scholarly journals Epigenetic processes in the male germline

2015 ◽  
Vol 27 (5) ◽  
pp. 725 ◽  
Author(s):  
Alan M. O'Doherty ◽  
Paul A. McGettigan
Keyword(s):  
Dna Methylation ◽  
High Throughput Sequencing ◽  
De Novo ◽  
Dna Packaging ◽  
Sperm Chromatin ◽  
Germline Development ◽  
Paternal Genome ◽  
Male Germline ◽  
Non Coding Rnas ◽  
Epigenetic Processes

Sperm undergo some of the most extensive chromatin modifications seen in mammalian biology. During male germline development, paternal DNA methylation marks are erased and established on a global scale through waves of demethylation and de novo methylation. As spermatogenesis progresses, the majority of the histones are removed and replaced by protamines, enabling a tighter packaging of the DNA and transcriptional shutdown. Following fertilisation, the paternal genome is rapidly reactivated, actively demethylated, the protamines are replaced with histones and the embryonic genome is activated. The development of new assays, made possible by high-throughput sequencing technology, has resulted in the revisiting of what was considered settled science regarding the state of DNA packaging in mammalian spermatozoa. Researchers have discovered that not all histones are replaced by protamines and, in certain experiments, various species of RNA have been detected in what was previously considered transcriptionally quiescent spermatozoa. Most controversially, several groups have suggested that environmental modifications of the epigenetic state of spermatozoa may operate as a non-DNA-based form of inheritance, a process known as ‘transgenerational epigenetic inheritance’. Other developments in the field include the increased focus on the involvement of short RNAs, such as microRNAs, long non-coding RNAs and piwi-interacting RNAs. There has also been an accumulation of evidence illustrating associations between defects in sperm DNA packaging and disease and fertility. In this paper we review the literature, recent findings and areas of controversy associated with epigenetic processes in the male germline, focusing on DNA methylation dynamics, non-coding RNAs, the biology of sperm chromatin packaging and transgenerational inheritance.

scholarly journals Nurse cell-derived small RNAs define paternal epigenetic inheritance in Arabidopsis

2021 ◽  
Author(s):  
Jincheng Long ◽  
James Walker ◽  
Wenjing She ◽  
Billy Aldridge ◽  
Hongbo Gao ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Small Rnas ◽  
Nurse Cell ◽  
De Novo ◽  
Epigenetic Inheritance ◽  
Genome Integrity ◽  
Nurse Cells ◽  
Male Germline ◽  
Methylation Patterns

AbstractThe plant male germline undergoes DNA methylation reprogramming, which methylates genes de novo and thereby alters gene expression and facilitates meiosis. Why reprogramming is limited to the germline and how specific genes are chosen is unknown. Here, we demonstrate that genic methylation in the male germline, from meiocytes to sperm, is established by germline-specific siRNAs transcribed from transposons with imperfect sequence homology. These siRNAs are synthesized by meiocyte nurse cells (tapetum) via activity of the tapetum-specific chromatin remodeler CLASSY3. Remarkably, tapetal siRNAs govern germline methylation throughout the genome, including the inherited methylation patterns in sperm. Finally, we demonstrate that these nurse cell-derived siRNAs (niRNAs) silence germline transposons, thereby safeguarding genome integrity. Our results reveal that tapetal niRNAs are sufficient to reconstitute germline methylation patterns and drive extensive, functional methylation reprogramming analogous to piRNA-mediated reprogramming in animal germlines.

