ABSTRACT
Over the past few years, medical researchers have witnessed the latest in a
series of technical innovations, which affects both our approach to and the
scope of our work. Such innovations have routinely occurred every 10 to 20 years over the past half-century, beginning with the identification of nucleic
acid as the material storing the genetic code, to the advent of molecular
cloning, the discovery of the polymerase chain reaction (PCR), and, most
recently, the capability of rapidly creating genetically modified animals (in
contrast to the slow process of breeding). The latest innovation, which began
with the Human Genome Project, has provided us with the tools to observe
cells and tissues as a sum of their parts, rather than individual genes or
proteins. This is quite a change for a classically reductionistic discipline. Functional genomics is the practice of assigning biological function to
novel genes without previously described functions, as well as assigning
additional function(s) to genes with previously known function, utilizing
genomics-based information. That such an endeavor is a reality is due to the availability of complete genetic sequence information for dozens of organ-
isms in combination with the ability to rapidly and simultaneously measure
the expression of every gene in almost any given cell or tissue. Technologies
have been developed, which allow the rapid sequencing of entire genomes
(genomics) and parallel measurement of gene expression at the mRNA
(transcriptomics) or protein (proteomics) level. These technologies are
widely available at a reasonable cost and are, for the most part, highly accu-
rate. The focus of this chapter will be the application of DNA microarray technology to both more fully characterize and accelerate our understand-
ing of the pathogenesis of lung disease, most notably asthma and chronic
obstructive pulmonary disease (COPD).
