Britannica Sources used in this answer

How can gene editing correct genetic errors in laboratory animals?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

CRISPR-Cas9; gene editing — gene editing The CRISPR-Cas9 gene-editing complex from the bacterium *Streptococcus pyogenes*.

Gene editing corrects genetic errors in laboratory animals by utilizing precise molecular tools to modify specific DNA sequences. Technologies such as CRISPR-Cas9 allow researchers to target and create double-stranded breaks in the DNA at exact locations within the genome.12

Once a break is introduced, the cell’s natural repair mechanisms can be directed to replace a defective or "bad" sequence with a "good" template sequence, effectively correcting the mutation. In laboratory settings, these tools have been injected into the bloodstream of animals to achieve gene editing in specific tissues or applied to early embryos to generate modified organisms. By successfully repairing genetic errors, researchers can achieve the clinical rescue of diseased animals, providing a vital platform for studying human disorders and developing potential gene therapy applications.21

While homologous recombination is also used to study gene function by "knocking out" specific genes, modern gene-editing technologies offer greater precision for directly correcting the underlying genetic mistakes associated with disease.234