scholarly journals THE IMPACT OF MISTRANSLATION ON PHENOTYPIC VARIABILITY AND FITNESS

Author(s):  
Laasya Samhita ◽  
Parth K Raval ◽  
Godwin Stephenson ◽  
Shashi Thutupalli ◽  
Deepa Agashe

ABSTRACTPhenotypic variation is widespread in natural populations, and can significantly alter their ecology and evolution. Phenotypic variation often reflects underlying genetic variation, but also manifests via non-heritable mechanisms. For instance, translation errors result in about 10% of cellular proteins carrying altered sequences. Thus, proteome diversification arising from translation errors can potentially generate phenotypic variability, in turn increasing variability in the fate of cells or of populations. However, this link remains unverified. We manipulated mistranslation levels in Escherichia coli, and measured phenotypic variability between single cells (individual level variation), as well as replicate populations (population level variation). Monitoring growth and survival, we find that mistranslation indeed increases variation across E. coli cells, but does not consistently increase variability in growth parameters across replicate populations. Interestingly, although any deviation from the wild type (WT) level of mistranslation reduces fitness in an optimal environment, the increased variation is associated with a survival benefit under stress. Hence, we suggest that mistranslation-induced phenotypic variation can impact growth and survival and has the potential to alter evolutionary trajectories.

2016 ◽  
Author(s):  
Thurston Herricks ◽  
David J. Dilworth ◽  
Fred D. Mast ◽  
Song Li ◽  
Jennifer J. Smith ◽  
...  

ABSTRACTCell growth is a complex phenotype widely used in systems biology to gauge the impact of genetic and environmental perturbations. Due to the magnitude of genome-wide studies, resolution is often sacrificed in favor of throughput, creating a demand for scalable, time-resolved, quantitative methods of growth assessment. We present ODELAY (One-cell Doubling Evaluation by Living Arrays of Yeast), an automated and scalable growth analysis platform. High measurement density and single cell resolution provide a powerful tool for large-scale multiparameter growth analysis based on the modeling of microcolony expansion on solid media. Pioneered in yeast but applicable to other colony forming organisms, ODELAY extracts the three key growth parameters (lag time, doubling time, and carrying capacity) that define microcolony expansion from single cells, simultaneously permitting the assessment of population heterogeneity. The utility of ODELAY is illustrated using yeast mutants, revealing a spectrum of phenotypes arising from single and combinatorial growth parameter perturbations.


1983 ◽  
Vol 40 (7) ◽  
pp. 948-954 ◽  
Author(s):  
Andre L. Mallet ◽  
L. E. Haley

Phenotypic differences were observed among pure population matings and crosses grown in two natural environments for the following characters: larval shell length, juvenile and adult shell length, weight, and survival at different times. For growth characters, the phenotypic variability between locations was greater than the variability among genetic groups within locations; however, the magnitude of the differences depended on the locality. The crosses exhibited higher survival than pure population matings, and locality had no effect on survival. In growth and survival, some crosses deviated positively from the mean of the parental populations. This may be a manifestation of heterosis. The genetic enhancement of commercially important characters in shellfish will eventually require the formation of a closed breeding unit with a broad genetic base for domestication and selection. It is recommended that an evaluation of natural populations as outlined in this study is a necessary prerequisite to achieve this objective.


2015 ◽  
Author(s):  
Paul François ◽  
Grégoire Altan-Bonnet

Some cells have to take decision based on the quality of surroundings ligands, almost irrespective of their quantity, a problem we name "absolute discrimination". An example of absolute discrimination is recognition of not-self by immune T Cells. We show how the problem of absolute discrimination can be solved by a process called "adaptive sorting". We review several implementations of adaptive sorting, as well as its generic properties such as antagonism. We show how kinetic proofreading with negative feedback implements an approximate version of adaptive sorting in the immune context. Finally, we revisit the decision problem at the cell population level, showing how phenotypic variability and feedbacks between population and single cells are crucial for proper decision.


2018 ◽  
Vol 40 (3) ◽  
Author(s):  
Carolina Ribeiro Diniz Boaventura Novaes ◽  
Elias Emanuel Silva Mota ◽  
Evandro Novaes ◽  
Mariana Pires de Campos Telles ◽  
Lázaro José Chaves

Abstract Eugenia dysenterica DC. (cagaita tree) is a fruit tree native to the Brazilian Cerrado. It is a promising species for cultivation, but little basic information exists on the phenotypic diversity and quantitative variation of its fruits and seeds at a population scale. Thus, the present study proposes to estimate the phenotypic parameters of the species’ fruits and seeds based on the variability among mother plants and among subpopulations, thereby aiming to increase knowledge for breeding and conservation of the species. For this, 25 natural subpopulations (local populations) were sampled in five Brazilian states. Within each subpopulation, 20 fruits were collected from each of six sampled mother plants. Data for biomass, transverse and longitudinal lengths of the fruits and seeds were subjected to estimates of descriptive parameters, correlation and hierarchical analysis of variance (ANOVA). Significant variation, including high levels of phenotypic variation, was observed among mother plants within the subpopulations and between the subpopulations. The high variation and the formation of phenotypically divergent groups are important elements for the breeding of cagaita tree, whose mother plants can now be selected for the traits studied. Phenotypic divergence between populations (PST) can be used as an indicator of the structuring of the phenotypic variation of the species in its natural area of occurrence.


