{"id":9905,"date":"2025-05-16T17:02:00","date_gmt":"2025-05-16T15:02:00","guid":{"rendered":"https:\/\/scienceetonnante.com\/blog\/?p=9905"},"modified":"2025-05-16T17:02:18","modified_gmt":"2025-05-16T15:02:18","slug":"lhypothese-du-monde-a-arn","status":"publish","type":"post","link":"https:\/\/scienceetonnante.com\/blog\/2025\/05\/16\/lhypothese-du-monde-a-arn\/","title":{"rendered":"L&rsquo;hypoth\u00e8se du Monde \u00e0 ARN"},"content":{"rendered":"\n<p>Dans la vid\u00e9o du jour, on \u00e9tudie l&rsquo;hypoth\u00e8se dite du \u00ab\u00a0Monde \u00e0 ARN\u00a0\u00bb, qui stipule que la vie sur Terre aurait, \u00e0 un moment donn\u00e9, repos\u00e9 sur l&rsquo;ARN, au lieu du bin\u00f4me ADN\/prot\u00e9ines. Voire que cette phase aurait pu avoir \u00e9merg\u00e9 spontan\u00e9ment d&rsquo;un monde inerte, et constituer ainsi la premi\u00e8re marche de l&rsquo;apparition de la vie sur Terre<\/p>\n\n\n\n<figure class=\"wp-block-embed is-type-video is-provider-youtube wp-block-embed-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<iframe title=\"L&#039;ARN aux Origines de la Vie sur Terre ? \u2014 Le Monde \u00e0 ARN\" width=\"770\" height=\"433\" data-src=\"https:\/\/www.youtube.com\/embed\/HR3fLfHu9U4?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" class=\"lazyload\" data-load-mode=\"1\"><\/iframe>\n<\/div><\/figure>\n\n\n\n<p>Comme \u00e0 mon habitude, ci-dessous quelques compl\u00e9ments et pr\u00e9cisions pour celles et ceux qui voudraient creuser<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Le cas des virus<\/h2>\n\n\n\n<p>Les plus attentifs d&rsquo;entre vous auront remarqu\u00e9 que j&rsquo;ai savamment esquiv\u00e9 la question de savoir si les virus sont \u00e0 consid\u00e9rer comme faisant partie ou non du vivant ! La question n&rsquo;a pas de r\u00e9ponse unique, et dans cette vid\u00e9o j&rsquo;ai plut\u00f4t choisi de me concentrer sur le couple ADN\/prot\u00e9ines comme caract\u00e9ristique de la vie sur Terre telle qu&rsquo;on la connait.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Transcription et traduction<\/h2>\n\n\n\n<p>J&rsquo;ai beaucoup simplifi\u00e9 tout ce qui tourne autour de l&rsquo;information g\u00e9n\u00e9tique et de sa circulation. Un point qui m\u00e9rite d&rsquo;\u00eatre mentionn\u00e9 : tout l&rsquo;ADN ne correspond pas \u00e0 des g\u00e8nes codant pour des prot\u00e9ines et donc tout l&rsquo;ARN ne sera pas traduit. En effet notamment chez les eukaryotes, on distingue les introns (s\u00e9quences non-codantes) et les exons (qui seront utilis\u00e9s pour la traduction en prot\u00e9ines.)<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" width=\"1024\" height=\"297\" data-src=\"https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2025\/05\/image-1024x297.png\" alt=\"\" class=\"wp-image-9910 lazyload\" data-srcset=\"https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2025\/05\/image-1024x297.png 1024w, https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2025\/05\/image-300x87.png 300w, https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2025\/05\/image-768x223.png 768w, https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2025\/05\/image.png 1101w\" data-sizes=\"(max-width: 1024px) 100vw, 1024px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 1024px; --smush-placeholder-aspect-ratio: 1024\/297;\" \/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">Nucl\u00e9osides et nucl\u00e9otides<\/h2>\n\n\n\n<p>J&rsquo;ai balay\u00e9 un peu vite le vocabulaire pr\u00e9cis concernant la structure de l&rsquo;ADN et de l&rsquo;ARN. Techniquement on appelle nucl\u00e9osides (avec un S) l&rsquo;association d&rsquo;une base et d&rsquo;un ribose, alors que pour faire un nucl\u00e9otide (avec T) il faut y ajouter le groupement phosphate qui va permettre d&rsquo;une certaine fa\u00e7on la polym\u00e9risation.