scholarly journals Evolution of the potassium channel gene Kcnj13 underlies colour pattern diversification in Danio fish

2020 ◽  
Author(s):  
Marco Podobnik ◽  
Hans Georg Frohnhöfer ◽  
Christopher M. Dooley ◽  
Anastasia Eskova ◽  
Christiane Nüsslein-Volhard ◽  
...  

AbstractThe genetic basis of morphological variation provides a major topic in evolutionary biology1-6. Colour patterns in fish are among the most diverse of all vertebrates. Species of the genus Danio display strikingly different colour patterns ranging from horizontal stripes, to vertical bars or spots7-10. Stripe formation in zebrafish, Danio rerio, oriented by the horizontal myoseptum, is a self-organizing process based on cell-contact-mediated interactions between three types of chromatophores with a leading role of iridophores11-14. We investigated genes known to regulate chromatophore interactions in zebrafish as candidates that might have evolved to produce a pattern of vertical bars in its sibling species, Danio aesculapii8,10. Using gene editing15-17 we generated several mutants in D. aesculapii that demonstrate a lower complexity in the interactions between chromatophores in this species, as well as a minor role of iridophores in patterning. Complementation tests in interspecific hybrids18,19 identified obelix/Kcnj13, which encodes an inwardly rectifying potassium channel (Kir7.1)20, as a gene evolved between D. rerio and D. aesculapii as well as in two of seven more Danio species tested. Our results demonstrate that the CRISPR/Cas9-system allows straightforward genetic tests also in non-model vertebrates to identify genes that underlie morphological evolution.

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Marco Podobnik ◽  
Hans Georg Frohnhöfer ◽  
Christopher M. Dooley ◽  
Anastasia Eskova ◽  
Christiane Nüsslein-Volhard ◽  
...  

AbstractThe genetic basis of morphological variation provides a major topic in evolutionary developmental biology. Fish of the genus Danio display colour patterns ranging from horizontal stripes, to vertical bars or spots. Stripe formation in zebrafish, Danio rerio, is a self-organizing process based on cell−contact mediated interactions between three types of chromatophores with a leading role of iridophores. Here we investigate genes known to regulate chromatophore interactions in zebrafish that might have evolved to produce a pattern of vertical bars in its sibling species, Danio aesculapii. Mutant D. aesculapii indicate a lower complexity in chromatophore interactions and a minor role of iridophores in patterning. Reciprocal hemizygosity tests identify the potassium channel gene obelix/Kcnj13 as evolved between the two species. Complementation tests suggest evolutionary change through divergence in Kcnj13 function in two additional Danio species. Thus, our results point towards repeated and independent evolution of this gene during colour pattern diversification.


Nature Plants ◽  
2016 ◽  
Vol 2 (11) ◽  
Author(s):  
Xiangchao Gan ◽  
Angela Hay ◽  
Michiel Kwantes ◽  
Georg Haberer ◽  
Asis Hallab ◽  
...  

Abstract Finding causal relationships between genotypic and phenotypic variation is a key focus of evolutionary biology, human genetics and plant breeding. To identify genome-wide patterns underlying trait diversity, we assembled a high-quality reference genome of Cardamine hirsuta, a close relative of the model plant Arabidopsis thaliana. We combined comparative genome and transcriptome analyses with the experimental tools available in C. hirsuta to investigate gene function and phenotypic diversification. Our findings highlight the prevalent role of transcription factors and tandem gene duplications in morphological evolution. We identified a specific role for the transcriptional regulators PLETHORA5/7 in shaping leaf diversity and link tandem gene duplication with differential gene expression in the explosive seed pod of C. hirsuta. Our work highlights the value of comparative approaches in genetically tractable species to understand the genetic basis for evolutionary change.


1987 ◽  
Author(s):  
E Lavenne-Pardonge ◽  
C Col-De Beys ◽  
M Moriau

The interest of release of TG and FPA for the diagnosis and treatment of prethrombotic and thrombotic disorders is well knownThe ratio of increase of these two parameters (Δ+βTG/+ FPA) seems to bring some additional informations.This ratio, normally about 1, increases in isolated or preponderant platelet activation and decreases when platelet activation plays a minor role than the plasmatic factors. A more logical choice of therapeutics and a better control of its effectiveness are so possible.This study includes 91 cases of established thrombosis (20 arterial and 71 venous) and 272 cases of prethrombotic disorders (58 Raynaud syndromes, 54 cases of venous insufficiency, 60 of hip prosthesis, 40 of coronary by-pass, 60 of valvular replacement). The ratio + TG/ + FPA was calculated before, during and after efficacious or inefficacious treatment. In the cases of established thrombosis, our results confirm the leading role of platelets in the development of arterial thrombosis. The cases of venous thrombosis may be divided in two groups : simple venous thrombosis when the plasmatic factors play a leading role and complicated or recurrent venous thrombosis where the platelets play an equivalent or even a greater role.In the cases of prethrombotic states, the role of the platelets which is important on the arterial side is generally far from negligeable on the venous side. In cases of valvular replacement or of coronary by-pass the modification of the ratio lead us very frequently to modify our prophylactic therapeutics


