TABLE OF CONTENTS In order to assess fully the potential adverse health effects of chronic and subchronic exposure to synthetic and natural chemicals and their complex mixtures, a more comprehensive understanding of the molecular, cellular, and tissue-level effects of these compounds is required within the context of the whole organism. Toxicogenomics is an emerging interdisciplinary field that incorporates -Omic technologies into toxicology with the goal of furthering the elucidation of mechanisms of toxicity. The omic technologies have evolved into three disciplines: genomics is the study of genes and their function, proteomics is the study of the levels and states of proteins found in a cell, and metabonomics is the study of metabolite levels in biological fluids as they change in the cell, tissue, or organism. Traditional toxicological studies have generally focused on selected aspects of toxicity and response ( i.e. expression-level change of one gene). By contrast, toxicogenomics attempts systematic integration and comprehensive assessment of data across all levels of biological organization with the aim of producing a complete picture of the molecular, cellular, and physiological basis of toxicity and associated disease.
Microarray technology was the first technology to emerge in the field of toxicogenomics. It permitted profiling of gene expression levels following exposure to a toxicant. Gene expression profiling may be better referred to as transcriptomics , since it is simply the study of the mRNA transcript levels within a cell or tissue.
The use of microarrays is based on the...
