{"id":7774,"date":"2015-10-31T17:00:59","date_gmt":"2015-10-31T16:00:59","guid":{"rendered":"https:\/\/sciencetonnante.wordpress.com\/?p=7774"},"modified":"2021-02-12T08:44:52","modified_gmt":"2021-02-12T07:44:52","slug":"modifier-le-genome-avec-crisprcas9-video","status":"publish","type":"post","link":"https:\/\/scienceetonnante.com\/blog\/2015\/10\/31\/modifier-le-genome-avec-crisprcas9-video\/","title":{"rendered":"Modifier le g\u00e9nome avec CRISPR\/Cas9 [Vid\u00e9o]"},"content":{"rendered":"<p>Une petite vid\u00e9o sur ce sujet qu&rsquo;il me parait indispensable de faire connaitre au plus grand nombre&#8230;<\/p>\n<p><iframe title=\"Modifier le g\u00e9nome avec CRISPR\" width=\"770\" height=\"433\" data-src=\"https:\/\/www.youtube.com\/embed\/bYVE05egjPg?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture\" allowfullscreen src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" class=\"lazyload\" data-load-mode=\"1\"><\/iframe><\/p>\n<p>Pour une fois, vous remarquerez que \u00e7a n&rsquo;est pas un sujet que j&rsquo;avais d\u00e9j\u00e0 trait\u00e9 sur le blog !<\/p>\n<p>Je n&rsquo;ai pas beaucoup de compl\u00e9ments \u00e0 ajouter \u00e0 la vid\u00e9o, \u00e0 part un truc un peu \u00e9tonnant que j&rsquo;ai compris sur le tard, c&rsquo;est que <strong>les palindromes&#8230;n&rsquo;en sont pas<\/strong> ! Il m&rsquo;a fallu retourner \u00e0 la toute premi\u00e8re publication de 1987 (voir [1]) pour m&rsquo;en rendre compte, mais si j&rsquo;ai bien compris on parle de s\u00e9quence ayant en fait une <strong>sym\u00e9trie \u00ab\u00a0dyadique\u00a0\u00bb<\/strong>, c&rsquo;est-\u00e0-dire que quand on les lit \u00e0 l&rsquo;envers, on retrouve ne retrouve pas les m\u00eames bases mais <span style=\"text-decoration: underline;\">leurs compl\u00e9mentaires<\/span>.<\/p>\n<p>Par exemple puisque A et T sont compl\u00e9mentaires ainsi que C et G, la s\u00e9quence<\/p>\n<p style=\"text-align: center;\">AGGCGCCT<\/p>\n<p>poss\u00e8de une sym\u00e9trie dyadique : les 4 premi\u00e8res bases (AGGC) sont compl\u00e9mentaires des 4 derni\u00e8res lues \u00e0 l&rsquo;envers (TCCG). Comme les deux s\u00e9quences sont compl\u00e9mentaires, leurs transcriptions ARN peuvent s&rsquo;apparier pour former une sorte d&rsquo;\u00e9pingle \u00e0 cheveux.<!--more--><\/p>\n<p>Mais \u00e7a n&rsquo;est pas tout, on peut entre les deux s\u00e9quences ins\u00e9rer des bases suppl\u00e9mentaires quelconques.<\/p>\n<p>Illustration ci-dessous extraite de la publication fondatrice de 1987, voir les s\u00e9quences soulign\u00e9es :<\/p>\n<p><a href=\"https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2015\/10\/capture-d_ecc81cran-2015-10-30-acc80-12-39-44.png\"><img decoding=\"async\" class=\"aligncenter size-large wp-image-7775 lazyload\" data-src=\"https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2015\/10\/capture-d_ecc81cran-2015-10-30-acc80-12-39-44.png?w=600\" alt=\"Capture d\u2019\u00e9cran 2015-10-30 \u00e0 12.39.44\" width=\"600\" height=\"150\" data-srcset=\"https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2015\/10\/capture-d_ecc81cran-2015-10-30-acc80-12-39-44.png 847w, https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2015\/10\/capture-d_ecc81cran-2015-10-30-acc80-12-39-44-300x75.png 300w, https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2015\/10\/capture-d_ecc81cran-2015-10-30-acc80-12-39-44-768x192.png 768w\" data-sizes=\"(max-width: 600px) 100vw, 600px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 600px; --smush-placeholder-aspect-ratio: 600\/150;\" \/><\/a><\/p>\n<p>Du coup apr\u00e8s transcription en ARN, quand l&rsquo;\u00e9pingle \u00e0 cheveux se forme, il y a une petite boucle qui correspond \u00e0 ces quelques bases interm\u00e9diaires. Exemple ci-dessous (merci <a href=\"https:\/\/en.wikipedia.org\/wiki\/Stem-loop\">Wikip\u00e9dia<\/a>)<\/p>\n<p><a href=\"https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2015\/10\/stem-loop-svg.png\"><img