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James D. Watson
James Dewey Watson (born April 6, 1928) is an American molecular biologist, best known as one of the co-discoverers of the structure of DNA. 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".[1] Additional recommended knowledge
Early lifeWatson was born in Chicago, Illinois, on April 6 1928, the son of a businessman, also named James Dewey Watson and Margaret Jean Mitchell [2]. His father was of midwestern English descent[3]. His mother's father Lauchlin Mitchell, a tailor, was from Glasgow, Scotland, and her mother, Lizzie Gleason, was the child of Irish parents from Tipperary[4]. Watson was fascinated with bird watching, a hobby he shared with his father.[5] At the age of 12, Watson starred on Quiz Kids, a popular radio show that challenged precocious youngsters to answer questions.[6] Thanks to the liberal policy of University president Robert Hutchins, he enrolled at the University of Chicago at the age of 15.[7] After reading Erwin Schrödinger's book What Is Life? in 1946, Watson changed his professional ambitions from the study of ornithology to genetics.[8] He earned his B.S. in Zoology from the University of Chicago in 1947. In his autobiography, Avoid Boring People, Watson describes the University of Chicago as an idyllic academic institution where he was instilled with the capacity for critical thought and an ethical compulsion not to suffer fools who impeded his search for truth, in contrast to his description of his later work at Harvard University.[9] He was attracted to the work of Salvador Luria. Luria eventually shared a Nobel Prize for his work on the Luria-Delbrück experiment, which concerned the nature of genetic mutations. Luria was part of a distributed group of researchers who were making use of the viruses that infect bacteria, called bacteriophages. Luria and Max Delbrück were among the leaders of this new "Phage Group", an important movement of geneticists from experimental systems such as Drosophila towards microbial genetics. Early in 1948 Watson began his Ph.D. research in Luria's laboratory at Indiana University and that spring he got to meet Delbrück in Luria's apartment and again that summer during Watson's first trip to the Cold Spring Harbor Laboratory (CSHL).[10] The Phage Group was the intellectual medium within which Watson became a working scientist. Importantly, the members of the Phage Group had a sense that they were on the path to discovering the physical nature of the gene. In 1949 Watson took a course with Felix Haurowitz that included the conventional view of that time: that proteins were genes and able to replicate themselves.[11] The other major molecular component of chromosomes, DNA, was thought by many to be a "stupid tetranucleotide", serving only a structural role to support the proteins. However, even at this early time, Watson, under the influence of the Phage Group, was aware of the work of Oswald Avery which suggested that DNA was the genetic molecule. Watson's research project involved using X-rays to inactivate bacterial viruses ("phage").[12] He gained his Ph.D. in Zoology at Indiana University in 1950. Watson then went to Copenhagen in September 1950 for a year of postdoctoral research, first heading to the laboratory of biochemist Herman Kalckar.[5] Kalckar was interested in the enzymatic synthesis of nucleic acids, and wanted to use phage as an experimental system. Watson, however, wanted to explore the structure of DNA, and his interests did not coincide with Kalckar's.[13] After working part of the year with Kalcker, Watson spent the remainder of his time in Copenhagen conducting experiments with microbial physiologist Ole Maaloe, then a member of the Phage Group.[14] The experiments, which Watson had learned of during the previous summer's Cold Spring Harbor phage conference, included the use of radioactive phosphate as a tracer to determine which molecular components of phage particles actually infect the target bacteria during viral infection.[13] The intention was to determine whether protein or DNA was the genetic material, but upon consultation with Max Delbrück,[13] they determined that their results were inconclusive and could not specifically identify the newly labeled molecules as DNA.[15] Watson never developed a constructive interaction with Kalckar, but he did accompany Kalckar to a meeting in Italy where Watson saw Maurice Wilkins talk about his X-ray diffraction data for DNA.[5] Watson was now certain that DNA had a definite molecular structure that could be solved.[16] In 1951 the chemist Linus Pauling published his model of the protein alpha helix, a result that grew out of Pauling's relentless efforts in X-ray crystallography and molecular model building. After obtaining some results from his phage and other experimental research conducted at Indiana University, Statens seruminstitute (Denmark), Cold Spring Harbor Laboratory, and the California Institute of Technology, Watson now had the desire to learn to perform X-ray diffraction experiments so that he could work to determine the structure of DNA. That summer, Luria met John Kendrew and arranged for a new postdoctoral research project for Watson in England.[5] In 1968, Watson married Elizabeth Lewis and became the Director of Cold Spring Harbor Laboratory. Between 1970 and 1972 Watson's two sons were born and by 1974 the young family made CSHL their permanent residence. Structure of DNA
