Gene Editing Techniques
There are a number of recognised gene editing methods. Editing the genome can be achieved using engineered nucleases such as
For the most part, gene editing companies can separate genome modifications into one of two experimental categories:
■Loss of function - functional forms of the genome are removed from the system and the effect studied
■Gain of function - active (often mutant) forms of the genome are introduced into the system and the effect studied
Up until recently most loss and gain of function analyses was performed using RNAi and transgenesis respectively - both enormously powerful techniques, but they do have limitations.
Transgene overexpression can lead to artefacts that are a consequence of that overexpression - and this is especially true in the case of oncogenes, where their over-abundance can lead to transformative effects that would not normally be seen in a physiological system.
■Large growth induction phenotype
■Milder growth induction phenotype
Overexpression of oncogenes can over represent their role in disease biology.
Genome editing allows scientists to perform the same types of loss and gain of function experiments, but manipulate genes of interest at the endogenous level. So for loss of function, the gene can be rendered non-functional or completely removed from the system. For gain of function, mutations or reporter tags can be expressed from the promoter of the gene itself.