scholarly journals Emergence of proto-organisms from bistable stochastic differentiation and adhesion

2016 ◽  
Vol 13 (117) ◽  
pp. 20160108 ◽  
Author(s):  
Salva Duran-Nebreda ◽  
Adriano Bonforti ◽  
Raúl Montañez ◽  
Sergi Valverde ◽  
Ricard Solé
Keyword(s):  
Evolutionary Biology ◽  
Spatial Organization ◽  
Organizational Complexity ◽  
Differentiated Cells ◽  
Differential Adhesion ◽  
Multicellular Aggregates ◽  
Conflict Mediation ◽  
Evolution Of Life ◽  
Living Organisms ◽  
High Degree

The rise of multicellularity in the early evolution of life represents a major challenge for evolutionary biology. Guidance for finding answers has emerged from disparate fields, from phylogenetics to modelling and synthetic biology, but little is known about the potential origins of multicellular aggregates before genetic programmes took full control of developmental processes. Such aggregates should involve spatial organization of differentiated cells and the modification of flows and concentrations of metabolites within well-defined boundaries. Here, we show that, in an environment where limited nutrients and toxic metabolites are introduced, a population of cells capable of stochastic differentiation and differential adhesion can develop into multicellular aggregates with conflict mediation mechanisms and a complex internal structure. The morphospace of possible patterns is shown to be very rich, including proto-organisms that display a high degree of organizational complexity, far beyond simple heterogeneous populations of cells. Our findings reveal that there is a potentially enormous richness of organismal complexity between simple mixed cooperators and embodied living organisms.

scholarly journals Isolation and characterization of adrenocortical progenitors involved in the adaptation to stress

2018 ◽  
Vol 115 (51) ◽  
pp. 12997-13002 ◽  
Author(s):  
Charlotte Steenblock ◽  
Maria F. Rubin de Celis ◽  
Luis F. Delgadillo Silva ◽  
Verena Pawolski ◽  
Ana Brennand ◽  
...  
Keyword(s):  
Lineage Tracing ◽  
Differentiated Cells ◽  
Isolation And Characterization ◽  
Proliferation And Differentiation ◽  
Response To Stress ◽  
Steroidogenic Cells ◽  
High Degree

The adrenal gland is a master regulator of the human body during response to stress. This organ shows constant replacement of senescent cells by newly differentiated cells. A high degree of plasticity is critical to sustain homeostasis under different physiological demands. This is achieved in part through proliferation and differentiation of adult adrenal progenitors. Here, we report the isolation and characterization of a Nestin+ population of adrenocortical progenitors located under the adrenal capsule and scattered throughout the cortex. These cells are interconnected with progenitors in the medulla. In vivo lineage tracing revealed that, under basal conditions, this population is noncommitted and slowly migrates centripetally. Under stress, this migration is greatly enhanced, and the cells differentiate into steroidogenic cells. Nestin+ cells cultured in vitro also show multipotency, as they differentiate into mineralocorticoid and glucocorticoid-producing cells, which can be further influenced by the exposure to Angiotensin II, adrenocorticotropic hormone, and the agonist of luteinizing hormone-releasing hormone, triptorelin. Taken together, Nestin+ cells in the adult adrenal cortex exhibit the features of adrenocortical progenitor cells. Our study provides evidence for a role of Nestin+ cells in organ homeostasis and emphasizes their role under stress. This cell population might be a potential source of cell replacement for the treatment of adrenal insufficiency.

scholarly journals Quantitative Assessment of Organic And Inorganic Contaminants In Charcoal Applied for Food Processing

2021 ◽  
Author(s):  
Zbigniew Jelonek ◽  
Monika Fabiańska ◽  
Iwona Jelonek
Keyword(s):  
Toxic Elements ◽  
Prolonged Exposure ◽  
Gas Chromatography Mass Spectrometry ◽  
Moderate Degree ◽  
Inorganic Contaminants ◽  
Low Degree ◽  
Wide Range ◽  
Polycyclic Aromatic ◽  
Living Organisms ◽  
High Degree