In late 1951 Crick and Watson began a series of informal exchanges with Maurice Wilkins during which some of Rosalind Franklin's findings were given to Watson and Crick by Wilkins without Franklin's permission or knowledge. In November, Watson attended a seminar by Franklin. She spoke about the X-ray diffraction data she had collected with Raymond Gosling. The data indicated that DNA was a helix of some sort. Soon after this seminar, Watson and Crick constructed an incorrect molecular model of DNA in which the phosphate backbones were on the inside of the structure. Franklin asserted that the phosphates almost certainly were on the outside, not the inside. Watson and Crick eventually came to see that she was right and used this information in their final determination of the helical structure. In 1952, the final details of the chemical structure of the DNA backbone were determined by biochemists like Alexander Todd. During 1952, Crick and Watson had been asked not to work on making molecular models of the structure of DNA.[18] Instead, Watson's official assignment was to perform X-ray diffraction experiments on tobacco mosaic virus. Tobacco mosaic virus was the first virus to be identified (1886) and purified (1935). Since electron microscopy revealed that virus crystals form inside infected plants, it made sense to isolate this virus for study by X-ray crystallography. Early X-ray diffraction images for tobacco mosaic virus had been collected before World War II. By 1954, Watson had deduced from his X-ray diffraction images that the tobacco mosaic virus had a helical structure.[19] Despite his official assignment, the lure of solving the puzzle of DNA structure continued to tantalize Watson; with his friend Crick, he continued to think about how to determine the structure of DNA. In April 1952, Watson's PhD research adviser, Luria, was to speak at a meeting in England. However, Luria was not allowed to travel due to cold war fears over his Marxist leanings. Watson used Luria's speaking slot to talk about his own work with radioactive DNA and the results of others in the Phage Group that indicated the genetic material of phages was DNA. It has been recorded that during this meeting Watson was discussing with others prior discoveries by other researchers such as the calculated width of the B-form DNA molecule as determined by X-ray diffraction studies. By 1952 estimates from X-ray data and electron microscopy agreed that the diameter of DNA was about 2 nanometers. Watson and Crick benefited from two travel-related strokes of luck in 1952. First, Erwin Chargaff visited England in 1952 and inspired Watson and Crick to learn more about nucleotide biochemistry. There are four nucleobases: guanine (G), cytosine (C), adenine (A) and thymine (T) in DNA. The so-called Chargaff ratios experimental results indicated that the amount of G is equal to C and the amount of A is equal to T. Jerry Donohue explained to Watson and Crick the correct structures of the four bases. The second travel-related event was that Linus Pauling's plans to visit England were disrupted. His planned visit was canceled for political reasons and he never gained access to the King's College X-ray diffraction data for DNA until it was published in 1953. In 1953, Crick and Watson were given permission by their lab director and Wilkins to again try to make a structural model of DNA. At this time, Crick and Watson became aware of a research progress report containing some of Franklin's findings. This report contained the data that she had previously discussed in her research seminar of November 1951. Crick and Watson continued to make use of Franklin's results in their thinking about the structure of DNA. BreakthroughWatson's key contribution was in discovering the nucleotide base pairs, the key to the structure and function of DNA. This key discovery was made in the Pauling "tradition", by playing with molecular models. Since he would have to wait for the Cavendish machine shop to make tin models of the four nucleobases, Watson, on February 21, 1953 made a molecule model of each using a straight edge, an exacto knife, white cardboard and paste. These molecules are all flat in their ring structures, so Watson could slide the cardboard models around on a table and examine how they might interact and fit together. After looking at the possible arrangements of his cardboard molecule models, Watson soon realized that the larger two-ring A and G nucleobases (technically referred to as purines) could be paired with the smaller one-ring T and C nucleobases, known as pyrimidines. Watson examined the possibility of hydrogen bonds between the pairs of purines and pyrimidines. After moving the A and T molecules around on the table he sat at, he brought together the distal (relative to its five-member ring) nitrogen of the A and the correct nitrogen-based hydrogen of T. Fortunately, the A and T were lying on the table both "face up" in that they were in the orientation as they occur in DNA and Watson then noticed the possibility of the second hydrogen bond involving an oxygen atom. He quickly saw that the other pair, C's nitrogen and G's nitrogen-based hydrogen had a similar relationship and that those two molecules formed three such bonds. As the accompanying diagram indicates, all five hydrogens involved have a covalent bond to a nitrogen (which has no "double" bond) and form the weaker hydrogen bond with either a nitrogen or an oxygen that each have one double valence bond to a carbon atom. Watson then saw that the two pairs could be superimposed on each other with similar overall structure. In particular, the hexagonal rings were equidistant and the relative orientations of the five-member rings of the "big" molecules, A and G were the same. The nitrogens with the "squiggly" lines are the ones that attach, as "ladder rungs", to the helical backbone and that these nitrogen atoms are equidistant and also superimpose in the two pairs, allowing the helical structure to be smooth. Watson sensed that too many pieces were falling into place for this to be anything but the answer. He was correct. The base pairs discovered by Watson were consistent with the biochemical data Chargaff had already published. Nobel PrizeWatson and Crick proceeded to deduce the double helix structure of DNA which they submitted to the journal Nature and was subsequently published on April 25 1953.