{"id":42922,"date":"2012-10-01T22:53:02","date_gmt":"2012-10-01T19:53:02","guid":{"rendered":"https:\/\/bilimvegelecek.com.tr\/?p=42922"},"modified":"2020-04-22T13:05:08","modified_gmt":"2020-04-22T10:05:08","slug":"dev-virusler-calismasi-yasam-agacini-sarsiyor","status":"publish","type":"post","link":"https:\/\/bilimvegelecek.com.tr\/index.php\/2012\/10\/01\/dev-virusler-calismasi-yasam-agacini-sarsiyor","title":{"rendered":"Dev Vir\u00fcsler \u00c7al\u0131\u015fmas\u0131 Ya\u015fam A\u011fac\u0131n\u0131 Sars\u0131yor"},"content":{"rendered":"

Haz\u0131rlayan: \u00d6yk\u00fc \u0130rig\u00fcl S\u00f6nmez<\/strong><\/p>\n

Yeni bir dev vir\u00fcsler \u00e7al\u0131\u015fmas\u0131, \u201cvir\u00fcslerin antik canl\u0131lar oldu\u011fu ve baz\u0131 bilim adamlar\u0131n\u0131n iddia etti\u011fi gibi ya\u015fama sald\u0131ran cans\u0131z molek\u00fcler kal\u0131nt\u0131lar olmad\u0131klar\u0131 fikrini\u201d destekliyor. Bu \u00e7al\u0131\u015fman\u0131n, pek \u00e7ok biliminsan\u0131n\u0131n hayat\u0131n temel alanlar\u0131n\u0131 temsil etti\u011fine kat\u0131ld\u0131\u011f\u0131 \u00fc\u00e7 temel \u015fubeye d\u00f6rd\u00fcnc\u00fc bir b\u00fcy\u00fck \u015fube ekleyerek, evrensel aile a\u011fac\u0131n\u0131 yeniden \u015fekillendirme ihtimali s\u00f6z konusudur.<\/p>\n

Yeni bulgular BMC Evrimsel Biyoloji<\/em> dergisinde ortaya konuldu.<\/p>\n

Ara\u015ft\u0131rmac\u0131lar uzak ge\u00e7mi\u015fe dikkatlice bakmak i\u00e7in yeni bir y\u00f6ntem kulland\u0131lar. Olduk\u00e7a karars\u0131z ve zamanla h\u0131zla de\u011fi\u015fen genetik dizileri kar\u015f\u0131la\u015ft\u0131rmak yerine, proteinlerin \u00fc\u00e7 boyutlu ve yap\u0131sal b\u00f6lgelerindeki ge\u00e7mi\u015f olaylar\u0131n izlerini ara\u015ft\u0131rd\u0131lar. K\u0131vr\u0131m olarak da adland\u0131r\u0131lan bu yap\u0131sal motifler nispeten istikrarl\u0131 molek\u00fcler fosillerdir ve bunlar Illinois \u00dcniversitesi Bitki Bilimleri B\u00f6l\u00fcm\u00fc ve Genomik Biyoloji Enstit\u00fcs\u00fc Profes\u00f6r\u00fc Gustavo Caetano-Anoll\u00e9s\u2019in de bildirdi\u011fi gibi, insan veya hayvan kemik fosilleri gibi antik evrimsel olaylar i\u00e7in ipu\u00e7lar\u0131 sa\u011flar.<\/p>\n

Caetano-Anoll\u00e9s, \u201cAyn\u0131 paleontologlar gibi, sistemin par\u00e7alar\u0131na ve onlar\u0131n zaman i\u00e7inde nas\u0131l de\u011fi\u015fti\u011fine bak\u0131yoruz.\u201d dedi. Caetano-Anoll\u00e9s\u2019in ekledi\u011fi \u00fczere, baz\u0131 protein katlamalar\u0131, organizmalarda tek bir grup ya da altk\u00fcmede g\u00f6r\u00fcn\u00fcrken, di\u011ferleri ise \u015fimdiye kadar \u00fczerinde \u00e7al\u0131\u015f\u0131lan t\u00fcm organizmalarda ortak g\u00f6r\u00fcld\u00fc.<\/p>\n

Caetano-Anoll\u00e9s, \u201cDaha s\u0131k ve daha \u00e7ok grupta g\u00f6r\u00fcnen yap\u0131lar\u0131n en eski yap\u0131lar oldu\u011funa dair \u00e7ok temel bir varsay\u0131m yapt\u0131k.\u201d dedi.<\/p>\n

Caetano-Anoll\u00e9s\u2019in belirtti\u011fi \u00fczere, t\u00fcm canl\u0131lar\u0131n akrabal\u0131\u011f\u0131n\u0131 belgelemek i\u00e7in gereken \u00e7abalar\u0131n \u00e7o\u011fu, vir\u00fcsleri denklemin d\u0131\u015f\u0131na itiyor.<\/p>\n