<\/p>\n\n\n\n<p>Le <a href=\"https:\/\/fr.m.wikipedia.org\/wiki\/Nucl\u00e9oside\" target=\"_blank\" rel=\"noopener\">tableau ci-dessous<\/a> nous montre \u00e7a pour les diff\u00e9rentes bases et les deux sucres<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" width=\"1024\" height=\"933\" data-src=\"https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2025\/05\/image-1-1024x933.png\" alt=\"\" class=\"wp-image-9911 lazyload\" data-srcset=\"https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2025\/05\/image-1-1024x933.png 1024w, https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2025\/05\/image-1-300x273.png 300w, https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2025\/05\/image-1-768x700.png 768w, https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2025\/05\/image-1-1536x1399.png 1536w, https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2025\/05\/image-1.png 1618w\" data-sizes=\"(max-width: 1024px) 100vw, 1024px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 1024px; --smush-placeholder-aspect-ratio: 1024\/933;\" \/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">Et les compartiments ?<\/h2>\n\n\n\n<p>Dans les crit\u00e8res traditionnellement consid\u00e9r\u00e9s pour d\u00e9finir la notion de syst\u00e8me vivant, il y a l&rsquo;id\u00e9e d&rsquo;une compartimentalisation. Par exemple avec une double membrane lipidique qui permet d&rsquo;isoler les cellules vivantes de leur ext\u00e9rieur. Tout ce qu&rsquo;on a discut\u00e9 concernant les hypoth\u00e8ses du monde \u00e0 ARN est relativement agnostique de cette notion. <\/p>\n\n\n\n<p>Voir par exemple cette <a href=\"https:\/\/www.sciencedirect.com\/science\/article\/pii\/S1674987117301305\" target=\"_blank\" rel=\"noopener\">review<\/a> <\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" width=\"1024\" height=\"348\" data-src=\"https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2025\/05\/image-2-1024x348.png\" alt=\"\" class=\"wp-image-9912 lazyload\" data-srcset=\"https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2025\/05\/image-2-1024x348.png 1024w, https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2025\/05\/image-2-300x102.png 300w, https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2025\/05\/image-2-768x261.png 768w, https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2025\/05\/image-2-1536x523.png 1536w\" data-sizes=\"(max-width: 1024px) 100vw, 1024px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 1024px; --smush-placeholder-aspect-ratio: 1024\/348;\" \/><\/figure>\n\n\n\n<p>On pourrait imaginer une \u00e9mergence du monde \u00e0 ARN aussi bien dans des compartiments du type \u00ab\u00a0proto-cellules\u00a0\u00bb, que dans des compartiments naturels comme certaines roches poreuses.<\/p>\n\n\n\n<p>Voir par exemple cet <a href=\"https:\/\/static.nsta.org\/case_study_docs\/case_studies\/origins_debate_adv.pdf\" target=\"_blank\" rel=\"noopener\">article<\/a> qui pr\u00e9sente les termes de la discussion sous la forme d&rsquo;un d\u00e9bat que l&rsquo;on peut organiser entre des \u00e9l\u00e8ves<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" width=\"915\" height=\"1024\" data-src=\"https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2025\/05\/Capture-decran-2025-05-16-a-14.18.57-915x1024.png\" alt=\"\" class=\"wp-image-9913 lazyload\" data-srcset=\"https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2025\/05\/Capture-decran-2025-05-16-a-14.18.57-915x1024.png 915w, https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2025\/05\/Capture-decran-2025-05-16-a-14.18.57-268x300.png 268w, https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2025\/05\/Capture-decran-2025-05-16-a-14.18.57-768x859.png 