{"id":1735,"date":"2015-01-21T16:07:26","date_gmt":"2015-01-21T14:07:26","guid":{"rendered":"http:\/\/bilimvegelecek.com.tr\/?p=1735"},"modified":"2015-01-21T16:07:26","modified_gmt":"2015-01-21T14:07:26","slug":"modern-genetik-yuzgeclerle-eller-arasindaki-iliskiyi-onayladi","status":"publish","type":"post","link":"https:\/\/bilimvegelecek.com.tr\/index.php\/2015\/01\/21\/modern-genetik-yuzgeclerle-eller-arasindaki-iliskiyi-onayladi","title":{"rendered":"Modern genetik, y\u00fczge\u00e7lerle eller aras\u0131ndaki ili\u015fkiyi onaylad\u0131"},"content":{"rendered":"<p><strong>G\u00f6rsel a\u00e7\u0131klamas\u0131:<\/strong> Benekli turnabal\u0131\u011f\u0131n\u0131n y\u00fczge\u00e7 geli\u015fiminden sorumlu genleri enjekte edilen fare embriyosunda, el-ayak autopod kemikleri olu\u015ftu. \u00a9 Andrew Gehrke, \u015eikago \u00dcniversitesi <\/p>\n<p>Biliminsanlar\u0131 uzun s\u00fcredir insan eli ve bal\u0131k y\u00fczgeci aras\u0131nda genetik bir ili\u015fkinin olup olmad\u0131\u011f\u0131n\u0131 ara\u015ft\u0131r\u0131yordu. Fakat evrimsel biyologlar, ya\u015fayan bal\u0131klar\u0131n y\u00fczge\u00e7lerinde, autopod denilen modern yap\u0131lar\u0131n (el bile\u011fi, parmaklar, ayak bile\u011fi ve ayak ba\u015fparma\u011f\u0131 i\u00e7eren) e\u015fde\u011ferlerinin neden olmad\u0131\u011f\u0131n\u0131 \u00e7\u00f6zememi\u015flerdi. 22 Aral\u0131k 2014\u2019te Proceeding of the National Academy of Sciences dergisinde yay\u0131mlad\u0131klar\u0131 makalede, bug\u00fcne kadar yanl\u0131\u015f bal\u0131k \u00fczerine odakland\u0131klar\u0131n\u0131 belirtiyorlar. Bir\u00e7ok \u00e7al\u0131\u015fma teolost bal\u0131\u011f\u0131 denilen devasa bir bal\u0131k grubunun \u00f6rnekleri \u00fczerinden yap\u0131l\u0131yordu.<br \/>\nSudan karaya ge\u00e7i\u015f formu olan Tiktaalik rosea\u2019y\u0131 bulan ekibin ba\u015f\u0131 Do\u00e7. Neil Shubin ve ayn\u0131 ekipten \u015eikago \u00dcniversitesi Anatomi ve Biyolojik Organizmalar B\u00f6l\u00fcm\u00fc\u2019nden Prof. Robert B. Bensley, \u201cFosiller bilek ve parmaklar\u0131n a\u00e7\u0131k bir \u015fekilde su k\u00f6kenli oldu\u011funu g\u00f6sterdi\u201d diyorlar. \u201cFakat y\u00fczge\u00e7 ve eller-ayaklar farkl\u0131 ama\u00e7lara sahip. Y\u00fczge\u00e7 ve eller-ayaklar farkl\u0131la\u015fmaya ba\u015flad\u0131klar\u0131ndan beri farkl\u0131 y\u00f6nlere evrilmi\u015fler. Biz fosillerden elde etti\u011fimiz bilgilere, molek\u00fcler ve genetik bilgileri ekleyerek onlar aras\u0131ndaki ba\u011flant\u0131y\u0131 daha iyi anlamak ve \u00e7\u00f6zmek istiyorduk.\u201d<br \/>\n\u0130lk bak\u0131\u015fta y\u00fczge\u00e7ler kara hayvanlar\u0131n\u0131n el-ayaklar\u0131ndan tamamen farkl\u0131 g\u00f6r\u00fcn\u00fcr. El ve ayak bilekleri, bir\u00e7ok ufak kemiklerden olu\u015fmu\u015ftur, devam\u0131nda uzun ince kemikler parmaklar\u0131 olu\u015fturmaktad\u0131r. Buna kar\u015f\u0131n g\u00fcn\u00fcm\u00fcz bal\u0131klar\u0131n\u0131n y\u00fczge\u00e7lerinde uzun kemikler, halkasal kemik olarak tan\u0131mlanan ufak kemiklerle sonlanmaktad\u0131r. Ara\u015ft\u0131rmac\u0131lar kemik \u015feklini belirleyen HoxA ve HoxD tak\u0131m\u0131 olarak da bilinen ana genlerin de birbirinden farkl\u0131 oldu\u011funu s\u00f6yl\u00fcyorlar. Ara\u015ft\u0131rmac\u0131lar ilk olarak teleost ad\u0131 verilen kemikli bal\u0131klardan elde edilen bu gen tak\u0131mlar\u0131n\u0131 bacaklar\u0131n geli\u015fimi i\u00e7in transgenik farelerde test etmi\u015fler. Fakat kontrol grubunda herhangi bir autopod geli\u015fimi g\u00f6r\u00fclmemi\u015f. Fakat antik genlerin nas\u0131l d\u00fczenlendi\u011fine bakt\u0131klar\u0131nda, teleost bal\u0131klar\u0131n ideal kar\u015f\u0131la\u015ft\u0131rma \u00f6rnekleri olmad\u0131klar\u0131n\u0131 fark etmi\u015fler. El bile\u011fi ve parmak in\u015fas\u0131n\u0131n genetik kodlar\u0131n\u0131 ara\u015ft\u0131rd\u0131klar\u0131nda, teleost t\u00fcrlerinde genetik \u015fifre korumas\u0131n\u0131n eksik oldu\u011funu