Gene function

Identifying the function of a gene

Often the same methods used to find genes also serve to identify their function. For example, by "knocking out" or silencing a gene, its function may be obvious, provided that the knock-out phenotype is not lethal.

An example of how knock-outs are being used to help identify gene function is in the Arabidopsis 2010 project (see http://www.arabidopsis.org/ ).

The first knockout mice were produced by Mario R. Capecchi, Martin Evans and Oliver Smithies in 1987-1989, for which they were awarded the Nobel Prize for Medicine in 2007

However, this approach often doesn't work, because of genetic redundancy (gene duplication), the effect of which is that silencing a gene does not produce any visible phenotypic change. The RNAi technique can mitigate this problem, because it simultaneously silences all genes which share the transgenic RNA sequence.

 

Wild-type Arabidopsis (l) and with the MPK4 gene (involved in pathogen resistance) knocked-out (r).