Information about transgenic organisms

Transgenic Organism, plant, animal, or bacteria that has been genetically modified to contain a gene from a different species. The new gene is inherited by offspring in the same way as the organism's own genes. The transgenic condition is achieved by injecting the foreign gene into the fertilized egg or into embryonic cells. The injected gene becomes part of the host cell's deoxyribonucleic acid (DNA) within the chromosome and is then inherited by all the …

…laboratory animals if the disease-associated gene occurs naturally in both humans and an appropriate study species, such as a mouse. In such human disorders, symptoms are caused by natural dysfunction of the gene. In the study animal the same gene can be deactivated or made dysfunctional, causing symptoms similar to those of the human disorder. Scrapie, a fatal disease of the brain in sheep and related to human Creutzfeldt-Jakob disease, has been studied this way.