A Day in History… February 28 — Watson & Crick: Discover DNA Structure

Feb 28

Edited by Gerald Boerner

Commentary:

Science is on a continuing quest to explain the mechanisms that make the the world run. This applies to both the physical and biological worlds. One of these quest was successfully explained in the the mid-20th century at Cambridge University in England. Two researchers, James Watson and Francis Crick, who were trying to understand how genetic information was was transferred from parents to their offspring. They knew that DNA was involved, but the mechanism by which it was accomplished.

Using data from X-ray defraction studies of isolated strands of this DNA in the labs at King’s College, London, to develop a model of this complex molecule. The breakthrough came when they hypothesized a pair of helix structures that combined via some definable chemical bonds. The resulting double helix structure enabled biologists to explain how genetic material from each parent could recombine to reproduce to yield a range of physical characteristics.

I remember being assigned to read a number of books during my first semester in graduate school. One of the books was Watson’s “The Double Helix” the followed this discovery. It was fascinating reading! In 1962, Watson, Crick, and Wilkins received the Nobel Prize for Physiology and Medicine for this discovery of the Double Helix; another collaborator, Rosalind Franklin, would have been a party of this award if she were still alive. This is but one of the findings that makes the history of science so fascinating.

But, now is the time to move on to the exploration of today’s topic… GLB

These Introductory Comments are copyrighted:
Copyright©2011 — Gerald Boerner — All Rights Reserved

[ 4117 Words ]

Quotations Related to DNA:

“If you can write DNA, you’re no longer limited to ‘what is’ but to what you could make.”
— Drew Endy

“The O.J. Simpson case, they had no understanding of that DNA evidence, and didn’t want to.”
— Joseph Wambaugh

“It was very interesting for me because DNA made music without much technical knowledge at all.”
— Arto Lindsay

“He told me that Francis Crick and Jim Watson had solved the structure of DNA, so we decided to go across to Cambridge to see it. This was in April of 1953.”
— Sydney Brenner

“Diversity has been written into the DNA of American life; any institution that lacks a rainbow array has come to seem diminished, if not diseased.”
— Joe Klein

“I met with my lawyers. They gave me all the wrong advice. For a long time I refused to accept the child was mine. I should have met her, arranged a DNA test and accepted my responsibility.”
— Boris Becker

“In the transmission of human culture, people always attempt to replicate, to pass on to the next generation the skills and values of the parents, but the attempt always fails because cultural transmission is geared to learning, not DNA.”
— Gregory Bateson

“Moreover, the concern of some that moving DNA among species would breach customary breeding barriers and have profound effects on natural evolutionary processes has substantially disappeared as the science revealed that such exchanges occur in nature.”
— Paul Berg

Watson & Crick: Discovering DNA’s Double Helix Structure

In molecular biology, the term double helix refers to the structure formed by double-stranded molecules of nucleic acids such as DNA and RNA. The double helical structure of a nucleic acid complex arises as a consequence of its secondary structure, and is a fundamental component in determining its tertiary structure. The term entered popular culture with the publication in 1968 of The Double Helix: A Personal Account of the Discovery of the Structure of DNA, by James Watson.

The DNA double helix is a spiral polymer of nucleic acids, held together by nucleotides which base pair together. In B-DNA, the most common double helical structure, the double helix is right-handed with about 10–10.5 nucleotides per turn. The double helix structure of DNA contains a major groove and minor groove, the major groove being wider than the minor groove. Given the difference in widths of the major groove and minor groove, many proteins which bind to DNA do so through the wider major groove.

DNA consists of two long polymers of simple units called nucleotides, with backbones made of sugars and phosphate groups joined by ester bonds. These two strands run in opposite directions to each other and are therefore anti-parallel. Attached to each sugar is one of four types of molecules called bases. It is the sequence of these four bases along the backbone that encodes information. This information is read using the genetic code, which specifies the sequence of the amino acids within proteins. The code is read by copying stretches of DNA into the related nucleic acid RNA, in a process called transcription.

The Autobiographical Account of this Discovery: The Book

The Double Helix: A Personal Account of the Discovery of the Structure of DNA is an autobiographical account of the discovery of the double helix structure of DNA written by James D. Watson and published in 1968. It was and remains a controversial account. Though it was originally slated to be published by Harvard University Press, Watson’s home university dropped the arrangement after protestations from Francis Crick and Maurice Wilkins, co-discoverers of the structure of DNA, and it was published privately. It has been criticized as being excessively sexist towards Rosalind Franklin, another participant in the discovery, who was deceased by the time Watson’s book was written. In 1998, the Modern Library placed The Double Helix at number 7 on its list of the 20th century’s best works of non-fiction.