[20] Watson, Crick, and Wilkins were awarded the Nobel Prize in Physiology or Medicine in 1962 for their research on the structure of nucleic acids.[1] Some regret that Franklin did not live long enough to share in the Nobel Prize.[21] Watson mentions in his autobiography, Avoid Boring People, that he was refused a $1,000 raise in salary after winning the Nobel. [9] The Double HelixIn 1968 Watson wrote The Double Helix, one of the Modern Library's 100 best non-fiction books. The account is the sometimes painful story of not only the discovery of the structure of DNA, but the personalities, conflicts and controversy surrounding their work. Controversy attended the publication of the book. Harvard professor Richard Lewontin wrote that the book had "debased the currency of his [Watson's] own life", and molecular biologist Robert L. Sinsheimer described Watson's portrayal of science as a "clawing climb up a slippery slope, impeded by the authority of fools, to be made with cadged data ... with malice toward most, and charity toward none." [9] It was originally to be published by Harvard University Press, but after objections from both Francis Crick and Maurice Wilkins, among others, Watson's home university where he had been a member of the biology faculty since 1955, dropped the book and it was instead published by a commercial publisher, an incident which caused some scandal. Watson's original title was to have been "Honest Jim," in part to raise the ethical questions of bypassing Franklin to gain access to her X-ray diffraction data before they were published. Watson seems to have never been particularly bothered by the way things turned out. If all that mattered was beating Pauling to the structure of DNA, then Franklin's cautious approach to analysis of the X-ray data was simply an obstacle that Watson needed to run around. Wilkins and others were there at the right time to help Watson and Crick do so. The Double Helix changed the way the public viewed scientists and the way they work.[22] In the same way, Watson's first textbook, The Molecular Biology of the Gene, set a new standard for textbooks, particularly through the use of concept heads—brief declarative subheadings. Its style has been emulated by almost all succeeding textbooks. His next great success was Molecular Biology of the Cell, although here his role was more that of coordinator of an outstanding group of scientist-writers. His third textbook was Recombinant DNA, which used the ways in which genetic engineering has brought us so much new information about how organisms function. All the textbooks are still in print. Genome projectIn 1989, Watson's achievement and success led to his appointment as the Head of the Human Genome Project at the National Institutes of Health, a position he held until April 10, 1992.[23] Watson left the Genome Project after conflicts with the new NIH Director, Bernadine Healy. Watson was opposed to Healy's attempts to acquire patents on gene sequences, and any ownership of the "laws of nature." Two years before stepping down from the Genome Project, he had stated his opinion on this long and ongoing controversy which he saw as an illogical barrier to research; he said, "The nations of the world must see that the human genome belongs to the world's people, as opposed to its nations." He left within weeks of the 1992 announcement that the NIH would be applying for patents on brain-specific cDNAs.[24] In 1994, Watson became President of CSHL. Dr. Francis Collins took over the role as Director of the Human Genome Project. He became the second person [25] to publish his fully sequenced genome online, after it was presented to him on May 31, 2007 by 454 Life Sciences Corporation in collaboration with scientists at the Human Genome Sequencing Center, Baylor College of Medicine. "I am putting my genome sequence on line to encourage the development of an era of personalized medicine,[26] in which information contained our genomes can be used to identify and prevent disease and to create individualized medical therapies," said Watson.[27] Awards
PositionsHarvard University, 1956-1976Watson 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. [9] Cold Spring Harbor Laboratory, 1968-2007In a retrospective summary of Watson's accomplishments at CSHL, Laboratory President Dr. Bruce Stillman 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." On October 25, 2007, Watson retired at the age of 79 from Cold Spring Harbor Laboratory "after nearly 40 years of distinguished service."[34] In a statement, Watson attributed his retirement to his age, and circumstances that he could never have anticipated or desired.[35] Allen Institute for Brain ScienceDr. Watson is now the Institute advisor for the newly-formed Allen Institute for Brain Science. The Institute, located in Seattle, Washington, was founded in 2003 by Philanthropists Paul G. Allen and Jody Allen Patton as a nonprofit corporation (501(c) (3)) and medical research organization. A multidisciplinary group of neuroscientists, molecular biologists, informaticists, engineers, mathematicians, statisticians, and computational biologists have been 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 Brain Atlas application located at www.brain-map.org. Upon completion of the Allen 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. Champalimaud Foundation, 2007-PresentIn January 2007, Dr. 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.[36] Honorary Degrees Awarded(arranged chronologically)