Ayr\u0131ca, \u201cBiz her zaman h\u00fccreleri kar\u015f\u0131la\u015ft\u0131rarak Son Evrensel Ortak Ata\u2019ya bakt\u0131k.\u201d diyerek ekledi: \u201cHi\u00e7bir zaman vir\u00fcsleri eklemedik. Yani biz bu vir\u00fcslerin nereden geldi\u011fini g\u00f6rmek i\u00e7in vir\u00fcsleri kar\u0131\u015f\u0131ma koyduk.\u201d<\/p>\n

Ara\u015ft\u0131rmac\u0131lar bakteri, vir\u00fcs, arke olarak bilinen mikroplar ve di\u011fer t\u00fcm canl\u0131lar\u0131 temsil eden binden fazla organizmada var olan t\u00fcm protein k\u0131vr\u0131mlar\u0131 i\u00e7in say\u0131m yapt\u0131lar. Caetano-Anoll\u00e9s\u2019in belirtti\u011fi \u00fczere, ara\u015ft\u0131rmac\u0131lar dev vir\u00fcsleri, b\u00fcy\u00fck ve karma\u015f\u0131k oldu\u011fu i\u00e7in ve en basit bakterinin genetik yap\u0131s\u0131na rakip oldu\u011fu veya kimi durumlarda bu yap\u0131y\u0131 ge\u00e7ti\u011fi i\u00e7in eklediler.<\/p>\n

\"\"
Caetano-Anoll\u00e9s\u2019in iletti\u011fi \u00fczere, dev vir\u00fcsler ile ilgili bir\u00e7ok \u00e7al\u0131\u015fma “ayn\u0131 y\u00f6ne i\u015faret ediyor ” ve bu \u00e7al\u0131\u015fma vir\u00fcslerin ya\u015fam kuma\u015f\u0131na g\u00f6m\u00fcl\u00fc oldu\u011funa dair daha fazla kan\u0131t sunuyor.<\/figcaption><\/figure>\n

“Dev vir\u00fcsler, sahip oldu\u011fumuz bir h\u00fccredeki makineye \u00e7ok benzer gibi g\u00f6r\u00fcnen inan\u0131lmaz bir makineye sahipler.” diyor Caetano-Anoll\u00e9s. \u201cOnlar olduk\u00e7a karma\u015f\u0131klar ve biz bunun nedenini a\u00e7\u0131klamak zorunday\u0131z.\u201d<\/p>\n

Caetano-Anoll\u00e9s\u2019in ekledi\u011fi \u00fczere, bu karma\u015f\u0131kl\u0131\u011f\u0131n bir k\u0131sm\u0131, genetik kodun proteinlere translasyonunu sa\u011flayan enzimleri i\u00e7erir. Biliminsanlar\u0131 bu enzimleri vir\u00fcslerde ortaya \u00e7\u0131kard\u0131\u011f\u0131nda olduk\u00e7a afallad\u0131lar; \u00e7\u00fcnk\u00fc vir\u00fcsler hi\u00e7bir bilinen protein yap\u0131 makinesine sahip de\u011fildir ve onlar i\u00e7in \u00e7al\u0131\u015fs\u0131nlar diye konak h\u00fccre proteinlerini y\u00f6nlendirmek zorunda kal\u0131rlar.<\/p>\n

Yeni yap\u0131lan bu \u00e7al\u0131\u015fmada, ara\u015ft\u0131rmac\u0131lar, y\u00fczlerce organizman\u0131n protein zenginlikleri aras\u0131ndaki evrimsel akrabal\u0131klar\u0131 haritalad\u0131lar ve bu bilgiyi vir\u00fcsleri de i\u00e7eren yeni bir Ya\u015fam A\u011fac\u0131 olu\u015fturmak i\u00e7in kulland\u0131lar. Bu yeni a\u011fa\u00e7ta, her biri ayr\u0131 bir \u201cs\u00fcpergrubu\u201d temsil eden ve a\u00e7\u0131k\u00e7a farkl\u0131la\u015fm\u0131\u015f d\u00f6rt \u015fube ortaya kondu. Dev vir\u00fcsler, bakteri, arke ve eukarya (bitkiler, hayvanlar ve \u00e7ekirdekli h\u00fccreleri olan di\u011fer t\u00fcm organizmalar) \u015fubelerinin yan\u0131nda d\u00f6rd\u00fcnc\u00fc \u015fube olarak kabul g\u00f6rd\u00fc.<\/p>\n