1986 ◽  
Vol 64 (4) ◽  
pp. 785-789 ◽  
Author(s):  
Roberto Aruga

A calculation method of the electrostatic and the nonelectrostatic parts of thermodynamic quantities of reaction, previously proposed and applied to association reactions in aqueous medium, is applied, in the present work, to reactions in mixed solvents. The aim of the present treatment is to clarify the importance of the various factors (dependent and independent of the dielectric constant) through which the solvent affects complex stability. The method is applied to ΔG0, ΔH0, and ΔS0 data of literature for proton–ligand and metal–ligand reactions in several water–methanol, water–ethanol, and water–dioxane mixtures. The conclusions of the present study seem to confirm a leading role of solvation equilibria in determining different stabilities of complex in different solvents, while a minor role is assigned to the dielectric properties of the solvent.


2019 ◽  
Vol 286 (1902) ◽  
pp. 20190435 ◽  
Author(s):  
M. J. Daniel ◽  
L. Koffinas ◽  
K. A. Hughes

Populations harbour enormous genetic diversity in ecologically important traits. Understanding the processes that maintain this variation is a long-standing challenge in evolutionary biology. Recent evidence indicates that a mating preference for novel sexual signals can be a powerful force maintaining genetic diversity. However, the proximate underpinnings of this preference, and its generality, remain unclear. Here, we test the hypothesis that preference for novel sexual signals is underpinned by habituation, a nearly ubiquitous form of learning whereby individuals become less responsive to repetitive stimuli. We use the Trinidadian guppy ( Poecilia reticulata ), in which male colour patterns are diverse yet heritable. We show that repeated exposure to males with a given colour pattern reduces female interest in males with that pattern, and that interest recovers following brief isolation. These results fulfil two core criteria of habituation: responsiveness decline and spontaneous recovery. To distinguish habituation from sensory adaptation and fatigue, we also demonstrate stimulus specificity and dishabituation. These results provide the first evidence that habituation causes a preference for novel sexual signals, addressing the mechanistic underpinnings of this mating preference. Given the pervasiveness of habituation among taxa and sensory contexts, our findings suggest that preference for novelty may play an underappreciated role in mate choice and the maintenance of genetic variation.


2017 ◽  
Vol 284 (1855) ◽  
pp. 20170744 ◽  
Author(s):  
Keith R. Willmott ◽  
Julia C. Robinson Willmott ◽  
Marianne Elias ◽  
Chris D. Jiggins

Mimicry is one of the best-studied examples of adaptation, and recent studies have provided new insights into the role of mimicry in speciation and diversification. Classical Müllerian mimicry theory predicts convergence in warning signal among protected species, yet tropical butterflies are exuberantly diverse in warning colour patterns, even within communities. We tested the hypothesis that microhabitat partitioning in aposematic butterflies and insectivorous birds can lead to selection for different colour patterns in different microhabitats and thus help maintain mimicry diversity. We measured distribution across flight height and topography for 64 species of clearwing butterflies (Ithomiini) and their co-mimics, and 127 species of insectivorous birds, in an Amazon rainforest community. For the majority of bird species, estimated encounter rates were non-random for the two most abundant mimicry rings. Furthermore, most butterfly species in these two mimicry rings displayed the warning colour pattern predicted to be optimal for anti-predator defence in their preferred microhabitats. These conclusions were supported by a field trial using butterfly specimens, which showed significantly different predation rates on colour patterns in two microhabitats. We therefore provide the first direct evidence to support the hypothesis that different mimicry patterns can represent stable, community-level adaptations to differing biotic environments.


Author(s):  
Katherine Guérard ◽  
Sébastien Tremblay

In serial memory for spatial information, some studies showed that recall performance suffers when the distance between successive locations increases relatively to the size of the display in which they are presented (the path length effect; e.g., Parmentier et al., 2005) but not when distance is increased by enlarging the size of the display (e.g., Smyth & Scholey, 1994). In the present study, we examined the effect of varying the absolute and relative distance between to-be-remembered items on memory for spatial information. We manipulated path length using small (15″) and large (64″) screens within the same design. In two experiments, we showed that distance was disruptive mainly when it is varied relatively to a fixed reference frame, though increasing the size of the display also had a small deleterious effect on recall. The insertion of a retention interval did not influence these effects, suggesting that rehearsal plays a minor role in mediating the effects of distance on serial spatial memory. We discuss the potential role of perceptual organization in light of the pattern of results.