The intimate first-person account of scientific discovery was unusual for its time. The book has been hailed as a highly personal view of scientific work, with its author seemingly caring only about the glory of priority and willing to appropriate data from others surreptitiously in order to obtain it. A 1980 Norton Critical Edition of The Double Helix edited by Gunther Stent, analyzed the events surrounding its initial publication. It presents a selection of both positive and negative reviews of the book, by such figures as Philip Morrison, Richard Lewontin, Alex Comfort, Jacob Bronowski, and more in-depth analyses by Peter Medawar, Robert K. Merton, and Andre Lwoff. Erwin Chargaff declined permission to reprint his unsympathetic review from the March 29, 1968 issue of Science, but letters in response from Max Perutz, Maurice Wilkins, and Watson are printed. Also included are retrospectives from a 1974 edition of Nature written by Francis Crick and Linus Pauling, and an analysis of Franklin’s work by her student Aaron Klug. The Norton edition concludes with the 1953 papers on DNA structure as published in Nature.

The book was made into a film dramatization as The Race for the Double Helix in 1987.

Other criticism

The booked leaned heavily on personalities, and some, like Rosalind Franklin, were treated cartoonishly.
— Burton Feldman

In the book Rosalind Franklin and DNA, author Anne Sayre is very critical of Watson’s account. She claims that Watson’s book did not give a balanced description of Rosalind Franklin and the nature of her interactions with Maurice Wilkins at King’s College, London. Sayre’s book raises doubts about the ethics of how Watson and Crick used some of Franklin’s results and whether adequate credit was given to her. Watson had very limited contact with Franklin during the time she worked on DNA. By providing more information about Franklin’s life than was included in Watson’s book, it was possible for Sayre to provide a different perspective on the role Franklin played in Watson and Crick’s discovery of the double helix structure of DNA. (See: King’s College (London) DNA Controversy)

In the book’s preface, Watson explains that he is describing his impressions at the time of the events, and not at the time he wrote the book. In the epilogue Watson writes; Since my initial impressions about [Franklin], both scientific and personal (as recorded in the early pages of this book) were often wrong I want to say something here about her achievements. He goes on to describe her superb work, and, despite this, the enormous barriers she faced as a woman in the field of science. He also acknowledged that it took years to overcome their bickering before appreciating Franklin’s generosity and integrity.

The Quest for Understanding: Discovering the Double Helix

Watson and Crick deduced the double helix structure of DNA. Sir Lawrence Bragg, the director of the Cavendish Laboratory (where Watson and Crick worked), made the original announcement of the discovery at a Solvay conference on proteins in Belgium on April 8, 1953; it went unreported by the press. Watson and Crick submitted a paper to the scientific journal Nature, which was published on April 25, 1953. This has been described by some other biologists and Nobel laureates as the most important scientific discovery of the 20th century. Bragg gave a talk at the Guys Hospital Medical School in London on Thursday, May 14, 1953, which resulted in an article by Ritchie Calder in the newspaper The News Chronicle of London, on May 15, 1953, entitled "Why You Are You. Nearer Secret of Life." The news reached readers of The New York Times the next day. Victor K. McElheny, in researching his biography, "Watson and DNA: Making a Scientific Revolution", found a clipping of a six-paragraph New York Times article written from London and dated May 16, 1953, with the headline "Form of ‘Life Unit’ in Cell Is Scanned." The article ran in an early edition and was then pulled to make space for news deemed more important. (The New York Times subsequently ran a longer article on June 12, 1953). The Cambridge University undergraduate newspaper Varsity also ran its own short article on the discovery on Saturday, May 30, 1953.

Watson subsequently presented a paper on the double helical structure of DNA at the 18th Cold Spring Harbor Symposium on Viruses in early June 1953, six weeks after the publication of the Watson & Crick paper in Nature. Many at the meeting had not yet heard of the discovery. The 1953 Cold Harbor Symposium was the first opportunity for many to see the model of the DNA Double Helix. Watson claimed that he was refused a $1,000 raise in salary after winning the Nobel Prize. Watson, Crick, and Wilkins were awarded the Nobel Prize in Physiology or Medicine in 1962 for their research on the structure of nucleic acids.

