{"id":34691,"date":"2019-06-13T06:45:22","date_gmt":"2019-06-13T03:45:22","guid":{"rendered":"https:\/\/bilimvegelecek.com.tr\/?p=34691"},"modified":"2019-06-13T06:31:54","modified_gmt":"2019-06-13T03:31:54","slug":"virusleri-yok-eden-crispr-mi-cilgin-bilim-insanlari-mi","status":"publish","type":"post","link":"https:\/\/bilimvegelecek.com.tr\/index.php\/2019\/06\/13\/virusleri-yok-eden-crispr-mi-cilgin-bilim-insanlari-mi","title":{"rendered":"CRISPR cephesinde son durum: Ku\u015f gribi, HIV ve \u00e7\u0131lg\u0131n biliminsanlar\u0131"},"content":{"rendered":"

Genler ve DNA dizileri \u00fczerinde do\u011frudan de\u011fi\u015fiklik yapma imkan\u0131 sunan CRISPR teknolojisinin nerede, ne zaman ve nas\u0131l kullan\u0131laca\u011f\u0131 tart\u0131\u015f\u0131ladursun, insanlar\u0131 do\u011frudan veya dolayl\u0131 yollardan etkileyen hastal\u0131klar kar\u015f\u0131s\u0131nda CRISPR\u2019\u0131n sundu\u011fu m\u00fcthi\u015f olanaklar ara\u015ft\u0131rmac\u0131lar\u0131n i\u015ftah\u0131n\u0131 kabart\u0131yor. Her y\u0131l binlerce domuzu telef ederek milyonlarca dolara mal olan TGEV vir\u00fcs\u00fcnden ya da milyonlarca insan\u0131 etkileyen, binlerce can alan s\u0131tmadan sonra CRISPR temelli gen d\u00fczenleme teknolojilerinin hedefine \u015fimdi de bir ba\u015fka pop\u00fcler illet, ku\u015f gribi Influenza A vir\u00fcs\u00fc oturdu. \u0130ngiltere\u2019deki Imperial College London ile \u0130sko\u00e7ya\u2019daki Roslin Enstit\u00fcs\u00fc ara\u015ft\u0131rmac\u0131lar\u0131n\u0131n ortak y\u00fcr\u00fctt\u00fc\u011f\u00fc \u00e7al\u0131\u015fmada ama\u00e7, ku\u015f gribi vir\u00fcs\u00fcn\u00fcn konak h\u00fccrede kendini \u00e7o\u011faltmak i\u00e7in kulland\u0131\u011f\u0131 ANP32A proteinini kodlayan geni inaktif hale getirerek vir\u00fcs\u00fcn belini k\u0131rmak, b\u00f6ylece ku\u015f gribine diren\u00e7li tavuklar \u00fcretmek. Ku\u015f t\u00fcrlerinde kitlesel \u00f6l\u00fcmlere yol a\u00e7acak kadar dramatik sonu\u00e7lar do\u011furan ku\u015f gribi vir\u00fcs\u00fcn\u00fcn baz\u0131 soylar\u0131, nadiren de olsa insanlar\u0131 etkileyebiliyor. Fakat genel anlamda ANP32 grubu proteinlerin memelilerdeki kar\u015f\u0131l\u0131\u011f\u0131 vir\u00fcs\u00fcn \u00e7o\u011falmas\u0131n\u0131 sa\u011flayan mekanizmayla tam etkile\u015fime girmedi\u011finden Influenza A ku\u015flar haricindeki t\u00fcrlerde -neyse ki- fazla etkili olam\u0131yor. <\/span>eLife<\/span><\/i> dergisinin 4 Haziran say\u0131s\u0131nda yay\u0131mlanan ara\u015ft\u0131rmaya g\u00f6re CRISPR tam da bu iki grup, yani ku\u015flarla memeliler aras\u0131ndaki ANP32A proteini fark\u0131ndan yola \u00e7\u0131karak i\u015f g\u00f6r\u00fcyor. Daha \u00f6nceki