◽  
Sensor Data ◽  
Ambulatory Assessment ◽  
Survival Models ◽  
Qualitative And Quantitative ◽  
Fine Grained ◽  
The Mean

Loneliness is the feeling associated with a perceived lack of qualitative and quantitative aspects of social relationships. Loneliness is thus evidently intwined with individuals’ social behaviors in day-to-day life. Yet, little is known about the bidirectional pathways between loneliness and social interactions in daily life. In this study, we thus investigate (a) how loneliness predicts the frequency and duration of social interactions and (b) how frequency and duration of social interactions predict changes in loneliness. We examine these questions using fine-grained ambulatory-assessed sensor data of student’s social behavior covering 10 weeks (N_participants = 45, N_observations = 74,645). Before (T1) and after (T2) the ambulatory assessment phase, participants completed the UCLA loneliness scale, covering subscales on intimate, relational, and collective loneliness. Using multistate survival models, we show that T1 loneliness subscales are not significantly associated with differences in social interaction frequency and duration– only relational loneliness predicted shorter social interaction encounters. In predicting changes in loneliness subscales (T1-T2), only the mean duration of social interactions was negatively associated with collective loneliness. Thus, effects of loneliness on the structure of social interactions may be small or limited to specific forms of loneliness, implying that the quality of interactions may be more important.

Cell-type specific calcium signalling in a Drosophila epithelium

1997 ◽  
Vol 110 (15) ◽  
pp. 1683-1692 ◽  
Author(s):  
P. Rosay ◽  
S.A. Davies ◽  
Y. Yu ◽  
A. Sozen ◽  
K. Kaiser ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Critical Role ◽  
Cell Signalling ◽  
Calcium Signalling ◽  
Malpighian Tubule ◽  
Fluid Secretion ◽  
Cell Types ◽  
Cytosolic Calcium ◽  
Atpase Inhibitor ◽  
Principal Cells

Calcium is a ubiquitous second messenger that plays a critical role in both excitable and non-excitable cells. Calcium mobilisation in identified cell types within an intact renal epithelium, the Drosophila melanogaster Malpighian tubule, was studied by GAL4-directed expression of an aequorin transgene. CAP2b, a cardioactive neuropeptide that stimulates fluid secretion by a mechanism involving nitric oxide, causes a rapid, dose-dependent rise in cytosolic calcium in only a single, genetically-defined, set of 77 principal cells in the main (secretory) segment of the tubule. In the absence of external calcium, the CAP2b-induced calcium response is abolished. In Ca2+-free medium, the endoplasmic reticulum Ca2+-ATPase inhibitor, thapsigargin, elevates [Ca2+]i only in the smaller stellate cells, suggesting that principal cells do not contain a thapsigargin-sensitive intracellular pool. Assays for epithelial function confirm that calcium entry is essential for CAP2b to induce a physiological response in the whole organ. Furthermore, the data suggest a role for calcium signalling in the modulation of the nitric oxide signalling pathway in this epithelium. The GAL4-targeting system allows general application to studies of cell-signalling and pharmacology that does not rely on invasive or cytotoxic techniques.

scholarly journals Dynamic modulation of sociality and aggression: an examination of plasticity within endocrine and neuroendocrine systems

2017 ◽  
Vol 372 (1727) ◽  
pp. 20160243 ◽  
Author(s):  
Aubrey M. Kelly ◽  
Maren N. Vitousek
Keyword(s):  
Social Interactions ◽  
Social Behaviour ◽  
Developmental Plasticity ◽  
Environmental Changes ◽  
Behavioural Plasticity ◽  
Functional Capabilities ◽  
Rapid Responses ◽  
Neuroendocrine Mechanisms ◽  
Behavioural Phenotypes ◽  
Neuroendocrine Systems

Endocrine and neuroendocrine systems are key mediators of behavioural plasticity and allow for the ability to shift social behaviour across dynamic contexts. These systems operate across timescales, modulating both rapid responses to environmental changes and developmental plasticity in behavioural phenotypes. Thus, not only do endocrine systems mediate behavioural plasticity, but also the systems themselves exhibit plasticity in functional capabilities. This flexibility at both the mechanistic and behavioural levels can be crucial for reproduction and survival. Here, we discuss how plasticity in nonapeptide and steroid actions may influence the expression of, and allow rapid shifts between, sociality and aggression—behavioural shifts that can be particularly important for social interactions. Recent findings of overlap in the mechanisms that modulate social and aggressive behaviour suggest the potential for a mechanistic continuum between these behaviours. We briefly discuss the potential for a sociality–aggression continuum and novel techniques that will enable probing of the functional connectivity of social behaviours. From an evolutionary perspective, we suggest that plasticity in endocrine and neuroendocrine mechanisms of behaviour may be important targets of selection, and discuss the conditions under which we would predict selection to have resulted in differences in endocrine plasticity across species that differ in social organization. This article is part of the themed issue ‘Physiological determinants of social behaviour in animals’.

