Genetic Etilogy of Renal Agenesis in the ACI Rat

ACI 大鼠肾发育不全的遗传病因学

• 批准号: 6901429
• 负责人: JAMES D SHULL
• 金额: $ 14.7万
• 依托单位: UNIVERSITY OF NEBRASKA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-04-01 至 2007-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6901429
• 关键词: congenital kidney disorder; developmental genetics; disease /disorder etiology; fluorescence microscopy; gene expression; gene mutation; genetic mapping; genetic markers; genetic susceptibility; histology; laboratory rat; nephrogenesis; transcription factor; vertebrate embryology

DESCRIPTION (provided by applicant): Unilateral renal agenesis (URA) is a common developmental defect in humans, occurring at a frequency of approximately 1 in 500-1000 live births. The frequency of URA in offspring of affected individuals is markedly higher than in the general population, indicating that genetic factors contribute to the genesis of URA. ACI rats spontaneously exhibit URA at an incidence of approximately 15%. In a series of genetic crosses between the ACI strain and two unaffected rat strains, Copenhagen (COP) and Brown Norway (BN), we have mapped to rat chromosome 14 (RNO14) a genetic locus, designated Renag1 (Renal agenesis 1), mat serves as the major, if not sole, determinant of URA in these crosses. The ACI allele of Renag 1 acts in an incompletely dominant and incompletely penetrant manner to confer URA. The overall goals of this proposed research are to define fully the genetic and embryologic bases of renal agenesis in the ACI rat. Specific Aim 1 is to fine map the location of Renagl on rat chromosome 14. We have mapped Renag1 to an approximate 15 centiMorgan (cM) interval on RNO14. To define the location of Renag1 to a resolution approaching 0.5 cM, we will generate up to 400 URA-affected (BN x ACI)F2 progeny and determine the genotypes of these rats at markers placed at a high density across the Renag1 region. Homozygosity for the BN allele at a marker will exclude that marker from residing within Renag1. Specific Aim 2 is to define the embryologic bases of renal agenesis in the ACI rat ACI females will be sacrificed at defined time points after mating and the developing embryos will be harvested, sectioned and examined microscopically. Knowledge of when the first discernable defect in renal development occurs in the ACI rat will provide novel and potentially important insights into when and where the molecular defect associated with Renag1 is manifested. Specific Aim 3 is to compare expression of Pax2, Gdnf and Ret during renal development in the ACI and BN rat strains. Proper renal development requires coordinated expression of Pax2, Gdnf and Ret. We hypothesize that Renag1-associated defect leading to URA in the ACI rat may result in qualitative and/or quantitative differences in Pax2, Gdnf and/or Ret expression relative to the BN rat. Expression of these genes during renal development will be evaluated at the protein and mRNA levels in both the ACI and BN rat strains. Upon completion of these Aims, we will better understand the genetic bases of renal agenesis in the ACI rat and will be able to assess the relevance of this animal model to renal agenesis in humans.

描述（由申请人提供）：单侧肾发育不全（URA）是人类常见的发育缺陷，发生率约为500-1000活产1例。受影响个体的后代患市建局的频率明显高于一般人群，这表明遗传因素对市建局的发生有影响。ACI大鼠自发表现URA，发生率约为15%。在ACI菌株与两个未受影响的大鼠菌株哥本哈根（COP）和布朗挪威（BN）之间的一系列遗传杂交中，我们在大鼠14号染色体（RNO14）上定位了一个遗传位点，称为Renag1（肾发育不全1），它是这些杂交中URA的主要（如果不是唯一）决定因素。renag1的ACI等位基因以不完全显性和不完全渗透的方式产生URA。本研究的总体目标是充分确定ACI大鼠肾发育不全的遗传和胚胎学基础。具体目的1是精细定位Renagl在大鼠14号染色体上的位置。我们将Renag1映射到RNO14上大约15厘米（cM）的间隔。为了在接近0.5 cM的分辨率上确定Renag1的位置，我们将产生多达400只受ura影响的（BN x ACI）F2后代，并在Renag1区域高密度放置的标记上确定这些大鼠的基因型。标记上BN等位基因的纯合性将使该标记不存在于Renag1中。具体目的2是明确ACI大鼠肾发育不全的胚胎学基础。ACI雌性将在交配后的规定时间点处死，收集发育中的胚胎，切片并进行显微镜检查。了解ACI大鼠肾脏发育中第一个可识别的缺陷何时发生，将为Renag1相关的分子缺陷何时何地表现提供新的和潜在的重要见解。特异性目的3是比较ACI和BN大鼠肾发育过程中Pax2、Gdnf和Ret的表达。正常的肾脏发育需要Pax2、Gdnf和Ret的协调表达。我们假设，导致ACI大鼠URA的renag1相关缺陷可能导致相对于BN大鼠Pax2、Gdnf和/或Ret表达的定性和/或定量差异。这些基因在肾脏发育过程中的表达将在ACI和BN大鼠品系的蛋白和mRNA水平上进行评估。在完成这些目标后，我们将更好地了解ACI大鼠肾脏发育不全的遗传基础，并将能够评估该动物模型与人类肾脏发育不全的相关性。