6 ALTERED CHROMATIN CONFORMATION IN BOVINE SPERMATOZOA PERTURBS DYNAMIC DNA METHYLATION IN THE MALE PRONUCLEUS AFTER FERTILIZATION IN VITRO

2013 ◽  
Vol 25 (1) ◽  
pp. 150 ◽  
Author(s):  
M. B. Rahman ◽  
M. M. Kamal ◽  
T. Rijsselaere ◽  
L. Vandaele ◽  
M. Shamsuddin ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Heat Stress ◽  
De Novo ◽  
Chromatin Condensation ◽  
Sperm Chromatin ◽  
Chromatin Conformation ◽  
Epigenetic Marks ◽  
Time Points ◽  
Male Pronucleus ◽  
De Novo Methylation

Soon after fertilization, mammalian zygotes need proper DNA methylation reprogramming, at which time the epigenetic marks that the oocyte and sperm have acquired during gametogenesis are erased to allow totipotent zygotic development. Aberrant epigenetic marks in the paternal genome are thought to be associated with altered chromatin condensation in spermatozoa of suboptimal quality. We have recently reported that heat stress on bulls during germ cell development, especially at the spermiogenesis stage, altered sperm chromatin condensation. The objective of this study was to investigate dynamic DNA methylation reprogramming in the male pronucleus after fertilization of oocytes with sperm known to have altered chromatin conformation. To evaluate dynamic DNA methylation reprogramming, zygotes collected at 3 different time points [i.e. 12, 18, and 24 h post-insemination (hpi)] were immunocytochemically investigated using an antibody against 5-methylcytosine (5mC). The total fluorescence intensity of the male pronuclei (n = 89, ≥25 in each group) was measured by ImageJ and data were analyzed by ANOVA. The DNA methylation pattern in male pronuclei when oocytes were fertilized with heat-stressed sperm did not change between time points (P > 0.05), whereas control zygotes clearly showed demethylation and de novo methylation at 18 and 24 hpi, respectively. The results of this study indicated that dynamic DNA methylation reprogramming patterns such as DNA demethylation followed by de novo methylation in the male pronucleus soon after fertilization were altered when oocytes were fertilized with heat-stressed sperm. In conclusion, altered sperm chromatin conformation due to heat stress perturbs dynamic DNA methylation reprogramming in the male pronucleus, which may hamper nuclear totipotency and embryo survival.

scholarly journals Epigenetic reprogramming during spermatogenesis and male factor infertility

Reproduction ◽  
2018 ◽  
Vol 156 (2) ◽  
pp. R9-R21 ◽  
Author(s):  
H M McSwiggin ◽  
A M O’Doherty
Keyword(s):  
Dna Methylation ◽  
Male Infertility ◽  
Deep Sequencing ◽  
Male Factor Infertility ◽  
Male Factor ◽  
Chromatin Dynamics ◽  
Sequencing Technologies ◽  
Male Germline ◽  
Male Factors ◽  
Epigenetic Processes

Infertility is an often devastating diagnosis encountered by around one in six couples who are trying to conceive. Moving away from the long-held belief that infertility is primarily a female issue, it is now recognised that half, if not more, of these cases may be due to male factors. Recent evidence has suggested that epigenetic abnormalities in chromatin dynamics, DNA methylation or sperm-borne RNAs may contribute to male infertility. In light of advances in deep sequencing technologies, researchers have been able to increase the coverage and depth of sequencing results, which in turn has allowed more comprehensive analyses of spermatozoa chromatin dynamics and methylomes and enabled the discovery of new subsets of sperm RNAs. This review examines the most current literature related to epigenetic processes in the male germline and the associations of aberrant modifications with fertility and development.

scholarly journals 135DNA METHYLATION PROFILES IN THE PREIMPLANTATION PORCINE EMBRYOS

2004 ◽  
Vol 16 (2) ◽  
pp. 190
Author(s):  
S. Yeo ◽  
Y.-K. Kang ◽  
D.-B Koo ◽  
J.-S Han ◽  
W.-K Chang ◽  
...  
Keyword(s):  
Dna Methylation ◽  
De Novo ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Mouse Embryos ◽  
Paternal Genome ◽  
Active Demethylation ◽  
Morula Stage ◽  
De Novo Methylation