Ara\u015ft\u0131rmac\u0131lar, \u00e7o\u011fu h\u00fccresel organizmada bulunan en eski protein katlamalar\u0131n\u0131n \u00e7o\u011funun dev vir\u00fcslerde de mevcut oldu\u011funu ke\u015ffetti. Caetano-Anoll\u00e9s\u2019in belirtti\u011fi \u00fczere, bu durum dev vir\u00fcslerin hayat a\u011fac\u0131n\u0131n k\u00f6k\u00fcne yak\u0131n, evrimde olduk\u00e7a erken ortaya \u00e7\u0131kt\u0131\u011f\u0131n\u0131 g\u00f6steriyor.<\/p>\n

Caetano-Anoll\u00e9s\u2019in a\u00e7\u0131klamalar\u0131na g\u00f6re, yap\u0131lan bu yeni analiz, ge\u00e7mi\u015fte dev vir\u00fcslerin bug\u00fcn olduklar\u0131ndan \u00e7ok daha karma\u015f\u0131k bir yap\u0131ya sahip olduklar\u0131na ve zamanla genomlar\u0131nda dramatik bir k\u00fc\u00e7\u00fclme oldu\u011funa dair bulunan kan\u0131tlara eklemeler yap\u0131yor ve bu k\u00fc\u00e7\u00fclme b\u00fcy\u00fck olas\u0131l\u0131kla evrimsel olarak parazitik ya\u015fam tarz\u0131n\u0131 benimsemelerini a\u00e7\u0131kl\u0131yor. Caetano-Anoll\u00e9s ve arkada\u015flar\u0131, k\u0131rp\u0131lm\u0131\u015f genomlara sahip k\u00fc\u00e7\u00fck vir\u00fcslerle k\u0131yasland\u0131\u011f\u0131nda dev vir\u00fcslerin kendi orijinal atalar\u0131na daha \u00e7ok benzedi\u011fini \u00f6nermektedir.<\/p>\n

Ayr\u0131ca Caetano-Anoll\u00e9s, ara\u015ft\u0131rmac\u0131lar\u0131n, vir\u00fcslerin \u201cbilgi da\u011f\u0131t\u0131mc\u0131lar\u0131\u201d gibi g\u00f6r\u00fcnd\u00fcklerini bulduklar\u0131n\u0131 ekleyerek, \u201cDi\u011fer organizmalar\u0131n vir\u00fcsler ile payla\u015ft\u0131klar\u0131 protein yap\u0131lar\u0131 belirli bir kalitedeler; onlar (yayg\u0131n olarak) di\u011fer yap\u0131lara g\u00f6re daha fazla da\u011f\u0131l\u0131m g\u00f6sterirler. Bu yap\u0131lar\u0131n her bir tanesi evrim a\u00e7\u0131s\u0131ndan inan\u0131lmaz bir ke\u015fiftir ve vir\u00fcsler bu yenili\u011fin da\u011f\u0131t\u0131m\u0131n\u0131 yapmaktad\u0131r.\u201d dedi<\/p>\n

Kaynak:<\/strong> \u201cStudy of Giant Viruses Shakes Up Tree of Life\u201d
\nhttp:\/\/www.sciencedaily.com\/releases\/2012\/09\/120913123520.htm<\/p>\n","protected":false},"excerpt":{"rendered":"

Haz\u0131rlayan: \u00d6yk\u00fc \u0130rig\u00fcl S\u00f6nmez Yeni bir dev vir\u00fcsler \u00e7al\u0131\u015fmas\u0131, \u201cvir\u00fcslerin antik canl\u0131lar oldu\u011fu ve baz\u0131 bilim adamlar\u0131n\u0131n iddia etti\u011fi gibi ya\u015fama sald\u0131ran cans\u0131z molek\u00fcler kal\u0131nt\u0131lar olmad\u0131klar\u0131 fikrini\u201d destekliyor. Bu \u00e7al\u0131\u015fman\u0131n, pek \u00e7ok biliminsan\u0131n\u0131n hayat\u0131n temel alanlar\u0131n\u0131 temsil etti\u011fine kat\u0131ld\u0131\u011f\u0131 \u00fc\u00e7 temel \u015fubeye d\u00f6rd\u00fcnc\u00fc bir b\u00fcy\u00fck \u015fube ekleyerek, evrensel aile a\u011fac\u0131n\u0131 yeniden \u015fekillendirme ihtimali s\u00f6z konusudur. […]<\/p>\n","protected":false},"author":429,"featured_media":42923,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[141,38],"tags":[6344,493,6347,6346,6345,492],"class_list":["post-42922","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-104-sayi","category-dergi-sayilari","tag-arke","tag-bakteri","tag-dev-virus","tag-eukarya","tag-mikrop","tag-virus"],"acf":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/posts\/42922","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\/429"}],"replies":[{"embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/comments?post=42922"}],"version-history":[{"count":0,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/posts\/42922\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/media\/42923"}],"wp:attachment":[{"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/media?parent=42922"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/categories?post=42922"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/tags?post=42922"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}