{"id":8416,"date":"2019-05-22T16:07:28","date_gmt":"2019-05-22T16:07:28","guid":{"rendered":"http:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/methylation\/"},"modified":"2019-05-22T16:07:28","modified_gmt":"2019-05-22T16:07:28","slug":"methylation","status":"publish","type":"post","link":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/methylation\/","title":{"rendered":"Methylation"},"content":{"rendered":"<p>A process that takes on a number of meanings depending on the context, but that has &#8216;addition&#8217; as a common entity. &nbsp;In terms of chemistry, it is a reaction that results in the addition of a methyl&nbsp;(-CH3 radical)&nbsp;group to a chemical substrate (e.g., molecule) or the substitution of an atom or group by a <a href=\"http:\/\/www.britannica.com\/EBchecked\/topic\/378576\/methyl-group\" class=\"cc-route-enabled\" target=\"_self\" data-editable-link=\"http:\/\/www.britannica.com\/EBchecked\/topic\/378576\/methyl-group&amp;target=_self\" rel=\"noopener noreferrer\">methyl group<\/a>. &nbsp;Mercury pollution caused by the methyl mercury produced by methylation of organic mercury resulted the epidemic of Miniamata disease in Japan. &nbsp;With regard to a protein, it is also involves an addition, this time the addition of a methyl group (or groups) to the amino acids&nbsp;<a href=\"http:\/\/www.merriam-webster.com\/dictionary\/arginine\" class=\"cc-route-enabled\" target=\"_self\" data-editable-link=\"http:\/\/www.merriam-webster.com\/dictionary\/arginine&amp;target=_self\" rel=\"noopener noreferrer\">arginine<\/a> or l<a href=\"http:\/\/www.merriam-webster.com\/dictionary\/lysine\" class=\"cc-route-enabled\" target=\"_self\" data-editable-link=\"http:\/\/www.merriam-webster.com\/dictionary\/lysine&amp;target=_self\" rel=\"noopener noreferrer\">ysine<\/a> in a protein. &nbsp;As for DNA methylation, it amounts to a enzymatically controlled modification of DNA during which methyl groups are added to particular positions on the nitrogen or nucleotide bases such as cytosine&nbsp;or adenine&nbsp;in eukaryotes. &nbsp;Methylation in this respect forms the basis of chromatin structure, which enables cells to form a plethora of structures essential for multicellular organisms to derive from a single sequence of DNA. &nbsp;In vertebrates, it typically occurs at so-called <a href=\"http:\/\/www.medterms.com\/script\/main\/art.asp?articlekey=26443\" class=\"cc-route-enabled\" target=\"_self\" data-editable-link=\"http:\/\/www.medterms.com\/script\/main\/art.asp?articlekey=26443?target=_self\" rel=\"noopener noreferrer\">CpG sites<\/a> or islands (i.e., where cytosine is directly followed by guanine in the DNA sequence). &nbsp;Located in the <a href=\"http:\/\/www.scfbio-iitd.res.in\/tutorial\/promoter.html\" class=\"cc-route-enabled\" target=\"_self\" data-editable-link=\"http:\/\/www.scfbio-iitd.res.in\/tutorial\/promoter.html&amp;target=_self\" rel=\"noopener noreferrer\">promotor regions of genes<\/a>, they are considered to play an important role in gene silencing or suppression. &nbsp;As a consequence, this effect is usually permanent and unidirectional, thereby serving to prevent reverting back to a stem cell or converting to another type of tissue. &nbsp;Given this particular function, DNA methylation is essential for typical ontogenetic development and cell differentiation. &nbsp;By the blastula stage, the methylation of embryonic cells is complete after undergoing of demethylation\/remethylation referred to as <a href=\"http:\/\/eprints.ulster.ac.uk\/21707\/\" class=\"cc-route-enabled\" target=\"_self\" data-editable-link=\"http:\/\/eprints.ulster.ac.uk\/21707\/&amp;target=_self\" rel=\"noopener noreferrer\">reprogramming<\/a>. &nbsp;In rats, it has been demonstrated that <a href=\"http:\/\/champagnelab.psych.columbia.edu\/docs\/conb.pdf\" class=\"cc-route-enabled\" target=\"_self\" data-editable-link=\"http:\/\/champagnelab.psych.columbia.edu\/docs\/conb.pdf&amp;target=_self\" rel=\"noopener noreferrer\">stress<\/a> during early (postnatal) development results in alteration to methylation processes such that functionally adverse alterations to DNA arise (e.g., alterations that prevent the brain responding appropriately to stress). &nbsp;All told, DNA methylation is an important &#8216;gateway&#8217; for the epigenetic modulation of development. &nbsp;Moreover, it is used in the&nbsp;<a href=\"http:\/\/www.ncbi.nlm.nih.gov\/pubmed\/16690734\" class=\"cc-route-enabled\" target=\"_self\" data-editable-link=\"http:\/\/www.ncbi.nlm.nih.gov\/pubmed\/16690734&amp;target=_self\" rel=\"noopener noreferrer\">diagnosing<\/a>&nbsp;the Prader-Willi and Angelman&#8217;s syndromes. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;<\/p>\n<p>See <a href=\"adenine\">Adenine<\/a>, <a href=\"amino_acids\">Amino acids<\/a>, <a href=\"angelman-s_syndrome\">Angelman&#8217;s syndrome<\/a>, <a href=\"blastula\">Blastula<\/a>, <a href=\"chromatin\">Chromatin<\/a>, <a href=\"cytosine\">Cytosine<\/a>, Differentiation, DNA (deoxyribuncleic acid), <a href=\"dna_double_helix\">DNA double helix<\/a>, <a href=\"enzyme\">Enzyme<\/a>, <a href=\"epigenetics\">Epigenetics<\/a>, <a href=\"eukaryote_cell_-or_organism-\">Eukaryote cell (or organism)<\/a>, <a href=\"guanine\">Guanine<\/a>, <a href=\"histone\">Histone<\/a>, <a href=\"mecp2_gene\">MECP2 gene<\/a>, <a href=\"methyl_mercury\">Methyl mercury<\/a>, <a href=\"miniamata_disease\">Miniamata disease<\/a>, <a href=\"nucleotide\">Nucleotide<\/a>, <a href=\"phosphorylation\">Phosphorylation<\/a>, <a href=\"prader-willi_syndrome\">Prader-Willi syndrome<\/a>, <a href=\"proteins\">Proteins<\/a>, <a href=\"psychosocial_stress\">Psychosocial stress<\/a>, <a href=\"social_stress\">Social stress<\/a><\/p>\n<p><\/p>\n<p><\/p>\n<p><\/body><\/html><\/p>\n","protected":false},"excerpt":{"rendered":"<p>A process that takes on a number of meanings depending on the context, but that has &#8216;addition&#8217; as a common entity. &nbsp;In terms of chemistry, it is a reaction that results in the addition of a methyl&nbsp;(-CH3 radical)&nbsp;group to a chemical substrate (e.g., molecule) or the substitution of an atom or group by a methyl &hellip; <\/p>\n<p class=\"link-more\"><a href=\"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/methylation\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Methylation&#8221;<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[2],"class_list":["post-8416","post","type-post","status-publish","format-standard","hentry","category-uncategorized","tag-glossary","entry"],"_links":{"self":[{"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/posts\/8416","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/comments?post=8416"}],"version-history":[{"count":0,"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/posts\/8416\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/media?parent=8416"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/categories?post=8416"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/tags?post=8416"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}