bulmu\u015flar. Teleost bal\u0131klar\u0131n genlerindeki radikal de\u011fi\u015fikliklerin yaratt\u0131\u011f\u0131 sorunlar\u0131n izlerini s\u00fcrm\u00fc\u015fler. 300 milyon y\u0131l \u00f6ncesinde, tetrapodlar\u0131 olu\u015fturan bal\u0131k benzeri t\u00fcrler di\u011fer kemikli bal\u0131klardan ayr\u0131ld\u0131ktan sonra, teleostlar\u0131n en eski atalar\u0131n\u0131n t\u00fcm genomular\u0131n\u0131n kendini ikiye katlayan bir s\u00fcre\u00e7ten ge\u00e7ti\u011fini ve bu olgunun evrimsel s\u00fcre\u00e7te bir\u00e7ok kez tekrar etti\u011fini bulmu\u015flar. Teleost bal\u0131klar t\u00fcm genetik bilgilerini iki kat\u0131na \u00e7\u0131kararak m\u00fcthi\u015f bir \u00e7e\u015fitlilik potansiyeline olanak sa\u011flam\u0131\u015f. Bu teleostlar\u0131n d\u00fcnya genelinde \u00e7e\u015fitli \u00e7evrelere adaptasyon sa\u011flamas\u0131na yard\u0131m etmi\u015f. Fakat t\u00fcm kemikli bal\u0131klar, genomun iki kat\u0131na \u00e7\u0131kmas\u0131 s\u00fcrecinden ge\u00e7memi\u015f. Kuzey Amerika\u2019n\u0131n birincil tatl\u0131 su bal\u0131\u011f\u0131 olan benekli turnabal\u0131\u011f\u0131, t\u00fcm genomun ikiye katlanmas\u0131 s\u00fcrecinden \u00f6nce teleost bal\u0131klar\u0131nda ayr\u0131lm\u0131\u015f.<br \/>\nAra\u015ft\u0131rma tak\u0131m\u0131, benekli turnabal\u0131\u011f\u0131 ile tetrapodlar\u0131 Hox geni a\u00e7\u0131s\u0131ndan kar\u015f\u0131la\u015ft\u0131rd\u0131\u011f\u0131nda, tahmin etmedikleri seviyede korunan omurgal\u0131 autopod d\u00fczenleyici bir d\u00fczenek bulmu\u015flar. Bunun halkal\u0131 kemikli bal\u0131klar ve tetrapodun autopodu aras\u0131nda y\u00fcksek derecede benzerlik oldu\u011funu destekledi\u011fini belirtiyorlar. Benekli turnabal\u0131\u011f\u0131n\u0131n y\u00fczge\u00e7 geli\u015fiminden sorumlu genlerini, geli\u015fmekte olan fareye enjekte ettiklerindeyse, farede gene autopod kemiklerin geli\u015fti\u011fi g\u00f6r\u00fclm\u00fc\u015f. Bu bulgu, d\u00f6rt ayakl\u0131 kara hayvanlar\u0131n\u0131n el ve ayak bileklerinin antik bal\u0131\u011f\u0131n y\u00fczgeciyle benzer bir \u015fekilde evrimle\u015fti\u011fini g\u00f6steriyor.<\/p>\n<p><strong>Haz\u0131rlayan: R\u0131za Acar<br \/>\n<em>\u0130T\u00dc Molek\u00fcler Biyoloji ve Genetik B\u00f6l\u00fcm\u00fc<\/strong><\/em><\/p>\n<p><strong>Kaynak:<\/strong> http:\/\/www.sciencedaily.com\/releases\/2014\/12\/141222165441.htm<\/p>\n","protected":false},"excerpt":{"rendered":"<p>G\u00f6rsel a\u00e7\u0131klamas\u0131: Benekli turnabal\u0131\u011f\u0131n\u0131n y\u00fczge\u00e7 geli\u015fiminden sorumlu genleri enjekte edilen fare embriyosunda, el-ayak autopod kemikleri olu\u015ftu. \u00a9 Andrew Gehrke, \u015eikago \u00dcniversitesi Biliminsanlar\u0131 uzun s\u00fcredir insan eli ve bal\u0131k y\u00fczgeci aras\u0131nda genetik bir ili\u015fkinin olup olmad\u0131\u011f\u0131n\u0131 ara\u015ft\u0131r\u0131yordu. Fakat evrimsel biyologlar, ya\u015fayan bal\u0131klar\u0131n y\u00fczge\u00e7lerinde, autopod denilen modern yap\u0131lar\u0131n (el bile\u011fi, parmaklar, ayak bile\u011fi ve ayak ba\u015fparma\u011f\u0131 i\u00e7eren) [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":1736,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[19,21,32],"tags":[],"class_list":["post-1735","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-bilim-gundemi","category-biyoloji","category-evrim"],"acf":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/posts\/1735","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\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/comments?post=1735"}],"version-history":[{"count":0,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/posts\/1735\/revisions"}],"wp:attachment":[{"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/media?parent=1735"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/categories?post=1735"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/tags?post=1735"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}