ANALYSIS OF GENE EXPRESSION IN AGING DROSOPHILA

细胞水平的衰老反映了基因表达的变化，因此可以在模式生物中进行遗传解剖。 一次一个基因的衰老分析涉及几个途径，包括中枢代谢，自由基积累和胰岛素功能调节寿命，但排除了对衰老的全基因组反应的综合理解。 微阵列基因表达成像技术与果蝇遗传学的力量相结合，为研究环境和遗传因素如何通过对基因活性的影响来影响衰老速率提供了一个很好的机会。 将5000个成体表达的序列标签排列在载玻片上，并与用两种不同的荧光染料标记的信使RNA制备物对杂交，所述荧光染料分离自处于不同衰老阶段的果蝇。 在多达150个计划的对比中比较5000个基因中的每一个的转录物的相对水平将允许确定伴随功能性衰老的基因表达变化的频率、幅度和身份。 这个为期一年的试点项目的目的是建立一个新的研究工具，用于衰老遗传学的研究，具体而言，通过满足四个目标：（一）确定重复处理中果蝇（Drosophila melanogaster）整个基因组中表达水平差异的来源和幅度;（二）描述基因表达随年龄变化的性二态性程度;（iii）开始研究环境变量如温度和生殖行为对衰老果蝇基因表达的影响;以及（iv）对寿命相似和不同的品系之间的基因型差异的影响进行初步分析。 这些实验的设计具有将微阵列研究与衰老的定量遗传分析相结合的长期目标，这将允许实验解剖响应于不同环境或遗传扰动的基因组表达的相关变化的原因。 将与北卡罗来纳州州立大学的生物统计学家建立合作关系，利用这一模型系统开发适当的协议，用于处理通过强大的微阵列技术获得的大量数据集的重要性问题。

Senescence at the cellular level reflects changes in gene expression, and is thus amenable to genetic dissection in model organisms. Analysis of senescence one gene at a time has implicated several pathways including central metabolism, free radical accumulation, and insulin function in modulation of longevity, but precluded the development of an integrated understanding of the genome-wide response to aging. The combination of microarray gene expression imaging technology with the power of Drosophila genetics presents a great opportunity for studying how environmental and genetic factors affect rates of senescence through their effects on gene activity. 5000 adult expressed sequence tags will be arrayed on glass slides and hybridized to pairs of messenger RNA preparations labeled with two different fluorescent dyes isolated from flies at various stages of senescence. Comparison of the relative levels of transcript for each of the 5000 genes in up to 150 planned contrasts will allow determination of the frequency, magnitude, and identity of changes in gene expression that accompany functional senescence. The aim of this one year pilot project is to establish a new research tool for research on the genetics of aging, specifically by meeting four objectives: (i) defining the sources and magnitude of the variance in expression levels throughout the genome of the fruitfly, Drosophila melanogaster in replicate treatments; (ii) characterizing the extent of sexual dimorphism in change in gene expression with age; (iii) beginning to study the effects of environmental variables such as temperature and reproductive behavior on gene expression in aging flies; and (iv) conducting a preliminary analysis of the effect of genotypic differences between lines with similar and divergent longevities. The experiments have been designed with the long term objective of integration of microarray studies with quantitative genetic analysis of aging that will allow experimental dissection of the causes of correlated changes in expression of suites of genes in response to different environmental or genetic perturbations. Collaborations will be established with biostatisticians at North Carolina State University to use this model system to develop appropriate protocols for dealing with significance issues in enormous data sets that are being obtained with powerful microarray technology.