2014 ◽  
Vol 24 (3) ◽  
pp. 195-205 ◽  
Author(s):  
Anne Cochrane ◽  
Gemma L. Hoyle ◽  
Colin J. Yates ◽  
Jeff Wood ◽  
Adrienne B. Nicotra

AbstractTemperature is a significant factor influencing seed germination and for many species temperature-mediated germination cues are vital for plant persistence. Rising temperatures forecast as a result of anthropogenic climate change may have a substantial influence on the population and range dynamics of plant species. Here, we report on the thermal constraints on seed germination in natural populations of four congeneric Banksia species collected from a longitudinal climate gradient in Western Australia. We investigated whether germination niche: (1) varied between species; (2) varied among populations of each species; and (3) varied in a consistent manner reflecting the climatic gradients of seed origin. We hypothesized that species would differ and that populations from warmer sites would have a broader temperature window for germination than populations from cooler sites. Species differed in the breadth of their germination niche, but temperatures that stimulated the most rapid and complete germination were similar across all species. A sharp reduction in germination percentage occurred above the optimum temperature, which coincided with significant delays in germination relative to the optimum. The temperatures causing these declines varied among populations. Across the species, there was a significant correlation between optimum germination temperature and mean annual temperature at seed source; however, there was no relationship at the population level for individual species. These data provide insight into the vulnerability of Banksia species to climate change, with those populations that require lower temperatures for germination, or have narrower optimal ranges for germination, likely to be most vulnerable to a warming climate.


2020 ◽  
Author(s):  
Guoyu Wu ◽  
Yuchao Li

Abstract Background:Correlation analysis is widely used in biological studies to infer molecular relationships within biological networks. Recently, single-cell analysis has drawn tremendous interests, for its ability to obtain high-resolution molecular phenotypes. It turns out that there is little overlap of co-expressed genes identified in single-cell level investigations with that of population level investigations. However, the nature of the relationship of correlations between single-cell and population levels remains unclear. In this manuscript, we aimed to unveil the origin of the differences between the correlation coefficients at the single-cell level and that at the population level, and bridge the gap between them. Results:Through developing formulations to link correlations at the single-cell and the population level, we illustrated that aggregated correlations could be stronger, weaker or equal to the corresponding individual correlations, depending on the variations and the correlations within the population. When the correlation-within is weaker than the individual correlation, the correlation at the population level is stronger than that at the single-cell level. Through a bottom-up approach to model interactions between molecules in a signaling cascade or a multi-regulator controlled gene expression, we surprisingly found that the existence of interaction between two components could not be excluded simply based on their low correlation coefficients, suggesting a reconsideration of connectivity within biological networks which was derived solely from correlation analysis. We also investigated the impact of technical random measurement errors on the correlation coefficients for the single-cell level and the population level. The results indicate that the aggregated correlation is relatively robust and less affected.Conclusions:Because of the heterogeneity among single cells, correlation coefficients calculated based on data of the single-cell level might be different from that of the population level. Depending on the specific question we are asking, proper sampling and normalization procedure should be done before we draw any conclusions.


1994 ◽  
Vol 72 (5) ◽  
pp. 693-700 ◽  
Author(s):  
G. L. Rapson ◽  
Jack Maze

Phenotypic properties indicating levels of variation and integration were compared among three populations of a rare bunch grass, Achnatherum (Oryzopsis) hendersonii (tribe Stipeae), and one parapatric population of each of its common relatives Achnatherum (Stipa) lemmonii and Achnatherum (Stipa) thurberiana, sampled from the Colockum Pass area of central Washington, U.S.A. Twenty-five randomly selected plants from each population were measured for both vegetative and spikelet features. The vegetative features were represented by morphometric measurements taken from one leaf on a tiller and the flag leaf on a flowering culm. The spikelet features were based on two to eight spikelets per plant. The three data sets were analyzed separately to compare population level variation both among individuals and among variables (variable covariation). Phenotypic variation among individuals is lowest for A. hendersonii in estimators of both size and shape; within-individual phenotypic variation, as evaluated through among-variable correlation coefficients, is highest for A. hendersonii and lowest for A. thurberiana. The lower level of among-individual variation for A. hendersonii is consistent with biological beliefs about rare species; its higher among-variable variation may indicate less precise control of integration. Key words: rarity, morphological variation and integration, Poaceae, Achnatherum.


Author(s):  
Leslie M. Loew

A major application of potentiometric dyes has been the multisite optical recording of electrical activity in excitable systems. After being championed by L.B. Cohen and his colleagues for the past 20 years, the impact of this technology is rapidly being felt and is spreading to an increasing number of neuroscience laboratories. A second class of experiments involves using dyes to image membrane potential distributions in single cells by digital imaging microscopy - a major focus of this lab. These studies usually do not require the temporal resolution of multisite optical recording, being primarily focussed on slow cell biological processes, and therefore can achieve much higher spatial resolution. We have developed 2 methods for quantitative imaging of membrane potential. One method uses dual wavelength imaging of membrane-staining dyes and the other uses quantitative 3D imaging of a fluorescent lipophilic cation; the dyes used in each case were synthesized for this purpose in this laboratory.


