Crossovers between epigenesis and epigenetics. A multicenter approach to the history of epigenetics (1901-1975)

The origin of epigenetics has been traditionally traced back to Conrad Hal Waddington's foundational work in 1940s. The aim of the present paper is to reveal a hidden history of epigenetics, by means of a multicenter approach. Our analysis shows that genetics and embryology in early XX century--far from being non-communicating vessels--shared similar questions, as epitomized by Thomas Hunt Morgan's works. Such questions were rooted in the theory of epigenesis and set the scene for the development of epigenetics. Since the 1950s, the contribution of key scientists (Mary Lyon and Eduardo Scarano), as well as the discussions at the international conference of Gif-sur-Yvette (1957) paved the way for three fundamental shifts of focus: 1. From the whole embryo to the gene; 2. From the gene to the complex extranuclear processes of development; 3. From cytoplasmic inheritance to the epigenetics mechanisms

Epigenetic inheritance. Concepts, mechanisms and perspectives

Parents' stressful experiences can influence an offspring's vulnerability to many pathological conditions, including psychopathologies, and their effects may even endure for several generations. Nevertheless, the cause of this phenomenon has not been determined, and only recently have scientists turned to epigenetics to answer this question. There is extensive literature on epigenetics, but no consensus exists with regard to how and what can (and must) be considered to study and define epigenetics processes and their inheritance. In this work, we aimed to clarify and systematize these concepts. To this end, we analyzed the dynamics of epigenetic changes over time in detail and defined three types of epigenetics: a direct form of epigenetics (DE) and two indirect epigenetic processes-within (WIE) and across (AIE). DE refers to changes that occur in the lifespan of an individual, due to direct experiences with his environment. WIE concerns changes that occur inside of the womb, due to events during gestation. Finally, AIE defines changes that affect the individual's predecessors (parents, grandparents, etc.), due to events that occur even long before conception and that are somehow (e.g., through gametes, the intrauterine environment setting) transmitted across generations. This distinction allows us to organize the main body of epigenetic evidence according to these categories and then focus on the latter (AIE), referring to it as a faster route of informational transmission across generations-compared with genetic inheritance-that guides human evolution in a Lamarckian (i.e., experience-dependent) manner. Of the molecular processes that are implicated in this phenomenon, well-known (methylation) and novel (non-coding RNA, ncRNA) regulatory mechanisms are converging. Our discussion of the chief methods that are used to study epigenetic inheritance highlights the most compelling technical and theoretical problems of this discipline. Experimental suggestions to expand this field are provided, and their practical and ethical implications are discussed extensivel

The modern versus extended evolutionary synthesis : sketch of an intra-genomic gene's eye view for the evolutionary-genetic underpinning of epigenetic and developmental evolution

Studying the phenotypic evolution of organisms in terms of populations of genes and genotypes, the Modern Synthesis (MS) conceptualizes biological evolution in terms of 'inter-organismal' interactions among genes sitting in the different individual organisms that constitute a population. It 'black-boxes' the complex 'intra-organismic' molecular and developmental epigenetics mediating between genotypes and phenotypes. To conceptually integrate epigenetics and evo-devo into evolutionary theory, advocates of an Extended Evolutionary Synthesis (EES) argue that the MS's reductive gene-centrism should be abandoned in favor of a more inclusive organism-centered approach. To push the debate to a new level of understanding, we introduce the evolutionary biology of 'intra-genomic conflict' (IGC) to the controversy. This strategy is based on a twofold rationale. First, the field of IGC is both ‘gene-centered’ and 'intra-organismic' and, as such, could build a bridge between the gene-centered MS and the intra-organismic fields of epigenetics and evo-devo. And second, it is increasingly revealed that IGC plays a significant causal role in epigenetic and developmental evolution and even in speciation. Hence, to deal with the ‘discrepancy’ between the ‘gene-centered’ MS and the ‘intra-organismic’ fields of epigenetics and evo-devo, we sketch a conceptual solution in terms of ‘intra-genomic conflict and compromise’ – an ‘intra-genomic gene’s eye view’ that thinks in terms of intra-genomic ‘evolutionarily stable strategies’ (ESSs) among numerous and various DNA regions and elements – to evolutionary-genetically underwrite both epigenetic and developmental evolution, as such questioning the ‘gene-de-centered’ stance put forward by EES-advocates

Regulation of skeletal muscle development and homeostasis by gene imprinting, histone acetylation and microRNA

