Gene transfer is to transfer a gene from one DNA molecule to another DNA molecule. Gene transfer represents a relatively new possibility for the treatment of rare genetic disorders and common multifactorial diseases by changing the expression of a person's genes. In 1928, Griffith reported that a nonpathogenic pneumoccocus strain could become pathogenic when it was mixed with cells of heat-killed pathogenic pneumoccocus, which suggested that the pathogenic genetic material could be transformed from the heat-killed pathogenic pneumoccocus to the nonpathogenic strain (Griffith, 1928). This is the first report for gene transfer observation. However, the transforming substance was not identified in these experiments. Up to 1944, Avery et al demonstrated that deoxyribonucleic acid (DNA) was the transforming substance (Avery, 1944). In 1952, Hershey and Chase showed that DNA was the only material transferred during bacteriophage infection, which suggested that the DNA is the genetic material (Hershey, 1952). The basic technique for introducing DNA into E. coli have inspired procedures for the introduction of DNA into cells from a wide variety of organisms, including mammalian …show more content…
During the 1970s it became possible to introduce exogenous DNA constructs into higher eukaryotic cells in vitro. Mammalian (germline) trans genesis was first achieved in the early 1980s. The model used in this study was mice. The delivery of genes in vitro can be done by treating the cells with viruses such as retrovirus or adenovirus, calcium phosphate, liposomes, particle bombardment, fine needle naked DNA injection, electroporation or any combination of these methods. These are the powerful tools for research and have possible applications in gene therapy. A number of valuable techniques used to transfer genes in animals and plants cells and their scope and contributions are explained