768w, https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2025\/05\/Capture-decran-2025-05-16-a-14.18.57-1373x1536.png 1373w, https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2025\/05\/Capture-decran-2025-05-16-a-14.18.57.png 1396w\" data-sizes=\"(max-width: 915px) 100vw, 915px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 915px; --smush-placeholder-aspect-ratio: 915\/1024;\" \/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">Bibliographie<\/h2>\n\n\n\n<p>Et pour finir, une petite bibliographie des papiers que j&rsquo;ai lu pour pr\u00e9parer cette vid\u00e9o :<br><br>Ferris, J. P., Hill, A. R., Jr., Liu, R., &amp; Orgel, L. E. (1996). Synthesis of long prebiotic oligomers on mineral surfaces. Nature, 381(6577), 59\u201361. https:\/\/www.nature.com\/articles\/381059a0<\/p>\n\n\n\n<p>Johnston, W. K., Unrau, P. J., Lawrence, M. S., Glasner, M. E., &amp; Bartel, D. P. (2001). RNA-catalyzed RNA polymerization: Accurate and general RNA-templated primer extension. Science, 292(5520), 1319\u20131325. https:\/\/doi.org\/10.1126\/science.1060786<\/p>\n\n\n\n<p>Doudna, J. A., &amp; Cech, T. R. (2002). The chemical repertoire of natural ribozymes. Nature, 418(6894), 222\u2013228. https:\/\/doi.org\/10.1038\/418222a<\/p>\n\n\n\n<p>Seelig, B. (2008). An autocatalytic network for ribozyme self-construction. Nature Chemical Biology, 4(11), 654\u2013655. https:\/\/doi.org\/10.1038\/nchembio1108-654<\/p>\n\n\n\n<p>Lincoln, T. A., &amp; Joyce, G. F. (2009). Self-sustained replication of an RNA enzyme. Science, 323(5918), 1229\u20131232. https:\/\/doi.org\/10.1126\/science.1167856<\/p>\n\n\n\n<p>Powner, M. W., Gerland, B., &amp; Sutherland, J. D. (2009). Synthesis of activated pyrimidine ribonucleotides in prebiotically plausible conditions. Nature, 459(7244), 239\u2013242. https:\/\/doi.org\/10.1038\/nature08013<\/p>\n\n\n\n<p>Mulkidjanian, A. Y., Bychkov, A. Y., Dibrova, D. V., Galperin, M. Y., &amp; Koonin, E. V. (2012). Origin of first cells at terrestrial, anoxic geothermal fields. Proceedings of the National Academy of Sciences, 109(14), E821\u2013E830. https:\/\/doi.org\/10.1073\/pnas.1117774109<\/p>\n\n\n\n<p>Robertson, M. P., &amp; Joyce, G. F. (2012). The origins of the RNA world. Cold Spring Harbor Perspectives in Biology, 4(5), a003608. https:\/\/doi.org\/10.1101\/cshperspect.a003608<\/p>\n\n\n\n<p>Cech, T. R. (2012). The RNA world in context. Cold Spring Harbor Perspectives in Biology, 4(7), a006742. https:\/\/doi.org\/10.1101\/cshperspect.a006742<\/p>\n\n\n\n<p>Higgs, P. G., &amp; Lehman, N. (2015). The RNA world: Molecular cooperation at the origins of life. Nature Reviews Genetics, 16(1), 7\u201317. https:\/\/doi.org\/10.1038\/nrg3841<\/p>\n\n\n\n<p>Horning, D. P., &amp; Joyce, G. F. (2016). Amplification of RNA by an RNA polymerase ribozyme. Proceedings of the National Academy of Sciences, 113(35), 9786\u20139791. https:\/\/doi.org\/10.1073\/pnas.1610103113<\/p>\n\n\n\n<p>Meinert, C., Myrgorodska, I., de Marcellus, P., Buhse, T., Nahon, L., Hoffmann, S. V., \u2026 Meierhenrich, U. J. (2016). Ribose and related sugars from ultraviolet irradiation of interstellar ice analogs. Science, 352(6282), 208\u2013212. https:\/\/doi.org\/10.1126\/science.aad8137<\/p>\n\n\n\n<p>Usami, K., &amp; Okamoto, A. (2017). Hydroxyapatite: Catalyst for a one-pot pentose formation. Organic &amp; Biomolecular Chemistry, 15(42), 8888\u20138893. https:\/\/doi.org\/10.1039\/C7OB02051A<\/p>\n\n\n\n<p>Kompanichenko, V. N. (2019). Exploring the Kamchatka geothermal region in the context of life\u2019s beginning. Life, 9(2), 41. https:\/\/doi.org\/10.3390\/life9020041<\/p>\n\n\n\n<p>Hud, N. V. (2019). RNA nucleosides built in one prebiotic pot. Science, 366(6461), 