Epigenetics is defined as heritable information other that the DNA sequence itself. The concept implies that the regulation of gene expression is highly complex and epigenetics can control from fine tuning to permanent gene activation/deactivation. Skeletal muscle is the main tissue for locomotion and energy metabolism in the body, and represent at least 40% of the body mass. Body mass and function vary according to age but also quickly adapt to physiological as well as pathological cues. Besides transcriptional mechanisms that control muscle differentiation, postnatal growth and remodeling, there are numerous epigenetic mechanisms of regulation that modulate muscle gene expression. In this review, we describe and discuss only some of the mechanisms of epigenetic regulation - such as DNA methylation, histone modifications, and microRNAs - that have been characterized in detail and that we believe are crucial for skeletal muscle development and disease

Epigenetics and organic plant breeding

One characteristic of process oriented organic plant breeding is that all breeding activities from the initial crosses up to final variety propagation are performed under organic growing conditions, allowing the plant to interact with its target environment across all generations. However, it is often argued that it is sufficient to select under conventional farming and test the released varieties under organic farming conditions

Epigenetics: What it is about?

Epigenetics has captured the attention of scientists in the past decades, yet its scope has been continuously changing. In this paper, we give an overview on how and why its definition has evolved and suggest several clarification on the concepts used in this field, in particular, on the notions of epigenetic information, epigenetic stability and epigenetic templating. Another issue that we address is the role of epigenetic information. Not only it is important in allowing alternative interpretations of genetic information, but it appears to be important in protecting the genetic information, moreover, we suggest that this function appeared first in evolution and only later on the epigenetic mechanisms were recruited to play a role in cell differentiation.Comment: 7 pages, 3 figure

‘Epigenetics and Society': a forum for the theoretical, ethical and societal appraisal of a burgeoning science

Epigenetics Communications is proud to announce the introduction of a new section entitled ‘Epigenetics and Society’ (EaS). EaS offers a forum for researcher from various disciplines to engage with the theoretical, interdisciplinary, ethical, social and political dimensions of epigenetics. Authors, within and beyond academia, are invited to submit manuscripts of original research, reviews or perspectives/correspondences dealing with these different facets of epigenetics. The EaS section is meant to provide an opportunity for sharing work across disciplinary borders in ways that both illuminate the science-society intersections around epigenetics and promote their operationalization in multidisciplinary and collaborative scientific practices

Negotiating Novelty: Constructing the Novel within Scientific Accounts of Epigenetics

Epigenetics is regarded by many as a compelling domain of biomedicine. The purported novelty of epigenetics has begun to have various societal ramifications, particularly in relation to processes of responsibilisation. Within sociology, it has stimulated hopeful debate about conceptual rapprochements between the biomedical and social sciences. This article is concerned with how novelty is socially produced and negotiated. The article engages directly with scientists’ talk and writings about epigenetics (as process and field of study). I aim to advance an explicitly sociological analysis about the novelty of epigenetics that underscores its social production rather than an account which participates in its reification. I attend to definitional skirmishes, comparisons with genetics, excitement and intrigue, and considerations of the ethical dimensions of epigenetics. Any assertions that epigenetics is exciting or important should not inadvertently elide reflexive consideration of how such characterisations might be part of the machinery by which they become real

DNA methylation and socioeconomic status in a Mexican-American birth cohort.

Background: Maternal social environmental stressors during pregnancy are associated with adverse birth and child developmental outcomes, and epigenetics has been proposed as a possible mechanism for such relationships. Methods: In a Mexican-American birth cohort of 241 maternal-infant pairs, cord blood samples were measured for repeat element DNA methylation (LINE-1 and Alu). Linear mixed effects regression was used to model associations between indicators of the social environment (low household income and education, neighborhood-level characteristics) and repeat element methylation. Results from a dietary questionnaire were also used to assess the interaction between maternal diet quality and the social environment on markers of repeat element DNA methylation. Results: After adjusting for confounders, living in the most impoverished neighborhoods was associated with higher cord blood LINE-1 methylation (β = 0.78, 95%CI 0.06, 1.50, p = 0.03). No other neighborhood-, household-, or individual-level socioeconomic indicators were significantly associated with repeat element methylation. We observed a statistical trend showing that positive association between neighborhood poverty and LINE-1 methylation was strongest in cord blood of infants whose mothers reported better diet quality during pregnancy (pinteraction = 0.12). Conclusion: Our findings indicate a small yet unexpected positive association between neighborhood-level poverty during pregnancy and methylation of repetitive element DNA in infant cord blood and that this association is possibly modified by diet quality during pregnancy. However, our null findings for other adverse SES indicators do not provide strong evidence for an adverse association between early-life socioeconomic environment and repeat element DNA methylation in infants