Dpp signalling orchestrates dorsal closure by regulating cell shape changes both in the amnioserosa and in the epidermis
Dpp signalling orchestrates dorsal closure by regulating cell shape changes both in the amnioserosa and in the epidermis
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DOI：
10.1016/j.mod.2007.09.002
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发表时间：
2007-11-01
影响因子：
2.6
通讯作者：
Jacinto, Antonio
中科院分区：
文献类型：
--
作者：
Fernandez, Beatriz Garcia;Arias, Alfonso Martinez;Jacinto, Antonio
在胚胎发育的最后阶段，果蝇胚胎表现出一个背孔，被称为浆膜（AS）的大细胞单层上皮覆盖。背侧闭合是通过AS和表皮内的细胞活动的协调来闭合该孔的过程。遗传分析表明，通过Jun N-末端激酶（JNK）和Decapentaplegic（Dpp）（分泌因子的BMP/TGF-β家族的果蝇成员）的信号传导控制这些活动。JNK激活最背表皮细胞dpp的表达，随后Dpp作为分泌信号控制侧表皮的伸长。我们的分析表明，Dpp功能不仅影响表皮细胞，而且还影响AS。Dpp信号缺陷的胚胎显示AS细胞形状变化的缺陷，特别是在减少其顶端表面积，导致有缺陷的AS收缩。我们的数据还表明，Dpp调节表皮和AS之间的粘附，并介导转录因子U形的表达在整个AS和表皮的梯度。总之，我们发现Dpp在协调AS的活动及其与LE细胞在背侧闭合过程中的相互作用中起着至关重要的作用。(c)2007爱思唯尔爱尔兰有限公司保留所有权利。
During the final stages of embryogenesis, the Drosophila embryo exhibits a dorsal hole covered by a simple epithelium of large cells termed the amnioserosa (AS). Dorsal closure is the process whereby this hole is closed through the coordination of cellular activities within both the AS and the epidermis. Genetic analysis has shown that signalling through Jun N-terminal Kinase (JNK) and Decapentaplegic (Dpp), a Drosophila member of the BMP/TGF-beta family of secreted factors, controls these activities. JNK activates the expression of dpp in the dorsal-most epidermal cells, and subsequently Dpp acts as a secreted signal to control the elongation of lateral epidermis. Our analysis shows that Dpp function not only affects the epidermal cells, but also the AS. Embryos defective in Dpp signalling display defects in AS cell shape changes, specifically in the reduction of their apical surface areas, leading to defective AS contraction. Our data also demonstrate that Dpp regulates adhesion between epidermis and AS, and mediates expression of the transcription factor U-shaped in a gradient across both the AS and the epidermis. In summary, we show that Dpp plays a crucial role in coordinating, the activity of the AS and its interactions with the LE cells during dorsal closure. (c) 2007 Elsevier Ireland Ltd. All rights reserved.