Imprinted genes are an exceptional cluster of genes which are expressed in a parent-of-origin dependent fashion. This allele-specific expression is dependent on differential DNA methylation which is established in the parental germlines in a sex-specific manner. The DNA methylation imprint is accompanied by heterochromatin modifications which must be continuously maintained through development. This review summarises the factors which are important for protecting the epigenetic modifications at imprinted differentially methylated regions (DMRs), including PGC7, ZFP57 and the ATRX/Daxx/H3.3 complex. We discuss how these factors maintain heterochromatin silencing, not only at imprinted DMRs, but also other heterochromatic regions in the genome.
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http://dx.doi.org/10.1007/s00018-016-2157-6 | DOI Listing |
In mammals, X-linked dosage compensation involves two processes: X-chromosome inactivation (XCI) to balance X chromosome dosage between males and females, and hyperactivation of the remaining X chromosome (Xa-hyperactivation) to achieve X-autosome balance in both sexes. Studies of both processes have largely focused on coding genes and have not accounted for transposable elements (TEs) which comprise 50% of the X-chromosome, despite TEs being suspected to have numerous epigenetic functions. This oversight is due in part to the technical challenge of capturing repeat RNAs, bioinformatically aligning them, and determining allelic origin.
View Article and Find Full Text PDFEpigenetics Chromatin
December 2024
Carol Davila University of Medicine and Pharmacy, Bucharest, Romania.
DNA methylation is an essential epigenetic mechanism for regulation of gene expression, through which many physiological (X-chromosome inactivation, genetic imprinting, chromatin structure and miRNA regulation, genome defense, silencing of transposable elements) and pathological processes (cancer and repetitive sequences-associated diseases) are regulated. Nanopore sequencing has emerged as a novel technique that can analyze long strands of DNA (long-read sequencing) without chemically treating the DNA. Interestingly, nanopore sequencing can also extract epigenetic status of the nucleotides (including both 5-Methylcytosine and 5-hydroxyMethylcytosine), and a large variety of bioinformatic tools have been developed for improving its detection properties.
View Article and Find Full Text PDFJ Exp Bot
December 2024
Centre of Plant Structural and Functional Genomics, Institute of Experimental Botany, Czech Acad Sci, Šlechtitelů 31, Olomouc 77900, Czech Republic.
Cytosine (DNA) methylation plays important roles in silencing transposable elements, plant development, genomic imprinting, stress responses, and maintenance of genome stability. To better understand the functions of this epigenetic modification, several tools have been developed to manipulate DNA methylation levels. These include mutants of DNA methylation writers and readers, targeted manipulation of locus-specific methylation, and the use of chemical inhibitors.
View Article and Find Full Text PDFEpigenomes
December 2024
School of Veterinary and Animal Science (FMVZ), São Paulo State University (Unesp), Botucatu 18618-681, SP, Brazil.
Early weaning management followed by energy supplementation can lead to metabolic alterations in the calf that exert long-term effects on the animal's health and performance. It is believed that the main molecular basis underlying these metabolic adaptations are epigenetic mechanisms that regulate, activate, or silence genes at different stages of development and/or in response to different environmental stimuli. However, little is known about postnatal metabolic programming in .
View Article and Find Full Text PDFTrends Genet
January 2025
Department of Environment and Genetics, La Trobe University, Melbourne, VIC 3168, Australia. Electronic address:
Why is it that the X chromosome that comes from the male parent is inactivated in female marsupials, female mice, and even female mealy bugs, or the whole paternal chromosome complement in some weird flies? A new paper by Milton et al. now reveals DNA methylation patterns established in the male germline before meiosis in wallabies that may constitute the elusive paternal imprint.
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