Identification of mutation causing Purkinje cell degeneration in the shaker rat

描述(申请人提供)：退行性共济失调是一组与小脑及其连接功能障碍相关的神经系统疾病。临床表现包括逐渐的动作和步态不协调，导致完全残疾，最终导致死亡。在人类中，遗传性共济失调的患病率从每10万人中有6例到20例不等，这与美国的ALS或多发性硬化症的患病率相当。人类共济失调的啮齿动物模型仅限于小鼠。Shaker大鼠是在Wistar Furth(WF)背景下发生的浦肯野细胞变性的自然X连锁模型。与大多数人类共济失调的啮齿动物模型不同，在这些模型中，神经元丢失并不明显，Shaker大鼠从出生时正常数量的浦肯野细胞发展到1岁时几乎完全丧失。我们提出了三个具体目标：我们将利用WF摇床频率与野生型棕色挪威大鼠的杂交F2‘S对摇床基因座进行精细定位。已经建立了一个由44个遗传标记组成的小组，用于区分WF和BN等位基因，在这个杂交组合中提供信息。第二个目标是通过对从症状前期和症状小脑中分离出来的Shaker和野生型RNA进行RNA测序来识别Shaker突变。第三个目标将在摇床突变不会导致摇床转录本丰度降低或内含子的情况下使用全基因组测序。这项建议的总体目标是在大鼠中识别导致小脑PC变性的第一个基因，并建立大鼠作为测试新治疗策略的模型系统。

DESCRIPTION (provided by applicant): Degenerative ataxias are a group of neurological disorder associated with dysfunction of cerebellum and its connection. The clinical manifestations include progressive incoordination of movements and gait leading to complete disability and eventually to death. In humans, the prevalence of hereditary ataxias range from 6 to 20 cases for every 100,000 which is comparable to the prevalence of ALS or multiple sclerosis in the US. Rodent models of human ataxias have been limited to mice. The Shaker rat is a naturally occurring X- linked model for Purkinje cell degeneration in the Wistar Furth (WF) background. In contrast to most rodent models of human ataxias in which neuronal loss is not pronounced, the shaker rat progresses from a normal number of Purkinje cells at birth to almost complete loss at 1 year. Three specific aims are proposed: We will fine-map the shaker locus using F2's from an intercross of WF shaker rates with wildtype Brown Norway rats. A panel of 44 genetic markers that distinguish WF and BN alleles, informative in this cross, has been established. A second aim will identify the shaker mutation by RNA sequencing of shaker and wildtype RNAs isolated from pre-symptomatic and symptomatic cerebella. The third aim will employ whole genome sequencing for the case that the shaker mutation does not cause reduced abundance of the shaker transcript or is intronic. The overall goal of this proposal is the identification of the first gene in the rat leading to cerebellar PC degeneration and the establishment of the rat as a model system in which to test novel treatment strategies.