Watson and Crick
Who Were Watson and Crick?
The names of scientists James Watson and Francis Crick come up almost any time someone discusses the early days of DNA science. Their discovery of the structure of the DNA double helix in 1953 is one of the greatest scientific discoveries of modern times. Though Watson and Crick relied on the work of others rather than conducting their own extensive research, they were the first to publish a paper on the double helix structure of DNA. And in 1962, they were awarded a Nobel Prize for this groundbreaking discovery.
Before James Watson and Francis Crick
The discovery made by James Watson and Francis Crick was made possible by the work of many scientists who came before them. In the late 19th and early 20th centuries, scientists slowly began to unravel the mystery of how genetic information is transmitted. While extracting the proteins from white blood cells in 1869, Swiss chemist Friedrich Miescher found a phosphorus-containing substance much different from a protein, which he called a nuclein. It was later known as nucleic acid.
By studying yeast, Russian biochemist Phoebus Leven proposed in 1919 that nucleic acids were molecules made of sugar, phosphate, and four nitrogenous bases — adenine, guanine, cytosine, and thymine. By 1944, Oswald Avery, Colin MacLeod, and Maclyn McCarty at Rockefeller Institute in New York showed that DNA was the substance that passed along the genetic information necessary for bacterial transformation—not proteins as others had previously assumed.
Then in 1950 Columbia University professor Erwin Chargaff published a paper showing that in every type of DNA he tested, the amount of adenine (A) equaled the amount of thymine (T), and the amount of guanine (G) equaled the amount of cytosine (C), hinting that the bases were paired. Finally, in 1951, Linus Pauling, Robert Corey, and Herman Branson published a pivotal paper describing the alpha helix structure common in proteins.
Watson and Crick: A Lucky Partnership
It was that same year of 1951 that 23-year-old James Watson, who'd received his PhD in Zoology from Indiana University, met 35-year-old Francis Crick, a Cambridge University doctoral student who had recently switched paths from physics to molecular biology. The two bonded over their fascination with DNA and Linus Pauling's work. As they were racing against other teams working to determine the structure of DNA—including Pauling at Caltech and the Kings College London team of Maurice Wilkins and Rosalind Franklin—their advantage was how well they complemented each other.
Watson and Crick did no experiments of their own. Rather they studied the work of others and discussed it for hours on end in their office at Cambridge University and the nearby pub, the Eagle. They also benefited greatly from conversations with their peers, such as Maurice Wilkins and Rosalind Franklin.
The Double Helix
At last Watson and Crick worked out how DNA had two sugar phosphate backbones connected by the nitrogenous base pairs of A-T and C-G. The two connected strands are antiparallel, meaning that if you were to split them apart and flip one upside down, the sugar phosphate backbone of one strand would look identical to the other. This antiparallel structure makes DNA more stable. Watson and Crick published their findings in the journal Nature in April 1953. Watson, Crick, and Wilkins shared the Nobel Prize for this discovery in 1962. Franklin died of ovarian cancer in 1958 and was not included in the prize.
The Legacy of Watson and Crick's Discovery
Watson and Crick continued to collaborate for a few years on the molecular study of viruses. Crick went on to study how DNA actually directs the formation of proteins, and then studied neurobiology until his death in 2004. Watson returned to the United States and directed the Cold Spring Harbor Laboratory, where he studied molecular biology and cancer, until he retired in 2007. Today, scientists continue to build upon Watson and Crick's discovery, which gave rise to modern molecular biology and paved the way for modern-day applications that would surely amaze Watson and Crick.