Abstract Thirty-one batches of commercial charcoal from various regions of Poland and Germany were tested for the presence of twenty toxic elements and polycyclic aromatic hydrocarbons (PAHs) using gas chromatography - mass spectrometry (GC-MS). Elements that are toxic to living organisms were determined using atomic absorption spectroscopy (AAS). They were classified as elements representing a very high degree of hazard (As, Cd, Cu, Hg, and Pb), high degree of hazard (Zn, Ba, Cr, Mn, and Mo), moderate degree of hazard (Co, Ni, Sn, and Te), and a low degree of hazard for living organisms and the environment (Ag, Bi, Ce, Se, Sr, and Zr). When it comes to the most toxic elements, the highest concentration in the whole tested material was recorded for Cu. In addition, considerable amounts of Ba, Mn, and Sr, i.e., elements representing high or moderate degree of hazard, were found in the tested charcoals. Moreover, all charcoals contained a wide range of PAHs, from naphthalene to benzo(ghi)perylene, with concentrations in the range between 12.55 and 3554.11 ng/g of charcoal. In total, 25 unsubstituted PAHs were identified in the charcoal extracts. PAHs distributions were dominated by 5-ring PAHs. The results indicate the high carcinogenicity with ∑PAHcarc/∑PAHtot close to 1, as well as high TEQ and MEQ values. Thus, prolonged exposure to charcoal and charcoal dust might cause serious health problems. This applies to employees actively involved in the production and transport of charcoal, and, to a lesser extent, also to users of this fuel.

Molecular interactions shaping the tetraspanin web

2017 ◽  
Vol 45 (3) ◽  
pp. 741-750 ◽  
Author(s):  
Sjoerd J. van Deventer ◽  
Vera-Marie E. Dunlock ◽  
Annemiek B. van Spriel
Keyword(s):  
Molecular Interactions ◽  
Intracellular Signaling ◽  
Spatial Organization ◽  
Complex Mixture ◽  
Point Of View ◽  
Intramolecular Interactions ◽  
Fundamental Understanding ◽  
High Degree ◽  
Partner Proteins ◽  
Insight Into

To facilitate the myriad of different (signaling) processes that take place at the plasma membrane, cells depend on a high degree of membrane protein organization. Important mediators of this organization are tetraspanin proteins. Tetraspanins interact laterally among themselves and with partner proteins to control the spatial organization of membrane proteins in large networks called the tetraspanin web. The molecular interactions underlying the formation of the tetraspanin web were hitherto mainly described based on their resistance to different detergents, a classification which does not necessarily correlate with functionality in the living cell. To look at these interactions from a more physiological point of view, this review discusses tetraspanin interactions based on their function in the tetraspanin web: (1) intramolecular interactions supporting tetraspanin structure, (2) tetraspanin–tetraspanin interactions supporting web formation, (3) tetraspanin–partner interactions adding functional partners to the web and (4) cytosolic tetraspanin interactions regulating intracellular signaling. The recent publication of the first full-length tetraspanin crystal structure sheds new light on both the intra- and intermolecular tetraspanin interactions that shape the tetraspanin web. Furthermore, recent molecular dynamic modeling studies indicate that the binding strength between tetraspanins and between tetraspanins and their partners is the complex sum of both promiscuous and specific interactions. A deeper insight into this complex mixture of interactions is essential to our fundamental understanding of the tetraspanin web and its dynamics which constitute a basic building block of the cell surface.

scholarly journals Replaying the tape of life in the twenty-first century

2015 ◽  
Vol 5 (6) ◽  
pp. 20150057 ◽  
Author(s):  
Virginie Orgogozo
Keyword(s):  
Experimental Evolution ◽  
First Century ◽  
Phenotypic Evolution ◽  
Phenotypic Differences ◽  
Diverse Species ◽  
Evolution Of Life ◽  
Long Time ◽  
Time Periods ◽  
Living Organisms ◽  
Life On Earth

Should the tape of life be replayed, would it produce similar living beings? A classical answer has long been ‘no’, but accumulating data are now challenging this view. Repeatability in experimental evolution, in phenotypic evolution of diverse species and in the genes underlying phenotypic evolution indicates that despite unpredictability at the level of basic evolutionary processes (such as apparition of mutations), a certain kind of predictability can emerge at higher levels over long time periods. For instance, a survey of the alleles described in the literature that cause non-deleterious phenotypic differences among animals, plants and yeasts indicates that similar phenotypes have often evolved in distinct taxa through independent mutations in the same genes. Does this mean that the range of possibilities for evolution is limited? Does this mean that we can predict the outcomes of a replayed tape of life? Imagining other possible paths for evolution runs into four important issues: (i) resolving the influence of contingency, (ii) imagining living organisms that are different from the ones we know, (iii) finding the relevant concepts for predicting evolution, and (iv) estimating the probability of occurrence for complex evolutionary events that occurred only once during the evolution of life on earth.

