請用此 Handle URI 來引用此文件:
http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/42740
標題: | Fgf與Hedgehog signalings在斑馬魚早期體節發育中
會調控FoxD5的表現 The Fgf and Hedgehog Signalings Modulate FoxD5 Expression during Early Somitogenesis of Zebrafish Embryos |
作者: | Wei-An Tseng 曾暐恩 |
指導教授: | 蔡懷楨(Huai-Jen Tsai) |
關鍵字: | 體節,軸側中胚層, somite,paraxial mesoderm, |
出版年 : | 2009 |
學位: | 碩士 |
摘要: | 在胚胎發育過程,forkhead box (Fox)轉錄因子扮演重要的功能,斑馬魚FoxD5在軸側中胚層表現,但體節形成過程中FoxD5在anterior pre-somitic mesoderm (PSM)的功能還不清楚,因此我們在斑馬魚胚胎當中利用FoxD5專一性Morpholinos (MO)來抑制FoxD5 mRNA的轉譯,會造成新生成的體節缺失,包括了ephrineB2a, notch2, notch3 and deltaC的stripe pattern消失,mespa在S-I的前後極性(anterior-posterior polarity)消失,而且mespb呈現salt and pepper的表現,以上結果都指出FoxD5在anterior PSM對於體節的形成是必須的;此外Fibronectin蛋白質的表現下降,指出knockdown of FoxD5會抑制體節的表皮化(epithelialization)。更進一步,浸泡胚胎FGFR抑制劑SU5402會造成FoxD5表現嚴重下降,利用Tg(hsp70l:dnfgfr1-EGFP)pd1胚胎熱誘導產生dominant-negative form FGFR來干擾Fgf signaling也有相同的結果。此外fgf3/fgf8-double-MOs注射的胚胎會造成FoxD5表現有顯著的消失,共同注射FoxD5 mRNA 和fgf3-/fgf8-double-MO可以部份回復mespa 與mespb的表現量,因此推測在體節形成中Fgf signaling是FoxD5上游的調控訊息。另一方面,浸泡Hedgehog (Hh) signaling抑制劑cyclopamine的胚胎會造成FoxD5在adaxial cells的表現消失,但是在新生成體節會異位性表現,在shh/twhh-MO注射的胚胎FoxD5在adaxial cells的表現也消失,推測Hh signaling 對於FoxD5在adaxial cells的表現是必需的。總而言之, FoxD5在維持體節前後極性與表皮化的過程中是必需的,而且FoxD5 在anterior PSM 的表現主要是受到Fgf signaling調控。因此本篇研究最重要的結果是我們是首先提出在體節形成過程當中有一條Fgf-FoxD5-Mesps訊息傳遞網絡。 The forkhead box (Fox) transcription factors play important roles during embryogenesis, and zebrafish FoxD5 is expressed in paraxial mesoderm. However, the roles that FoxD5 plays in anterior pre-somitic mesoderm (PSM) during somitogenesis are largely unknown. Therefore, we knocked down FoxD5 in embryos with injection of FoxD5-specific morpholinos (MOs), resulting in defects of the newly formed somites and absence of anterior-posterior polarity of mespa and mespb, indicating that FoxD5 is necessary for somite patterning in anterior PSM. Additionally, knockdown of FoxD5 inhibits epithelialization in somites. Furthermore, we treated embryos with FGFR inhibitor SU5402, resulting in significant reduction of FoxD5 expression. This finding was consistent with results obtained from embryos derived from transgenic line which, when treated with heat, produced the dominant-negative form of FGFR. Moreover, a significant loss of FoxD5 expression was observed in the fgf3-/fgf8-double-MOs-injected embryos. However, co-injection of FoxD5 mRNA with fgf3-/fgf8-double-MOs could rescue the expression levels of mespa and mespb in the morphants, suggesting that Fgf signaling acts as an upstream modulator of FoxD5 during somitogenesis. On the other hand, when embryos were treated with Hedgehog (Hh) inhibitor, cyclopamine, FoxD5 transcripts were lost in the adaxial cells, but FoxD5 expression was extended in the newly formed somites. In the shh/twhh-MO-injected embryos, FoxD5 expression was also reduced in the adaxial cells, suggesting that Hh signaling is required for FoxD5 expression in the adaxial cells. Taken together, we concluded that FoxD5 is necessary to maintain anterior-posterior polarity and mesenchymal-to-epithelial transition processes during early somitogenesis and that the striped pattern of FoxD5 in anterior PSM is mainly regulated by the Fgf signaling. Thus, we propose an Fgf-FoxD5-Mesps signaling network during somite formation. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/42740 |
全文授權: | 有償授權 |
顯示於系所單位: | 分子與細胞生物學研究所 |
文件中的檔案:
檔案 | 大小 | 格式 | |
---|---|---|---|
ntu-98-1.pdf 目前未授權公開取用 | 24.94 MB | Adobe PDF |
系統中的文件,除了特別指名其著作權條款之外,均受到著作權保護,並且保留所有的權利。