Kidney development and cystogenesis in Medaka

描述（由申请人提供）：常染色体显性多囊肾病（ADPKD）是一种遗传性疾病，发生率为1:100，以肾小管囊肿形成、液体运输失调和细胞外粘附改变为特征。ADPKD是由分别编码多囊蛋白1和多囊蛋白2的PKD1或PKD2基因突变引起的。ADPKD中囊肿形成的主要原因和机制尚不清楚。由于基因冗余，我们试图在斑马鱼中敲除pkdl的尝试失败了。Medaka是一种独特的近交水生脊椎动物鱼类模型系统，与斑马鱼相比，其基因数目冗余度较低。medaka的使用为开发一种新的系统来研究器官发生和了解膀胱发生的机制提供了机会。鉴于PKD1突变占人类所有ADPKD病例的85%，我们针对medaka中的pkdl来了解其功能。初步结果表明，在medaka（与斑马鱼相反）中靶向pkdl可导致肾原囊肿的形成。我们还利用medaka建立了一个系统用于肾脏、膀胱发生的研究，该系统对多囊素-1相互作用蛋白（如多囊素-2）的缺陷敏感，可用于评估大量多囊素-1相互作用蛋白的体内相关性。

DESCRIPTION (provided by applicant): Autosomal dominant polycystic kidney disease (ADPKD) is a hereditary disease occurring at a frequency of 1:1000 in humans and characterized by cyst formation in kidney tubules, deregulated fluid transport and alteration of extracellular adhesion. ADPKD is caused by mutations in the PKD1 or PKD2 gene that encode polycystin-1 and polycystin-2, respectively. The primary causes and mechanisms of cyst formation in ADPKD remain elusive. Our attempts to knockdown pkdl in zebrafish failed because of gene redundancy. Medaka is a unique inbred aquatic vertebrate fish model system, which shows lower redundancy in gene number compared to zebrafish. The use of medaka provides an opportunity to develop a novel system to study organogenesis and to understand the mechanisms of cystogenesis. Given that PKD1 mutations account for 85% of all ADPKD cases in humans, we have targeted pkdl in medaka to understand its function(s). Preliminary results demonstrate that targeting pkdl in medaka (in contrast to zebrafish) causes prronephric cysts formation. We have also established a system using medaka for studies of kidney, cystogenesis that is sensitive for the defect of polycystin-1 interacting proteins such as polycystin-2, which can be used to assess the in vivo relevance of the large number of polycystin-1 interacting proteins. In specific aim 1, we will test the in vivo function of specific polycystin-1 motifs by disrupting pkdl mRNA splicing and generate an allelic series of deletions in medaka. For this purpose, we propose to use our urogenital specific medaka transgenic GFP line to monitor the progress of cyst formation, and to analyze the kidney phenotypes as well as other potential defects in organogenesis caused by the defers. In specific aim 2, we will validate the biological significance of polycystin-1 interacting proteins.