\u0130nsanlar\u0131n da dahil oldu\u011fu bir\u00e7ok t\u00fcrde \u00e7o\u011falmadan sorumlu olan germ h\u00fccreleri y\u00fcksek oranda birbirlerine ba\u011fl\u0131d\u0131r ve sitoplazmalar\u0131n\u0131 (h\u00fccre i\u00e7eri\u011fi) birbirleriyle payla\u015f\u0131rlar.<\/p>\n
Hermafrodit (hem erkek hem de di\u015fi \u00fcreme organ\u0131 bulunduran canl\u0131lar) bir solucan (nematod) t\u00fcr\u00fc olan Caenorhabditis elegans<\/em>‘\u0131n yumurta ve sperm \u00fcreten gonad dokusunda 500 kadar germ h\u00fccresi birbirlerine ba\u011flan\u0131r. Bu h\u00fccreler bir \u201csitoplazmik koridor\u201d etraf\u0131nda d\u00fczenlenir. Ayn\u0131 zamanda h\u00fccre b\u00f6l\u00fcnmesini te\u015fvik eden \u201csitoplazmik al\u0131\u015fveri\u015f\u201d ger\u00e7ekle\u015ftirilebilir, b\u00f6ylece d\u00f6llenmeye haz\u0131r olan oositler (olgunla\u015fmam\u0131\u015f yumurta h\u00fccreleri) \u00fcretilir.<\/p>\n Ge\u00e7mi\u015f \u00e7al\u0131\u015fmalarda, C. elegans<\/em> gonadlar\u0131n\u0131n gerekenden daha fazla germ h\u00fccresi \u00fcretti\u011fi, bunlar\u0131n yaln\u0131zca yar\u0131s\u0131 kadar\u0131n\u0131n oosit haline geldi\u011fi, geri kalan h\u00fccrelerin ise \u00e7ok h\u00fccreli organizmalarda meydana gelen programl\u0131 h\u00fccre \u00f6l\u00fcm\u00fc olan fizyolojik apoptoz nedeniyle yap\u0131ca k\u00fc\u00e7\u00fcl\u00fcp \u00f6ld\u00fckleri raporlanm\u0131\u015ft\u0131. Ayr\u0131ca fizyolojik h\u00fccre \u00f6l\u00fcm\u00fcn\u00fcn genetik arka plan\u0131 ve biyokimyasal sinyal yolaklar\u0131 ortaya \u00e7\u0131kar\u0131lm\u0131\u015ft\u0131. Fakat germ h\u00fccrelerinde apoptozu ba\u015flatan mekanizmalar belirlenememi\u015fti. Biliminsanlar\u0131 yeni \u00e7al\u0131\u015fmalar\u0131nda germ hatt\u0131nda ya\u015fam ile \u00f6l\u00fcm aras\u0131ndaki h\u00fccrelerin \u201cgelece\u011fini\u201d belirleyen mekanizman\u0131n nas\u0131l i\u015fledi\u011fini ara\u015ft\u0131rd\u0131.<\/p>\n E\u015fey h\u00fccreleri, bir solucan\u0131n gonad\u0131nda olgunla\u015fma s\u00fcrecindeyken ilk olarak boyut ve hacim bak\u0131m\u0131nda homojen bir \u015fekilde b\u00fcy\u00fcrler. Nature Physics<\/em>\u2019te yay\u0131nlanan yeni \u00e7al\u0131\u015fmada homojen b\u00fcy\u00fcmenin aniden baz\u0131 h\u00fccrelerin b\u00fcy\u00fcd\u00fc\u011f\u00fc ve baz\u0131 h\u00fccrelerin k\u00fc\u00e7\u00fcl\u00fcp \u00f6ld\u00fc\u011f\u00fc heterojen bir karaktere b\u00fcr\u00fcnd\u00fc\u011f\u00fcne dikkat \u00e7ekildi.<\/p>\n Peki hangi germ h\u00fccreleri b\u00fcy\u00fcr veya hangileri apoptoza g\u00f6nderilir? Bu \u201cse\u00e7imde\u201d rol oynayan temel mekanizma \u015fudur: H\u00fccre i\u00e7erisinde meydana gelen bas\u0131n\u00e7 farkl\u0131l\u0131klar\u0131 \u201chidrolik dengesizlikler\u201d olarak adland\u0131r\u0131lan olaya yol a\u00e7ar, bu durum e\u015fit h\u00fccre hacimlerinin simetrik yap\u0131s\u0131n\u0131 karars\u0131z hale getirir. B\u00f6ylece asimetrik h\u00fccreler (b\u00fcy\u00fcyen-k\u00fc\u00e7\u00fcl\u00fcp \u00f6len) olu\u015fur. Ara\u015ft\u0131rma ekibi, germ h\u00fccrelerinin hacimlerini yapay olarak azaltarak, h\u00fccre hacmindeki azalman\u0131n h\u00fccrelerde k\u00fc\u00e7\u00fclmeye ve h\u00fccre \u00f6l\u00fcm\u00fcne yol a\u00e7t\u0131\u011f\u0131n\u0131 g\u00f6zlemledi. H\u00fccre boyutu kritik e\u015fi\u011fin alt\u0131na indi\u011finde, apoptoz te\u015fvik edilir ve h\u00fccre \u00f6l\u00fcr.