Antoine Boutros - Experiments aiming at identifying the structure of DNA caught the attention of a young American scientist, by the name of James Watson, who had just graduated from Indiana University and was willing to share in the effort of exploring this mysterious realm. Meantime, another British scientist named Crick Francis was taking a similar step while preparing his thesis in Cambridge University. None of the two was prepared to embark on this mission that defied great scientists like Linus Pauling, the most influential chemist of the century, especially that Watson had problems in Chemistry, Crystallography and Mathematics while Crick was ignorant in genetic matters.

But after only two years of joint efforts within Cambridge, the two young scientists fulfilled their dream of formulating a theory of the structure of the DNA. Their achievement was greeted with total approval since it was able to answer all the questions arose as to this discovery and to comply with the laws of science and chemistry pertaining to the molecule.

Their findings suggested that the DNA does not resemble one braided rope as commonly believed, but rather made up of two strands entwined in a spiral form that gives a shape of a double helix. This helix may open in a zipper-like manner breaking the two strands or braids. Each braid will then constitute a new base-pair strand which will be replicated over again, in the same manner, passing genetic instruction from one cell to another. The couple also noticed that information that reaches the proteins, carrying instructions for building life, cannot be transferred back and consequently cannot get out of it, and that proteins get transformed without altering information they carry.

Crick called this mechanism the Central Dogma which was pretty similar to theological doctrines that refused all kinds of interpretations. This excessive self-esteem lead Crick to rush out of his laboratory and head to a neighboring bar, right beside the university, to declare to the scientists having their break there, that he and Watson had discovered the secret of life, as he put it.

American scientist Barbara McClintock had been conducting similar experiments for several decades and she was awarded a Nobel Price in 1983 for all the ways she paved and the windows she opened. Barbara McClintock provided counter evidence to the common theory holding that the flow of genetic information is exclusively one way and proved that information may be transferred from the protein to the DNA.

How did Watson and Crick make this discovery?

By going through Thomas Pauling’s findings, Watson and Crick concluded that the long and complicated strand of DNA suggested a double spiral form, while Wilkins’ crystallography images allowed them to obtain unpublished information on the DNA structure. Thus, the two scientists made full use of the previous efforts and findings without even asking the permission for it or conducting any personal research, and managed, thanks to their sharp and powerful analytical skills and wide imagination, to discover what the others failed to see.

Had the two scientists delayed a little, a Cambridge scientist called Rosalinda Franklin, could have outraced them to the same results thanks to her personal efforts and independent research. As a matter of fact, Franklin was the one who offered Watson and Crick the evidence they needed to reach their conclusions, and the technical facilities she provided in terms of molecule x-rays allowed the world to form a new theory which shed light on the capabilities of genetic engineering and the understanding of the living material.

However, she dropped her researches, as soon as Watson and Crick revealed the results of their findings, and shifted to another study which focused on the analysis of tobacco virus.

In 1962, a Nobel Prize was awarded to seven scientists for their research on molecular Biology. Among these were Watson, Crick and Rosalinda who unfortunately passed away before receiving the honors which her efforts deserve.

In his book “The Double Helix” published in 1968, Watson revealed with an unusual honesty the mysteries behind the DNA discovery and described the internal scientific climate which is fraught with skirmishes, academic rivalry, and fraud in order to obtain the biggest award which all scientists dream of.

While the secret of the DNA took half a century to unravel, it took another century to test and confirm the discovery.

Scientist Arthur Kornberg from Stanford University did it all in 1967, 102 years after the experiment of Miecher (please refer to last issue), and he was able to form a one-braided artificial DNA in a test tube and to examine its replication.

The evidence proving that the DNA is indeed the genetic material that carries genetic information and passes from one cell to another, will be addressed in the next issue.