At Harvard University, starting in 1956, Watson achieved a series of academic promotions from Assistant Professor, to Associate Professor to full Professor of Biology. He championed a switch in focus for the school from classical biology to molecular biology, stating that disciplines such as ecology, developmental biology, taxonomy, physiology, etc. had stagnated and could only progress once the underlying disciplines of molecular biology and biochemistry had elucidated their underpinnings, going so far as to discourage their study by students. He left the school in 1976.

In 1968, Watson became the Director of the Cold Spring Harbor Laboratory. Between 1970 and 1972, the Watsons’ two sons were born, and by 1974 the young family made Cold Springs Harbor their permanent residence. Watson served as the Laboratory’s Director and president for about 35 years, and later he assumed the role of Chancellor. In October 2007, Watson resigned as a result of controversial remark about race made to the press. Watson has one son who has schizophrenia. In a retrospective summary of his accomplishments there, Bruce Stillman, the laboratory’s president said, "Jim Watson created a research environment that is unparalleled in the world of science." It was "under his direction [that the Lab has] made major contributions to understanding the genetic basis of cancer."

Generally in his roles as Director, President, and Chancellor, Watson led CSHL to its present day mission, which is "dedicat[ion] to exploring molecular biology and genetics in order to advance the understanding and ability to diagnose and treat cancers, neurological diseases, and other causes of human suffering." In October 2007, Watson was suspended following criticism of views on race and intelligence attributed to him, and a week later, on the 25th, he retired at the age of 79 from Cold Spring Harbor Laboratory from what the lab called "nearly 40 years of distinguished service", In a statement, Watson attributed his retirement to his age, and circumstances that he could never have anticipated or desired.

In January 2007, Watson accepted the invitation of Leonor Beleza, president of the Champalimaud Foundation, to become the head of the foundation’s scientific council, an advisory organ. He will be in charge of selecting the remaining council members.

Watson was also a former adviser for the Allen Institute for Brain Science. The Allen Institute, located in Seattle, Washington, was founded in 2003 by Philanthropists Paul G. Allen and Jody Allen as a 501(c)(3) nonprofit corporation medical research organization. A multidisciplinary group of neuroscientists, molecular biologists, informaticists, engineers, mathematicians, statisticians, and computational biologists were brought together to form the scientific core of the Allen Institute. Utilizing the mouse model system, these fields have joined together to investigate expression of 20,000 genes in the adult mouse brain and to map gene expression to a cellular level beyond neuroanatomic boundaries. The data generated from this joint effort is contained in the publicly available Allen Mouse Brain Atlas application located at www.brain-map.org. Upon completion of the Allen Mouse Brain Atlas, this consortium of scientists will pursue additional questions to further our understanding of neuronal circuitry and the neuroanatomic framework that defines the functionality of the brain.

Contributors to the Discovery of DNA’s Double Helix

James Dewey Watson (born: 1928) is an American molecular biologist, geneticist, and zoologist, best known as one of the co-discoverers of the structure of DNA with Francis Crick, in 1953. Watson, Francis Crick, and Maurice Wilkins were awarded the 1962 Nobel Prize in Physiology or Medicine "for their discoveries concerning the molecular structure of nucleic acids and its significance for information transfer in living material". He studied at the University of Chicago and Indiana University and subsequently worked at the University of Cambridge’s Cavendish Laboratory in England, where he first met his future collaborator and personal friend Francis Crick.

In 1956, Watson became a junior member of Harvard University’s Biological Laboratories, holding this position until 1976, promoting research in molecular biology. Between 1988 and 1992, Watson was associated with the National Institutes of Health, helping to establish the Human Genome Project. Watson has written many science books, including the seminal textbook The Molecular Biology of the Gene (1965) and his bestselling book The Double Helix (1968) about the DNA structure discovery.

From 1968 he served as director of Cold Spring Harbor Laboratory (CSHL) on Long Island, New York, greatly expanding its level of funding and research. At CSHL, he shifted his research emphasis to the study of cancer. In 1994, he became its president for ten years, and then subsequently he served as its chancellor until 2007, when he resigned, due to a controversy over comments he made claiming black Africans were on average less intelligent than whites during an interview.

Francis Harry Compton Crick OM FRS (1916 – 2004) was an English molecular biologist, biophysicist, and neuroscientist, and most noted for being one of two co-discoverers of the structure of the DNA molecule in 1953, together with James D. Watson. He, Watson and Maurice Wilkins were jointly awarded the 1962 Nobel Prize for Physiology or Medicine "for their discoveries concerning the molecular structure of nucleic acids and its significance for information transfer in living material".

