scholarly journals The Key Role of Epigenetics in the Persistence of Asexual Lineages

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Emilie Castonguay ◽  
Bernard Angers
Keyword(s):  
Phenotypic Plasticity ◽  
Recent Work ◽  
Molecular Mechanism ◽  
Crucial Role ◽  
Environmental Variation ◽  
Epigenetic Modifications ◽  
Epigenetic Variation ◽  
Epigenetic Mechanisms ◽  
Evolutionary Persistence

Asexual organisms, often perceived as evolutionary dead ends, can be long-lived and geographically widespread. We propose that epigenetic mechanisms could play a crucial role in the evolutionary persistence of these lineages. Genetically identical organisms could rely on phenotypic plasticity to face environmental variation. Epigenetic modifications could be the molecular mechanism enabling such phenotypic plasticity; they can be influenced by the environment and act at shorter timescales than mutation. Recent work on the asexual vertebrate Chrosomus eos-neogaeus (Pisces: Cyprinidae) provides broad insights into the contribution of epigenetics in genetically identical individuals. We discuss the extension of these results to other asexual organisms, in particular those resulting from interspecific hybridizations. We finally develop on the evolutionary relevance of epigenetic variation in the context of heritability.

scholarly journals Epigenetic mechanisms in sexual differentiation of the brain and behaviour

2016 ◽  
Vol 371 (1688) ◽  
pp. 20150114 ◽  
Author(s):  
Nancy G. Forger
Keyword(s):  
Gene Expression ◽  
Sex Differences ◽  
Sexual Differentiation ◽  
Wide Distribution ◽  
Epigenetic Modifications ◽  
Epigenetic Mechanism ◽  
Epigenetic Mechanisms ◽  
Genome Wide ◽  
The Brain

Circumstantial evidence alone argues that the establishment and maintenance of sex differences in the brain depend on epigenetic modifications of chromatin structure. More direct evidence has recently been obtained from two types of studies: those manipulating a particular epigenetic mechanism, and those examining the genome-wide distribution of specific epigenetic marks. The manipulation of histone acetylation or DNA methylation disrupts the development of several neural sex differences in rodents. Taken together, however, the evidence suggests there is unlikely to be a simple formula for masculine or feminine development of the brain and behaviour; instead, underlying epigenetic mechanisms may vary by brain region or even by dependent variable within a region. Whole-genome studies related to sex differences in the brain have only very recently been reported, but suggest that males and females may use different combinations of epigenetic modifications to control gene expression, even in cases where gene expression does not differ between the sexes. Finally, recent findings are discussed that are likely to direct future studies on the role of epigenetic mechanisms in sexual differentiation of the brain and behaviour.

scholarly journals How might epigenetics contribute to ecological speciation?

2013 ◽  
Vol 59 (5) ◽  
pp. 686-696 ◽  
Author(s):  
Gilbert Smith ◽  
Michael G. Ritchie
Keyword(s):  
Phenotypic Plasticity ◽  
Sex Differentiation ◽  
Ecological Speciation ◽  
Epigenetic Variation ◽  
Epigenetic Mechanisms ◽  
Epigenetic Marks ◽  
Multiple Generations ◽  
Ecological Selection ◽  
Environmental Induction ◽  
Conflict Regulation

Abstract Speciation research has seen a renewed interest in ecological speciation, which emphasises divergent ecological selection leading to the evolution of reproductive isolation. Selection from divergent ecologies means that phenotypic plasticity can play an important role in ecological speciation. Phenotypic plasticity involves the induction of phenotypes over the lifetime of an organism and emerging evidence suggests that epigenetic marks such as cytosine and protein (histone) modifications might regulate such environmental induction. Epigenetic marks play a wide role in a variety of processes including development, sex differentiation and allocation, sexual conflict, regulation of transposable elements and phenotypic plasticity. Here we describe recent studies that investigate epigenetic mechanisms in a variety of contexts. There is mounting evidence for environmentally induced epigenetic variation and for the stable inheritance of epigenetic marks between generations. Thus, epigenetically-based phenotypic plasticity may play a role in adaptation and ecological speciation. However, there is less evidence for the inheritance of induced epigenetic variation across multiple generations in animals. Currently few studies of ecological speciation incorporate the potential for the involvement of epigenetically-based induction of phenotypes, and we argue that this is an important omission.

scholarly journals Non-genetic inheritance in evolutionary theory - the importance of plant studies

