Characterization and genetic analysis of aging in Daphnia

描述（由申请人提供）：本项目将开发微甲壳类水蚤作为衰老生物学的模型系统。水蚤是淡水微甲壳动物，通过循环单性生殖繁殖，使实验室研究人员能够轻松产生数千个基因相同的个体。生物人口统计学和生理学方法量化的遗传变异的寿命和老化率将结合分析全基因组基因表达和发展的转基因个体。其目标是建立一个模型系统，其中关于老龄化的信息可以从分子，细胞，生理和人口统计学的方法进行整合，并放置在已知的生态压力施加在老龄化和对可用资源的反应的背景下。拟议的工作包括A）TCO中衰老的表征，其整个基因组已被测序的蚤状蚤克隆，B）来自该领域的新分离物的遗传多样性集合中衰老的表征，C）TCO克隆和新分离物中对饮食限制的响应的表征，D）应用全基因组微阵列技术来量化TCO和新分离物中基因表达的年龄依赖性的全局模式，E）研究由饮食限制诱导的年龄依赖性基因表达变化的规模和模式，F）鉴定具有年龄依赖性调节或其表达预测寿命的新基因和途径，G）开发用于活水蚤的遗传转化的技术，H）参与已知调节饮食限制对衰老的影响的途径的关键基因的过表达，和I）在关键基因已经过表达的水蚤克隆中观察衰老和对饮食限制的反应。 公共卫生相关性：衰老是随着个人年龄的增长，身体机能逐渐衰退。开发新的模式生物来了解衰老的生物学，可以更广泛地了解遗传机制和潜在干预措施的后果，如饮食限制，减少衰老的负面影响。在这项工作中，一个新的模式生物，水蚤，是通过识别不同的衰老速率的遗传变异，识别基因与年龄相关的表达，并确定关键基因对衰老过程的影响。

DESCRIPTION (provided by applicant): This project will develop the microcrustacean Daphnia as a model system for the biology of aging. Daphnia are freshwater microcrustaceans that reproduce through cyclic parthenogenesis, allowing laboratory investigators to generate thousands of genetically identical individuals easily. Biodemographic and physiological methods for quantifying genetic variation of lifespan and rates of aging will be coupled with analyses of genome-wide gene expression and the development of transgenic individuals. The goal is to establish a model system where information on aging can be integrated from molecular, cellular, physiological and demographic approaches and placed in the context of known ecological pressures exerted on aging and on the response to available resources. The proposed work includes A) characterization of aging in TCO, the Daphnia pulex clone whose entire genome has been sequenced, B) characterization of aging in a genetically diverse collection of new isolates from the field, C) characterization of the response to dietary restriction in the TCO clone and new isolates, D) application of whole-genome microarray technology to quantify global patterns of age-dependency in gene expression in TCO and new isolates, E) investigation of the scale and pattern of changes in age-dependent gene expression induced by dietary restriction, F) identification of novel genes and pathways with age- dependent regulation or whose expression is predictive of lifespan, G) development of a technique for heritable transformation of live Daphnia, H) overexpression of key genes involved in pathways known to regulate the effects of dietary restriction on aging, and I) observation of aging and response to dietary restriction in Daphnia clones where key genes have been overexpressed. PUBLIC HEALTH RELEVANCE: Aging is the progressive decline of bodily faculties as individuals grow older. The development of new model organisms to understand the biology of aging allows for a broader understanding of the genetic mechanisms and consequences of potential interventions, such as dietary restriction, that reduce the negative effects of aging. In this work, a new model organism, Daphnia, is developed through the identification of genetic variants with different rates of aging, identification of genes with age-dependent expression, and determination of the effects of key genes on aging processes.