DNA methylation at CpG dinucleotides is an important epigenetic regulation process, which is associated with gene expression without any change in DNA sequence. During early development of the mouse embryo, dynamic changes in DNA methylation of the genome occur. After fertilization, active demethylation occurs on the paternal genome followed by passive demethylation until morula stage and then de novo methylation at the blastocyst stage. This study was designed to investigate changes in DNA methylation of in vivo- and in vitro-fertilized (IVF) porcine embryos. DNA methylation states were observed in preimplantation porcine embryos by using an immunofluorescence method after staining with an antibody against 5-methylcytosine. In contrast to the data from mouse embryos, active demethylation of the genome from the paternal pronucleus was not observed in the porcine embryos. Also, no passive demethylation was detected in in vivo- and IVF-derived embryos until the morula stage. Moreover, differential de novo methylation was not shown on the genome of the inner cell mass. Whole genomes of inner cell mass and trophectoderm cells were fully methylated. Our results demonstrate that DNA methylation of porcine embryos is different from that of mouse embryos during preimplantation development, suggesting that the machinery to regulate DNA methylation may be species-specific in mammals.

Altered chromatin condensation of heat-stressed spermatozoa perturbs the dynamics of DNA methylation reprogramming in the paternal genome after in vitro fertilisation in cattle

2014 ◽  
Vol 26 (8) ◽  
pp. 1107 ◽  
Author(s):  
Mohammad Bozlur Rahman ◽  
Md. Mostofa Kamal ◽  
Tom Rijsselaere ◽  
Leen Vandaele ◽  
Mohammed Shamsuddin ◽  
...  
Keyword(s):  
Dna Methylation ◽  
De Novo ◽  
Chromatin Condensation ◽  
Dna Demethylation ◽  
In Vitro Fertilisation ◽  
Paternal Genome ◽  
Time Points ◽  
Fertilisation Rate ◽  
De Novo Methylation

Shortly after penetration of the oocyte, sperm DNA is actively demethylated, which is required for totipotent zygotic development. Aberrant DNA methylation is thought to be associated with altered chromatin condensation of spermatozoa. The objectives of this study were to investigate the dynamics of DNA methylation reprogramming in the paternal pronucleus and subsequent fertilisation potential of heat-stressed bull spermatozoa having altered chromatin condensation. Hence, bovine zygotes (n = 1239) were collected at three different time points (12, 18 and 24 h post insemination, hpi), and stained with an antibody against 5-methylcytosine. Fluorescence intensities of paternal and maternal pronuclei were measured by ImageJ. DNA methylation patterns in paternal pronuclei derived from heat-stressed spermatozoa did not differ between time points (P > 0.05), whereas control zygotes clearly showed demethylation and de novo methylation at 18 and 24 hpi, respectively. Moreover, heat-stressed spermatozoa showed a highly reduced (P < 0.01) fertilisation rate compared with non-heat-stressed or normal control spermatozoa (53.7% vs 70.2% or 81.5%, respectively). Our data show that the normal pattern of active DNA demethylation followed by de novo methylation in the paternal pronucleus is perturbed when oocytes are fertilised with heat-stressed spermatozoa, which may be responsible for decreased fertilisation potential.

scholarly journals MethylRAD: a simple and scalable method for genome-wide DNA methylation profiling using methylation-dependent restriction enzymes

Open Biology ◽  
2015 ◽  
Vol 5 (11) ◽  
pp. 150130 ◽  
Author(s):  
Shi Wang ◽  
Jia Lv ◽  
Lingling Zhang ◽  
Jinzhuang Dou ◽  
Yan Sun ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Method Development ◽  
High Throughput Sequencing ◽  
De Novo ◽  
Biological Significance ◽  
Restriction Enzymes ◽  
Phylogenetic Groups ◽  
Patinopecten Yessoensis ◽  
Dna Methylation Profiling ◽  
Methylation Profiling