Professional & Honorary Affiliations
Political activismDuring his tenure as a professor at Harvard, Watson participated in several political protests:
Controversies
Watson's sometimes abrasive and aggressive personality (once described by E. O. Wilson as "the most unpleasant human being I had ever met"[9]) has made him the subject of several controversies; the controversy over his book The Double Helix was merely one such example. In his autobiography, Avoid boring People, he describes his academic colleagues as "dinosaurs", "deadbeats", "fossils", "has-beens", "mediocre", and "vapid".[9] Use of King's College resultsAn enduring controversy has been generated by Watson and Crick's use of DNA X-ray diffraction data collected by Rosalind Franklin and Raymond Gosling. The controversy arose from the fact that some of Franklin's unpublished data was used by Watson and Crick in their construction of the double helix model of DNA.[18] Franklin's experimental results provided estimates of the water content of DNA crystals and these results were consistent with the two sugar-phosphate backbones being on the outside of the molecule. Franklin personally told Crick and Watson that the backbones had to be on the outside. Her identification of the space group for DNA crystals revealed to Crick that the two DNA strands were antiparallel. The X-ray diffraction images collected by Gosling and Franklin provided the best evidence for the helical nature of DNA. Franklin's experimental work thus proved crucial in Watson and Crick's discovery. Watson and Crick had three sources for Franklin's unpublished data: 1) her 1951 seminar, attended by Watson, 2) discussions with Wilkins, who worked in the same laboratory with Franklin, 3) a research progress report that was intended to promote coordination of Medical Research Council-supported laboratories. Watson, Crick, Wilkins and Franklin all worked in MRC laboratories. Prior to publication of the double helix structure, Watson and Crick had little interaction with Franklin. Crick and Watson felt that they had benefited from collaborating with Wilkins. They offered him a co-authorship on the article that first described the double helix structure of DNA. Wilkins turned down the offer, a fact that may have led to the terse character of the acknowledgment of experimental work done at King's College in the eventual published paper. Rather than make any of the DNA researchers at King's College co-authors on the Watson and Crick double helix article, the solution that was arrived at was to publish two additional papers from King's College along with the helix paper. Biographer Brenda Maddox suggested that because of the importance of her work to Watson and Crick's model building, Franklin should have had her name on the original Watson and Crick manuscript.[39] Franklin may have never known the extent to which her unpublished data had helped in the double helix discovery. According to one critic, unprotected by libel laws, Watson's portrayal of Franklin in The Double Helix was negative, giving the appearance that she was Wilkins' assistant and was unable to interpret her own DNA data.[40] In his book The Double Helix, Watson described being intimidated by Franklin and that they were unable to establish constructive scientific interactions during the time period when Franklin was doing DNA research. In the book's epilogue, written after Franklin's death, Watson acknowledges his early impressions of Franklin were often wrong, that she faced enormous barriers as a woman in the field of science even though her work was superb, and that it took years to overcome their bickering before appreciating Franklin's generosity and integrity. A review of the handwritten correspondence from Franklin to Watson, located in the archives at Cold Spring Harbor Laboratory, reveals that the two scientists later had exchanges of constructive scientific correspondence. In fact, Franklin consulted with Watson on her Tobacco Mosaic Virus RNA research. Franklin's letters begin on friendly terms with "Dear Jim", and conclude with equally benevolent and respectful sentiments like "Best Wishes, Yours, Rosalind". As is typical with scientific research, each of the scientists published their own unique contributions to the discovery of the structure of DNA in separate articles, and all of the contributors published their findings in the same volume of Nature. These classic molecular biology papers are identified as: Watson J.D. and Crick F.H.C. "A Structure for Deoxyribose Nucleic Acid" Nature 171, 737-738 (1953),[20] Wilkins M.H.F., Stokes A.R. & Wilson, H.R. "Molecular Structure of Deoxypentose Nucleic Acids" Nature 171, 738-740 (1953),[41] Franklin R. and Gosling R.G. "Molecular Configuration in Sodium Thymonucleate" Nature 171, 740-741 (1953).[42] Franklin did not receive a Nobel Prize for her important contribution because the Nobel Prize is not awarded posthumously.[43] The wording on the DNA sculpture outside Clare College's Thirkill Court, Cambridge, England is: On the base:
