The story of DNA and what it’s done for us
24/04/2013 - 10.42
Dr Michael Whitehead, MSc Course leader Forensic and Molecular Biology
Today we live in an era where knowledge about DNA (Deoxyribonucleic Acid) and our genetic code has a profound effect upon our society.
Why is this? Well, it may be through the capture and conviction of criminals based on DNA fingerprinting, for example, or by people surviving disease through genetic diagnosis and treatment.
It is therefore worth celebrating the 60th anniversary of the publication of James Watson and Francis Crick’s paper in which they describe the structure of DNA. The story of DNA goes back much further, however.
The first person to identify DNA was Friedrich Miescher, a German surgeon who obtained DNA (which he called nuclein) from bloody bandages in the 1870s. At the same time, luminaries such as Charles Darwin and Gregor Mendel were proposing the ideas of evolution, inheritance and genetics. This led to an important search - which substance within the body was the genetic material?
It was not until the 1930s and 40s that work by Fred Griffith and Oswald Avery showed that DNA was the genetic material that carried inherited information. It was in the 1950s that Crick and Watson started working together at Cambridge. Using experiments performed by Erwin Chargaff, Maurice Wilkins and Rosalind Franklin, Watson and Crick were able to deduce the famous Double Helix structure of DNA in a small, two page publication entitled “Molecular Structure of Nucleic Acids”, published on April 25, 1953.
Since that time we have seen an explosion in DNA research and what we have been able to understand about ourselves and all life on earth. This year also marks another important DNA anniversary, without which we would not be entering the genomics era. 2013 is the 20th anniversary of Kary Mullis being awarded the Nobel Prize in 1993 “for his invention of the Polymerase Chain Reaction (PCR) method.”
This test-tube based method meant tiny amounts of DNA could be turned into huge amounts of DNA very quickly; experiments which previously took months now take hours. This year is also the 10th anniversary of the publication of the complete Human Genome sequence (the letters A, G, C and T which encode the information providing a recipe for making each living thing).
In 1990 the Human Genome Project was started, to determine the entire DNA sequence of human beings. It took 13 years and cost nearly $3 billion. Today we can obtain the same sequence information from individual people in weeks, at the cost of a few thousand dollars. We can therefore find out about what susceptibility to diseases and cancers we have and how we respond to drug treatments.
Some of the information we may be afraid to learn, or it may prove essential to extend our lives. Either way, we are in the exciting time of Genomics and I’m sure discoveries over the next few years will present us with even more opportunities and challenges.