Despite recent successes in cloning various mammals and amphibians, the low efficiency of animals production and abnormal symptoms in many cloned animals are crucial problems in cloning technology. To overcome these problems, scientists focus on mechanisms of cloning. A possible cause of the low success frequency of cloning is the insufficient dedifferentiation and the inadequate reprogramming of the high differentiated adult somatic nucleus in enucleated oocytes, which caused by incomplete methylation and premature de novo remethylation of donor DNA. In cloned embryos the methylation level is higher than normal embryos, and this may cause aberrant expression of several important genes, especially imprinting genes. Study on these mechanisms is very important to improve the rate of successful cloned animals.
Animals ; Cloning, Organism ; DNA Methylation ; genetics ; physiology ; Epigenesis, Genetic ; genetics ; physiology ; Genomic Imprinting ; genetics ; physiology ; Humans

Mixed linked leukemia 4 (MLL4) is a specific methyltransferase of histone 3 position lysine 4 (H3K4). It is also one of the important members of COMPASS/Set1-like protein complex. Both MLL4 protein itself and its mediated H3K4 methylation modification can cause changes in chromatin structure and function, thus regulating gene transcription and expression. With the studies of MLL4 protein in recent years, the roles of MLL4 gene, MLL4 protein and protein complex in the development of tissues and organs, tumor diseases and other physiological and pathophysiological processes have been gradually revealed. In this paper, the research progress of MLL4 gene, MLL4 protein characteristics, biological function and its effect on disease were reviewed, in order to further understand the effect of histone methyltransferase on gene expression regulation, as well as its non-enzyme dependent function. This paper may provide new ideas for the prevention, diagnosis and treatment of related diseases.
DNA-Binding Proteins ; physiology ; Histone-Lysine N-Methyltransferase ; physiology ; Histones ; chemistry ; Humans ; Methylation

Animals ; DNA Methylation ; DNA-Cytosine Methylases ; chemistry ; metabolism ; physiology ; Embryonic Development ; physiology ; Humans ; Mice ; Site-Specific DNA-Methyltransferase (Adenine-Specific) ; chemistry ; metabolism ; physiology

Human physiology and pathology can be affected by different nutritional conditions. At cellular level, the availability of a nutritional component not only mediates metabolic reactions but also transmits signals for diverse biological activities. Epigenetic regulation such as DNA methylation and histone post-translational modifications is considered as one of the nutrient-mediated signaling receivers as almost all of the epigenetic enzyme activities require intermediary metabolites as cofactors. The gut microbiome as “forgotten organ” has been suggested as a metabolite generator as well as a nutrient sensor for its host organism, affecting human health and diseases. Given the metabolite-dependent activities of epigenetic regulators, the gut microbiome has a high potential to influence the epigenetics in human physiology. Here, I review the involvement of gut microbiome in diverse human diseases and the mechanisms of epigenetic regulation by different metabolites. Thereafter, I discuss how the gut microbiome-generated metabolites affect host epigenetics, raising a possibility to develop a therapeutic intervention based on the interaction between the microbiome and epigenetics for human health.
DNA Methylation ; Epigenomics* ; Gastrointestinal Microbiome* ; Histones ; Humans* ; Metabolism ; Microbiota ; Pathology ; Physiology ; Protein Processing, Post-Translational

No abstract available.
Colorectal Neoplasms/*genetics/*mortality ; CpG Islands/*physiology ; *DNA Methylation ; Female ; Humans ; Male ; *Phenotype

No abstract available.
Colorectal Neoplasms/*genetics/*mortality ; CpG Islands/*physiology ; *DNA Methylation ; Female ; Humans ; Male ; *Phenotype

BACKGROUNDIt is still unclear whether the vitrification procedure itself is associated with the incidence of abnormal DNA methylation during oocytes vitrification. The purpose of this study was to evaluate the epigenetic profile of mouse oocytes, which went through vitrification either at a mature stage or at an immature stage following in vitro maturation (IVM) by analyzing the global DNA methylation.

