{"id":24996,"date":"2014-06-01T13:09:42","date_gmt":"2014-06-01T10:09:42","guid":{"rendered":"https:\/\/bilimvegelecek.com.tr\/?p=24996"},"modified":"2018-05-10T13:25:40","modified_gmt":"2018-05-10T10:25:40","slug":"akilli-tasarim-gercek-oldu-dna-alfabesi-genisletilmis-ilk-yari-sentetik-canli-uretildi","status":"publish","type":"post","link":"https:\/\/bilimvegelecek.com.tr\/index.php\/2014\/06\/01\/akilli-tasarim-gercek-oldu-dna-alfabesi-genisletilmis-ilk-yari-sentetik-canli-uretildi","title":{"rendered":"Ak\u0131ll\u0131 tasar\u0131m ger\u00e7ek oldu:  DNA alfabesi geni\u015fletilmi\u015f ilk yar\u0131-sentetik canl\u0131 \u00fcretildi"},"content":{"rendered":"<p>Genetikle uzaktan yak\u0131ndan ilgilenmi\u015f hemen herkes DNA\u2019n\u0131n t\u00fcm canl\u0131larda ayn\u0131 n\u00fckleotidlerle kal\u0131t\u0131m\u0131 sa\u011flad\u0131\u011f\u0131n\u0131 hat\u0131rlayacakt\u0131r. Adenin (A), Timin (T), Guanin (G) ve Sitozin (C) n\u00fckleotidleri \u00e7ift halinde(A-T ve G-C) dizilerek ya\u015fam\u0131n temel \u00f6zelliklerini ta\u015f\u0131yan d\u00f6rt harfli \u201cgenetik alfabeyi\u201d olu\u015fturur. Scripps Ara\u015ft\u0131rma Enstit\u00fcs\u00fc\u2019nden (The Scripps Research Institute) biliminsanlar\u0131 bu alfabeye yeni n\u00fckleotidleri eklemeyi daha \u00f6nce ba\u015farm\u0131\u015flard\u0131. 7 May\u0131s 2014\u2019te ise bunu canl\u0131 bir h\u00fccreye ba\u015far\u0131yla aktard\u0131klar\u0131n\u0131, DNA\u2019n\u0131n kararl\u0131 yap\u0131s\u0131n\u0131 bozmad\u0131\u011f\u0131n\u0131 ve <em>E. coli<\/em> h\u00fccrelerine ba\u015far\u0131yla kopyalatabildiklerini <em>Nature<\/em>\u2019da yay\u0131nlanan \u00e7evrimi\u00e7i makale ile duyurdular. d5SICS ve dNaM isimli n\u00fckleotidler \u00e7oktan X ve Y baz \u00e7ifti olarak an\u0131lmaya ba\u015fland\u0131.<\/p>\n<p><strong>Ara\u015ft\u0131rman\u0131n ge\u00e7mi\u015fi<\/strong><\/p>\n<p>Floyd E. Romesber ve ekibi 90\u2019lar\u0131n sonlar\u0131ndan beri yeni ve i\u015flevli DNA baz \u00e7ifti olu\u015fturmak i\u00e7in \u00e7al\u0131\u015f\u0131yor. Bu molek\u00fcllerin k\u00e2\u011f\u0131t \u00fczerinde bug\u00fcne kadar hi\u00e7 varolmam\u0131\u015f protein ve canl\u0131lar\u0131 kodlamay\u0131 sa\u011flayabilecek olmas\u0131, \u00e7al\u0131\u015fmalar\u0131n temel motivasyonunu olu\u015fturuyor.<\/p>\n<figure id=\"attachment_24999\" aria-describedby=\"caption-attachment-24999\" style=\"width: 266px\" class=\"wp-caption alignright\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-24999\" src=\"https:\/\/bilimvegelecek.com.tr\/wp-content\/uploads\/2018\/05\/5-Sentetik-DNA-tablo-266x300.jpg\" alt=\"\" width=\"266\" height=\"300\" \/><figcaption id=\"caption-attachment-24999\" class=\"wp-caption-text\">Geni\u015fletilmi\u015f Genetik Alfabe<\/figcaption><\/figure>\n<p>Bu olduk\u00e7a zorlu bir g\u00f6rev, \u00e7\u00fcnk\u00fc herhangi bir yeni \u00e7ift do\u011fal n\u00fcklotid \u00e7iftlerine (A-T ve G-C) benzemek zorundad\u0131r. Yeni bazlar hidrojen ba\u011flar\u0131yla bir fermuar gibi birbirine tutunarak dizilen DNA\u2019n\u0131n stabil (dengeli) yap\u0131s\u0131n\u0131 bozmamal\u0131d\u0131r. DNA kopyalanmas\u0131 ve transkripsiyon s\u00fcre\u00e7lerinde DNA zinciri a\u00e7\u0131l\u0131rken ve yeniden birle\u015firken do\u011fal polimeraz enzimleriyle uyumlu \u00e7al\u0131\u015fmal\u0131d\u0131r. Ayn\u0131 zamanda do\u011fal DNA tamir mekanizmalar\u0131ndan da etkilenmemelidir.