2015 ◽  
Vol 26 (3-4) ◽  
pp. 116-123
Author(s):  
A. P. Korzh ◽  
T. V. Zahovalko

Recently, the number of published works devoted to the processes of synanthropization of fauna, is growing like an avalanche, which indicates the extreme urgency of this theme. In our view, the process of forming devices to coexist with human and the results of his life reflects the general tandency of the modern nature evolution. Urbanization is characteristic for such a specific group of animals like amphibians, the evidence of which are numerous literature data. Many researchers use this group to assess the bioindicative quality of the environment. For this aim a variety of indicators are used: from the cellular level of life of organization up to the species composition of the group in different territories. At the same time, the interpretation of the results is not always comparable for different areas and often have significantly different interpretations by experts. Urban environment, primarily due to the contamination is extremely aggressive to amphibians. As a consequence, the urban populations of amphibians may be a change in the demographic structure, affecting the reproductive ability of the population, the disappearance of the most sensitive species or individuals, resizing animals, the appearance of abnormalities in the development, etc. At the same time play an important amphibians in the ecosystems of cities, and some species in these conditions even feel relatively comfortable. Therefore, it is interesting to understand the mechanisms of self-sustaining populations of amphibians in urban environments. To assess the impact of natural and anthropogenic factors on the development of amphibian populations were used cognitive modeling using the program Vensim PLE. Cognitive map of the model for urban and suburban habitat conditions were the same. The differences concerned the strength of connections between individual factors (migration, fertility, pollution) and their orientation. In general, factors like pollution, parasites, predators had negative impact on the population, reducing its number. The birth rate, food and migration contributed to raising number of individuals. Some of the factors affected on the strength to of each other as well: the majority of the factors affected the structure of the population, had an influence on the fertility. Thanks to it the model reflects the additive effect of complex of factors on the subsequent status of the population. Proposed and analyzed four scenarios differing strength and duration of exposure. In the first scenario, a one-time contamination occurs and not subsequently repeated. The second and third scenario assumes half board contamination, 1 year (2 scenario) and two years (scenario 3). In the fourth scenario, the pollution affected the population of amphibians constantly. In accordance with the results of simulation, much weaker than the natural populations respond to pollution - have them as an intensive population growth and its disappearance at constant pollution is slow. Changes to other parameters of the model showed that this pollution is the decisive factor -only the constant action leads to a lethal outcome for the populations. All other components of the model have a corrective effect on the population dynamics, without changing its underlying trand. In urban areas due to the heavy impact of pollution maintaining the population is only possible thanks to the migration process – the constant replenishment of diminishing micropopulations of natural reserves. This confirms the assumption that the form of existence metapopulations lake frog in the city. In order to maintain the number of amphibians in urban areas at a high level it is necessary to maintain existing migration routes and the creation of new ones. Insular nature of the placement of suitable habitats in urban areas causes the metapopulation structure of the types of urbanists. Therefore, the process of urbanization is much easier for those species whicht are capable of migration in conditions of city. In the initial stages of settling the city micropopulationis formed by selective mortality of the most susceptible individuals to adverse effects. In future, maintaining the categories of individuals is provided mainly due to migration processes metapopulisation form of the species of existence is supported). It should be noted that the changes in the previous levels are always saved in future. In the case of reorganizations of individuals we of morphology can assume the existence of extremely adverse environmental conditions that threaten the extinction of the micropopulations. 


2019 ◽  
Vol 80 (4) ◽  
pp. 200-204 ◽  
Author(s):  
Brittany Cormier ◽  
Lana Vanderlee ◽  
David Hammond

Purpose: In 2010, Health Canada implemented a national campaign to improve understanding of “percent daily value” (%DV) in Nutrition Facts Tables (NFTs). This study examined sources of nutrition information and knowledge of %DV information communicated in the campaign. Methods: Respondents aged 16–30 years completed the Canada Food Study in 2016 (n = 2665). Measures included sources of nutrition information, NFT use, and %DV knowledge based on the campaign message (“5% DV or less is a little; 15% DV or more is a lot”). A logistic regression examined correlates of providing “correct” responses to %DV questions related to the campaign messaging. Results: Overall, 7.2% (n = 191) respondents correctly indicated that 5% is “a little”, and 4.3% (n = 115) correctly indicated 15% DV was “a lot”. Only 4.0% (n = 107) correctly answered both. Correct recall of %DV amounts was not associated with number of information sources reported, but was greater among those who were female, were younger, and reported greater NFT understanding and serving size information use (P < 0.05 for all). Conclusions: Results show low awareness of messaging from the Nutrition Facts Education Campaign among young Canadians. Such a mass media campaign may be insufficient on its own to enhance population-level understanding of %DV.


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