32\u201333. https:\/\/doi.org\/10.1126\/science.aaz1130<\/p>\n\n\n\n<p>Becker, S., Feldmann, J., Wiedemann, S., Okamura, H., Schneider, C., Iwan, K., \u2026 Carell, T. (2019). Unified prebiotically plausible synthesis of pyrimidine and purine RNA ribonucleotides. Science, 366(6461), 76\u201382. https:\/\/doi.org\/10.1126\/science.aax2747<\/p>\n\n\n\n<p>Damer, B., &amp; Deamer, D. (2020). The hot spring hypothesis for an origin of life. Astrobiology, 20(4), 429\u2013452. https:\/\/doi.org\/10.1089\/ast.2019.2045<\/p>\n\n\n\n<p>Muchowska, K. B., Varma, S. J., &amp; Moran, J. (2020). Non-enzymatic metabolic reactions and life\u2019s origins. Chemical Reviews, 120(15), 7708\u20137744. https:\/\/doi.org\/10.1021\/acs.chemrev.0c00191<\/p>\n\n\n\n<p>Wo\u0142os, A., Roszak, R., \u017b\u0105d\u0142o-Dobrowolska, A., Beker, W., Mikulak-Klucznik, B., Sp\u00f3lnik, G., \u2026 Grzybowski, B. A. (2020). Synthetic connectivity, emergence, and self-regeneration in the network of prebiotic chemistry. Science, 369(6511), eaaw1955. https:\/\/doi.org\/10.1126\/science.aaw1955<\/p>\n\n\n\n<p>Blokhuis, A., Lacoste, D., &amp; Nghe, P. (2020). Universal motifs and the diversity of autocatalytic systems. Proceedings of the National Academy of Sciences, 117(41), 25230\u201325236. https:\/\/doi.org\/10.1073\/pnas.2013527117<\/p>\n\n\n\n<p>Yu, A. M., Gasper, P. M., Cheng, L., Lai, L. B., Kaur, S., Gopalan, V., Chen, A. A., &amp; Lucks, J. B. (2021). Computationally reconstructing cotranscriptional RNA folding from experimental data reveals rearrangement of non-native folding intermediates. Molecular Cell, 81(4), 870\u2013883.e10. https:\/\/doi.org\/10.1016\/j.molcel.2020.12.017<\/p>\n\n\n\n<p>Pavlinova, P., Lambert, C. N., Malaterre, C., &amp; Nghe, P. (2022). Abiogenesis through gradual evolution of autocatalysis into template-based replication. FEBS Letters, 597(3), 344\u2013379. https:\/\/doi.org\/10.1002\/1873-3468.14507<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Dans la vid\u00e9o du jour, on \u00e9tudie l&rsquo;hypoth\u00e8se dite du \u00ab\u00a0Monde \u00e0 ARN\u00a0\u00bb, qui stipule que la vie sur Terre aurait, \u00e0 un moment donn\u00e9, repos\u00e9 sur l&rsquo;ARN, au lieu du bin\u00f4me ADN\/prot\u00e9ines. Voire que cette phase aurait pu avoir \u00e9merg\u00e9 spontan\u00e9ment d&rsquo;un monde inerte, et constituer ainsi la premi\u00e8re marche de l&rsquo;apparition de la<\/p>\n","protected":false},"author":1,"featured_media":9907,"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],"tags":[137,60],"class_list":{"0":"post-9905","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-biologie","8":"tag-astrobiologie","9":"tag-vie"},"jetpack_featured_media_url":"https:\/\/scienceetonnante.com\/blog\/wp-content\/uploads\/2025\/05\/feature-image-ARN-world.png","jetpack_sharing_enabled":true,"post_mailing_queue_ids":[],"_links":{"self":[{"href":"https:\/\/scienceetonnante.com\/blog\/wp-json\/wp\/v2\/posts\/9905","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=9905"}],"version-history":[{"count":3,"href":"https:\/\/scienceetonnante.com\/blog\/wp-json\/wp\/v2\/posts\/9905\/revisions"}],"predecessor-version":[{"id":9915,"href":"https:\/\/scienceetonnante.com\/blog\/wp-json\/wp\/v2\/posts\/9905\/revisions\/9915"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/scienceetonnante.com\/blog\/wp-json\/wp\/v2\/media\/9907"}],"wp:attachment":[{"href":"https:\/\/scienceetonnante.com\/blog\/wp-json\/wp\/v2\/media?parent=9905"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/scienceetonnante.com\/blog\/wp-json\/wp\/v2\/categories?post=9905"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/scienceetonnante.com\/blog\/wp-json\/wp\/v2\/tags?post=9905"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}