<\/p>\n<p>T\u00fcm bu zorluklara kar\u015f\u0131n 2008\u2019de Romesberg ve \u00e7al\u0131\u015fma arkada\u015flar\u0131, hedeflerine y\u00f6nelik b\u00fcy\u00fck bir ba\u015far\u0131 sa\u011flad\u0131; yay\u0131nlad\u0131klar\u0131 makalede DNA zincirine ba\u011flanabilen do\u011fal n\u00fcklotidler kadar uyumlu ve uygun enzimler sa\u011fland\u0131\u011f\u0131nda, kopyalama i\u015flemini aksatmayan bir dizi n\u00fckleotid tan\u0131mlad\u0131lar. Takip eden y\u0131lda yap\u0131lan bir \u00e7al\u0131\u015fmada ise, ara\u015ft\u0131rmac\u0131lar bu yar\u0131 sentetik DNA\u2019n\u0131n RNA\u2019ya transkripsiyonunu sa\u011flayan enzimleri ke\u015ffetti.<\/p>\n<p>Ancak bu sadele\u015ftirilmi\u015f deney t\u00fcp\u00fc ortam\u0131nda yap\u0131lan bir \u00e7al\u0131\u015fmayd\u0131. Rosemberg\u2019in laboratuvar\u0131ndan, bu yeni makalenin yazar\u0131 da olan Malyshev, as\u0131l meydan okuman\u0131n \u00e7ok daha karma\u015f\u0131k bir ortam olan h\u00fccre olaca\u011f\u0131n\u0131 s\u00f6ylemi\u015fti.<\/p>\n<p><strong>Mikroalg at\u0131l\u0131ma \u00f6nc\u00fcl\u00fck ediyor<\/strong><\/p>\n<p>Yeni \u00e7al\u0131\u015fmada plazmid olarak bilinen halkasal DNA\u2019y\u0131 kendi yapay n\u00fckleotidleriyle birlikte \u00fcrettiler ve yayg\u0131n bir bakteri olan <em>Escherichia coli<\/em> h\u00fccrelerine ba\u015far\u0131yla aktard\u0131rlar. Plazmid DNA\u2019s\u0131, do\u011fal olarak bulunan A-T ve G-C baz \u00e7iftlerine ek olarak Romesberg\u2019in laboratuvar\u0131nda \u00fcretilen d5SICS and dNaM isimli n\u00fckleotidleri de i\u00e7eriyor. As\u0131l ba\u015far\u0131 ise <em>E. coli<\/em> h\u00fccrelerinin bu plazmidleri olabildi\u011fince normal \u015fekilde \u00e7o\u011faltmas\u0131.<\/p>\n<p>Bu yeni canl\u0131 formunun kontrolden \u00e7\u0131k\u0131p do\u011faya sal\u0131nmas\u0131ndan korkanlar g\u00f6n\u00fcllerini ferah tutabilir, \u00e7\u00fcnk\u00fc d5SICS ve dNaM n\u00fckleotidlerinin yap\u0131 bloklar\u0131 h\u00fccre i\u00e7inde do\u011fal olarak bulunmuyor. Bu y\u00fczden bu yapay n\u00fckleotidlere sahip <em>E. coli<\/em> h\u00fccreleri DNA\u2019lar\u0131n\u0131 kopyalamak i\u00e7in ara\u015ft\u0131rmac\u0131lar\u0131n d\u0131\u015far\u0131dan \u00e7\u00f6zelti ekleyerek gerekli yap\u0131 bloklar\u0131n\u0131 sa\u011flamas\u0131n\u0131 gereksinim duyuyorlar. N\u00fckleotid trifosfat olarak bilinen bu yap\u0131 bloklar\u0131n\u0131n h\u00fccre i\u00e7ine ula\u015fmas\u0131 i\u00e7in, ara\u015ft\u0131rmac\u0131lar\u0131n \u00f6zel trifosfat ta\u015f\u0131y\u0131c\u0131 molek\u00fclleri ke\u015ffetmeleri gerekiyordu. Aranan ta\u015f\u0131y\u0131c\u0131 molek\u00fcller bir mikroalg t\u00fcr\u00fcnde bulundu ve b\u00f6ylece biliminsanlar\u0131 hedeflerine do\u011fru b\u00fcy\u00fck bir ad\u0131m atm\u0131\u015f oldular.<\/p>\n<p>Tekrar b\u00fcy\u00fck bir zorlukla kar\u015f\u0131la\u015f\u0131lmad\u0131\u011f\u0131 halde, projeyi bitirmek ekibin bir y\u0131l\u0131n\u0131 daha ald\u0131. \u00c7al\u0131\u015fma ekibi b\u00f6ylece makul bir h\u0131z ve kararl\u0131l\u0131kla kopyalanabilen yar\u0131-sentetik plazmiti geli\u015ftirmi\u015f oldu. <em>E. coli<\/em> h\u00fccrelerinin yeti\u015fmesine \u00e7ok b\u00fcy\u00fck bir engel te\u015fkil etmiyordu ve yapay n\u00fckleotidlerin DNA tamir mekanizmalar\u0131yla eksildi\u011fine dair herhangi bir iz yoktu.