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Rana sylvatica (also known as Boreorana sylvatica) is one of the few vertebrates that spend extreme winters showing no physiological signs of life. Up to 70% of the total body water of the wood frog freezes as extracellular ice. Survival in extreme conditions requires regulation at transcriptional and translational levels to activate prosurvival pathways. N6-methyladenosine ([m.sup.6]A) methylation is one of the most common RNA modifications, regulating transcript processing and translation by executing important functions that affect regulatory pathways in stress conditions. In the study, regulation of [m.sup.6]A-related proteins in the liver of R. sylvatica was analyzed during 24 h frozen and 8 h thaw conditions. Decreases in the activity of demethylases of 28.44 [+ or -] 0.4% and 24.1 [+ or -] 0.9% of control values in frozen and thaw tissues, respectively, were observed. Total protein levels of [m.sup.6]A methyltransferase complex components methyltransferase-like 14 and Wilm's tumor associated protein were increased by 1.28-fold and 1.42-fold, respectively, during freezing. Demethylase fat mass and obesity, however, showed a decreasing trend, with a significant decrease in abundance during recovery from frozen conditions. Levels of mRNA degraders YTHDF2 and YTHDC2 also decreased under stress. Overall, increased levels of [m.sup.6]A methylation complex components, and suppressed levels of readers/erasers, provide evidence for the potential role of RNA methylation in freezing survival and its regulation in a hypometabolic state. Key words: epigenetics, freeze tolerance, RNA methylation, metabolic rate depression, Rana sylvatica (Boreorana sylvatica), Introduction The wood frog, Rana sylvatica (Boreorana sylvatica), is one of the freeze-tolerant model organisms that survive sub-zero temperatures for several months. During freezing, the wood frog employs multiple adaptation [...]

Cutting-edge DNA methylation-based epigenetic aging techniques were applied to Gulf of Mexico northern red snapper (Lutjanus campechanus; n = 10; 1-26 years old) and red grouper (Epinephelus morio; n = 10; 2-14 years old). Bisulfiteconverted restriction site-associated DNA sequencing was used to identify CpG sites (cytosines followed by guanines) that exhibit age-correlated DNA methylation, and species-specific epigenetic clocks developed from hundreds of CpG sites in each species showed strong agreement between predicted and otolith-derived age [r.sup.2] > 0.99 for both species). Results suggest epigenetic age estimation could provide an accurate and efficient approach to mass-aging fishes in a non-invasive manner. Des methodes epigenetiques de pointe de determination de l'age reposant sur la methylation de l'ADN ont ete appliquees au vivaneau campeche (Lutjanus campechanus; n = 10; 1-26 ans) et au merou rouge (Epinephelus morio; n = 10; 2-14 ans). Le sequencage avec conversion au bisulfite d'ADN associe a des sites de restriction a ete utilise pour cerner des sites CpG (cytosines suivies de guanines) qui presentent une methylation de l'ADN correlee a l'age, et des horloges epigenetiques propres a l'espece developpees a partir de centaines de sites CpG de chaque espece ont revele de fortes concordances entre les ages predits et les ages obtenus par analyse d'otolites [r.sup.2] > 0,99 pour les deux especes). Les resultats donnent a penser que l'estimation epigenetique de l'age pourrait constituer une approche non invasive exacte et efficiente de determination des ages de quantites massives de poissons., Introduction Age data are fundamental to determining life history parameters (e.g., age-at-length, age-at-maturity, age-related fecundity) and are thus critical for fisheries assessment and management, particularly when age-structured stock assessment models [...]

Lineage-specific epigenomic changes during human corticogenesis have been difficult to study owing to challenges with sample availability and tissue heterogeneity. For example, previous studies using single-cell RNA sequencing identified at least 9 major cell types and up to 26 distinct subtypes in the dorsal cortex alone.sup.1,2. Here we characterize cell-type-specific cis-regulatory chromatin interactions, open chromatin peaks, and transcriptomes for radial glia, intermediate progenitor cells, excitatory neurons, and interneurons isolated from mid-gestational samples of the human cortex. We show that chromatin interactions underlie several aspects of gene regulation, with transposable elements and disease-associated variants enriched at distal interacting regions in a cell-type-specific manner. In addition, promoters with increased levels of chromatin interactivity--termed super-interactive promoters--are enriched for lineage-specific genes, suggesting that interactions at these loci contribute to the fine-tuning of transcription. Finally, we develop CRISPRview, a technique that integrates immunostaining, CRISPR interference, RNAscope, and image analysis to validate cell-type-specific cis-regulatory elements in heterogeneous populations of primary cells. Our findings provide insights into cell-type-specific gene expression patterns in the developing human cortex and advance our understanding of gene regulation and lineage specification during this crucial developmental window. Analysis of cis-regulatory chromatin interactions, open chromatin and transcriptomes for different cell types isolated from mid-gestational human cortex samples provides insights into gene regulation during development., Author(s): Michael Song [sup.1] [sup.2] , Mark-Phillip Pebworth [sup.3] [sup.4] , Xiaoyu Yang [sup.1] , Armen Abnousi [sup.5] , Changxu Fan [sup.6] [sup.7] , Jia Wen [sup.8] , Jonathan D. [...]

This work highlights recent studies in epigenetic mechanisms that play a role in alcoholism, which is a complex multifactorial disorder. There is a large body of evidence showing that alcohol can modify gene expression through epigenetic processes, namely DNA methylation and nucleosomal remodeling via histone modifications. In that regard, chronic exposure to ethanol modifies DNA and histone methylation, histone acetylation, and microRNA expression. The alcohol-mediated chromatin remodeling in the brain promotes the transition from use to abuse and addiction. Unravelling the multiplex pattern of molecular modifications induced by ethanol could support the development of new therapies for alcoholism and drug addiction targeting epigenetic processes. Key words: epigenetics, alcohol metabolism, DNA methylation, histone modifications, chromatin remodeling. Ce travail met en lumiere les etudes recentes des mecanismes epigenetiques qui jouent un role dans l'alcoolisme, une maladie complexe multifactorielle. De nombreuses preuves ont montre que l'alcool peut modifier l'expression genique au moyen de processus epigenetiques, a savoir la methylation d'ADN et le remodelage nucleosomique par les modifications d'histones. Dans cette veine, l'exposition chronique a l'alcool modifie l'ADN et la methylation des histones, l'acetylation des histones et l'expression de microARN. Le remodelage de la chromatine medie par l'alcool dans le cerveau favorise la transition de l'usage vers l'abus et la dependance. La resolution du patron multiplexe des modifications moleculaires induites par l'alcool implique la capacite de developper de nouvelles therapies de l'alcoolisme et de la dependance aux drogues qui ciblent les processus epigenetiques. [Traduit par la Redaction] Mots-cles: epigenetique, metabolisme de l'alcool, methylation d'ADN, modifications d'histones, remodelage de la chromatine., Introduction Revealing the action of alcohol at the molecular level means a better understanding of the effects of alcohol on behavior (Ceccanti et al. 2015a, 2018a, 2018b; Coriale et al. [...]