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Marta Robertson ◽  
Christina Richards
Keyword(s):  
Evolutionary Theory ◽  
Evolutionary Process ◽  
Epigenetic Inheritance ◽  
Causal Role ◽  
Epigenetic Variation ◽  
Epigenetic Mechanisms ◽  
Epigenetic Machinery ◽  
Evolutionary Studies ◽  
Modern Evolutionary Theory

AbstractEmerging evidence points to a causal role for epigenetic variation in evolution, but evolutionary biologists have been reluctant to incorporate epigenetics into modern evolutionary theory. Part of this ambivalence comes from the assumption that epigenetic inheritance is only relevant to the evolution of plants, which is perpetuated by a comparative lack of evolutionary studies in animals. However, although most of the evidence for epigenetic inheritance comes from plants, plants and animals share many homologous epigenetic mechanisms, and plants provide a more tractable system for investigating the causal role of epigenetic mechanisms underlying phenotypic variation and its relationship with fitness. The insights from studies of epigenetic inheritance in plants may be applicable across a broad range of taxa once we establish commonalities and differences in epigenetic machinery. In this paper we present evidence for a role of epigenetic mechanisms in the evolutionary process and discuss common objections to incorporating epigenetics into evolutionary theory. This review is not exhaustive, but is meant to demonstrate that epigenetic inheritance can be incorporated into current evolutionary theory without overhauling its foundations.

scholarly journals JALT2015 Conference Article: On Emotions in Foreign Language Learning and Use

2015 ◽  
Vol 39 (3) ◽  
pp. 13 ◽  
Author(s):  
Jean-Marc Dewaele
Keyword(s):  
Foreign Language ◽  
Language Learning ◽  
Recent Work ◽  
Learning Process ◽  
Crucial Role ◽  
Foreign Language Learning ◽  
Language Anxiety ◽  
Foreign Language Anxiety ◽  
Language Classroom

Emotions are at the heart of the foreign language learning process. Without emotion, boredom would reign and very little learning would take place. I report on some recent work that has investigated the role of emotion in the foreign language classroom, both positive (foreign language enjoyment) and negatives ones (foreign language anxiety). It seems that both learners and teachers play a crucial role in managing emotions in the classroom. I also report on the difficulties associated with the communication of emotions in a foreign language and on their relative absence in foreign language course books and during classes. This leaves learners ill-prepared to recognise and express emotions appropriately in a foreign language, which is an essential part of sociopragmatic competence. 外国語学習過程の中心には「感情」がある。感情がなければ飽きるのも早く、学びも限られてしまう。本論では、外国語の授業で感情が果たす肯定的な（例：外国語学習の楽しみ）および否定的な（例：外国語学習不安）役割について報告する。そして最近の研究を基に、いかに学習者と教員双方がクラスでの感情のコントロールに深くかかわっているかを考察する。また、外国語で感情を伝えることの難しさについても触れ、外国語の教科書や授業で感情表現が扱われることの少なさが、社会語用論的能力の主な要素である感情表現の理解不足につながっていることを指摘する。

scholarly journals How does epigenetics influence the course of evolution?

2021 ◽  
Vol 376 (1826) ◽  
Author(s):  
Alyson Ashe ◽  
Vincent Colot ◽  
Benjamin P. Oldroyd
Keyword(s):  
Natural Selection ◽  
Phenotypic Plasticity ◽  
Dna Sequence ◽  
Genome Stability ◽  
Epigenetic Variation ◽  
Sequence Evolution ◽  
Phenotypic Variance ◽  
Epigenetic Mechanisms ◽  
The One ◽  
A Minor