2019 ◽  
pp. 22-29
Author(s):  
Н. В. Фрадкіна

The purpose and tasks of the work are to analyze the contemporary Ukrainian mass culture in terms of its value and humanistic components, as well as the importance of cultural studies and Ukrainian studies in educational disciplines for the formation of a holistic worldview of modern youth.Analysis of research and publications. Scientists repeatedly turned to the problems of the role of spirituality in the formation of society and its culture. This problem is highlighted in the publications by O. Losev, V. Lytvyn, D. Likhachev, S. Avierintsev, M. Zakovych, I. Stepanenko and E. Kostyshyn.Experts see the main negative impact of mass culture on the quality approach, which determines mass culture through the market, because mass culture, from our point of view, is everything that is sold and used in mass demand.One of the most interesting studies on this issue was the work by the representatives of Frankfurt School M. Horkheimer and T. Adorno «Dialectics of Enlightenment» (1947), devoted to a detailed analysis of mass culture. Propaganda at all socio-cultural levels in the form is similar in both totalitarian and democratic countries. It is connected, according to the authors, with the direction of European enlightenment. The tendency to unify people is a manifestation of the influence of mass culture, from cinema to pop. Mass culture is a phenomenon whose existence is associated with commerce (accumulation in any form – this is the main feature of education), in general, the fact that it exists in this form is related to the direction of the history of civilization.Modern mass culture, with its externally attractive and easily assimilated ideas and symbols, appealing to the trends of modern fashion, becomes a standard of prestigious consumption, does not require intense reflection, allows you to relax, distract, not teach, but entertains, preaches hedonism as the main spiritual value. And as a consequence, there are socio-cultural risks: an active rejection of other people, which leads to the formation of indifference; cruelty as a character trait; increase of violent and mercenary crime; increase in the number of alcohol and drug addicts; anti-patriotism; indifference to the values of the family and as a result of social orphanhood and prostitution.Conclusions, perspectives of research. Thus, we can conclude that modern Ukrainian education is predominantly formed by the values of mass culture. Namely, according to the «Dialectic» by Horkheimer and Adorno, «semi-enlightenment becomes an objective spirit» of our modern society.It is concluded that only high-quality education can create the opposite of the onset of mass culture and the destruction of spirituality in our society. It is proved that only by realizing the importance of cultivating disciplines in the educational process and the spiritual upbringing of the nation, through educational reforms, humanitarian knowledge will gradually return to student audiences.Formation of youth occurs under the influence of social environment, culture, education and self-education. The optimal combination of these factors determines both the process of socialization itself and how successful it will be. In this context, one can see the leading role of education and upbringing. It turns out that the main task of modern education is to spread its influence on the development of spiritual culture of the individual, which eventually becomes a solid foundation for the formation of the individual. Such a subject requires both philosophical and humanitarian approaches in further integrated interdisciplinary research, since the availability of such research will provide the theoretical foundation for truly modern educational and personal development.


1991 ◽  
Vol 18 (3) ◽  
pp. 333-362 ◽  
Author(s):  
MADELEINE LY-TIO-FANE

SUMMARY The recent extensive literature on exploration and the resulting scientific advances has failed to highlight the contribution of Austrian enterprise to the study of natural history. The leading role of Joseph II among the neutral powers which assumed the carrying trade of the belligerents during the American War of Independence, furthered the development of collections for the Schönbrunn Park and Gardens which had been set up on scientific principles by his parents. On the conclusion of peace, Joseph entrusted to Professor Maerter a world-encompassing mission in the course of which the Chief Gardener Franz Boos and his assistant Georg Scholl travelled to South Africa to collect plants and animals. Boos pursued the mission to Isle de France and Bourbon (Mauritius and Reunion), conveyed by the then unknown Nicolas Baudin. He worked at the Jardin du Roi, Pamplemousses, with Nicolas Cere, or at Palma with Joseph Francois Charpentier de Cossigny. The linkage of Austrian and French horticultural expertise created a situation fraught with opportunities which were to lead Baudin to the forefront of exploration and scientific research as the century closed in the upheaval of the Revolutionary Wars.


2020 ◽  
pp. 81-92
Author(s):  
Andrey Ivanovich Shutenko ◽  
◽  
Elena Nikolaevn Shutenko ◽  
Julia Petrovna Derevyanko ◽  
◽  
...  

The article is devoted to the problem of educational communications development as a sphere of implementation of modern information-communication technologies in the higher education system. The purpose of the article is to present the structure and functions of educational communications aimed at the development of personal potential and self-realization of students. Methodology. The study is based on the methodology of personal and communicative-informational approaches in education, psychological-pedagogical provisions on the structure of communication, the leading role of learning activity, didactic principles of building an educational-informational environment. In theoretical terms, the study is based on the idea of the indirect implementation of ICT in education through the development of educational communications. The developing structure of educational communications, including didactic, informational-gnostic, interactive, psychological, attractive-motivational, value-semantic components, is presented. The possibilities of developing personal potential in educational communications are considered. The author’s developmental model of ICT functions is presented, which includes clusters of actual and latent functions aimed at the formation of information-educational space for the development of students’ personal potential. In conclusion, a inference was made about the prospects of the indirect introduction of modern ICT as tools for the development and functioning of various educational communications. At the same time, it is essential that these communications perform psychological and pedagogical tasks and functions.


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