DNA History

Answer: James Watson, Francis Crick and Maurice Wilkins
The Double Helix structure of DNA is one of the most significant discoveries of all time. James Watson, Francis Crick and Maurice Wilkins received a Nobel Prize for the Double Helix model of DNA in 1962 ! Another important figure, without whom this discovery would not have been possible was Rosalind Elsie Franklin. Unfortunately, Franklin died at the age of 37 from Ovarian Cancer just four years before the Nobel prize was awarded to Watson, Cricks and Wilkins.It is a tremendous shame that Franklin did not receive due credit for her essential role in this discovery, either during her lifetime or after her untimely death...

On July 5, 1996, Dolly (a sheep), the first organism ever to be cloned from adult cells, was born. Earlier, clones of other organisms such as cows and frogs had been created from early embryo cells and not adult cells.

In 1949, Erwin Chargaff, a biochemist, reported that the amount of DNA and its nitrogenous bases varies from one species to another. He also found that the amount of adenine equals the amount of thymine, and the amount of guanine equals the amount of cytosine in DNA from every species !

In 1944, Oswald Avery, and his colleagues Maclyn McCarty and Colin MacLeod identified the transforming agent in Griffith's experiment as DNA.

Dr Walter Gilbert of Harvard University and Frederick Sanger developed a method for decoding DNA. This technique sparked off the biotech revolution because it enabled researchers to begin cloning genes.

This famous breakthrough resulted from an experiment carried out by Franklin Griffith in 1928. He discovered that genetic information can be transferred from heat-killed bacteria cells to live ones.

The experiment performed by Meselson and Stahl is sometimes referred to as "The most beautiful experiment in biology." The experiment showed that DNA replication is semi-conservative.

In 1972, Paul Berg combined the DNA of two different organisms, thus creating the first recombinant DNA molecules. He developed a technique for splitting DNA molecules at selected sites, attaching segments of the molecule to the DNA of a virus, and then introducing it into bacterial cells. The foreign DNA was incorporated by the host, which then produced proteins not usually found in the host. This joining of two pieces of DNA from different species is called recombinant DNA. The process is a cornerstone of genetic engineering. He won a Nobel Prize for his work in 1980.

The Human Genome project revealed that humans have approximately 35000 genes which is lower than expected. Even an insect as simple as the fruitfly has as many as 20000 genes.

In 1968, Robert Holley, Har Gobind Khorana, and Marshall Nirenberg shared the Nobel prize in medicine for the elucidation of the process of protein synthesis. They also discovered which amino acids are designated by each of the three letter codes. They also determined that the translation of the code was universal amongst different organisms.