Differential Expression of Echinoid and its Relationship with Cadherin in Drosophila Embryo

果蠅胚胎中Echinoid的差別性表現及其和Cadherin的關係

潘怡庭(Yi-Ting Pan)

指導教授 ： 徐瑞洲

國立清華大學/生命科學院/分子醫學研究所/碩士(2010年)

摘要

Echinoid (Ed) is a homophilic immunoglobulin domain-containing cell adhesion molecule (CAM) that localizes to adherens junctions (AJs) and cooperates with Drosophila melanogaster epithelial-cadherin (DE-Cad) to mediate cell adhesion. Ed takes part in many processes of dorsal closure. In this process, Ed is differentially expressed, appearing in epidermis but not amnioserosa (AS). And an actomyosin cable forms in the leading edge (LE) to act as a supracellular purse-string to drive dorsal closure. Here we show that in addition to Ed expression border, it is indeed the differential Ed localization in Ed-expressing cells that drives actomyosin assembling. Because Ed and Cad are the major CAMs in AJs, how they are mediated and weather they communicate with each other are important. Here we show that Ed is mediated by a Dynamin and Rab5 dependent endocytosis pathway in embryo. However, redundant pathways might be involved to mediate Cad endocytosis.

關鍵字

Echinoid ； 果蠅胚胎

並列摘要

Echinoid (Ed)是一個包括免疫球蛋白區域的同型性細胞黏著分子，位於adherens junctions (AJ)，與DE-Cadherin (DE-Cad)合作調控細胞之間的黏合。Ed參與胚胎表皮細胞閉鎖的許多過程。在這個過程中，Ed差異性的表現———表現在表皮細胞中而非amnioserosa (AS)中。Actomyosin cable在表皮細胞先端形成，驅動背部閉鎖的進行。之前的研究認為actin會在Ed表現的界線上累積；在這裡我們更進一步地發現，在一個有能力表現Ed的細胞中，Ed的不均勻分佈會造成actomyosin cable在沒有Ed分佈的細胞膜下方形成。另一方面，由於Ed和Cad是構成AJ的兩大重要細胞黏著分子，我們亦嘗試探討其之間的關係；我們證實Ed在果蠅胚胎裡是透過Dynamin和Rab5調控而進行胞吞作用，Cad可能也受此胞吞作用途徑的調控，但同時還存在其他作用途徑可以調節Cad。

並列關鍵字

Echinoid ； Drosophila embryo ； differential expression

參考文獻

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