Epigenetics is the study of changes in gene activity that can be transmitted through cell divisions but cannot be explained by changes in the DNA sequence. Epigenetic mechanisms are central to gene regulation, phenotypic plasticity, development and the preservation of genome integrity. Epigenetic mechanisms are often held to make a minor contribution to evolutionary change because epigenetic states are typically erased and reset at every generation, and are therefore, not heritable. Nonetheless, there is growing appreciation that epigenetic variation makes direct and indirect contributions to evolutionary processes. First, some epigenetic states are transmitted intergenerationally and affect the phenotype of offspring. Moreover, bona fide heritable ‘epialleles' exist and are quite common in plants. Such epialleles could, therefore, be subject to natural selection in the same way as conventional DNA sequence-based alleles. Second, epigenetic variation enhances phenotypic plasticity and phenotypic variance and thus can modulate the effect of natural selection on sequence-based genetic variation. Third, given that phenotypic plasticity is central to the adaptability of organisms, epigenetic mechanisms that generate plasticity and acclimation are important to consider in evolutionary theory. Fourth, some genes are under selection to be ‘imprinted' identifying the sex of the parent from which they were derived, leading to parent-of-origin-dependent gene expression and effects. These effects can generate hybrid disfunction and contribute to speciation. Finally, epigenetic processes, particularly DNA methylation, contribute directly to DNA sequence evolution, because they act as mutagens on the one hand and modulate genome stability on the other by keeping transposable elements in check. This article is part of the theme issue ‘How does epigenetics influence the course of evolution?'

scholarly journals Epigenetics of obesity

2020 ◽  
Vol 19 (6) ◽  
pp. 2632
Author(s):  
O. M. Drapkina ◽  
O. T. Kim
Keyword(s):  
Gene Expression ◽  
Deoxyribonucleic Acid ◽  
Fat Distribution ◽  
Epigenetic Modifications ◽  
Lifestyle Changes ◽  
Epigenetic Mechanisms ◽  
Epigenetic Changes ◽  
Critical Periods ◽  
Affect Gene Expression

The pathophysiology of obesity is complex and includes changes in eating behavior, genetic, epigenetic, environmental factors, and much more. To date, ~40 genetic polymorphisms are associated with obesity and fat distribution. However, since these options do not fully explain the inheritance of obesity, other options, such as epigenetic changes, need to be considered. Epigenetic modifications affect gene expression without changing the deoxyribonucleic acid sequence. In addition, environmental exposure during critical periods of development can affect the epigenetic tags and lead to obesity. A deeper understanding of the epigenetic mechanisms underlying obesity can aid in prevention based on lifestyle changes. This review focuses on the role of epigenetic modifications in the development of obesity and related conditions.

scholarly journals The Role of Gene Elongation in the Evolution of Histidine Biosynthetic Genes

2020 ◽  
Vol 8 (5) ◽  
pp. 732 ◽  
Author(s):  
Sara Del Duca ◽  
Sofia Chioccioli ◽  
Alberto Vassallo ◽  
Lara Mitia Castronovo ◽  
Renato Fani
Keyword(s):  
Molecular Mechanism ◽  
Crucial Role ◽  
Biosynthetic Pathway ◽  
Tandem Duplication ◽  
Evolutionary Model ◽  
Biosynthetic Genes ◽  
Gene Coding ◽  
Phylogenetic Divergence ◽  
Elongation Event

Gene elongation is a molecular mechanism consisting of an in-tandem duplication of a gene and divergence and fusion of the two copies, resulting in a gene constituted by two divergent paralogous modules. The aim of this work was to evaluate the importance of gene elongation in the evolution of histidine biosynthetic genes and to propose a possible evolutionary model for some of them. Concerning the genes hisA and hisF, which code for two homologous (β/α)8-barrels, it has been proposed that the two extant genes could be the result of a cascade of gene elongation/domain shuffling events starting from an ancestor gene coding for just one (β/α) module. A gene elongation event has also been proposed for the evolution of hisB and hisD; structural analyses revealed the possibility of an early elongation event, resulting in the repetition of modules. Furthermore, it is quite possible that the gene elongations responsible for the evolution of the four proteins occurred before the earliest phylogenetic divergence. In conclusion, gene elongation events seem to have played a crucial role in the evolution of the histidine biosynthetic pathway, and they may have shaped the structures of many genes during the first steps of their evolution.

scholarly journals Epigenetics in disease etiopathogenesis

Genetika ◽  
2019 ◽  
Vol 51 (3) ◽  
pp. 975-994
Author(s):  
Mila Glavaski ◽  
Karmen Stankov
Keyword(s):  
Environmental Factors ◽  
Polycystic Ovary ◽  
Disease Onset ◽  
Bovine Milk ◽  
Epigenetic Modifications ◽  
Bone Diseases ◽  
Hereditary Diseases ◽  
Epigenetic Mechanisms ◽  
Epigenetic Changes

