An anteroposterior dorsal gradient in the Drosophila embryo
An anteroposterior dorsal gradient in the Drosophila embryo
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DOI：
10.1101/gad.11.15.1963
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发表时间：
1997-08-01
影响因子：
10.5
通讯作者：
Levine, M
中科院分区：
文献类型：
--
作者：
Huang, AM;Rusch, J;Levine, M
果蝇胚胎的背腹侧 (DV) 模式是由广泛的背侧 (D1) 核梯度启动的，该梯度由包括 Toll 受体和 Pelle 激酶在内的保守信号通路调节。我们研究了使用 bicoid 3' UTR 在早期胚胎前部区域表达 Toll 受体 Toll(10b) 的组成型激活形式的后果。局部化的Toll(10b)产物导致沿胚胎长度形成异位的前后(AP)D1核梯度。对真实背侧靶基因和确定的合成启动子的分析表明，异位梯度足以沿着胚胎的 AP 轴产生 DV 模式反应的完整库。例如，中胚层决定簇在胚胎的前三分之一处被激活，而神经源基因在中央区域表达。这些结果提出了Toll信号成分在早期胚胎的质膜或合胞质中扩散的可能性。这项研究还提供了证据，表明神经源性抑制因子可能对于早期胚胎中清晰的中胚层/神经外胚层边界的建立很重要。
Dorsoventral (DV) patterning of the Drosophila embryo is initiated by a broad Dorsal (Dl) nuclear gradient, which is regulated by a conserved signaling pathway that includes the Toll receptor and Pelle kinase. We investigate the consequences of expressing a constitutively activated form of the Toll receptor, Toll(10b), in anterior regions of the early embryo using the bicoid 3' UTR. Localized Toll(10b) products result in the formation of an ectopic, anteroposterior (AP) Dl nuclear gradient along the length of the embryo. The analysis of both authentic dorsal target genes and defined synthetic promoters suggests that the ectopic gradient is sufficient to generate the full repertory of DV patterning responses along the AP axis of the embryo. For example, mesoderm determinants are activated in the anterior third of the embryo, whereas neurogenic genes are expressed in central regions. These results raise the possibility that Toll signaling components diffuse in the plasma membrane or syncytial cytoplasm of the early embryo. This study also provides evidence that neurogenic repressors may be important for the establishment of the sharp mesoderm/neuroectoderm boundary in the early embryo.