Between openness and closure: Helmuth Plessner and the boundaries of social life

2017 ◽  
Vol 18 (1) ◽  
pp. 36-54 ◽  
Author(s):  
Alexander Dobeson
Keyword(s):  
Social Theory ◽  
Physical Environment ◽  
Social Life ◽  
Philosophical Anthropology ◽  
Degree Of Freedom ◽  
Specific Relation ◽  
Original Contribution ◽  
Helmuth Plessner ◽  
Living Organisms ◽  
High Degree

This article introduces the basic notions of the widely neglected Philosophical Anthropology of Helmuth Plessner. Instead of defining man as a privileged holder of consciousness, Plessner claims that all living organisms can be defined by their specific relation to their physical boundaries. In contrast to other living organisms such as plants and animals, however, the ‘eccentric’ nature of man allows for a comparatively high degree of freedom from the physical environment, which enables him to transcend, objectify, and deconstruct the boundaries of the same. The article concludes by outlining Plessner’s original contribution to contemporary debates in social theory, in particular constructivism and post-humanist studies.

scholarly journals Shedding light on biology of bacterial cells

2016 ◽  
Vol 371 (1707) ◽  
pp. 20150499 ◽  
Author(s):  
Johannes P. Schneider ◽  
Marek Basler
Keyword(s):  
Light Microscopy ◽  
Live Cell Imaging ◽  
Spatial Organization ◽  
Cell Imaging ◽  
Live Cell ◽  
Bacterial Cells ◽  
Resolution Limit ◽  
Detection Techniques ◽  
Living Organisms ◽  
Cellular Components

To understand basic principles of living organisms one has to know many different properties of all cellular components, their mutual interactions but also their amounts and spatial organization. Live-cell imaging is one possible approach to obtain such data. To get multiple snapshots of a cellular process, the imaging approach has to be gentle enough to not disrupt basic functions of the cell but also have high temporal and spatial resolution to detect and describe the changes. Light microscopy has become a method of choice and since its early development over 300 years ago revolutionized our understanding of living organisms. As most cellular components are indistinguishable from the rest of the cellular contents, the second revolution came from a discovery of specific labelling techniques, such as fusions to fluorescent proteins that allowed specific tracking of a component of interest. Currently, several different tags can be tracked independently and this allows us to simultaneously monitor the dynamics of several cellular components and from the correlation of their dynamics to infer their respective functions. It is, therefore, not surprising that live-cell fluorescence microscopy significantly advanced our understanding of basic cellular processes. Current cameras are fast enough to detect changes with millisecond time resolution and are sensitive enough to detect even a few photons per pixel. Together with constant improvement of properties of fluorescent tags, it is now possible to track single molecules in living cells over an extended period of time with a great temporal resolution. The parallel development of new illumination and detection techniques allowed breaking the diffraction barrier and thus further pushed the resolution limit of light microscopy. In this review, we would like to cover recent advances in live-cell imaging technology relevant to bacterial cells and provide a few examples of research that has been possible due to imaging. This article is part of the themed issue ‘The new bacteriology’.

scholarly journals Effect of traditional agriculture technology on communities of soil invertebrates

2018 ◽  
Vol 8 (1) ◽  
pp. 33-40 ◽  
Author(s):  
K. V. Andrusevich ◽  
M. M. Nazarenko ◽  
T. Yu. Lykholat ◽  
I. P. Grygoryuk
Keyword(s):  
Species Composition ◽  
Spatial Organization ◽  
Soil Surface ◽  
Soil Invertebrates ◽  
Degree Of Saturation ◽  
Forest Belt ◽  
Soil Animals ◽  
Soil Mesofauna ◽  
Living Organisms ◽  
Effective Use

The study of peculiarities specific for the spatial organization of communities of living organisms allows to develop principles of the rational and effective use of the biosphere natural resources and optimal adaptation of mankind to the natural environment. The aim of the research was to study communities of the soil mesofauna as an integral indicator of the state of soils under conditions of applying the traditional farming technology, to carry out the quantitative accounting of the soil mesofauna, and assessment of morphometric parameters of sunflower plants in places of selecting soil and zoological samples, to determine the species composition and abundance, as well as to analyze the ecological structure of the soil mesofauna community. Rheophilous species predominate on black steam, and mesophilic species predominate under sunflower. This can be explained by the fact that in the periodic cultivation of black steam, the evaporation from the soil surface is much higher. Ultra-mega-coenotrophs are dominant on black steam, and megacoenotrophs are dominant under sunflower. Since both demonstration trails are laid on one field, but have strategically been divided into a plot under black steam and a plot under sunflower, one can assume a different degree of saturation of the soil solution, as during the growth the crop being cultivated uses soil nutrients. Among topomorphs of soil animals, exactly soil animals are dominant, which is characteristic for both demonstration trails being studied. In the composition of trophomorphs of soil animals, phytophages are dominant in soil of the test demonstration trail on black steam, and in soil of the test demonstration trail, where sunflower was cultivated, phyto- and saprophages predominate in equal proportions. As a result of the correlation analysis, statistically reliable dependences are obtained: – numbers of soil animals in soil of the demonstration trail on black steam – on the distance from forest belt areas (-0.23) and length and width of sunflower leaves - on the distance from forest belt areas (0.53 and 0.53 respectively). The species composition, abundance and distribution in space of soil invertebrates are an informative indicator, which reflects the ecological state of soils, intensity in development of soil horizons as well as intensity of processes occurring in them.

