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

眼缺损包括一组常见的眼部缺陷，影响所有年龄段的人，尤其是幼儿。这些病理是视力问题的常见原因，可导致视网膜脱离和白内障，并经常导致受影响患者失明。缺损通常是先天性疾病，通过检测眼睛任何结构（包括角膜、视网膜和视神经）中的缺口、间隙、孔或裂缝来诊断。与眼缺损相关的眼结构缺陷是由于眼胚胎形成失败所致。在胚胎发生期间，形成的眼睛和视神经经历戏剧性的形状变化，导致眼睛一侧上存在的裂隙（脉络膜裂隙）闭合，并最终形成眼睛的完整地球仪。如果脉络膜裂的闭合被破坏，就会形成眼缺损。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立，但我们不知道它们是如何发挥作用的，以及它们在缺损条件下如何受到影响。如果我们要了解缺损病理学并找到预防或治疗方法，解决这些问题是至关重要的。在这个项目中，我们将使用小而透明的斑马鱼胚胎，以促进对完整动物正常发育和疾病的研究。再加上其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体斑马鱼胚胎中发育中眼睛的所有细胞。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，我们将在眼睛发育过程中的不同时间点产生缺乏POM细胞的鱼，并比较这些和健康条件下脉络膜裂闭合的过程。此外，我们将使用遗传技术来确定负责在脉络膜裂闭合过程中POM和视网膜细胞之间通信的分子。这些分析将使我们能够建立人类眼病的新模型，并使我们能够进一步了解正常的眼睛发育和遗传性眼部畸形的原因。

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.