Today marks 65 years since two Cambridge University scientists unveiled their momentous discovery of ‘DNA’ – since described as ‘the building block of life’.
Francis Crick and James Watson outlined their remarkable work in an article published in ‘Nature’ magazine on April 25th, 1953. It described the structure of a chemical called ‘deoxyribonucleic acid’, or DNA for short.
In simplistic terms, DNA is the material which makes up genes, which in turn pass on hereditary characteristics from parents to their children, grandchildren and so on. A man might look like his great-great-grandfather because they share the same DNA profile.
As well as writing their article, Crick and Watson built a scale model to demonstrate the structure of DNA. It consists of a ‘double helix’ of two strands of coiled around each other, somewhat resembling a ladder which has been twisted many times. The strands are made up of complementary elements which can fit together and, when uncoiled, can produce two copies of the original. In other words, DNA can accurately self-replicate, making it the fundamental unit by which organisms, not just human ones, produce the next generation.
The two scientists had been ‘sitting on’ their discovery for some weeks, awaiting the publication of their article and others by colleagues in the Nature journal. Almost two months earlier, on February 28th, they had walked into a Cambridge pub to celebrate the fact they had unravelled the structure of DNA, leading Crick to announce: “We have discovered the secret of life!” Some might have scoffed at such a bold statement, but it was nothing short of the truth.
They were not the only scientists working on DNA. In London, Maurice Wilkins and Rosalind Franklin, working for the Medical Research Council, had used X-rays to isolate and photograph DNA and produce other crucial evidence. Their work was also in the series of five articles published together in ‘Nature’, but it was Crick and Watson who put the pieces together and managed to unravel the mystery.
They would be awarded the Nobel Prize for their work in 1962 and their rudimentary model of a section of DNA, built from laboratory clamps and pieces of metal, is now in the Science Museum in London. Watson also published a popular account of their discovery in 1968, his book “The Double Helix” becoming a bestseller both inside and outside the scientific community.
The discovery of DNA opened the door for countless other studies and paved the way for many of the powerful and sometimes controversial technologies now in widespread use, including genetic engineering, cloning and stem cell research. It has also enabled DNA profiling and ‘fingerprinting’, providing vital evidence in countless criminal cases, including previously unsolved ‘cold cases’.
Watson later helped launch the ‘Human Genome Project’, a huge international research project which seeks to understand the meaning of the ‘life code’ contained in the DNA molecule. Scientists investigating inherited genetic conditions also seek to isolate ‘mistakes’ in DNA structure which, if corrected, could prevent the condition being passed on to future generations.
The consequences of Crick and Watson’s discovery have been far-reaching and their announcement 65 years ago today is still sparking new research and scientific and medical discoveries. The 50th anniversary, in 2003, was marked by the establishment in the UK of National DNA Day, which since 2012 has become International DNA Day.