Advances in transgene delivery for the generation of transgenic livestock

The emergence of transgenic livestock technology revolutionizing the course of biological research offers a direct approach for improving the quality (e.g., milk quality) and efficiency (e.g., growth) of livestock production, developing disease-resistant livestock and for providing a system for generating pharmaceuticals or nutraceutical recombinant proteins and xenotransplantation products. In transgenic animal production, efficient gene delivery into target cells is critical. Pronuclear microinjection and somatic cell nuclear transfer are the most widely used transgene delivery methods for producing transgenic livestock. However, due to the poor effectiveness of these methods, the progress of transgenesis in livestock species for agricultural use has been modest and has remained confined. The sperm-mediated gene transfer (SMGT) method, targeting male germ cells, is a more straightforward and relatively inexpensive strategy for altering the genome of animals. To improve the efficacy of gene delivery using sperm, viral and nonviral vectors are frequently utilized. The nonviral transgene delivery systems involve the utilization of liposomes, electroporation, calcium phosphate, DMSO, and linkers (receptors). Although nanoparticles are yet to be extensively exploited for gene delivery in transgenic animal production, magnetic and silver nanoparticles have been used to deliver transgenes to livestock. The current advancement in genome editing technologies along with gene delivery techniques is expected to bring the desired success in producing agriculturally important and commercially viable transgenic livestock.