decoding=\"async\" class=\"aligncenter size-large wp-image-7779 lazyload\" data-src=\"https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2015\/10\/stem-loop-svg.png?w=600\" alt=\"Stem-loop.svg\" width=\"600\" height=\"409\" data-srcset=\"https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2015\/10\/stem-loop-svg.png 640w, https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2015\/10\/stem-loop-svg-300x204.png 300w\" data-sizes=\"(max-width: 600px) 100vw, 600px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 600px; --smush-placeholder-aspect-ratio: 600\/409;\" \/><\/a><\/p>\n<p>Et visiblement cette structure particuli\u00e8re joue un r\u00f4le cl\u00e9 dans le m\u00e9canisme CRISPR\/Cas. (Encore que ce ne soit pas le cas forc\u00e9ment avec Cas9, qui fonctionne selon le m\u00e9canisme \u00ab\u00a0Type 2\u00a0\u00bb ci-dessous (<a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:The_Stages_of_CRISPR_immunity.svg\">source<\/a>), mais on touche un peu les limites de ma compr\u00e9hension du sujet.)<\/p>\n<p><a href=\"https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2015\/10\/the_stages_of_crispr_immunity-svg.png\"><img decoding=\"async\" class=\"aligncenter size-full wp-image-7781 lazyload\" data-src=\"https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2015\/10\/the_stages_of_crispr_immunity-svg.png\" alt=\"The_Stages_of_CRISPR_immunity.svg\" width=\"593\" height=\"768\" data-srcset=\"https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2015\/10\/the_stages_of_crispr_immunity-svg.png 593w, https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2015\/10\/the_stages_of_crispr_immunity-svg-232x300.png 232w\" data-sizes=\"(max-width: 593px) 100vw, 593px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 593px; --smush-placeholder-aspect-ratio: 593\/768;\" \/><\/a><\/p>\n<p><em>[1] Ishino, Yoshizumi, et al. \u00ab\u00a0Nucleotide sequence of the iap gene, responsible for alkaline phosphatase isozyme conversion in Escherichia coli, and identification of the gene product.\u00a0\u00bb Journal of bacteriology 169.12 (1987): 5429-5433.<\/em><\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Une petite vid\u00e9o sur ce sujet qu&rsquo;il me parait indispensable de faire connaitre au plus grand nombre&#8230; Pour une fois, vous remarquerez que \u00e7a n&rsquo;est pas un sujet que j&rsquo;avais d\u00e9j\u00e0 trait\u00e9 sur le blog ! Je n&rsquo;ai pas beaucoup de compl\u00e9ments \u00e0 ajouter \u00e0 la vid\u00e9o, \u00e0 part un truc un peu \u00e9tonnant que<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[7,20],"tags":[27,35],"class_list":{"0":"post-7774","1":"post","2":"type-post","3":"status-publish","4":"format-standard","6":"category-biologie","7":"category-medecine","8":"tag-adn","9":"tag-genetique"},"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"post_mailing_queue_ids":[],"_links":{"self":[{"href":"https:\/\/scienceetonnante.com\/blog\/wp-json\/wp\/v2\/posts\/7774","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/scienceetonnante.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/scienceetonnante.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/scienceetonnante.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/scienceetonnante.com\/blog\/wp-json\/wp\/v2\/comments?post=7774"}],"version-history":[{"count":1,"href":"https:\/\/scienceetonnante.com\/blog\/wp-json\/wp\/v2\/posts\/7774\/revisions"}],"predecessor-version":[{"id":9168,"href":"https:\/\/scienceetonnante.com\/blog\/wp-json\/wp\/v2\/posts\/7774\/revisions\/9168"}],"wp:attachment":[{"href":"https:\/\/scienceetonnante.com\/blog\/wp-json\/wp\/v2\/media?parent=7774"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/scienceetonnante.com\/blog\/wp-json\/wp\/v2\/categories?post=7774"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/scienceetonnante.com\/blog\/wp-json\/wp\/v2\/tags?post=7774"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}