The Discovery Of The Structure Of DNA

James Watson and Francis Crick discovered the structure of DNA, but only by drawing on the work of many scientists who came before them. (Maddox, 2003) In 1944, Oswald T. Avery, Colin M. MacLeod, and Maclyn McCarty published “Studies on the Chemical Nature of the Substance Inducing Transformation of Pneumococcal Types”, which was the first scientific work to identify DNA as the molecule that carried genetic information, and became a breakthrough at that time. (Avery, Macleod, & McCarty, 1944) Before Avery and coworkers published their paper, there was very little interest in DNA among scientists in the field of genetics. Very little was known about DNA, however, early analyses suggested that it was a very simple molecule, at least in terms of its chemical composition. This view was best embodied by the so-called “tetranucleotide hypothesis”, which held that DNA was composed of equal amounts of four nucleotides, adenine, guanine, thymine, and cytosine. (Fredholm, 2003) DNA was thought to be “too simple” as a molecule to carry so much genetic information. Instead, there was much interest in proteins as the chemical identity of genes, which was understandable in light of the tetranucleotide hypothesis. In contrast to the supposed simplicity of DNA, proteins, composed of varying amounts of 20 amino acids, appeared to possess the chemical diversity required to function as genes.

Avery et al. made a remarkable contribution by investigating a process called transformation. In simple terms, transformation is a process through which cells undergo a genetic change following the uptake of foreign DNA. This information was not known prior to the work of Avery and coworkers. Transformation was originally discovered by Robert Griffi...

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...eta. Before Watson and Crick. Retrieved July 23, 2011, from PBS Online : http://www.pbs.org/wgbh/nova/evolution/before-watson-crick.html

Francis Crick and James Watson are recognized as the main scientists involved in the identification of DNA and its structure, which is one of the most important discoveries of the twentieth century. However, were it not for Rosalind Franklin, Linus Pauling, Colin Avery and Maurice Wilkins, the two men would likely not have made the discovery following the critical events that preceded their work.

McCarty, M. (2003, January). Genome.gov. Discovering Genes are made of DNA. Retrieved July 23, 2011, from Genome.gov website: www.genome.gov/10001772

The Human Genome Project (HGP) has served to explore our genetic environment to make us aware of the beneficial resources that might contribute to understanding and improving our lives.