Functional genomics enables the discovery of gene function and involvement in biochemical, cellular, and physiological pathways. The availability of complete genome sequences, combined with readily programmable tools to modify the genome, allows these analyses to be performed on a genome-wide scale. The basic aim of a genomic screen is to understand the emergence of a specific phenotype by modifying gene function in a targeted, purposeful manner. When individual genes are deleted or modulated in a cell or organism, changes in phenotype or behavior can be directly or indirectly observed through carefully planned experiments. Functional genomics screening allows this analysis to be performed in a systematic and parallelized manner, elucidating intricate pathways and disease states and facilitating novel drug target identification.
There are two fundamental ways that functional genomics can link genetics to phenotype. Forward genetic screening involves modifying many genes, selecting for the cells or organisms with the phenotype of interest, and then identifying the genes whose modulation triggered the phenotypic change. Reverse genetic screening analyzes the phenotype of cells or organisms following the disruption of a specific gene or combination of genes.
Advances in gene editing, gene silencing, gene modulation, next generation sequencing (NGS), and phenotypic screening technologies enable efficient execution of functional genomic screens in a wide variety of model systems.