The transgenic animals are those animals in which the genetic arrangements are changed by insertion of foreign genes, the produced modified animals are called transgenic animals and process is known as transgenesis. The transgenic effectiveness and precise regulation of gene expression are the significant limiting factors in the production of transgenic animals. Transgenesis may involve whole organisms, rather than individual cells and there may be in vivo alteration of body function. There are many methods used for the production of transgenic animals such as DNA microinjection, embryonic stem cell-mediated gene transfer, gene knock out method, retrovirus-mediated gene transfer and Somatic Cell Nuclear Transfer. The transgenic animals have numerous applications in scientific biological models, animals improving Livestock, Research, Disease Models of Alzheimer's Mouse, Huntington's Mouse, Xeno-transplanters, Recombinant therapeutic proteins, Blood substitutes, Antibodies and transgenic animals, Carcass composition and growth enhancement, in the aquaculture industries, Production of pharmaceuticals in transgenic animals. Many technical methods have been used for the detection of transgenic products such as southern blotting technique, northern blotting, quantitative Real-Time reverse transcriptase polymerase chain reaction, western blotting, enzyme linked immunoabsorbent assays and green fluorescent protein. The transgenic animals show both negative and positive impacts in the modern era of the biological science.
