ABSTRACT
With recent increased interests in systems biology, a number of analytical approaches have been developed to globally profile a tier of organization in a cell, tissue, or organism. Genomics, the first of the ‘‘-omic’’ technologies to embrace global analysis, describes the genes present in an organism. This approach is notably compared with other -omic approaches in that it is not context dependent, with a genome not being directly influenced by the environment. Large-scale genome projects are now being complemented by other -omic strategies, including transcriptomics, proteomics, and metabolomics or metabonomics to profile all the mRNA, proteins, or small molecule metabolites in a tissue, cell, or organism. One of the major challenges of these ‘‘-omic’’ technologies is that the transcriptome, proteome, and metabolome are all context dependent and will vary with pathology, development stage, and environmental factors. Thus, the possibility of globally profiling the transcriptome, proteome, or metabolome of an organism is a real analytical challenge, because by definition these efforts must also take into consideration all factors that influence metabolism. However, one major advantage that metabonomics has over the other ‘‘-omic’’ approaches is that the analytical approaches are relatively cheap on a per sample basis, suggesting that databases which embrace both environmental and genomic influences on the metabolism of a given cell, tissue, organ, or even organism may be possible.
