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Epigenome
An epigenome consists of a record of the chemical changes to the DNA and histone proteins of an organism; these changes can be passed down to an organism's offspring via transgenerational stranded epigenetic inheritance. Changes to the epigenome can result in changes to the structure of chromatin and changes to the function of the genome. The epigenome is involved in regulating gene expression, development, tissue differentiation, and suppression of transposable elements. Unlike the underlying genome, which remains largely static within an individual, the epigenome can be dynamically altered by environmental conditions. Cancer Epigenetics is a currently active topic in cancer research. Human tumors undergo a major disruption of DNA methylation and histone modification patterns. The aberrant epigenetic landscape of the cancer cell is characterized by a global genomic hypomethylation, CpG island promoter hypermethylation of tumor suppressor genes, an altered histone code for c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Human Epigenome Consortium
The International Human Epigenome Consortium (IHEC) is a scientific organization, founded in 2010, that helps to coordinate global efforts in the field of Epigenomics. The initial goal was to generate at least 1,000 reference (baseline) Human epigenome, human epigenomes from different types of normal and disease-related human cell types. Structure and funding IHEC’s operations are funded by its full members (national and regional scientific funding agencies), and staffed largely on a volunteer basis by scientists and other experts from participating funding agencies and epigenome mapping projects. Current IHEC Member Countries * CIHR, Canadian Institutes for Health Research (Canada) * European Commission (EU) * Federal Ministry of Education and Research, Project Management Agency within the German Aerospace Centre (Germany) * Genome Institute of Singapore (Singapore) * Hong Kong Epigenomics Project (Hong Kong) * Japan Agency for Medical Research and Development (Japan) * N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epigenome
An epigenome consists of a record of the chemical changes to the DNA and histone proteins of an organism; these changes can be passed down to an organism's offspring via transgenerational stranded epigenetic inheritance. Changes to the epigenome can result in changes to the structure of chromatin and changes to the function of the genome. The epigenome is involved in regulating gene expression, development, tissue differentiation, and suppression of transposable elements. Unlike the underlying genome, which remains largely static within an individual, the epigenome can be dynamically altered by environmental conditions. Cancer Epigenetics is a currently active topic in cancer research. Human tumors undergo a major disruption of DNA methylation and histone modification patterns. The aberrant epigenetic landscape of the cancer cell is characterized by a global genomic hypomethylation, CpG island promoter hypermethylation of tumor suppressor genes, an altered histone code for c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epigenome Editing
Epigenome editing or Epigenome engineering is a type of genetic engineering in which the epigenome is modified at specific sites using engineered molecules targeted to those sites (as opposed to whole-genome modifications). Whereas gene editing involves changing the actual DNA sequence itself, epigenetic editing involves modifying and presenting DNA sequences to proteins and other DNA binding factors that influence DNA function. By "editing” epigenomic features in this manner, researchers can determine the exact biological role of an epigenetic modification at the site in question. The engineered proteins used for epigenome editing are composed of a DNA binding domain that target specific sequences and an effector domain that modifies epigenomic features. Currently, three major groups of DNA binding proteins have been predominantly used for epigenome editing: Zinc finger proteins, Transcription Activator-Like Effectors (TALEs) and nuclease deficient Cas9 fusions (CRISPR). Gener ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epigenetics
In biology, epigenetics is the study of stable phenotypic changes (known as ''marks'') that do not involve alterations in the DNA sequence. The Greek prefix '' epi-'' ( "over, outside of, around") in ''epigenetics'' implies features that are "on top of" or "in addition to" the traditional genetic basis for inheritance. Epigenetics most often involves changes that affect the regulation of gene expression, but the term can also be used to describe any heritable phenotypic change. Such effects on cellular and physiological phenotypic traits may result from external or environmental factors, or be part of normal development. The term also refers to the mechanism of changes: functionally relevant alterations to the genome that do not involve mutation of the nucleotide sequence. Examples of mechanisms that produce such changes are DNA methylation and histone modification, each of which alters how genes are expressed without altering the underlying DNA sequence. Gene expression c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bisulfite Sequencing
Bisulfite sequencing (also known as bisulphite sequencing) is the use of bisulfite treatment of DNA before routine sequencing to determine the pattern of methylation. DNA methylation was the first discovered epigenetic mark, and remains the most studied. In animals it predominantly involves the addition of a methyl group to the carbon-5 position of cytosine residues of the dinucleotide CpG, and is implicated in repression of transcriptional activity. Treatment of DNA with bisulfite converts cytosine residues to uracil, but leaves 5-methylcytosine residues unaffected. Therefore, DNA that has been treated with bisulfite retains only methylated cytosines. Thus, bisulfite treatment introduces specific changes in the DNA sequence that depend on the methylation status of individual cytosine residues, yielding single-nucleotide resolution information about the methylation status of a segment of DNA. Various analyses can be performed on the altered sequence to retrieve this informat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Epigenome
