Advances in Genome Engineering Approaches

Targeted genome editing is essential for functional characterization of a gene of interest. Targeted gene inactivation via homologous recombination made it feasible to create gene knockout animal models to ascertain the physiological role of the target genes; however, lower efficiency of site specific insertion of the genetically modified construct through homologous recombination has limited a wider applicability of this approach. Development of targeted gene knockdown through RNA interferce (RNAi) offered a cost effective, high-throughput alternative to homologous recombination, however, RNAi-mediated gene knockdown is incomplete, produces experiment to experiment variation, and could provide only a temporary inhibition of the gene function. Development of genome engineering methodologies utilizing nucleases linked to the guide sequences targeting a gene of interest, such as Zinc Finger Nucleases (ZFN), Transcription Activator like Effector Nucleases (TALEN) and Clustered Palindromic Repeats (CRISPR), are quite encouraging. A brief overview of recent advances in genome engineering approaches is provided with their respective advantages and limitations.