Developing Models of Retinal and Eye Defects

描述（由申请人提供）：脊椎动物的眼睛和视网膜提供了重要的模型来识别发育的基本过程，如诱导、形态发生、模式和细胞命运规范。虽然已经发现了描述眼睛发育早期事件的大量信息，但对后期分化和成熟的许多过程却知之甚少。例如，脊椎动物视网膜的层状组织具有良好的特征，每一层内神经元的非随机或马赛克排列是互补的。虽然马赛克排列的必要性是直观的：神经元分布或细胞聚集的间隙会导致视野部分的代表性不足或过采样，但对调节马赛克模式的遗传机制知之甚少。在接下来的五年里，我们将对enu诱变斑马鱼的胚胎后期幼虫和成年后代进行新的基因筛选，以发现影响视觉系统的新的隐性和显性突变。对晚发性突变的系统筛查应提供急需的人类遗传性疾病模型，如视网膜色素变性、先天性白内障和青光眼。提出了三个具体目标：具体目标1：通过对自由游动的5日龄幼虫的杆镶嵌进行原位免疫组织化学筛选，恢复特异性影响光感受器细胞规范和镶嵌图案的新型隐性突变。特异性目的II：通过对幼虫眼晶状体、角膜和瞳孔缺陷的形态学筛查，鉴定对前段发育和维持至关重要的基因。特异性目的III：通过对成年斑马鱼视网膜的组织学和免疫荧光分析，鉴定导致光感受器细胞营养不良的突变作为人类视网膜疾病的模型。最初的诱变程序和随后的育种策略将一个定位面板纳入诱变系，以促进更有效的定位和随后的突变基因克隆。突变表型的描述和图像将在PI的网站和斑马鱼信息网络上提供，并通过斑马鱼国际资源中心进行分发。

DESCRIPTION (provided by applicant): The vertebrate eye and retina have provided important models to identify fundamental processes of developmental such as induction, morphogenesis, patterning and cell fate specification. While a considerate amount of information describing the early events of eye development has been uncovered, many processes of later stages of differentiation and maturation are less well understood. For example, the well characterized, laminar organization of the vertebrate retina is complimented by the non-random or mosaic arrangement of neurons within each of the layers. Though the necessity of the mosaic arrangement is intuitive: gaps in the distribution of neurons or clustering of cells would result in under representation or oversampling of portions of the visual field, little is known of the genetic mechanisms regulating the mosaic patterning. Over the next five years, we propose a novel genetic screen of post-embryonic stage larvae and adult progeny of ENU-mutagenized zebrafish to uncover novel recessive and dominant mutations affecting the visual system. A systematic screen for late onset mutations should provide much needed models of inherited diseases in humans such as retinitis pigmentosa, congenital cataracts and glaucoma. Three specific aims are proposed: SPECIFIC AIM I: Recover novel, recessive mutations that specifically affect the specification and mosaic patterning of photoreceptor cells through an in situ immunohistochemical screen of the rod mosaic in free swimming, 5 day old larvae. SPECIFIC AIM II: Identify genes essential to the development and maintenance of the anterior segment, through a morphological screen for defects in the lens, cornea and pupil of the larval eye. SPECIFIC AIM III: Identify mutations resulting in photoreceptor cell dystrophies as models of human retinal disease through the histological and immunofluorescent analysis of retinas of adult zebrafish. The initial mutagenesis procedure and subsequent breeding strategy incorporated a mapping panel into the mutagenized lines to facilitate more efficient mapping and the subsequent cloning of the mutated genes. Descriptions and images of the mutant phenotypes will be available at the PI's website and the Zebrafish Information Network and distribution will be handled through the Zebrafish International Resource Center.