August 30, 2007

The Unsung Hero (ine) of Genetics

photo of Rosalind FranklinWe all credit Watson and Crick for their discovery that the DNA molecule was arranged in a double helix pattern. But how many of us know about this charming and intelligent lady, Rosalind Franklin, who made their discoveries much easier, by 'providing' them with the distinctive diffraction X-ray photograph, termed 'Photograph 51'?

Working in scientific arena was traditionally a man's domain then, and women were frowned upon. Naturally, as expected, she also had been subject to much harassment by her male colleagues. At the same time, she also used to make fun of her male colleagues.

While working on Signer DNA (DNA molecules, extracted from the thymus gland of calf; used for their distinctive X-ray diffraction pattern ), at King's College, London, she found out that there were two forms of DNA; a 'wet' form (B-DNA), that was longer and a 'dry' form, that was shorter. They continued with working on the wet forms.

Watson and Crick were also behind the same trail of determining the nature of DNA, but they were far behind any possible breakthrough. They did not even know about Chargaff's Rule, that stated that for every Adenine molecule, there was an equal number of Thymine molecule, and the number of Cytosine molecules were equal to that of the Guanine molecule (A=T, G=C). By sheer luck, Watson chanced upon Photograph 51 (picture shown here), 9 months after it was kept in a vault by Rosalind. He was quick enough to deduce the 'double helical' structure by intuition and reasoning. The 'x' like speckled banding had enough tell-tale signs.
Photograph 51
Watson, Crick and Wilkins were awarded the Nobel Prize in Physiology or Medicine, in 1962, for their discovery about nucleic acids (not exclusively for DNA). Rosalind was long dead by then. She died of ovarian carcinoma in 1958, possibly due to extreme radiation exposure. It is also true that some of her own family members also died of cancer and that cancer incidences were particularly high in Ashkenazi Jews, which she was. Whatever the cause of her death were, the contribution she made toward the understanding of DNA structure, have certainly paved the way for modern genetics. In our minds, she will continue to dwell forever.
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