Transgene

A transgene is a gene that has been introduced into the genome of an organism from an external source. In genetic engineering, a transgene typically includes a coding sequence along with regulatory elements that enable expression in the recipient, and it may originate from the same species or a different one. The term emphasizes the presence of the foreign genetic material within the host’s genome, as opposed to native genes.

Transgenes are usually delivered using vectors or delivery methods that promote integration into the host genome or, in some cases, transient expression. Common methods include plasmid or viral vectors, Agrobacterium-mediated transfer in plants, particle bombardment, and various transfection or infection techniques. A transgene is often accompanied by regulatory sequences such as promoters, enhancers, and terminators, and may include selectable markers to identify successful integration. Expression can be stable (heritable) or temporary, depending on the approach and the host system.

Applications of transgenes span agriculture, medicine, and research. Transgenic crops may carry traits such as pest resistance, herbicide tolerance, or enhanced nutritional content. Transgenic animals and microorganisms can produce therapeutic proteins or serve as models for human diseases. In medicine, gene therapy aims to deliver transgenes to patient cells to treat genetic disorders or other diseases, using viral or non-viral delivery systems. Researchers use transgenic organisms to study gene function and biology.

Safety, ethics, and regulation are central considerations. Potential environmental impacts, gene flow to wild relatives, and long-term effects are evaluated by regulatory authorities in many jurisdictions, with guidelines varying by country.