Introduction – A Historical OverviewThe history of rDNA technology dates back to 1865 when Gregor Mendel, using pea, demonstrated and proved some of the fundamental laws of genetics such as 1) Law of segregation, 2) Law of independent assortment and 3) Law of dominance. Mendel laid the foundation of genetics on which experiments were carried out in subsequent years. Later in 1915, TH Morgan established the fact that the chromosome contains genes and that these genes are linked by inheritance using Drosophila as a model organism. In 1928, Frederick Griffith observed the transformation of "rough" colonies of Streptococcus pnuemoniae into "smooth" colonies, which meant that at this time, certain information was transmitted to the non-virulent strain to make it virulent. The famous "One gene, one enzyme" hypothesis was put forward by Beadle and Tatum in 1941. In 1944, Avery, MacLeod and McCarty purified DNA and proved that they carried genetic information, until that the protein is considered the transporter. Even before the structure was elucidated, in 1947, Erwin Chargoff postulated certain rules that DNA follows. Hershey and Chase conducted a series of experiments in 1952 to prove that DNA is the genetic material. DNA was crystallized and its helical nature was discovered by X-ray crystallography by Franklin and Wilkins in 1953 and it was the same year that the 3D structure of DNA was solved by James Watson and Francis Crick. The latter proposed the "central dogma of life", in which DNA produces mRNA and protein is synthesized from mRNA by transcription and translation respectively. While Watson and Crick alluded to a semi-conservative model of DNA replication, it was Meselson and Stahl who, in 1958, proved that the rep... middle of article... hyperacute organ rejection genetic. » Proceedings of the National Academy of Sciences 91.23 (1994): 11153-11157.2. Holton, TA and MW Graham. “A simple and efficient method for direct cloning of PCR products using ddT-tailed vectors.” Joseph A., et al. “Human growth hormone: cloning and complementary expression of DNA in bacteria.” » Science 205.4406 (1979): 602-607.4. “First fruit: the creation of the Flavr Savr tomato and the birth of biotechnological foods. " (2002). 5. Schnieke, Angelika E., et al. "Human factor IX transgenic sheep produced by nuclear transfer from transfected fetal fibroblasts. ., et al. “Cytoplasmic inclusion bodies in Escherichia coli producing biosynthetic human insulin proteins." 215.4533 (1982): 687-689.