scholarly journals A conserved expression signature predicts growth rate and reveals cell & lineage-specific differences

2019 ◽  
Author(s):  
Zhisheng Jiang ◽  
Serena Francesca Generoso ◽  
Marta Badia ◽  
Bernhard Payer ◽  
Lucas B. Carey
Keyword(s):  
Cell Lineage ◽  
Gene Expression Signature ◽  
Cell Types ◽  
Eukaryotic Cell ◽  
Rna Seq ◽  
Cell Type Specificity ◽  
Expression Signature ◽  
Differentiated Cells ◽  
Different Cell Types ◽  
High Degree

By performing RNA-seq on cells FACS sorted by their proliferation rate, this study identifies a gene expression signature capable of predicting proliferation rates in diverse eukaryotic cell types and species. This signature, applied to scRNAseq data from C.elegans, reveals lineage-specific differences in proliferation during development. In contrast to the universality of the proliferation signature, mitochondria and metabolism related genes show a high degree of cell-type specificity; mouse pluripotent stem cells (mESCs) and differentiated cells (fibroblasts) exhibit opposite relations between mitochondria state and proliferation. Furthermore, we identified a slow proliferating subpopulation of mESCs with higher expression of pluripotency genes. Finally, we show that fast and slow proliferating subpopulations are differentially sensitive to mitochondria inhibitory drugs in different cell types.

scholarly journals The evolution of multicellular complexity: the role of relatedness and environmental constraints

2020 ◽  
Vol 287 (1931) ◽  
pp. 20192963
Author(s):  
R. M. Fisher ◽  
J. Z. Shik ◽  
J. J. Boomsma
Keyword(s):  
Physical Environment ◽  
Evolutionary Biology ◽  
Social Evolution ◽  
Group Formation ◽  
Environmental Constraints ◽  
Evolutionary Transition ◽  
Organizational Complexity ◽  
Slime Moulds ◽  
The Many

A major challenge in evolutionary biology has been to explain the variation in multicellularity across the many independently evolved multicellular lineages, from slime moulds to vertebrates. Social evolution theory has highlighted the key role of relatedness in determining multicellular complexity and obligateness; however, there is a need to extend this to a broader perspective incorporating the role of the environment. In this paper, we formally test Bonner's 1998 hypothesis that the environment is crucial in determining the course of multicellular evolution, with aggregative multicellularity evolving more frequently on land and clonal multicellularity more frequently in water. Using a combination of scaling theory and phylogenetic comparative analyses, we describe multicellular organizational complexity across 139 species spanning 14 independent transitions to multicellularity and investigate the role of the environment in determining multicellular group formation and in imposing constraints on multicellular evolution. Our results, showing that the physical environment has impacted the way in which multicellular groups form, highlight that environmental conditions might have affected the major evolutionary transition to obligate multicellularity.

scholarly journals Emergent patterns from probabilistic generalizations of lateral activation and inhibition

2016 ◽  
Vol 13 (118) ◽  
pp. 20151077 ◽  
Author(s):  
Lisa Willis ◽  
Alexandre Kabla
Keyword(s):  
Probabilistic Model ◽  
Spatial Organization ◽  
Travelling Waves ◽  
Great Insight ◽  
Per Se ◽  
Living Organisms

The combination of laterally activating and inhibiting feedbacks is well known to spontaneously generate spatial organization. It was introduced by Gierer and Meinhardt as an extension of Turing's great insight that two reacting and diffusing chemicals can spontaneously drive spatial morphogenesis per se . In this study, we develop an accessible nonlinear and discrete probabilistic model to study simple generalizations of lateral activation and inhibition. By doing so, we identify a range of modes of morphogenesis beyond the familiar Turing-type modes; notably, beyond stripes, hexagonal nets, pores and labyrinths, we identify labyrinthine highways, Kagome lattices, gyrating labyrinths and multi-colour travelling waves and spirals. The results are discussed within the context of Turing's original motivating interest: the mechanisms which underpin the morphogenesis of living organisms.

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