CRISPR-Cas9 in the Tailoring of Genetically Engineered Animals

Abstract

CRISPR-Cas9 enables targeted genome editing and has become a pivotal tool in biomedical research and animal genome engineering. This review highlights its application in generating genetically modified animals used as preclinical disease models, bioreactors for recombinant protein production, and potential sources of xenotransplantation organs. We also discuss its role in improving livestock traits, welfare, and breeding efficiency. The benefits and limitations of CRISPR-Cas9 are examined, emphasizing its transformative potential in research and agricultural biotechnology.

Keywords: CRISPR-Cas9; genetically engineered animals; genome editing; model organisms; xenotransplantation.

Figure 1

The CRISPR-Cas9 system, highlighting its key components and mode of action. The Cas9 nuclease is guided by a single-guide RNA (sgRNA), which combines CRISPR RNA (crRNA) and trans-activating CRISPR RNA (tracrRNA), to a complementary genomic DNA sequence adjacent to a protospacer adjacent motif (PAM). The Cas9 protein introduces a double-strand break via its two nuclease domains: the histidine–asparagine–histidine endonuclease domain (HNH), which cleaves the DNA strand complementary to the sgRNA, and the RuvC domain, which cleaves the non-complementary strand. This site-specific cleavage underpins the use of CRISPR-Cas9 in precise genome editing applications. Figure created with elements from BioIcons (CC 0) and Servier Medical Art (CC 3.0).

Figure 2

Key applications of genome editing technologies in animals across biomedical and agricultural fields. In preclinical research, genetically modified models facilitate the study of human diseases and accelerate therapeutic testing. In xenotransplantation, genome editing reduces the zoonotic risk and immunogenicity, improving organ compatibility. Recombinant protein production in animals enables the low-cost and efficient synthesis of therapeutic proteins with reduced immunoreactivity. In the livestock sector, genetic modifications enhance animal health, increase muscle mass, reduce fat content, and improve the nutritional value of animal products. These applications highlight the broad utility of CRISPR-Cas9-based genome editing in advancing biomedicine and agriculture. Figure created with BioIcons (CC 0) and NIAID BioArt (Public Domain).