Characterization and genetic analysis of aging in Daphnia

项目描述（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。水蚤是一种淡水微甲壳类动物，通过循环孤雌生殖进行繁殖，使实验室研究人员能够轻松地产生数千个基因相同的个体。生物人口学和生理学方法将与全基因组基因表达分析和转基因个体的开发相结合，用于量化寿命和衰老速度的遗传变异。目标是建立一个模型系统，在这个系统中，可以从分子、细胞、生理和人口统计学的方法中综合有关老龄化的信息，并将其置于已知的对老龄化和对现有资源的反应所施加的生态压力的背景下。建议的工作包括A) TCO的衰老特征，水蚤克隆的全基因组测序，B)从该领域获得的遗传多样性新分离物的衰老特征，C) TCO克隆和新分离物对饮食限制的反应特征，D)应用全基因组微阵列技术量化TCO和新分离物基因表达的年龄依赖性全球模式。E)研究饮食限制引起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可预测寿命的新基因和途径，G)开发活水蚤遗传转化技术，H)过度表达参与已知调节饮食限制对衰老影响的途径的关键基因，(1)观察关键基因过表达的水蚤克隆的衰老和对饮食限制的反应。

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.