ara\u015ft\u0131rmalarda ku\u015flardaki ANP32A geninin 33 bazl\u0131k ilave bir k\u0131s\u0131m i\u00e7erdi\u011fi, bu k\u0131sm\u0131n kodlad\u0131\u011f\u0131 ilk 4 aminoasidin mutasyon sonucu eksik oldu\u011fu t\u00fcrlerde vir\u00fcs\u00fcn yeterince etki g\u00f6stermedi\u011fi saptanm\u0131\u015ft\u0131. Bu bilgiden yola \u00e7\u0131k\u0131p CRISPR\u2019\u0131 kullanarak laboratuvar ortam\u0131nda b\u00fcy\u00fctt\u00fckleri tavuk h\u00fccrelerinin ilgili geninden bu 33 bazl\u0131k k\u0131sm\u0131 kesip alan ara\u015ft\u0131rmac\u0131lar ku\u015f gribi vir\u00fcs\u00fcn\u00fcn yay\u0131lmas\u0131n\u0131 durdurmay\u0131 ba\u015farm\u0131\u015flar. Buraya kadar her\u015fey tamam\u2026 Fakat i\u015f laboratuvar s\u0131n\u0131rlar\u0131ndan \u00e7\u0131k\u0131p g\u00fcndelik hayat\u0131m\u0131za de\u011fmeye ba\u015flad\u0131\u011f\u0131nda tart\u0131\u015fma farkl\u0131 bir boyut kazan\u0131yor. Ara\u015ft\u0131rmac\u0131lar genetik yap\u0131s\u0131 ku\u015f gribinin \u00fcreyemeyece\u011fi \u015fekilde de\u011fi\u015ftirilmi\u015f tavuk \u00fcretimine ge\u00e7meden \u00f6nce s\u00f6z konusu DNA de\u011fi\u015fiminin hayvan\u0131n h\u00fccrelerinde ba\u015fka ne gibi etkiler g\u00f6sterdi\u011finin ara\u015ft\u0131r\u0131laca\u011f\u0131n\u0131 belirtiyorlar; ancak \u201cgeneti\u011fi de\u011fi\u015ftirilmi\u015f\u201d laf\u0131ndan ho\u015flanmayan t\u00fcketiciyi ikna etmek kolay olmayacak. Hele de etik de\u011ferlere g\u00f6sterilen bu \u00f6zenin yan\u0131na yakla\u015fmayan bir CRISPR sklandal\u0131na ait an\u0131lar hen\u00fcz bu kadar tazeyken\u2026 Kas\u0131m 2018\u2019de uluslararas\u0131 bir toplant\u0131da CRISPR-Cas9 teknolojisini kullanarak HIV vir\u00fcs\u00fcne diren\u00e7li ikiz k\u0131zlar\u0131n d\u00fcnyaya gelmesini sa\u011flad\u0131\u011f\u0131n\u0131 a\u00e7\u0131klayan \u00c7inli bilim insan\u0131 He Jiankui\u2019den bahsediyoruz. Dahas\u0131 <\/span>Nature Medicine<\/span><\/i> dergisinin 3 Haziran say\u0131s\u0131nda yay\u0131mlanan bir \u00e7al\u0131\u015fma Jiankui\u2019nin deneyiyle su y\u00fcz\u00fcne \u00e7\u0131kan CRISPR korkusunu daha da kam\u00e7\u0131layacak gibi duruyor.<\/span><\/p>\n

California \u00dcniversitesi\u2019nden ara\u015ft\u0131rmac\u0131lar\u0131n \u0130ngiltere bazl\u0131 veritabanlar\u0131na kay\u0131tl\u0131 400.000 genom ve ilgili sa\u011fl\u0131k kay\u0131tlar\u0131 \u00fczerinde yapt\u0131klar\u0131 tarama He Jiankui\u2019nin HIV direnci olu\u015fturmak \u00fczere CRISPR d\u00fczenlemesine tabi tuttu\u011fu <\/span>CCR5<\/span><\/i> geni hakk\u0131nda tedirgin edici bir istatistik ortaya koyuyor. Buna g\u00f6re genin mutasyonlu kopyas\u0131ndan, yani Jiankui\u2019nin \u00e7al\u0131\u015fmas\u0131nda yapay olarak olu\u015fturdu\u011fu versiyondan iki tane ta\u015f\u0131yanlar\u0131n 41-78 ya\u015f aral\u0131\u011f\u0131ndaki \u00f6l\u00fcm oranlar\u0131n\u0131n normal bireylere g\u00f6re %21 fazla oldu\u011fu g\u00f6r\u00fclm\u00fc\u015f. Daha \u00f6nceki \u00e7al\u0131\u015fmalarda da <\/span>CCR5<\/span><\/i> mutant\u0131ndan iki kopya ta\u015f\u0131yanlar\u0131n, yani hem anneden hem babadan mutasyonlu kopya alm\u0131\u015f olanlar\u0131n influenza\/grip enfeksiyonu sonras\u0131 \u00f6l\u00fcm oranlar\u0131n\u0131n 4 kat artt\u0131\u011f\u0131 belirlenmi\u015fti.<\/span><\/p>\n

\"\"
He Jiankui II. Uluslararas\u0131 \u0130nsan Genomunu D\u00fczenleme Zirvesi\u2019ndeki me\u015fhur konu\u015fmas\u0131n\u0131 yaparken. Kaynak: Alex Hoffard\/EPA-EFE\/Shutterstock.<\/figcaption><\/figure>\n

Nature Medicine<\/span><\/i>\u2019deki \u00e7al\u0131\u015fmada ifade edilen %21\u2019lik belirgin fark da muhtemelen gribe ba\u011fl\u0131 \u00f6l\u00fcm vakalar\u0131yla ili\u015fkili. Ba\u011f\u0131\u015f\u0131kl\u0131k h\u00fccrelerinin y\u00fczeyinde bulunan CCR5 proteini baz\u0131 HIV soylar\u0131 taraf\u0131ndan vir\u00fcs\u00fcn h\u00fccre i\u00e7ine giri\u015fine arac\u0131l\u0131k ediyor. Dolay\u0131s\u0131yla genin mutasyonlu formunu do\u011fal olarak ta\u015f\u0131yan bireyler, HIV\u2019e kar\u015f\u0131 da do\u011fal bir ba\u011f\u0131\u015f\u0131kl\u0131k g\u00f6steriyor. Zaten He Jiankui de Kuzey Avrupal\u0131lar\u0131n %11\u2019inde g\u00f6r\u00fclen bu mutasyonu CRISPR arac\u0131l\u0131\u011f\u0131yla yapay olarak olu\u015fturmu\u015f, sonu\u00e7ta biri mutant genden tek kopya, di\u011feri iki kopya ta\u015f\u0131yan ikiz k\u0131zlar d\u00fcnyaya gelmi\u015fti. Ne var ki %21\u2019lik oran\u0131n da ortaya koydu\u011fu \u00fczere \u00e7o\u011fu hayvan t\u00fcr\u00fcnde de bulunan ve gayet iyi korunmu\u015f bu genin etkiledi\u011fi pek \u00e7ok \u00f6zellik oldu\u011fu ya da mutasyonun farkl\u0131 \u00e7evrelerde farkl\u0131 etkiler g\u00f6sterebilece\u011fi muhakkak. S\u00f6z\u00fcn \u00f6z\u00fc evrimin genomumuzdan s\u00f6k\u00fcp atmad\u0131\u011f\u0131n\u0131 bizim yapay olarak ortadan kald\u0131rmam\u0131z, Jiankui\u2019nin \u00e7al\u0131\u015fmas\u0131n\u0131n etik eksikleri bir yana, belki pek de hay\u0131rlara vesile olmuyor. Fakat bilim camias\u0131 nas\u0131l bir tav\u0131r tak\u0131n\u0131rsa tak\u0131ns\u0131n ya da ne kadar g\u00fc\u00e7l\u00fc bir istatistik ortaya koyarsa koysun d\u00fcnyan\u0131n bir yerlerinde CRISPR\u2019\u0131 kullanarak g\u00f6z al\u0131c\u0131 i\u015flere imza atmak isteyen birileri illa ki \u00e7\u0131k\u0131yor. <\/span>Nature<\/span><\/i> dergisinin 10 Haziran tarihli