{"id":18927,"date":"2017-11-30T17:13:06","date_gmt":"2017-11-30T14:13:06","guid":{"rendered":"http:\/\/109.232.216.219\/~bilimvegelecek\/?p=18927"},"modified":"2018-02-08T17:14:59","modified_gmt":"2018-02-08T14:14:59","slug":"18927","status":"publish","type":"post","link":"https:\/\/bilimvegelecek.com.tr\/index.php\/2017\/11\/30\/18927","title":{"rendered":"54 milyon y\u0131ll\u0131k kaplumba\u011fadan keratin ve protein elde edildi!"},"content":{"rendered":"

Kuzey Karolina Devlet \u00dcniversitesi, \u0130sve\u00e7\u2019teki Lund \u00dcniversitesi ve Hyogo \u00dcniversitesi\u2019nden ara\u015ft\u0131rmac\u0131lar, 54 milyon y\u0131ll\u0131k deniz kaplumba\u011fas\u0131ndan orijinal pigment, beta-keratin ve kas proteinleri elde etti. \u00c7al\u0131\u015fma, milyonlarca y\u0131l boyunca kalmay\u0131 ba\u015farm\u0131\u015f orijinal molek\u00fclleri kan\u0131t toplulu\u011funa ekliyor ve ayr\u0131ca modern deniz kaplumba\u011fas\u0131n\u0131n ortak bir pigment temelli sa\u011fkal\u0131m \u00f6zelliklerinin en az 54 milyon y\u0131l \u00f6nce geli\u015fti\u011fine dair do\u011frudan kan\u0131t sunuyor.<\/p>\n

Tasbacka danica<\/em>, 56-34 milyon y\u0131l \u00f6nce Eosen d\u00f6neminde ya\u015fayan bir deniz kaplumba\u011fas\u0131 t\u00fcr\u00fcd\u00fcr. Danimarka, Jutland\u2019daki F\u00fcr formasyonunda son derece iyi korunmu\u015f bir\u00a0T. danica<\/em>\u00a0fosili 2008\u2019de ele ge\u00e7irilmi\u015ftir. \u00d6rnek, 3 in\u00e7 (74 milimetre) uzunlu\u011fundan daha azd\u0131. 2013\u2019te Lund \u00dcniversitesi\u2019nden paleontolog Johan Lindgren, deniz kaplumba\u011fas\u0131n\u0131n sol \u201comzunun\u201d yak\u0131n\u0131ndaki bir b\u00f6lgeden yumu\u015fak doku kal\u0131nt\u0131lar\u0131 ortaya \u00e7\u0131kard\u0131. Biyomolek\u00fcler analiz i\u00e7in be\u015f k\u00fc\u00e7\u00fck numune toplad\u0131.<\/p>\n

Modern deniz kaplumba\u011fas\u0131 yavrular\u0131n\u0131n kabuklar\u0131 koyu renklidir; bu pigmentasyon onlar\u0131n havadaki y\u0131rt\u0131c\u0131lardan (mart\u0131 gibi) kendilerini korumalar\u0131n\u0131 ve okyanus y\u00fczeyinde y\u00fczerken rahat nefes almalar\u0131n\u0131 sa\u011flar. Kaplumba\u011falar s\u00fcr\u00fcngen olduklar\u0131ndan so\u011fukkanl\u0131d\u0131rlar; koyu renkler de g\u00fcne\u015f \u0131\u015f\u0131\u011f\u0131ndan \u0131s\u0131 almalar\u0131n\u0131 ve v\u00fccut \u0131s\u0131lar\u0131n\u0131 d\u00fczenlemelerini sa\u011flar. Bu y\u00fcksek v\u00fccut \u0131s\u0131s\u0131, daha h\u0131zl\u0131 bir b\u00fcy\u00fcme sa\u011flar ve okyanus y\u00fczeyinde savunmas\u0131z olduklar\u0131 zaman\u0131 azalt\u0131r.<\/p>\n

T. danica<\/em>\u00a0yavru fosilinin, bu renklenmeyi ya\u015fayan benzerleriyle payla\u015ft\u0131\u011f\u0131 anla\u015f\u0131l\u0131yor. Ara\u015ft\u0131rmac\u0131lar, kaplumba\u011fa fosili i\u00e7indeki melanozomlar olabilecek yuvarlak organelleri ve koyu rengi veren ciltteki pigment i\u00e7eren yap\u0131lar\u0131 (veya epidermis) g\u00f6r\u00fcyorlard\u0131.<\/p>\n

