CILIA IN EYE DEVELOPMENT AND DISEASE

描述(由申请人提供)：纤毛在许多发育过程中扮演着重要的角色。在神经系统中，纤毛是脊椎动物和无脊椎动物感觉神经元的关键结构成分。在脊椎动物的视觉系统中，细胞的光敏成分被称为外节，通过紧紧围绕纤毛轴丝的狭窄收缩连接到细胞体的其余部分，被称为连接纤毛。在没有纤毛的情况下，光感受器外节不形成。 越来越多的证据表明，睫毛缺陷会导致Bardet-Biedl综合征(BBS)，这是一组人类疾病，涉及光感受器丢失，从而导致失明。BBS的临床表现还包括多指、肥胖、肾脏疾病、嗅觉障碍和智力低下。为了了解纤毛在光感受器分化和疾病中的作用，我们计划采用正向和反向遗传方法。在大规模的基因筛查中，我们发现了elipsa基因的突变，这些突变导致纤毛早期丧失，外节形成缺失，随后光感受器细胞死亡和失明。我们建议应用分子和遗传学方法来研究elipsa在光感受器分化和存活中的作用。 为了实现其功能，Elipsa很可能与其他蛋白质相互作用。为了确定它们的身份，我们使用了一种被称为酵母双杂交筛选的分子遗传学方法。这一努力导致了几个因子的分离，其中一个已知是调节细胞内小泡运输的酶家族的效应器。我们正计划利用这一发现来研究光感受器细胞内的运输--这一过程被认为对光感受器功能和生存至关重要。 在这些努力的同时，我们将应用互补的反向遗传学方法来研究纤毛发生。使用这种被称为TILLING的方法，我们将产生选定BBS基因的斑马鱼突变。突变菌株将使我们能够详细研究BBS基因在纤毛形成和维持中的作用，以及它们与其他参与纤毛发生的遗传途径的关系。这些研究的结果将提高我们为感光障碍的感光细胞丢失提供治疗的能力。

DESCRIPTION (provided by applicant): Cilia play an essential role in many developmental processes. In the context of the nervous system, cilia are a key structural component of sensory neurons in both vertebrates and invertebrates. In the vertebrate visual system, the photosensitive component of the cell, known as the outer segment, connects to the rest of the cell body via a narrow constriction that tightly surrounds a ciliary axoneme, and is referred to as the connecting cilium. In the absence of this cilium, the photoreceptor outer segment does not form. A growing body of evidence indicates that ciliary defects cause Bardet-Biedl Syndrome (BBS), a group of human disorders that involve photoreceptor loss and consequently blindness. The clinical manifestations of BBS also involve polydactyly, obesity, kidney disease, anosmia, and mental retardation. To understand the role of cilia in photoreceptor differentiation and disease, we are planning to take both forward and reverse genetic approaches. In a large-scale genetic screen, we identified mutations in the elipsa gene that lead to early loss of cilia, the absence of outer segment formation, and subsequently photoreceptor cell death and blindness. We propose to apply molecular and genetic approaches to study the role of elipsa in photoreceptor differentiation and survival. To carry out its function, Elipsa most likely interacts with other proteins. To determine their identity, we used a molecular genetic approach known as the yeast two-hybrid screen. This effort led to the isolation of several factors, one of which is known to function as an effector of an enzyme family that regulates the trafficking of intracellular vesicles. We are planning to capitalize on this finding to study the intracellular trafficking in the photoreceptor cell - a process known to be of paramount importance of photoreceptor function and survival. In parallel to these efforts, we will apply a complementary reverse genetic approach to study ciliogenesis. Using this approach, known as TILLING, we will generate zebrafish mutants of selected BBS genes. The mutant strains will allow us to study in the detail the role of BBS genes in cilia formation and maintenance, as well as their relationship to other genetic pathways involved in ciliogenesis. The results of these studies will enhance our ability to produce treatment for photoreceptor loss in photoreceptor disorders.