ABSTRACT
Functional genomics, in its classical definition, is the highthroughput technology-based clarification of gene functions and
interactions using “dynamic aspects” such as gene transcription, translation, and protein-protein interaction.2-4 More recently, metabolomics, the systematic and exhaustive profiling of metabolites involving multiple disciplines, is becoming a very important tool in functional genomics for elucidating genetic and cellular functions.5 Most scientists believe that the integrative experimental approach, combining different “omics” fields (genomics, transcriptomics, proteomics, metabolomics), is the best approach for comprehensive understanding of gene functions.6 However, this same approach is sometimes a limiting factor for the full potential of metabolomics and inasmuch as the metabolome is considered as a result of the execution of the genetic information, metabolomics is deemed an important tool for characterizing phenotypes. In fact, this premise has been demonstrated in discriminating silent mutants through the use of metabolic fingerprinting and footprinting.7,8 These results show that metabolomics can distinguish very similar phenotypes with very high resolution. Metabolic profiling can also discriminate between normal and abnormal cells for finding disease-related biomarkers.9-11 As machines and equipment for acquiring metabolic information become more advanced and complex, the metabolic data obtained become more comprehensive, thus leading to more accurate explanation of biological functions. Recently, Yoshida and colleagues1 have developed an entirely different approach in utilizing metabolomics for characterization of phenotypes. In this study, quantitative changes in replicative lifespan were assessed in yeast strains using metabolic profiles acquired from GC/MS and CE/MS data (Figure 7.1). In this chapter, the use of metabolomics for the discrimination of quantitative changes and systematic prediction of a quantitative phenotype (longevity in Saccharomyces cerevisiae) is described.