<\/p>\n Ara\u015ft\u0131rmac\u0131lar, yeni nesil g\u00f6r\u00fcnt\u00fcleme teknikleri kullanarak h\u00fccreler aras\u0131ndaki s\u0131v\u0131 al\u0131\u015fveri\u015fini ve t\u00fcm gonad h\u00fccrelerinin hacimlerine dair net bilgiler almak i\u00e7in solucan\u0131n t\u00fcm bedenini g\u00f6r\u00fcnt\u00fcledi. Biliminsanlar\u0131 bulgular\u0131n\u0131n heyecan verici oldu\u011funu belirtiyor. \u00c7al\u0131\u015fman\u0131n s\u00fcperviz\u00f6r\u00fc Stephan Grill, \u201cya\u015fam\u201d ve \u201c\u00f6l\u00fcm\u201d karar\u0131n\u0131n mekanik bir niteli\u011finin oldu\u011funa ve bu kararlarda doku hidroli\u011finin belirleyici rol\u00fcne dikkat \u00e7ekerek bu ara\u015ft\u0131rma ile birlikte bir organizman\u0131n yumurtaya do\u011fru geli\u015fecek h\u00fccreyi nas\u0131l se\u00e7ti\u011finin daha iyi anla\u015f\u0131labilece\u011fini belirtiyor.<\/p>\n Kaynak:<\/strong> https:\/\/phys.org\/news\/2021-05-mechanical-cue-cell-death-decision.html<\/p>\n","protected":false},"excerpt":{"rendered":" \u0130nsanlar\u0131n da dahil oldu\u011fu bir\u00e7ok t\u00fcrde \u00e7o\u011falmadan sorumlu olan germ h\u00fccreleri y\u00fcksek oranda birbirlerine ba\u011fl\u0131d\u0131r ve sitoplazmalar\u0131n\u0131 (h\u00fccre i\u00e7eri\u011fi) birbirleriyle payla\u015f\u0131rlar. Hermafrodit (hem erkek hem de di\u015fi \u00fcreme organ\u0131 bulunduran canl\u0131lar) bir solucan (nematod) t\u00fcr\u00fc olan Caenorhabditis elegans‘\u0131n yumurta ve sperm \u00fcreten gonad dokusunda 500 kadar germ h\u00fccresi birbirlerine ba\u011flan\u0131r. Bu h\u00fccreler bir \u201csitoplazmik koridor\u201d […]<\/p>\n","protected":false},"author":1390,"featured_media":47501,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[19],"tags":[537,306,7749,5302],"class_list":["post-50562","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-bilim-gundemi","tag-apoptoz","tag-hucre","tag-hucre-olumu","tag-solucan"],"acf":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/posts\/50562","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\/1390"}],"replies":[{"embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/comments?post=50562"}],"version-history":[{"count":0,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/posts\/50562\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/media\/47501"}],"wp:attachment":[{"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/media?parent=50562"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/categories?post=50562"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/tags?post=50562"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}