Crick was an important theoretical molecular biologist and played a crucial role in research related to revealing the genetic code. He is widely known for use of the term “central dogma” to summarize an idea that genetic information flow in cells is essentially one-way, from DNA to RNA to protein.

During the remainder of his career, he held the post of J.W. Kieckhefer Distinguished Research Professor at the Salk Institute for Biological Studies in La Jolla, California. His later research centered on theoretical neurobiology and attempts to advance the scientific study of human consciousness. He remained in this post until his death; "he was editing a manuscript on his death bed, a scientist until the bitter end" said Christof Koch.

Maurice Hugh Frederick Wilkins CBE FRS (1916 – 2004) was a New Zealand-born English physicist and molecular biologist, and Nobel Laureate whose research contributed to the scientific understanding of phosphorescence, isotope separation, optical microscopy and X-ray diffraction, and to the development of radar. He is best known for his work at King’s College London on the structure of DNA. In recognition of this work, he, Francis Crick and James Watson were awarded the 1962 Nobel Prize for Physiology or Medicine, "for their discoveries concerning the molecular structure of nucleic acids and its significance for information transfer in living material." His obituary provides extensive information on the topics mentioned here.

At that time Wilkins also introduced Francis Crick to the importance of DNA. Wilkins knew that proper experiments on the threads of purified DNA would require better x-ray equipment. Wilkins ordered a new x-ray tube and a new microcamera. Before the DNA sample from Signer was available, Gosling had been trying to make x-ray diffraction images of sperm. However, Franklin did not start using the new equipment until September 1951. By the summer of 1950 Randall had arranged for a three year research fellowship that would fund Rosalind Franklin in his laboratory. Franklin was delayed in finishing her work in Paris. Late in 1950, Randall wrote to Franklin to inform her that rather than work on protein, she should take advantage of Wilkins’s preliminary work and that she should do x-ray studies of DNA fibers made from Signer’s samples of DNA.

Early in 1951 Franklin finally arrived. Wilkins was away on holiday and missed an initial meeting at which Raymond Gosling stood in for him along with Alex Stokes, who, like Crick, would solve the basic mathematics that make possible a general theory of how helical structures diffract x-rays. No work had been done on DNA in the laboratory for several months; the new x-ray tube sat unused, waiting for Franklin. Franklin ended up with the DNA from Signer, Gosling became her PhD student, and she had the expectation that DNA x-ray diffraction work was her project. Wilkins returned to the laboratory expecting that Franklin would be his collaborator and that they would work together on the DNA project that he had started. Franklin felt that DNA was now her project and would not collaborate with Wilkins, who then pursued parallel studies.

Rosalind Elsie Franklin (1920 – 1958) was a British biophysicist who was trained as a chemist and specialized in X-ray crystallography, She made important contributions to the scientific understanding of the molecular structures of coal and graphite and, using X-ray diffraction, DNA, RNA and viruses. The DNA work achieved the most fame because DNA (deoxyribonucleic acid) plays essential roles in cell metabolism and genetics and the discovery of its structure helped scientists understand how genetic information is passed from parents to children.

By using a technique called X-ray diffraction, Franklin obtained results which led to the realization that a DNA molecule consists of an intertwined double helix of atoms. An X-ray diffraction experiment directs a beam of X-rays through a sample of a substance onto a screen. A pattern of spots is formed. This is recorded, and used to calculate the arrangement of atoms in the sample. Franklin worked on DNA in the Medical Research Council Biophysics Unit at King’s College, London, using her expertise in dealing with amorphous materials.

Franklin’s role in the discovery of the structure of DNA remains controversial. She recorded a photograph of a DNA molecule that her supervisor, Maurice Wilkins, showed to James Watson and Francis Crick without her knowledge or permission. This image helped Watson and Crick construct a model of DNA, which enabled them to fully understand the molecule’s structure. Wilkins, Crick and Watson were awarded a Nobel Prize jointly, some years later, after Franklin’s death. Hostility between Franklin and her colleagues is a matter of record. There has been extensive comment in biographical works and other publications that her work did not bring adequate recognition during her lifetime. Some claim this was due to prejudice. The arguments have focused on details that include the restriction of the Senior Common Room at King’s College to men, cultural differences between a rich, cosmopolitan sophisticate and boisterous British ex-sevicemen ("macho rowdies") and Watson’s reference to Franklin as "Rosie" and his comments on her appearance in his memoir The Double Helix, which he wrote on his return to Harvard from Cambridge.

Franklin died at the age of 37 from complications arising from ovarian cancer. Several major institutions and awards have been named in her memory.

