Analysis of cellular & genetic interactions between retina & periocular mesenchyme that underlie choroid fissure closure

眼部缺陷症包括一组影响所有年龄段的人，尤其是年幼儿童的常见眼睛缺陷。这些病变是导致视力问题的常见原因，可导致视网膜脱离和白内障，并经常导致受影响的患者失明。眼球瘤通常是先天性疾病，通过检测眼部任何结构(包括角膜、视网膜和视神经)中的缺口、缝隙、孔洞或裂隙来诊断。与缺损相关的眼结构缺陷是由于眼的胚胎形成失败造成的。在胚胎发育过程中，形成眼和视神经会经历剧烈的形状变化，导致眼睛一侧的裂隙(脉络膜裂隙)闭合，最终形成完整的眼球。如果脉络膜裂隙闭合被破坏，就会形成眼部缺损。我们和其他人最近的研究表明，视网膜外的细胞在脉络膜裂隙闭合中起着关键作用。虽然这些眼周间充质细胞(POM)的重要性现在已经确定，但我们不知道它们是如何发挥作用的，以及它们在缺损情况下是如何受到影响的。如果我们要了解缺损的病理并找到预防或治疗它们的方法，解决这些问题是根本的。在这个项目中，我们将使用小而透明的斑马鱼胚胎，以便于研究完整动物的正常发育和疾病。再加上它对遗传分析的适应性，这些特征使鱼胚胎成为研究正常和病理条件下眼睛形成的极好的模型系统。事实上，高度复杂的成像技术将使我们能够可视化活着的斑马鱼胚胎中发育中的眼睛中的所有细胞。我们将使用各种方法来标记POM细胞亚群，并评估它们在眼睛形成过程中的行为。然后，我们将在眼睛发育的不同时间点培育出没有POM细胞的鱼，并比较这些情况下和健康条件下脉络膜裂隙闭合的过程。此外，我们将使用基因技术来确定在脉络膜裂隙闭合过程中负责POM和视网膜细胞之间通讯的分子。这些分析将使我们能够为人类眼睛疾病建立新的模型，并将使我们能够进一步深入了解正常的眼睛发育和遗传性眼睛畸形的原因。

Eye colobomas encompass a group of common eye defects affecting people of all ages, but especially young children. These pathologies are a common cause of visual problems, can cause retinal detachment and cataracts, and often lead to blindness in affected patients. Colobomas are usually congenital conditions diagnosed by detection of a notch, gap, hole or fissure in any of the structures of the eye, including the cornea, retina and optic nerve. The defects in the ocular structures associated with the colobomas result from a failure in the embryonic formation of the eye. During embryogenesis, the forming eye and optic nerve undergo dramatic shape changes that lead to the closure of a fissure present on one side of the eye (the choroid fissure), and eventually to the formation of the intact globe of the eye. If choroid fissure closure is disrupted, an ocular coloboma develops. Recent studies by us and others indicate that cells outside the retina play a critical role in choroid fissure closure. Although the importance of these periocular mesenchyme cells (POM) is now established, we do not know how they function, and how they are affected in coloboma conditions. Resolving these issues is fundamental if we are to understand coloboma pathologies and find ways of preventing or treating them. In this project, we will use zebrafish embryos which are small and transparent facilitating the study of normal development and disease in the intact animal. Together with its amenability to genetic analysis, these features make the fish embryo an excellent model system to study eye formation in normal and pathological conditions. Indeed, highly sophisticated imaging techniques will allow us to visualise all of the cells in the developing eye in the living zebrafish embryo. We will use a variety of approaches to label subpopulations of POM cells and assess their behaviour during eye formation. We will then generate fish devoid of POM cells at different time points during eye development and compare the process of choroid fissure closure in these and in healthy conditions. In addition, we will use genetic techniques to identify the molecules responsible for the communication between POM and retinal cells during choroid fissure closure. These analyses will enable us to establish new models for human eye diseases and will allow us to gain further insight into normal eye development and into the causes of hereditary ocular malformations.