Functions and mechanisms of epigenetic inheritance in animals

Abstract

| The idea that epigenetic determinants such as DNA methylation, histone modifications or RNA can be passed to the next generation through meiotic products (gametes) is long standing. Such meiotic epigenetic inheritance (MEI) is fairly common in yeast, plants and nematodes, but its extent in mammals has been much debated. Advances in genomics techniques are now driving the profiling of germline and zygotic epigenomes, thereby improving our understanding of MEI in diverse species. Whereas the role of DNA methylation in MEI remains unclear, insights from genome-wide studies suggest that a previously underappreciated fraction of mammalian genomes bypass epigenetic reprogramming during development. Notably , intergenerational inheritance of histone modifications, tRNA fragments and microRNAs can affect gene regulation in the offspring. It is important to note that MEI in mammals rarely constitutes transgenerational epigenetic inheritance (TEI), which spans multiple generations. In this Review , we discuss the examples of MEI in mammals, including mammalian epigenome reprogramming, and the molecular mechanisms of MEI in vertebrates in general. We also discuss the implications of the inheritance of histone modifications and small RNA for embryogenesis in metazoans, with a particular focus on insights gained from genome-wide studies.

Intergenerational fitness effects of the early life environment in a wild rodent

“…Additionally, dietary protein content has a major impact on mammalian phenotypes, such as mass at birth (Zambrano et al, ), hypertension (Harrison & Langley‐Evans, ) and epigenetic patterns (Burdge et al, ; Lillycrop, Phillips, Jackson, Hanson, & Burdge, ). Changes in epigenetic patterns could potentially lead to intergenerational effects (Bonduriansky & Day, ; Burton & Metcalfe, ; Heard & Martienssen, ; Skvortsova, Iovino, & Bogdanovi, ; Youngson & Whitelaw, ). In our study, protein restriction during the early life of bank voles elicited negative effects on F1 body size both as newborns and as adults.…”

Antipsychotic Medications and DNA Methylation in Schizophrenia and Bipolar Disorder: A Systematic Review

“…In contrast, pharmacoepigenetics, the study of how alterations in gene expression beyond the underlying genetic code influence medication outcomes or how medications influence epigenomics, is still in the beginning stages. Epigenetics encompasses several mechanisms that influence gene expression including DNA methylation, histone modifications, and RNA‐based mechanisms such as micro RNA . Although all forms of epigenetic mechanisms have been the subject of study in relation to antipsychotic treatment, most studies have analyzed DNA methylation in one form or another.…”

“…several mechanisms that influence gene expression including DNA methylation, histone modifications, and RNA-based mechanisms such as micro RNA. 7 Although all forms of epigenetic mechanisms have been the subject of study in relation to antipsychotic treatment, most studies have analyzed DNA methylation in one form or another.…”

Introduction: Special Issue on Transplacental/Transgenerational Mutagenesis and Carcinogenesis

“…After birth or later in life, following exposure to tumor promoters, these initiated cells are likely to propagate the mutations due to promoter-induced cell proliferation, eventually developing into cancer. Susceptibility to transplacental carcinogenesis is influenced by gene expression and ontogeny of drug metabolizing enzymes (Hines, 2013), DNA repair enzymes (Pachkowski et al, 2011), and signal transduction pathways and epigenetics (Skvortsova et al, 2018). Epigenetic modifications such as DNA methylation (Messerschmidt et al, 2014), posttranslational modifications of the histone proteins involved in genome packaging (Corujo and Buschbeck, 2018) and noncoding RNAs, such as microRNAs are known to act during transcription or translation (Cech and Steitz, 2014) and may affect gene expression.…”

“…Epigenetic modifications such as DNA methylation (Messerschmidt et al, 2014), posttranslational modifications of the histone proteins involved in genome packaging (Corujo and Buschbeck, 2018) and noncoding RNAs, such as microRNAs are known to act during transcription or translation (Cech and Steitz, 2014) and may affect gene expression. These epigenetic modifications are likely to be heritable mitotically and/or meiotically (Skvortsova et al, 2018). Akin to transplacental carcinogenesis, prenatal exposure to physical agents (e.g., X-rays) and chemical agents (e.g., urethane) has also been shown to be associated in transgenerational carcinogenesis involving germline alterations.…”