Raymond Gosling (born: 1926) is a distinguished scientist who worked with both Maurice Wilkins and Rosalind Franklin at King’s College London in deducing the structure of DNA, under the direction of Sir John Randall. His other KCL colleagues included Alex Stokes and Herbert Wilson.

Work at King’s and DNA

At King’s College London, Gosling worked on X-ray diffraction with Maurice Wilkins, analyzing samples of DNA which they prepared by hydrating and drawing out into thin filaments and photographing in a hydrogen atmosphere.

Gosling was then assigned to Rosalind Franklin when she joined King’s College London in 1951. Together they produced the first X-ray diffraction photographs of the "form B" paracrystalline arrays of highly hydrated DNA. She was his academic supervisor. During the next two years, the pair worked closely together to perfect the technique of x-ray diffraction photography of DNA and obtained at the time the sharpest diffraction images of DNA. This work led directly to the 1962 Nobel Prize for Physiology or Medicine being awarded to Francis Crick, James D. Watson and Maurice Wilkins. Gosling was the co-author with Franklin of one of the three papers published in "Nature" in April 1953.

Gosling briefly remained at King’s College London following the completion of his thesis in 1954 before lecturing in physics at Queen’s College, University of St Andrews, and at the University of the West Indies

Please take time to further explore more about THE DOUBLE HELIX (BOOK),
DOUBLE HELIX, DNA (DEOXYRIBONUCLEIC ACID), JAMES D. WATSON,
FRANCIS CRICK, MAURICE WILKINS, ROSALIND FRANKLIN, and
RAYMOND GOSLING by accessing the Wikipedia articles
referenced below…

References

Other Events on this Day:

In 1827…
The Baltimore and Ohio Railroad, the first commercial railroad in the United States to carry passengers and freight, is incorporated.

In 1849…
The steamship California, carrying gold-seekers, arrives in San Francisco from New York, marking the beginning of regular steamboat travel between the East and West Coasts.

In 1854…
Opponents of slavery meet in Ripon, Wisconsin, and agree to form a new political group, which later becomes the Republican Party.

In 1932…
The last Ford Model A (the successor to the Model T) rolls off the factory line.

In 1933…
Four days before his inauguration as president, Franklin D. Roosevelt announces the appointment of Frances Perkins as secretary of labor. Perkins will become the first female member of a presidential Cabinet.

In 1953…
Scientists James D. Watson and Francis H.C. Crick discover the double-helix structure of the human genetic molecule deoxyribonucleic acid, better known as DNA, at Cambridge University in England. Along with Maurice Wilkins, Watson and Crick will be awarded the 1962 Nobel Prize in Physiology or Medicine for their work on nucleic acids.

In 1969…
Airman First Class John Levitow was recovery from shrapnel wounds suffered when he protected his eight companions from a magnesium flare in the Helicopter.

In 1983…
Set in the waning days of the Korean War, “Goodbye, Farewell and Amen,” the final episode of the sitcom M*A*S*H, airs after 11 seasons. Nearly 106 million American television viewers watch the finale, a record finally surpassed more than a quarter century later by the two most recent Super Bowls.

Dates and events based on:

William J. Bennett and John Cribb, (2008) The American Patriot’s Almanac Daily Readings on America. (Kindle Edition)

Background information is from Wikipedia articles on:

Wikipedia: The Double Helix (Book)…
http://en.wikipedia.org/wiki/The_Double_Helix

Wikipedia: Double Helix…
http://en.wikipedia.org/wiki/Double_helix

Wikipedia: DNA (Deoxyribonucleic Acid)…
http://en.wikipedia.org/wiki/DNA

Wikipedia: James D. Watson…
http://en.wikipedia.org/wiki/James_D._Watson

Wikipedia: Francis Crick…
http://en.wikipedia.org/wiki/Francis_Crick

Wikipedia: Maurice Wilkins…
http://en.wikipedia.org/wiki/Maurice_Wilkins

Wikipedia: Rosalind Franklin…
http://en.wikipedia.org/wiki/Rosalind_Franklin

Wikipedia: Raymond Gosling…
http://en.wikipedia.org/wiki/Raymond_Gosling

Brainy Quote: DNA Quotes…
http://www.brainyquote.com/quotes/keywords/dna.html

Other Posts on related Topics:

Prof. Boerner’s Exploration: Edwin H. Armstrong Patents FM Radio in 1933…
http://www.boerner.net/jboerner/?p=15993

Prof. Boerner’s Exploration: Philo Farnsworth: Inventor of the Television…
http://www.boerner.net/jboerner/?p=14256