14.4: Functional Genomics – Determining Function(s)

Having identified putative genes within a genome sequence, how do we determine their function? Techniques of functional genomics are an experimental approach to address this question. One widely used technique in functional genomics is called microarray analysis (Figure \(\PageIndex{1}\)). Microarrays can measure the abundance of mRNA for hundreds or thousands of genes at once. The abundance of mRNA of a particular gene is usually correlated with the activity of that gene. For example, genes that are involved in neuronal development likely produce more mRNA in brain tissue than in heart tissue. We can therefore learn about the relationship between particular genes and particular processes by comparing transcript abundance under different conditions. This can identify tissue specific expression (e.g. the nerve/heart example above), as well as differences in temporal expression (development), or exposure to external agents (eg, disease, hormones, drugs, etc.).