Human epigenome is the complete set of structural modifications of chromatin and chemical modifications of histones and nucleotides (such as cytosine methylation). These modifications affect t according to cellular type and development status. Various studies show that epigenome depends on exogenous factors. Chemical modifications Different types of chemical modifications exist and the ChIP-seq experimental procedure can be performed in order to study them. The epigenetic profiles of human tissues reveals the following distinct histone modifications in different functional areas: Methylation DNA functionally interacts with a variety of epigenetic marks, such as cytosine methylation, also known as 5-methylcytosine (5mC). This epigenetic mark is widely conserved and plays major roles in the regulation of gene expression, in the silencing of transposable elements and repeat sequences. Individuals differ with their epigenetic profile, for example the variance in CpG methylatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NCBI Epigenomics
The Epigenomics database at the National Center for Biotechnology Information was a database for whole-genome epigenetics data sets. It was retired on 1 June 2016. The Epigenomics database The Epigenomics database of the National Center for Biotechnology Information (NCBI) at the National Institutes of Health (NIH) was launched in June 2010 as a means to collect maps of epigenetic modifications and their occurrence across the human genome. This database provides a publicly available resource for maps in stem cells and primary ''ex vivo'' tissues that detail genome-wide landscapes of epigenetic factors that occur in human development and disease. Content of Epigenomics database The primary resources for the content of the Epigenomics Database are derived from two archival databases at the NCBI: The Gene Expression Omnibus (GEO) and the Sequence Read Archive (SRA). The Gene Expression Omnibus is a data system for high-throughput genomic data that is generated from microarray and next ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DNA Methylation
DNA methylation is a biological process by which methyl groups are added to the DNA molecule. Methylation can change the activity of a DNA segment without changing the sequence. When located in a gene promoter, DNA methylation typically acts to repress gene transcription. In mammals, DNA methylation is essential for normal development and is associated with a number of key processes including genomic imprinting, X-chromosome inactivation, repression of transposable elements, aging, and carcinogenesis. As of 2016, two nucleobases have been found on which natural, enzymatic DNA methylation takes place: adenine and cytosine. The modified bases are N6-methyladenineD. B. Dunn, J. D. Smith: ''The occurrence of 6-methylaminopurine in deoxyribonucleic acids.'' In: ''Biochem J.'' 68(4), Apr 1958, S. 627–636. PMID 13522672. ., 5-methylcytosineB. F. Vanyushin, S. G. Tkacheva, A. N. Belozersky: ''Rare bases in animal DNA.'' In: ''Nature.'' 225, 1970, S. 948–949. PMID 4391887. and N4- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alzheimer's Disease
Alzheimer's disease (AD) is a neurodegeneration, neurodegenerative disease that usually starts slowly and progressively worsens. It is the cause of 60–70% of cases of dementia. The most common early symptom is difficulty in short-term memory, remembering recent events. As the disease advances, symptoms can include primary progressive aphasia, problems with language, Orientation (mental), disorientation (including easily getting lost), mood swings, loss of motivation, self-neglect, and challenging behaviour, behavioral issues. As a person's condition declines, they often withdraw from family and society. Gradually, bodily functions are lost, ultimately leading to death. Although the speed of progression can vary, the typical life expectancy following diagnosis is three to nine years. The cause of Alzheimer's disease is poorly understood. There are many environmental and genetic risk factors associated with its development. The strongest genetic risk factor is from an alle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene Expression
Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product that enables it to produce end products, protein or non-coding RNA, and ultimately affect a phenotype, as the final effect. These products are often proteins, but in non-protein-coding genes such as transfer RNA (tRNA) and small nuclear RNA (snRNA), the product is a functional non-coding RNA. Gene expression is summarized in the central dogma of molecular biology first formulated by Francis Crick in 1958, further developed in his 1970 article, and expanded by the subsequent discoveries of reverse transcription and RNA replication. The process of gene expression is used by all known life—eukaryotes (including multicellular organisms), prokaryotes (bacteria and archaea), and utilized by viruses—to generate the macromolecular machinery for life. In genetics, gene expression is the most fundamental level at which the genotype gives rise to the phenotype, '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transgenerational Epigenetic Inheritance
Transgenerational epigenetic inheritance is the transmission of epigenetic markers from one organism to the next (i.e., from parent to child) that affects the traits of offspring without altering the nucleic acid primary structure, primary structure of DNA (i.e. the sequence of nucleotides) —in other words, epigenetics, epigenetically. The less precise term "epigenetic inheritance" may cover both cell–cell and organism–organism information transfer. Although these two levels of epigenetic inheritance are equivalent in unicellular organisms, they may have distinct mechanisms and evolutionary distinctions in multicellular organisms. Environmental factors can induce the epigenetic marks (epigenetic tags) for some epigenetically influenced traits, while some marks are heritable, thus leading some to consider that with epigenetics, modern biology no longer rejects the Lamarckism, inheritance of acquired characteristics (Lamarckism) as strongly as it once did. Epigenetic categories ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ChIP-sequencing
ChIP-sequencing, also known as ChIP-seq, is a method used to analyze protein interactions with DNA. ChIP-seq combines chromatin immunoprecipitation (ChIP) with massively parallel DNA sequencing to identify the binding sites of DNA-associated proteins. It can be used to map global binding sites precisely for any protein of interest. Previously, ChIP-on-chip was the most common technique utilized to study these protein–DNA relations. Uses ChIP-seq is primarily used to determine how transcription factors and other chromatin-associated proteins influence phenotype-affecting mechanisms. Determining how proteins interact with DNA to regulate gene expression is essential for fully understanding many biological processes and disease states. This epigenetic information is complementary to genotype and expression analysis. ChIP-seq technology is currently seen primarily as an alternative to ChIP-chip which requires a hybridization array. This introduces some bias, as an array is restrict ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
