Genetic Architecture of Hsp90-buffered variation

Hsp90 缓冲变异的遗传结构

• 批准号: 7055242
• 负责人: Suzannah Rutherford
• 金额: $ 33.45万
• 依托单位: FRED HUTCHINSON CANCER RESEARCH CENTER
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-05-01 至 2008-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7055242
• 关键词: Drosophilidae; computer data analysis; functional /structural genomics; gene environment interaction; gene expression; genetic mapping; genetic markers; genetic polymorphism; genotype; heat shock proteins; high performance liquid chromatography; molecular cloning; polymerase chain reaction; protein structure function; quantitative trait loci

DESCRIPTION (provided by applicant): Our present knowledge of the genes involved insusceptibilities to complex human diseases such as cancer is limited due to the large number of genetic and environmental factors involved and their complex interactions. Cancer is characterized by aberrant signaling through pathways required for regulated cell growth, death, or DNA maintenance. Single gene mutations in these pathways cause rare cancers, but common polymorphic alleles of unknown genes with modest effects on signaling are responsible for most cancers. To find these genes, human studies are difficult, costly, and biased toward previously known biological mechanisms and genes of large effect. An alternative approach is to find modifiers of conserved signaling pathways in model organismsand then study their human homologs variants associated with disease. The Hsp90 stress protein supports the activities of many conserved tumor suppressors, oncogenes, and cell cycle regulators. When Drosophila Hsp90 is limiting, polygenic variation with potent effects on development is expressed as strain specific abnormalities. We believe that the developmental novelties result from natural genetic variation affecting the strength of signaling through the developmental, regulatory, and growth control pathways determined by Hsp90 targets. Thus, a network of natural variation influencingHsp90-dependent signaling pathways in flies models the architecture of signaling variation for cancer predisposition in humans, and has the potential to drive the evolution of development. To identify natural Hsp90-buffered polymorphisms and place them in pathways we used laboratory selection for Hsp90-dependent eye abnormalities to generate replicate 'deformed eye' lines with a high fraction of affected flies. An inbred wild-type genetic background with normal eyes was crossed into the selection lines to construct over 1,400 recombinant isogenic mapping lines (clones). For each recombinant line, on average 50 flies having identical recombinant genotypes were scored for trait penetrance (probability affected) and saved for genotyping. Our specific aims are to 1) localize deformed eye polymorphisms by SQTL (Suppressor of Quantitative Trait Loci) and deletion mapping to test the idea that varied genetic architectures for deformed eye arose in the replicate lines. 2) Clone the wild-type alleles of deformed eye polymorphisms as suppressors of trait penetrance to determine whether hidden polymorphisms reside in Hsp90 targets or in peripheral genes of small effect. 3) Identify developmental processes and pathways responsible for the pathology of deformed eye to bring Hsp90-buffered variation into biological context. We expect this research will identify conserved Hsp90 target pathways and an extended network of naturally polymorphic genes that influence their function.

描述（由申请人提供）：由于涉及大量的遗传和环境因素及其复杂的相互作用，我们目前对涉及复杂人类疾病如癌症的易感性的基因的了解是有限的。癌症的特征在于通过调节细胞生长、死亡或DNA维持所需的途径的异常信号传导。这些途径中的单基因突变导致罕见的癌症，但对信号传导具有适度影响的未知基因的常见多态性等位基因是大多数癌症的原因。为了找到这些基因，人类研究是困难的，昂贵的，并偏向于以前已知的生物学机制和基因的大作用。另一种方法是在模式生物中找到保守信号通路的修饰剂，然后研究与疾病相关的人类同源变体。Hsp90应激蛋白支持许多保守的肿瘤抑制因子、癌基因和细胞周期调节因子的活性。当果蝇Hsp90是有限的，多基因变异与发展的有力影响表示为应变具体异常。我们认为，发展新奇的结果从自然的遗传变异影响信号的强度，通过发育，调节和生长控制途径确定的Hsp90目标。因此，果蝇中影响Hsp90依赖性信号通路的自然变异网络模拟了人类癌症易感性的信号变异结构，并有可能推动发展的演变。为了确定自然热休克蛋白90缓冲多态性，并将它们的途径，我们使用实验室选择热休克蛋白90依赖性的眼睛异常，以产生复制的“变形眼”线与高比例的受影响的苍蝇。将具有正常眼睛的近交野生型遗传背景与选择系杂交以构建超过1，400个重组等基因作图系（克隆）。对于每个重组系，平均对50只具有相同重组基因型的果蝇进行性状变异率（受影响的概率）评分，并保存用于基因分型。我们的具体目标是：1）通过SQTL（Suppressor of Quantitative Trait Loci）和缺失作图来定位畸形眼的多态性，以验证畸形眼在复制系中出现不同遗传结构的想法。2)克隆畸形眼多态性的野生型等位基因作为性状突变的抑制因子，以确定隐藏的多态性是否存在于Hsp90靶基因或影响较小的外周基因中。3)确定发育过程和途径，负责畸形眼的病理，使热休克蛋白90缓冲变异到生物学背景。我们希望这项研究将确定保守的热休克蛋白90的目标途径和扩展网络的自然多态性基因，影响他们的功能。