Discovery of DNA Structure: Jubilee Science

It’s the Queen’s Platinum Jubilee and we’re doing our bit here on the programme to mark the occasion by selecting some of the standout scientific highlights that have happened during the last seven decades. To kick us off, all of us are the products of the genes we inherit from our parents. They are written into the molecules of DNA - millions of miles of it - packed inside almost all of our cells. DNA is life’s recipe book, so understanding it marks one of the biggest breakthroughs in biology. It’s a British achievement that’s changed the world and one of the first scientific highlights of the Queen’s reign. Chris Smith tells the story…

In 1953, not long after Queen Elizabeth II came to the throne, two scientists walked into a bustling Cambridge pub and announced, over a beer, that they "had discovered the secret of life". That pub - the Eagle - now has a brass plate documenting the occasion and the place where Francis Crick and James Watson made that pronouncement not long after Noon on February 28th.

Although many present at the time probably dismissed it as mere braggadocio, it really was a turning point for biology. What the duo had discovered was the structure of the DNA molecule that's present in the heart - or nucleus - of most of the cells in most living things.

Assisted by x-ray images of DNA, crystals prepared by Rosalind Franklin, Watson and Crick worked out what DNA was made of and how it fitted together. It consists of two strings of letters, one the mirror image of the other, and both twisting together into a long helix.

There are four letters or bases in the DNA, alphabet dubbed A, C, T, and G, And the order of those letters spells out words that we call "genes". These are the master recipes of all of the chemicals, molecules, and structures that an organism uses to operate. And, incredibly, the same code works in all living things, whether it's a bacterium, a banana or a person. So a gene from a jellyfish can be added to a human cell and it will make it glow green, just like it did in its original owner. And that is why Watson and Creek claimed, quite rightly, to have found the secret of life over their lunchtime pint back in 1953.

Since then, the world of molecular biology has exploded. Just in time for her Majesty's Golden Jubilee, back in 2002, a team at the UK Sanger Centre, together with US researchers, announced they had decoded the 3 billion genetic letters in the human genome.

In the years since, techniques have become even more powerful. Millions of COVID tests being done every day during the pandemic used the PCR technique to look for genetic signatures of the coronavirus to make those diagnoses. The process of DNA fingerprinting means we can reunite long lost relatives, absolve people of crimes they didn't commit, and catch the criminals who did do it.

Now, 70 years since Watson and Crick made their announcement, we're using that same science they unlocked to edit DNA, cure diseases, and even make tomatoes containing extra Vitamin D as we heard last week. I wonder if they saw that coming all those decades ago?