ADVANCEMENTS IN THE PRODUCTION AND APPLICATIONS OF TRANSGENIC ANIMALS: A MODERN REVIEW

In genetic engineering, a transgenic animal possesses foreign DNA that has been intentionally introduced into its genome. We discuss cloning vectors which are used to genetically modify animals by introducing a short DNA fragment containing foreign desired DNA, which duplicates itself and then transferred into the other organism. Various types of vectors are plasmid vectors, cosmid vectors, bacteriophage, yeast artificial chromosomes, bacterial artificial chromosomes, and human artificial chromosomes. Different gene insertion techniques to insert the vector carrying the desired gene into the host cell including heat shock, electroporation, gene gun, microinjection, and liposomes have been discussed. We have compiled a list of numerous transgenic technologies and methodologies which includes transgenesis through the gonads such as sperm-mediated gene transfers and fertilised egg that is done by DNA microinjection, retrovirus-mediated gene transfers and more advanced techniques like cre-lox technique, viral vector, cytoplasmic injection, primordial germ cells, Spermatogonia manipulation. The general role of transgenic animals like rats, fish, cattle, and monkeys has also been mentioned. These genetically fabricated animals have an immense impact on human health and recombinant therapeutic application. This review focuses on various methods of transgenesis and their applications such as recombinant therapeutic protein, medical application, xenotransplantation, and human gene therapy.
Key words: genetic engineering, transgenic animals, restriction enzymes, vectors.