scholarly journals Resetting Epigenetic Memory by Reprogramming of Histone Modifications in Mammals

2016 ◽  
Vol 63 (6) ◽  
pp. 1066-1079 ◽  
Author(s):  
Hui Zheng ◽  
Bo Huang ◽  
Bingjie Zhang ◽  
Yunlong Xiang ◽  
Zhenhai Du ◽  
...  
Keyword(s):  
Histone Modifications ◽  
Epigenetic Memory

scholarly journals Epigenetic Memory Independent of Symmetric Histone Inheritance

2019 ◽  
Author(s):  
Daniel S Saxton ◽  
Jasper Rine
Keyword(s):  
Gene Regulation ◽  
Dna Replication ◽  
Gene Silencing ◽  
Histone Modifications ◽  
Epigenetic Memory ◽  
Important Form

AbstractHeterochromatic gene silencing is an important form of gene regulation that usually requires specific histone modifications. A popular model posits that inheritance of modified histones, especially in the form of H3-H4 tetramers, underlies inheritance of heterochromatin. Because H3-H4 tetramers are randomly distributed between daughter chromatids during DNA replication, rare occurrences of asymmetric tetramer inheritance within a heterochromatic domain would have the potential to destabilize heterochromatin. This model makes a prediction that shorter heterochromatic domains would experience unbalanced tetramer inheritance more frequently, and thereby be less stable. In contrast to this prediction, we found that shortening a heterochromatic domain in Saccharomyces had no impact on the strength of silencing nor its heritability. Additionally, we found that replisome mutations that disrupt inheritance of H3-H4 tetramers had only minor effects on heterochromatin stability. These findings suggest that histones carry little or no memory of the heterochromatin state through DNA replication.

A statistical mechanics model for the collective epigenetic histone modification dynamics

2014 ◽  
Author(s):  
Hang Zhang ◽  
XIAO-JUN TIAN ◽  
Abhishek Mukhopadhyay ◽  
Kenneth S Kim ◽  
Jianhua Xing
Keyword(s):  
Histone Modifications ◽  
Nearest Neighbor ◽  
Covalent Modification ◽  
Type Model ◽  
Theoretical Studies ◽  
Lateral Interactions ◽  
Epigenetic Memory ◽  
Cellular Processes ◽  
Mechanics Model ◽  
Cell Phenotypes

Epigenetic histone modifications play an important role in the maintenance of different cell phenotypes. The exact molecular mechanism for inheritance of the modification patterns over cell generations remains elusive. We construct a Potts-type model based on experimentally observed nearest-neighbor enzyme lateral interactions and nucleosome covalent modification state biased enzyme recruitment. The model can lead to effective nonlocal interactions among nucleosomes suggested in previous theoretical studies, and epigenetic memory is robustly inheritable against stochastic cellular processes.

scholarly journals Generalized nucleation and looping model for epigenetic memory of histone modifications

2016 ◽  
Vol 113 (29) ◽  
pp. E4180-E4189 ◽  
Author(s):  
Fabian Erdel ◽  
Eric C. Greene
Keyword(s):  
Histone Modifications ◽  
Domain Size ◽  
Biochemical Properties ◽  
Long Term Memory ◽  
Epigenetic Memory ◽  
Independent Manner ◽  
Position Effects ◽  
Histone Modifiers ◽  
Short And Long Term ◽  
Underlying Mechanisms

Histone modifications can redistribute along the genome in a sequence-independent manner, giving rise to chromatin position effects and epigenetic memory. The underlying mechanisms shape the endogenous chromatin landscape and determine its response to ectopically targeted histone modifiers. Here, we simulate linear and looping-driven spreading of histone modifications and compare both models to recent experiments on histone methylation in fission yeast. We find that a generalized nucleation-and-looping mechanism describes key observations on engineered and endogenous methylation domains including intrinsic spatial confinement, independent regulation of domain size and memory, variegation in the absence of antagonists, and coexistence of short- and long-term memory at loci with weak and strong constitutive nucleation. These findings support a straightforward relationship between the biochemical properties of chromatin modifiers and the spatiotemporal modification pattern. The proposed mechanism gives rise to a phase diagram for cellular memory that may be generally applicable to explain epigenetic phenomena across different species.

scholarly journals Epigenetic memory independent of symmetric histone inheritance

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Daniel S Saxton ◽  
Jasper Rine
Keyword(s):  
Gene Regulation ◽  
Dna Replication ◽  
Gene Silencing ◽  
Histone Modifications ◽  
Epigenetic Memory ◽  
Important Form

Heterochromatic gene silencing is an important form of gene regulation that usually requires specific histone modifications. A popular model posits that inheritance of modified histones, especially in the form of H3-H4 tetramers, underlies inheritance of heterochromatin. Because H3-H4 tetramers are randomly distributed between daughter chromatids during DNA replication, rare occurrences of asymmetric tetramer inheritance within a heterochromatic domain would have the potential to destabilize heterochromatin. This model makes a prediction that shorter heterochromatic domains would experience unbalanced tetramer inheritance more frequently, and thereby be less stable. In contrast to this prediction, we found that shortening a heterochromatic domain in Saccharomyces had no impact on the strength of silencing nor its heritability. Additionally, we found that replisome mutations that disrupt inheritance of H3-H4 tetramers had only minor effects on heterochromatin stability. These findings suggest that histones carry little or no memory of the heterochromatin state through DNA replication.

How do histone modifications contribute to transgenerational epigenetic inheritance in C. elegans?

2020 ◽  
Vol 48 (3) ◽  
pp. 1019-1034 ◽  
Author(s):  
Rachel M. Woodhouse ◽  
Alyson Ashe
Keyword(s):  
Histone Modifications ◽  
Molecular Mechanisms ◽  
Epigenetic Inheritance ◽  
Nematode Caenorhabditis Elegans ◽  
Histone Methyltransferases ◽  
Transgenerational Epigenetic Inheritance ◽  
C Elegans ◽  
Recent Developments ◽  
Gene Regulatory

Gene regulatory information can be inherited between generations in a phenomenon termed transgenerational epigenetic inheritance (TEI). While examples of TEI in many animals accumulate, the nematode Caenorhabditis elegans has proven particularly useful in investigating the underlying molecular mechanisms of this phenomenon. In C. elegans and other animals, the modification of histone proteins has emerged as a potential carrier and effector of transgenerational epigenetic information. In this review, we explore the contribution of histone modifications to TEI in C. elegans. We describe the role of repressive histone marks, histone methyltransferases, and associated chromatin factors in heritable gene silencing, and discuss recent developments and unanswered questions in how these factors integrate with other known TEI mechanisms. We also review the transgenerational effects of the manipulation of histone modifications on germline health and longevity.

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