Lindgren, yumu\u015fak dokular\u0131n yap\u0131sal ve kimyasal kompozisyonunu belirlemek i\u00e7in fosil deniz kaplumba\u011fas\u0131n\u0131n koyu renkli bir kabu\u011fa sahip olup olmad\u0131\u011f\u0131n\u0131 ara\u015ft\u0131rd\u0131 ve ara\u015ft\u0131rmac\u0131lar, numuneyi, alan emisyonu tarama, elektron mikroskobu taramas\u0131 (FEG-SEM) dahil olmak \u00fczere, y\u00fcksek \u00e7\u00f6z\u00fcn\u00fcrl\u00fckl\u00fc analitik tekniklerden ge\u00e7irdi: Transmisyon elektron mikroskobu (TEM), in situ imm\u00fcnohistokimya, zaman ak\u0131\u015fl\u0131 ikincil iyon k\u00fctle spektrometresi (ToF-SIMS) ve k\u0131z\u0131l\u00f6tesi (IR) mikroskopik inceleme gibi.<\/p>\n

Lindgren, kan, pigment ve proteinin bile\u015fenleri olan heme, eumelanin ve proteinli molek\u00fcllerin varl\u0131\u011f\u0131n\u0131 do\u011frulamak i\u00e7in numuneler \u00fczerinde ToF-SIMS ger\u00e7ekle\u015ftirdi.<\/p>\n

Kuzey Karolina eyaletindeki Kuzey Carolina Do\u011fal Bilimler M\u00fczesi\u2019nde Biyoloji Bilimlerinden Prof. Mary Schweitzer\u2019den bir randevu al\u0131p, histokimyasal analizler yaparak hem alfa hem de beta-keratin, bir kas proteini olan tropomyosin, hemoglobin ve antikor testinin pozitif \u00e7\u0131kt\u0131\u011f\u0131n\u0131 belirledi. TEM, Hyogo \u00dcniversitesi evrim biyolojisi uzman\u0131 Takeo Kuriyama taraf\u0131ndan ger\u00e7ekle\u015ftirildi ve Schweitzer\u2019in imm\u00fcnogold testi bulgular\u0131 do\u011frulad\u0131.<\/p>\n

Sonunda, bu kan\u0131tlar, bu molek\u00fcllerin, bu eski kaplumba\u011falar\u0131n g\u00fcn\u00fcm\u00fczdeki karde\u015fleriyle pigmentasyona dayal\u0131 bir hayatta kalma \u00f6zelli\u011fini payla\u015ft\u0131klar\u0131n\u0131 do\u011frulayarak orijinal olduklar\u0131n\u0131 g\u00f6sterdi.<\/p>\n

Schweitzer, \u201cBir keratin matrisinde g\u00f6m\u00fcl\u00fc bir melanozomda \u00f6karyotik melaninin varl\u0131\u011f\u0131, mikrop bula\u015f\u0131c\u0131l\u0131\u011f\u0131 olas\u0131l\u0131\u011f\u0131n\u0131 ortadan kald\u0131r\u0131r, \u00e7\u00fcnk\u00fc mikrop \u00f6karyotik melanin veya keratin yapamaz\u201d diyor, \u201cBu y\u00fczden, bu yavrular\u0131n koyu renklerinin modern deniz kaplumba\u011falar\u0131n\u0131nkiyle ortak oldu\u011funu biliyoruz.\u201d Ve ekliyor: \u201cVeriler \u00e7oklu proteinlerin korunmas\u0131n\u0131 desteklemekle kalm\u0131yor, ayn\u0131 zamanda renklenme fizyolojisininde Eosen\u2019e kadar bug\u00fcnk\u00fc gibi oldu\u011funu g\u00f6steriyor.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"

Kuzey Karolina Devlet \u00dcniversitesi, \u0130sve\u00e7\u2019teki Lund \u00dcniversitesi ve Hyogo \u00dcniversitesi\u2019nden ara\u015ft\u0131rmac\u0131lar, 54 milyon y\u0131ll\u0131k deniz kaplumba\u011fas\u0131ndan orijinal pigment, beta-keratin ve kas proteinleri elde etti. \u00c7al\u0131\u015fma, milyonlarca y\u0131l boyunca kalmay\u0131 ba\u015farm\u0131\u015f orijinal molek\u00fclleri kan\u0131t toplulu\u011funa ekliyor ve ayr\u0131ca modern deniz kaplumba\u011fas\u0131n\u0131n ortak bir pigment temelli sa\u011fkal\u0131m \u00f6zelliklerinin en az 54 milyon y\u0131l \u00f6nce geli\u015fti\u011fine dair do\u011frudan […]<\/p>\n","protected":false},"author":383,"featured_media":18928,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[19,32,232],"tags":[2286,816,464],"class_list":["post-18927","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-bilim-gundemi","category-evrim","category-yerbilimleri","tag-deniz-kaplumbagasi","tag-fosil","tag-paleontoloji"],"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