Genetic Analysis of Hip Fragility

髋部脆弱的遗传分析

• 批准号: 7714823
• 负责人: CHARLES H TURNER
• 金额: $ 38.5万
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-04-04 至 2011-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7714823
• 关键词: Affect; Alleles; Behavioral; Biology; Bone Diseases; Candidate Disease Gene; Cell Culture Techniques; Cellular biology; Chromosome Mapping; Chromosomes; Chromosomes, Human, Pair 1; Chromosomes, Human, Pair 4; Complex; Cost Measures; DNA Sequence; Europe; Evaluation; Exons; Gene Expression; Gene Expression Profiling; Gene Expression Regulation; Genes; Genetic; Genetic Recombination; Genetic Techniques; Genome; Genomics; Genotype; Goals; Hip region structure; Histology; Housing; Human; Inbred Strains Rats; Individual; Information Networks; Laboratory Rat; Literature; Location; Maps; Measurement; Measures; Metabolic; Modeling; Mus; Neck; Osteoblasts; Osteoclasts; Osteoporosis; Phenotype; Population; Proteins; Quantitative Trait Loci; RNA Interference; RNA Splicing; Rattus; Reporting; Research; Single Nucleotide Polymorphism; Site; Structure; Transcript; Variant; Work; base; bone; bone cell; congenic; cost; genetic analysis; genetic linkage analysis; genetic variant; genome wide association study; genome-wide; hemodynamics; in vivo; progenitor; public health relevance; research study; skeletal; trait

DESCRIPTION (provided by applicant): In 2001, our group began studies to determine the genetics causes of bone fragility. We chose to study rats, rather than mice, because the laboratory rat has proven to be an excellent model for human bone disorders, like osteoporosis. Because rats are larger than mice, it is easier to measure bone structure and strength at the femoral neck, which is a skeletal site of primary focus. Our first study involved a cross between Fischer 344 (F344) and Lewis (LEW) rats. Our second study focusing on Copenhagen 2331 (COP) and Dark Agouti (DA) rats began in 2003 and is the subject of this competitive renewal application. We have successfully mapped quantitative trait loci (QTLs) for femoral neck and femoral midshaft phenotypes, the primary and secondary goals of the project. Our work in the past five years has provided a clear direction for our proposed research in the next five years: we will identify genes within QTLs that affect bone biology. This project has three Aims. First, we will identify causative genes within our two QTLs with largest effect size: Chromosome (Chr) 4 for F344 and LEW rats (13% effect) and Chr 1 for COP and DA rats (14% effect). We plan to generate congenic rat models and conduct gene expression profiling followed by functional studies in vivo and using cultured osteoblasts and osteoclasts to identify genes that directly affect bone biology. Second, we will work with a large, world-wide research consortium to conduct a genome wide association study (GWAS) in heterogeneous stock (HS) rats. The GWAS led by Jonathan Flint will provide phenotypes and genotypes for over 2000 rats. Phenotypes will include: behavioral, metabolic, hematological, hemodynamic, immunological and skeletal (our contribution). Each rat will be genotyped for about 20,000 single nucleotide polymorphisms (SNPs). The results will allow us to identify new QTLs that affect bone traits and to reduce the number of candidate genes at each QTL from several dozen to a mere handful. Finally, we will identify gene expression QTLs (eQTLs) using a genome screen to map transcript abundance in 2nd filial (F2) rats derived from COP and DA progenitors. Variations in expression of individual genes will be mapped to locations on the genome to produce eQTLs. eQTL mapping allows one to identify cis-eQTLs for which expression levels can be correlated with a chosen bone phenotype to identify and prioritize genes most likely to alter bone biology. Also, we will identify trans- genes controlled by a given QTL and with this information we will construct networks of genes that underlie complex bone traits. Another unique feature of eQTL mapping is its ability to identify allele-specific regulation of gene expression on a genome-wide scale. Completion of these Aims will accelerate our progress toward identifying genes that affect bone fragility. PUBLIC HEALTH RELEVANCE: Our study will identify genes that cause bone fragility. We will use several inbred strains of rats in our experiments and apply modern genetics techniques like gene expression microarrays and single nucleotide polymorphism genotyping. Our goal is to find genetic causes for bone weakening conditions like osteoporosis so better treatments can be developed.

描述（由申请人提供）：2001年，我们小组开始研究确定骨脆性的遗传原因。我们选择研究大鼠而不是小鼠，因为实验室大鼠已被证明是人类骨骼疾病（如骨质疏松症）的极好模型。由于大鼠比小鼠大，因此更容易测量股骨颈的骨结构和强度，股骨颈是主要关注的骨骼部位。我们的第一项研究涉及Fischer 344（F344）和刘易斯（LEW）大鼠之间的交叉。我们的第二项研究集中在哥本哈根2331（COP）和黑暗Agglomerate（DA）大鼠开始于2003年，是这个竞争性更新申请的主题。我们已经成功地绘制了股骨颈和股骨中段表型的数量性状基因座（QTL），这是该项目的主要和次要目标。我们在过去五年的工作为我们未来五年的研究提供了明确的方向：我们将确定影响骨生物学的QTL内的基因。这个项目有三个目标。首先，我们将确定我们的两个QTL中的致病基因具有最大的效应大小：F344和LEW大鼠的染色体（Chr）4（13%效应）和COP和DA大鼠的Chr 1（14%效应）。我们计划建立同类大鼠模型，进行基因表达谱分析，然后进行体内功能研究，并使用培养的成骨细胞和破骨细胞来鉴定直接影响骨生物学的基因。第二，我们将与一个大型的全球研究联盟合作，在异质性（HS）大鼠中进行全基因组关联研究（GWAS）。由Jonathan Flint领导的GWAS将为2000多只大鼠提供表型和基因型。表型将包括：行为、代谢、血液学、血液动力学、免疫学和骨骼（我们的贡献）。将对每只大鼠进行约20，000个单核苷酸多态性（SNP）的基因分型。这些结果将使我们能够识别影响骨骼性状的新QTL，并将每个QTL的候选基因数量从几十个减少到几个。最后，我们将确定基因表达QTL（eQTL），使用基因组筛选，以映射转录丰度在第二个子代（F2）大鼠来自COP和DA祖细胞。单个基因表达的变异将被定位到基因组上的位置以产生eQTL。eQTL作图允许鉴定cis-eQTL，其表达水平可以与所选骨表型相关，以鉴定和优先考虑最可能改变骨生物学的基因。此外，我们将确定由一个给定的QTL控制的转基因，并利用这些信息，我们将构建复杂的骨骼性状的基因网络。eQTL定位的另一个独特的功能是它能够在全基因组范围内识别基因表达的等位基因特异性调控。这些目标的完成将加速我们在确定影响骨脆性的基因方面的进展。公共卫生相关性：我们的研究将确定导致骨脆性的基因。我们将在实验中使用几种近交系大鼠，并应用现代遗传学技术，如基因表达微阵列和单核苷酸多态性基因分型。我们的目标是找到骨质疏松症等骨质疏松症的遗传原因，以便开发更好的治疗方法。