Dynamic coupling of pattern formation and morphogenesis in the developing vertebrate retina.
Dynamic coupling of pattern formation and morphogenesis in the developing vertebrate retina.
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DOI：
10.1371/journal.pbio.1000214
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发表时间：
2009-10
期刊：
影响因子：
9.8
通讯作者：
Brand M
中科院分区：
文献类型：
--
作者：
Picker A;Cavodeassi F;Machate A;Bernauer S;Hans S;Abe G;Kawakami K;Wilson SW;Brand M
在这篇研究文章中，Picker 等人。显示视网膜中的细胞如何获取其空间坐标。在胚胎发育过程中，模式形成必须与组织形态发生紧密同步，以协调细胞空间身份的建立及其运动。在脊椎动物视网膜中，为了在视网膜顶盖图中正确表示空间，需要沿着背腹轴和鼻颞轴（前-后）进行图案化。然而，目前尚不清楚在早期眼睛形态发生的复杂过程中，视网膜中轴向细胞位置的规范是如何发生的。通过研究斑马鱼胚胎，我们发现眼睛外翻期间形态发生组织的重排导致视网膜原基鼻半部分的祖细胞靠近眼睛外部三种成纤维细胞生长因子 Fgf8/3/24 的来源。三重突变分析表明，这种组合的 Fgf 信号通过调节鼻转录因子 Foxg1 完全控制鼻视网膜身份。令人惊讶的是，鼻颞轴的规范很早就沿着外翻眼的背腹轴发生。通过对 GFP 标记的视网膜祖细胞进行体内成像，我们发现随后的眼睛形态发生需要逐渐压缩鼻半部的组织，并将细胞定向移动到视网膜的颞半部。平衡这些过程可驱动鼻颞视网膜轴与身体前后轴的逐渐对齐，并由 Fgf 信号对 Foxg1 介导的细胞凝聚力的前馈效应控制。因此，通过 Fgf 信号传导，组织模式与形态发生细胞行为的机械耦合和动态同步导致眼睛中细胞位置身份的分级分配，从而形成视网膜顶盖图。脊椎动物的大脑包含来自眼睛的感觉输入的点对点表示。这种视觉图是在胚胎发育过程中形成的，由视网膜的神经元细胞向大脑发送有针对性的轴突投射。由于投影需要将视网膜中的相邻细胞位置连接到大脑中的相邻目标区域，因此所有视网膜细胞必须拥有一个定义的空间坐标作为地图形成的先决条件。如何在动态进化的胚胎中建立和维持这样的视网膜坐标系是一个基本但尚未解决的问题。通过结合斑马鱼胚胎的遗传分析和体内成像，我们追踪了视网膜细胞坐标的发育起源。我们发现，从眼睛外部发出的三个相关的 Fgf 信号在视网膜形成之初就定义了视网膜中的相对细胞位置。但视网膜细胞相对于身体轴的绝对位置在随后的发育过程中发生了极大的重新排列。令人惊讶的是，在这个阶段，最初定义的视网膜细胞位置的相同 Fgf 信号现在平衡了不对称的细胞运动和细胞形状的变化，这是视网膜和谐生长和眼睛中细胞坐标最终对齐所必需的。
In this Research Article, Picker et al. show how cells in the retina get their spatial coordinates. During embryonic development, pattern formation must be tightly synchronized with tissue morphogenesis to coordinate the establishment of the spatial identities of cells with their movements. In the vertebrate retina, patterning along the dorsal-ventral and nasal-temporal (anterior-posterior) axes is required for correct spatial representation in the retinotectal map. However, it is unknown how specification of axial cell positions in the retina occurs during the complex process of early eye morphogenesis. Studying zebrafish embryos, we show that morphogenetic tissue rearrangements during eye evagination result in progenitor cells in the nasal half of the retina primordium being brought into proximity to the sources of three fibroblast growth factors, Fgf8/3/24, outside the eye. Triple-mutant analysis shows that this combined Fgf signal fully controls nasal retina identity by regulating the nasal transcription factor Foxg1. Surprisingly, nasal-temporal axis specification occurs very early along the dorsal-ventral axis of the evaginating eye. By in vivo imaging GFP-tagged retinal progenitor cells, we find that subsequent eye morphogenesis requires gradual tissue compaction in the nasal half and directed cell movements into the temporal half of the retina. Balancing these processes drives the progressive alignment of the nasal-temporal retina axis with the anterior-posterior body axis and is controlled by a feed-forward effect of Fgf signaling on Foxg1-mediated cell cohesion. Thus, the mechanistic coupling and dynamic synchronization of tissue patterning with morphogenetic cell behavior through Fgf signaling leads to the graded allocation of cell positional identity in the eye, underlying retinotectal map formation. The vertebrate brain contains a point-to-point representation of sensory input from the eye. This visual map forms during embryonic development, by neuronal cells of the retina sending targeted axon projections to the brain. Since the projection needs to wire up neighboring cell positions in the retina to neighboring target areas in the brain, all retinal cells must harbor a defined spatial coordinate as prerequisite for map formation. How such a retinal coordinate system is established and maintained in the dynamically evolving embryo is a fundamental, but unresolved, question. By combining genetic analysis and in vivo imaging in zebrafish embryos, we have tracked the developmental origin of cell coordinates in the retina. We find that three related Fgf signals emanating from outside the eye define relative cell positions in the retina very early, already at the onset of its formation. But the absolute position of retinal cells relative to the body axes is greatly rearranged during subsequent development. In this phase, surprisingly, the same Fgf signals that at first defined retinal cell positions now balance asymmetric cell movements and cell shape changes, which are required for harmonic retinal growth and the final alignment of cell coordinates in the eye.
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影响因子：
16.2
作者：
Hindges, R;McLaughlin, T;O'Leary, DDM
通讯作者：
O'Leary, DDM
影响因子：
4.6
作者：
Herrera, E;Marcus, R;Mason, C
通讯作者：
Mason, C
MARCKS 在原肠胚形成运动期间皮质肌动蛋白动力学中的重要作用。
DOI：
10.1083/jcb.200310027
发表时间：
2004-01-19
期刊：
The Journal of cell biology
影响因子：
--
作者：
Iioka H;Ueno N;Kinoshita N
通讯作者：
Kinoshita N
影响因子：
4.6
作者：
Herzog, W;Sonntag, C;Hammerschmidt, M
通讯作者：
Hammerschmidt, M
影响因子：
64.5
作者：
DRESCHER, U;KREMOSER, C;BONHOEFFER, F
通讯作者：
BONHOEFFER, F