haberine g\u00f6re en son kahraman aday\u0131 Rusya\u2019dan: Kulakov T\u0131p Ara\u015ft\u0131rmalar\u0131 Merkezi\u2019nin y\u00f6neticisi molek\u00fcler biyolog Denis Rebrikov. Onun da hedefinde HIV pozitif kad\u0131nlar ile <\/span>CCR5<\/span><\/i> geni CRISPR ile d\u00fczenlenecek embriyolar\u0131 var. Bat\u0131l\u0131 biliminsanlar\u0131 konuyla ilgili endi\u015fe ve tepkilerini dile getiredursunlar Rus yetkili makamlar\u0131ndan klinik ara\u015ft\u0131rma onay\u0131 bekleyen Rubrikov \u00c7inli meslekta\u015f\u0131na k\u0131yasla \u00e7ok daha kararl\u0131 ve c\u00fcretkar g\u00f6r\u00fcn\u00fcyor; \u00fcstelik Jiankui\u2019nin aksine gizlenme ihtiyac\u0131 bile duymuyor. Kullanaca\u011f\u0131 y\u00f6ntemin hedef d\u0131\u015f\u0131 d\u00fczenlemeleri en az indirece\u011fi iddias\u0131ndaki Rubrikov bilim yapma arzusunun mu yoksa ki\u015fisel ihtiraslar\u0131n\u0131n m\u0131 etkisiyle hareket etti\u011fini kendi s\u00f6zleriyle ele veriyor: \u201cSan\u0131r\u0131m bunu yapacak kadar \u00e7\u0131lg\u0131n biriyim!\u201d Bakal\u0131m bilim \u00e7evreleri Jiankui\u2019ye g\u00f6sterdikleri keskin ve ele\u015ftirel tavr\u0131 bu \u00e7\u0131lg\u0131n bilim adam\u0131na da g\u00f6sterecekler mi, g\u00f6rece\u011fiz\u2026<\/span><\/p>\n

Kaynak
\n<\/b>1) \u201cChicken cells gene-edited to resist bird flu\u201d, The University of Edinburgh News, 4 Haziran 2019.
\n<\/span>2) \u201cCRISPR baby mutation significantly increases mortality\u201d, Berkeley News, 3 Haziran 2019.
\n<\/span>3) David Cyranoski, \u201cRussian biologist plans more CRISPR-edited babies\u201d, Nature News, 10 Haziran 2019.<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

Genler ve DNA dizileri \u00fczerinde do\u011frudan de\u011fi\u015fiklik yapma imkan\u0131 sunan CRISPR teknolojisinin nerede, ne zaman ve nas\u0131l kullan\u0131laca\u011f\u0131 tart\u0131\u015f\u0131ladursun, insanlar\u0131 do\u011frudan veya dolayl\u0131 yollardan etkileyen hastal\u0131klar kar\u015f\u0131s\u0131nda CRISPR\u2019\u0131n sundu\u011fu m\u00fcthi\u015f olanaklar ara\u015ft\u0131rmac\u0131lar\u0131n i\u015ftah\u0131n\u0131 kabart\u0131yor. Her y\u0131l binlerce domuzu telef ederek milyonlarca dolara mal olan TGEV vir\u00fcs\u00fcnden ya da milyonlarca insan\u0131 etkileyen, binlerce can alan s\u0131tmadan […]<\/p>\n","protected":false},"author":184,"featured_media":31959,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[19,3729],"tags":[4579,4910,202],"class_list":["post-34691","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-bilim-gundemi","category-genetik","tag-crispr-cas9","tag-hiv-direnci","tag-kus-gribi"],"acf":[],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t