The term epigenetics refers to heritable changes in gene expression that are not caused by modifications in DNA sequence. Epigenetic changes are DNA methylation, histone modifications, nucleosome positioning, and non-coding RNA (including microRNA) mediated modifications. Epigenetic mechanisms are involved in malignant diseases, imprinting defects, and some hereditary diseases. Recent research explained the role of epigenetic disorders in infections, autoimmune, neurodegenerative and bone diseases, as well as in psoriasis, endometriosis, and polycystic ovary syndrome. Epigenetic modifications have a potential clinical application as diagnostic and prognostic biomarkers, and also as therapeutic targets in oncology, endocrinology, cardiology, and neuropsychiatry. Stress, anxiety, depression, emotions and many other psychological factors may affect epigenetic mechanisms. Influence of preconception parental stress exposure transmits to the next generation through epigenetic changes, as direct results of prenatal and postnatal environmental factors. Epigenetic changes identify environmental factors which affect health and cause disease onset. Milk is the sophisticated system of communication between mother and infant, operating via epigenetic mechanisms. Lifelong consumption of bovine milk causes epigenetic disorders. Recent studies provide important information about the role of bioactive dietary nutrients which modify epigenome in malignancy prevention and therapy. Any interruption in the balance of intestinal microbiota initiates aberrant epigenetic modifications. Epigenetic patterns act as the ?molecular watches? and they play the central role in the establishment of biological rhythms. Epigenetic mechanisms can determine the result of assisted reproductive technology and genetic engineering. The extensive research about the association of epigenetics and pharmacology led to the development of pharmacoepigenetics. All these results emphasize the importance of further research which will take into account all factors that may affect epigenetic mechanisms.

scholarly journals NRF2-Related Epigenetic Modifications in Cardiac and Vascular Complications of Diabetes Mellitus

2021 ◽  
Vol 12 ◽  
Author(s):  
Jie Wang ◽  
Mengjie Xiao ◽  
Jie Wang ◽  
Shudong Wang ◽  
Jingjing Zhang ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Diabetic Complications ◽  
Vascular Complications ◽  
Epigenetic Modifications ◽  
Related Factor ◽  
Nuclear Factor ◽  
Epigenetic Mechanisms ◽  
Prevention And Treatment ◽  
New Strategies

Diabetes mellitus (DM) is a highly prevalent chronic disease that is accompanied with serious complications, especially cardiac and vascular complications. Thus, there is an urgent need to identify new strategies to treat diabetic cardiac and vascular complications. Nuclear factor erythroid 2-related factor 2 (NRF2) has been verified as a crucial target for the prevention and treatment of diabetic complications. The function of NRF2 in the treatment of diabetic complications has been widely reported, but the role of NRF2-related epigenetic modifications remains unclear. The purpose of this review is to summarize the recent advances in targeting NRF2-related epigenetic modifications in the treatment of cardiac and vascular complications associated with DM. We also discuss agonists that could potentially regulate NRF2-associated epigenetic mechanisms. This review provides a better understanding of strategies to target NRF2 to protect against DM-related cardiac and vascular complications.

MANUSCRIPT EVIDENCE FOR ALPHABET-SWITCHING IN THE WORKS OF CICERO: COMMON NOUNS AND ADJECTIVES

2018 ◽  
Vol 68 (2) ◽  
pp. 498-516
Author(s):  
Neil O'Sullivan
Keyword(s):  
Recent Work ◽  
Code Switching ◽  
Consistent Pattern ◽  
Current Interest ◽  
Reliable Transmission ◽  
Accurate Record ◽  
The Way

Of the hundreds of Greek common nouns and adjectives preserved in our MSS of Cicero, about three dozen are found written in the Latin alphabet as well as in the Greek. So we find, alongside συμπάθεια, also sympathia, and ἱστορικός as well as historicus. This sort of variation has been termed alphabet-switching; it has received little attention in connection with Cicero, even though it is relevant to subjects of current interest such as his bilingualism and the role of code-switching and loanwords in his works. Rather than addressing these issues directly, this discussion sets out information about the way in which the words are written in our surviving MSS of Cicero and takes further some recent work on the presentation of Greek words in Latin texts. It argues that, for the most part, coherent patterns and explanations can be found in the alphabetic choices exhibited by them, or at least by the earliest of them when there is conflict in the paradosis, and that this coherence is evidence for a generally reliable transmission of Cicero's original choices. While a lack of coherence might indicate unreliable transmission, or even an indifference on Cicero's part, a consistent pattern can only really be explained as an accurate record of coherent alphabet choice made by Cicero when writing Greek words.

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