Characterization of the Murine pcy Mutation

多囊肾病(PKD)是儿童和成人进行性肾功能衰竭的主要原因之一。目前，还没有已知的治疗方法可以抑制或延缓PKD患者进展为肾功能衰竭。尽管最近对PKD中最常见的两个基因PKD1和PKD2进行了分子鉴定，但对PKD肾功能衰竭的遗传学和发病机制仍知之甚少。纯合子pcy/pcy小鼠发展成一种缓慢进展的PKD，具有许多类似于人类PKD的特征。了解pcy小鼠的分子损伤将对PKD肾功能衰竭的发生发展的遗传学和致病途径提供重要的补充见解。这一建议旨在阐明pcy小鼠的分子缺陷，并提高我们对决定肾囊性疾病表型严重程度的修饰基因的理解。为了在分子水平上鉴定和鉴定pcy突变，我们将(1)使用RPCI-23小鼠基因组文库分离BACS重叠群中最小的pcy区间，以便通过NIH小鼠基因组测序计划进行测序；(2)通过系统地鉴定位于我们pcy区间内的候选基因来鉴定pcy基因。为了提高我们对调节多囊肾病表型严重程度的修饰基因的理解，我们将(1)使用标记辅助选择育种方法将两个定位的修饰基因座分离到不同的同源品系中，(2)使用基因表达谱来分类在轻度PKD同源小鼠的肾脏和在年龄匹配的重度PKD同源小鼠肾脏中差异表达的基因集。

Polycystic kidney diseases (PKD) are among the leading causes of progressive renal failure in children and adults. Currently, there is no known therapy that can inhibit or retard the progression to renal failure in PKD patients. Despite the recent molecular identification of PKD1 and PKD2, the two genes most commonly mutated in human PKD, the genetics and pathogenesis of renal failure in PKD remains poorly understood. Homozygous pcy/pcy mice develop a slowly progressive form PKD that has many characteristics resembling human PKD. Understanding the molecular lesion in pcy mice will provide important additional insights into the genetics and pathogenic pathways involved in the development of renal failure in PKD. This proposal aim to elucidate the molecular defect in the pcy mouse and to improve our understanding of modifier genes that determine the severity of the renal cystic disease phenotype. Towards the identification and characterization of the pcy mutation at the molecular level, we will (1) isolate the minimal pcy interval in BACs contigs using the RPCI-23 mouse genomic library for sequencing by the NIH mouse genome sequencing project and (2) identify the pcy gene by systematically characterize; candidate genes located within our pcy interval. Towards improving our understanding of modifier genes that regulates the severity of the polycystic kidney disease phenotype, we will (1) isolate the two mapped modifier loci into separate congenic strains using marker assisted selective breeding approaches and (2) use gene expression profiling to catalog the set of genes that are differentially expressed in the kidneys of congenic mice with the mild PKD and in the kidneys of age matched congenic mice with the severe PKD.