<\/p>\n<p>Malyshev h\u00fccreye yap\u0131 bloklar\u0131n\u0131n ak\u0131\u015f\u0131n\u0131n kesilmesi durumunda, h\u00fccre \u00e7o\u011falmas\u0131 s\u0131ras\u0131nda d5SICS ve dNaM n\u00fckleotidlerinin do\u011fal n\u00fckleotidlerle de\u011fi\u015fti\u011fini,\u00a0 bunun d\u0131\u015f\u0131nda yap\u0131y\u0131 bozan herhangi bir fakt\u00f6r tespit etmediklerini s\u00f6yl\u00fcyor. Maltshev\u2019e g\u00f6re \u00e7al\u0131\u015fmalar\u0131nda sa\u011flad\u0131klar\u0131 iki b\u00fcy\u00fck at\u0131l\u0131m, ayn\u0131 zamanda sistemin kontrol edilebilirli\u011fini de sa\u011fl\u0131yor. Trasfer molek\u00fcl\u00fc olmadan yeni bazlar olu\u015fturulam\u0131yor ve h\u00fccre d5SICS ve dNaM n\u00fckleotidlerini kaybederek A, T, G ve C\u2019ye geri d\u00f6n\u00fcyor.<\/p>\n<p>\u00c7al\u0131\u015fman\u0131n yeni ad\u0131m\u0131, geni\u015fletilmi\u015f alfabesiyle DNA\u2019n\u0131n RNA\u2019ya transkripsiyonunu, dolay\u0131s\u0131yla protein yap\u0131c\u0131 molek\u00fcller haline d\u00f6n\u00fc\u015fmesini ger\u00e7ekle\u015ftirmek olacak. Romesberg\u2019e g\u00f6re yeni n\u00fckleotidler sayesinde, yapay aminoasitlerle yeni proteinler kodlamak m\u00fcmk\u00fcn olacak. B\u00f6ylece tedavi ve tan\u0131da kulland\u0131\u011f\u0131m\u0131z proteinlerin \u00fcretiminde bug\u00fcne kadar hi\u00e7 sahip olmad\u0131\u011f\u0131m\u0131z bir yap\u0131m g\u00fcc\u00fcne sahip olabilece\u011fiz. Ayn\u0131 \u015fekilde laboratuvar reaktiflerinin \u00fcretimi ve nanomateryal gibi di\u011fer uygulamalar da m\u00fcmk\u00fcn olabilir.<\/p>\n<p><strong>Kaynak:<\/strong> Scripps Research Institute (2014, May 7); \u201cSemi-synthetic organism: Scientists create first living organism that transmits added letters in DNA \u2018alphabet\u2019\u201d; Retrieved 19 May 2014, www.sciencedaily.com\/releases\/2014\/05\/140507132129.htm<\/p>\n<p><strong>\u0130lgili makale: <\/strong>Denis A. Malyshev, Kirandeep Dhami, Thomas Lavergne, Tingjian Chen, Nan Dai, Jeremy M. Foster, Ivan R. Corr\u00eaa, Floyd E. Romesberg; \u201cA semi-synthetic organism with an expanded genetic alphabet\u201d, <em>Nature<\/em>, 2014; DOI: 10.1038\/nature13314<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Genetikle uzaktan yak\u0131ndan ilgilenmi\u015f hemen herkes DNA\u2019n\u0131n t\u00fcm canl\u0131larda ayn\u0131 n\u00fckleotidlerle kal\u0131t\u0131m\u0131 sa\u011flad\u0131\u011f\u0131n\u0131 hat\u0131rlayacakt\u0131r. Adenin (A), Timin (T), Guanin (G) ve Sitozin (C) n\u00fckleotidleri \u00e7ift halinde(A-T ve G-C) dizilerek ya\u015fam\u0131n temel \u00f6zelliklerini ta\u015f\u0131yan d\u00f6rt harfli \u201cgenetik alfabeyi\u201d olu\u015fturur. Scripps Ara\u015ft\u0131rma Enstit\u00fcs\u00fc\u2019nden (The Scripps Research Institute) biliminsanlar\u0131 bu alfabeye yeni n\u00fckleotidleri eklemeyi daha \u00f6nce ba\u015farm\u0131\u015flard\u0131. 7 [&hellip;]<\/p>\n","protected":false},"author":601,"featured_media":24998,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[161,19],"tags":[272,292,3169,3170,2055],"class_list":["post-24996","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-124-sayi","category-bilim-gundemi","tag-dna","tag-genetik","tag-nuklotid","tag-polimeraz","tag-rna"],"acf":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/posts\/24996","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/users\/601"}],"replies":[{"embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/comments?post=24996"}],"version-history":[{"count":0,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/posts\/24996\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/media\/24998"}],"wp:attachment":[{"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/media?parent=24996"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/categories?post=24996"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/tags?post=24996"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}