METHODSMetaphase II (M II) stage and germinal vesicle (GV) stage oocytes were collected from adult female mice and were vitrified respectively. The M II oocytes were assessed for cryo-survival and global DNA methylation. The GV oocytes were assessed for cryo-survival and only the surviving GV oocytes were cultured in vitro for subsequent assessment of global DNA methylation in mature oocytes. In vivo matured fresh M II oocytes without undergoing vitrification were used as control. The level of global DNA methylation in the M II oocytes was then examined by immunofluorescence using an anti-5-methylcytosine (anti-5-MeC) monoclonal antibody and fluorescein isothiocyanate (FITC)-conjugated goat anti-mouse IgG under a laser scanning confocal microscope.

RESULTSIn terms of the effect of vitrification on global DNA methylation status in matured oocytes, in the M II-v group, all the examined oocytes (90/90) were found with hypermethylation, including 63.3% (57/90) of them displaying DNA methylation of a very high level, 25.6% (23/90) with a high level, and 11.1% (10/90) with an intermediate level, whereas in the GV-v group, all the matured oocytes (129/129) were also examined with hypermethylation, including 67.4% (87/129) of them displaying DNA methylation of a very high level, 23.3% (30/129) with a high level, and 9.3% (12/129) with an intermediate level. Statistically, it was similar between both groups, which were similar to the control: 68.6% (83/121) of fresh M II oocytes displayed DNA methylation of a very high level, 21.5% (26/121) with a high level, and 9.9%(12/121) with an intermediate level (P > 0.05). In terms of the effect of IVM on global DNA methylation status in matured oocytes, in the in vivo matured oocytes group, all oocytes examined (94/94) were found with hypermethylation, including 80.9% (76/94) displaying DNA methylation of a very high level and 19.1% (18/94) with a high level, whereas in the in vitro matured oocytes group, all oocytes examined (69/69) were also found with hypermethylation: 85.2% (56/69) of them displayed with DNA methylation of very high level, 11.9% (11/69) with high level, and 2% (2/69) with intermediate level. This result was similar to that in in vivo matured fresh M II oocytes (P > 0.05).

CONCLUSIONThe vitrification procedure at GV stage does not induce widespread alteration of global DNA methylation status of mouse oocytes subsequently matured in vitro.

Animals ; DNA Methylation ; physiology ; Female ; Fertilization in Vitro ; Mice ; Microscopy, Confocal ; Oocytes ; cytology ; metabolism ; Vitrification

DNA Methylation ; Helicobacter Infections ; complications ; Helicobacter pylori ; Humans ; Stomach Neoplasms ; etiology ; genetics ; Telomerase ; physiology

OBJECTIVE To explore the biological processes and pathways associated with memory function which may be regulated by gene promoter methylation. METHODS The genome-wide promoter methylation statuses in 9 healthy individuals were analyzed with a Multiplex HG18 CpG Promoter chip. Genes with promoter methylation statuses strongly correlated with both immediate and delayed visual memory function were preceded for pathway and physical interactions analysis. RESULTS Sixty nine genes have been correlated with both immediate and delayed visual memory functions. Twenty two pathways, with a Q-value of < 0.05, were identified by the pathway and physical interactions analysis, which included energy metabolism, axon guidance, tyrosine kinase activity, anterograde synaptic vesicle transport, and leukocyte migration and differentiation. CONCLUSION Pathways related with memory function may be regulated by DNA methylation.
Adolescent ; Adult ; DNA Methylation ; Female ; Humans ; Male ; Memory ; Promoter Regions, Genetic ; Signal Transduction ; physiology

Epigenetic factors play an important role in male infertility though about 60%－65% of the disease is idiopathic and its underlying causes are not yet clear. Many studies have indicated that epigenetic modifications, including DNA methylation, histone tail modifications, chromatin remodeling, and non-coding RNAs, may be involved in idiopathic male infertility. Abnormal methylation is associated with decreased sperm quality and fertility. It is known that 1 881 miRNAs are related to male fertility and such non-coding RNAs as piRNA, IncRNA, and circRNA play a regulating role in male reproduction. This review focuses on the value of epigenetics in the etiology and pathogenesis of male infertility, aiming to provide some evidence for the establishment of some strategies for the treatment and prediction of the disease.
DNA Methylation ; Epigenesis, Genetic ; Fertility ; Humans ; Infertility, Male ; genetics ; Male ; MicroRNAs ; physiology ; RNA, Small Interfering ; Spermatozoa