On the helices:
Statement claiming links between race and intelligence
On October 14, 2007, a biographical article written by one of Watson's former assistants[44], Charlotte Hunt-Grubbe, appeared in the Sunday Times Magazine in anticipation of his soon to be released, in the UK, memoir Avoid Boring People: Lessons from a Life in Science.[44] Watson was quoted as saying he was "inherently gloomy about the prospect of Africa" as "all our social policies are based on the fact that their intelligence is the same as ours — whereas all the testing says not really."[44][45] Hunt-Grubbe stated that Watson's "hope" was "everyone is equal" but quoted him as having said "people who have to deal with black employees find this not true." Furthermore, Grubbe suggested that Watson believed "you should not discriminate on the basis of colour" by quoting him as having said "there are many people of colour who are very talented, but don’t promote them when they haven’t succeeded at the lower level."[44] Watson was then attributed as having written "there is no firm reason to anticipate that the intellectual capacities of peoples geographically separated in their evolution should prove to have evolved identically. Our wanting to reserve equal powers of reason as some universal heritage of humanity will not be enough to make it so."[44] The quotes attributed to him drew attention and criticism from press in several countries and was widely discussed on CNN[46], the BBC[47], several papers[48], peers[45] and by civil rights advocates.[49] The common perception was that of Watson claiming a link between race and intelligence with the BBC stating that "[Watson] claimed black people were less intelligent than white people".[47] In his book, the origin of the final written quote, Watson does not directly mention race as a factor in his hypothesized divergence of intellect between geographically isolated populations.[50] On October 18th, The London Science Museum canceled a talk that Watson was scheduled to give the following day,[47] stating that they believed Watson's comments had "gone beyond the point of acceptable debate." On the same day the Board of Trustees at Cold Spring Harbor Laboratory suspended Watson's administrative responsibilities, stating that "this action follows the Board’s public statement yesterday disagreeing with the comments attributed to Dr. Watson in the October 14, 2007 edition of The Sunday Times U.K."[51] that they "vehemently disagree with...and are bewildered and saddened" by.[48] Dr. Francis Collins, director of the National Human Genome Research Institute a position inherited from Watson[45], said "I am deeply saddened by the events of the last week...in the aftermath of a racist statement...that was both profoundly offensive and utterly unsupported by scientific evidence."[48][45]. On October 19th, Watson issued an apology, stating that he was "mortified" and "cannot understand how I could have said what I am quoted as having said."[52][53] He also claimed to "understand why people, reading those words, have reacted in the ways they have . . . To all those who have drawn the inference from my words that Africa, as a continent, is somehow genetically inferior, I can only apologize unreservedly. That is not what I meant. More importantly from my point of view, there is no scientific basis for such a belief."[54] In an attempt to clarify his position, Watson said that "we do not yet adequately understand the way in which the different environments in the world have selected over time the genes which determine our capacity to do different things," and "the overwhelming desire of society today is to assume that equal powers of reason are a universal heritage of humanity." Adding that "it may well be. But simply wanting this to be the case is not enough. This is not science. To question this is not to give in to racism. This is not a discussion about superiority or inferiority, it is about seeking to understand differences, about why some of us are great musicians and others great engineers."[53][54] Despite the apology and subsequent attempt to clarify his position the controversy continued. He returned to the US and Cold Harbor on the 19th October putting his further engagements in doubt. The University of Edinburgh's formally retracted an invitation to the "DNA, Dolly and Other Dangerous Ideas: The Destiny of 21st Century Science" Enlightenment Lecture on October 22nd.[55] Watson resigned from Cold Spring Harbor Laboratory on October 25th.[56][46] Watson cited reasons for his retirement other than the controversy, though did refer to it; "Closer now to 80 than 79, the passing on of my remaining vestiges of leadership is more than overdue. The circumstances in which this transfer is occurring, however, are not those which I could ever have anticipated or desired."[57] It was announced on December 9, 2007 in a Sunday Times article[58] that 16% of Watson's DNA is of African origin, sixteen times the European average of 1% suggesting that he might have had a great-grandparent of African origin. This conclusion was reached by deCODE Genetics, an Icelandic genetic company, which analysed Watson's genetic code, which he published on the internet in the interests of science. Other statements
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This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "James_D._Watson". A list of authors is available in Wikipedia. |