Characterization of dynamic DNA methylomes in diverse phylogenetic groups has attracted growing interest for a better understanding of the evolution of DNA methylation as well as its function and biological significance in eukaryotes. Sequencing-based methods are promising in fulfilling this task. However, none of the currently available methods offers the ‘perfect solution’, and they have limitations that prevent their application in the less studied phylogenetic groups. The recently discovered Mrr-like enzymes are appealing for new method development, owing to their ability to collect 32-bp methylated DNA fragments from the whole genome for high-throughput sequencing. Here, we have developed a simple and scalable DNA methylation profiling method (called MethylRAD) using Mrr-like enzymes. MethylRAD allows for de novo (reference-free) methylation analysis, extremely low DNA input (e.g. 1 ng) and adjustment of tag density, all of which are still unattainable for most widely used methylation profiling methods such as RRBS and MeDIP. We performed extensive analyses to validate the power and accuracy of our method in both model (plant Arabidopsis thaliana ) and non-model (scallop Patinopecten yessoensis ) species. We further demonstrated its great utility in identification of a gene ( LPCAT1 ) that is potentially crucial for carotenoid accumulation in scallop adductor muscle. MethylRAD has several advantages over existing tools and fills a void in the current epigenomic toolkit by providing a universal tool that can be used for diverse research applications, e.g. from model to non-model species, from ordinary to precious samples and from small to large genomes, but at an affordable cost.

scholarly journals De novo DNA methylation of the paternal genome in 2-cell mouse embryos

2014 ◽  
Vol 13 (4) ◽  
pp. 8632-8639 ◽  
Author(s):  
X.S. Ma ◽  
X.G. Wang ◽  
L. Qin ◽  
C.L. Song ◽  
F. Lin ◽  
...  
Keyword(s):  
Dna Methylation ◽  
De Novo ◽  
Mouse Embryos ◽  
Paternal Genome

scholarly journals In vivo targeting of de novo DNA methylation by histone modifications in yeast and mouse

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Marco Morselli ◽  
William A Pastor ◽  
Barbara Montanini ◽  
Kevin Nee ◽  
Roberto Ferrari ◽  
...  
Keyword(s):  
Dna Methylation ◽  
De Novo ◽  
Gene Body ◽  
Mammalian Development ◽  
H3k4 Methylation ◽  
H3k36 Methylation ◽  
Male Germline ◽  
Yeast Strains ◽  
Dna Methylation Analysis

Methylation of cytosines (5meC) is a widespread heritable DNA modification. During mammalian development, two global demethylation events are followed by waves of de novo DNA methylation. In vivo mechanisms of DNA methylation establishment are largely uncharacterized. Here, we use Saccharomyces cerevisiae as a system lacking DNA methylation to define the chromatin features influencing the activity of the murine DNMT3B. Our data demonstrate that DNMT3B and H3K4 methylation are mutually exclusive and that DNMT3B is co-localized with H3K36 methylated regions. In support of this observation, DNA methylation analysis in yeast strains without Set1 and Set2 shows an increase of relative 5meC levels at the transcription start site and a decrease in the gene-body, respectively. We extend our observation to the murine male germline, where H3K4me3 is strongly anti-correlated while H3K36me3 correlates with accelerated DNA methylation. These results show the importance of H3K36 methylation for gene-body DNA methylation in vivo.

Maternal diet as a modifier of offspring epigenetics

2015 ◽  
Vol 6 (2) ◽  
pp. 88-95 ◽  
Author(s):  
K. A. Lillycrop ◽  
G. C. Burdge
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Early Life ◽  
Disease Risk ◽  
Important Determinant ◽  
Maternal Diet ◽  
Substantial Body ◽  
Highly Sensitive ◽  
Non Coding Rnas ◽  
Epigenetic Processes

There has been a substantial body of evidence, which has shown that genetic variation is an important determinant of disease risk. However, there is now increasing evidence that alterations in epigenetic processes also play a role in determining susceptibility to disease. Epigenetic processes, which include DNA methylation, histone modifications and non-coding RNAs play a central role in regulating gene expression, determining when and where a gene is expressed as well as the level of gene expression. The epigenome is highly sensitive to a variety of environmental factors, especially in early life. One factor that has been shown consistently to alter the epigenome is maternal diet. This review will focus on how maternal diet can modify the epigenome of the offspring, producing different phenotypes and altered disease susceptibilities.

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