Lithic Technological Organization and Hafting in Early Villages

2019 ◽  
Vol 84 (4) ◽  
pp. 708-727
Author(s):  
Colin P. Quinn ◽  
Nathan Goodale ◽  
William Andrefsky ◽  
Ian Kuijt ◽  
Bill Finlayson
Keyword(s):  
Social Interactions ◽  
Holistic Approach ◽  
Food Storage ◽  
Social Dimensions ◽  
Social Strategies ◽  
Early Neolithic ◽  
Technological Organization ◽  
Lithic Technological Organization ◽  
Economic Decision Making

Hafting is an important part of lithic technology that can increase our understanding of socioeconomic behavior in the past. In this article, we develop a holistic approach to studying hafting by using the concept of curation within a broader assessment of lithic technological organization in early villages. Early villages were loci of socioeconomic transformation as part of the shift from mobile foraging to more sedentary cultivation lifeways. We suggest that an examination of hafting can provide new insights into how early villagers negotiated technological requirements, economic decision making, and social interactions in these novel contexts. As a case study, we develop a curation index and apply it to an archaeological context of hafted and unhafted pointed tools from the early Neolithic village of Dhra’, Jordan. This curation index allows for a discussion of the technological, economic, and social dimensions of hafting strategies at Dhra’. The presence of multiple hafting traditions within early Neolithic villages of Southwest Asia is evidence of persistent social segmentation despite food storage and ritual practices that emphasized communal integration. Through the lens of lithic technological organization, we demonstrate that hafting and curation patterns can increase our understanding of technological, economic, and social strategies in early villages.

Social Adjustment of Remitted Bipolar and Unipolar Out-patients

1991 ◽  
Vol 159 (2) ◽  
pp. 239-244 ◽  
Author(s):  
F. Bauwens ◽  
A. Tracy ◽  
D. Pardoen ◽  
M. Vander Elst ◽  
J. Mendlewicz
Keyword(s):  
Social Interactions ◽  
Social Adjustment ◽  
Leisure Activities ◽  
Social Maladjustment ◽  
Residual Symptoms ◽  
The Social ◽  
The Mean ◽  
Bipolar Patients ◽  
Normal Controls ◽  
Social Adjustment Scale

Various areas of social adjustment were compared using the Social Adjustment Scale in 27 remitted bipolars, 24 remitted unipolars and 25 normal controls matched for age and sex. Scores for global adjustment and for social and leisure activities were significantly worse in patients than in controls. The maladjustment in social and leisure activities appeared only in ‘contact with friends' for bipolar patients and ‘diminished social interactions' for unipolar patients. Unipolar patients differed significantly from controls on the items investigating sexual adjustment. In unipolars, social maladjustment seemed to be independent of the course of the disease; in bipolars, it was partly related to the mean number of lifetime episodes and current residual symptoms.

Use of water extraction variability to screen for sunflower genotypes well adapted to soil water limitation

2012 ◽  
Vol 39 (12) ◽  
pp. 999
Author(s):  
Ando M. Radanielson ◽  
Jeremie Lecoeur ◽  
Angelique Christophe ◽  
Lydie Guilioni
Keyword(s):  
Soil Water ◽  
Phenotypic Variability ◽  
Water Extraction ◽  
Breeding Programs ◽  
Mean Values ◽  
Relative Value ◽  
Water Uptake Capacity ◽  
Extraction Properties ◽  
Soil Water Extraction ◽  
The Mean

In conditions of water deficit, plant yield depends mostly on the ability of the plant to explore soil profile and its water uptake capacity per unit volume of soil. In this study, the value of soil water extraction properties for use in sunflower breeding was evaluated. Five experiments were carried out in pots, in greenhouses, from 2005 to 2009, in Montpellier, France. Elite sunflower cultivars and experimental hybrids obtained from a factorial cross between five female and five male inbred lines were grown. The soil water extraction performance of the plants was characterised by the soil water content at minimal stomatal conductance (SWCgs = 0) and the index of water extraction (IEgen), which was calculated as the relative value of SWCgs = 0 to the performance of the cultivar NKMelody. Heritability (H2) was estimated for the experimental hybrids. Phenotypic variability of the SWCgs = 0 was observed with a significant effect of the environment and the genotype. The latest released cultivars were observed as the best performing one in water extraction with an IEgen under 0.85. This trait was found to be suitable for use in comparisons of the soil water extraction performances of different genotypes. The high H2 value for SWCgs = 0 (0.77 and 0.81) and the significant correlation (r2 = 0.70, P < 0.001) between the values obtained for the experimental hybrids and the mean values of the general combining ability (GCA) for the parental lines showed that this trait is heritable and could be used in plant breeding programs. Phenotyping methods and the usefulness of this trait in crop modelling are discussed.

scholarly journals Crab scars reveal survival advantage of left-handed snails

2006 ◽  
Vol 2 (3) ◽  
pp. 439-442 ◽  
Author(s):  
Gregory P Dietl ◽  
Jonathan R Hendricks
Keyword(s):  
Social Interactions ◽  
Structure And Function ◽  
Snail Species ◽  
Left Handedness ◽  
Left Handed ◽  
Selection Processes ◽  
Living Organisms ◽  
And Function ◽  
First Time ◽  
Crab Predation

Biological asymmetries are important elements of the structure and function of many living organisms. Using the Plio–Pleistocene fossil record of crab predation on morphologically similar pairs of right- and left-handed snail species, we show here for the first time, contrary to traditional wisdom, that rare left-handed coiling promotes survival from attacks by right-handed crabs. This frequency-dependent result influences the balance of selection processes that maintain left-handedness at the species level and parallels some social interactions in human cultures, such as sports that involve dual contests between opponents of opposite handedness.

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