Molecular biology / m ə ˈ l ɛ k j ʊ l ər / is a branch of biology that seeks to understand the molecular basis of biological activity in and between cells , including biomolecular synthesis, modification, mechanisms, and interactions.
145-422: Though cells and other microscopic structures had been observed in living organisms as early as the 18th century, a detailed understanding of the mechanisms and interactions governing their behavior did not emerge until the 20th century, when technologies used in physics and chemistry had advanced sufficiently to permit their application in the biological sciences. The term 'molecular biology' was first used in 1945 by
290-443: A 2D gel electrophoresis . The Bradford assay is a molecular biology technique which enables the fast, accurate quantitation of protein molecules utilizing the unique properties of a dye called Coomassie Brilliant Blue G-250. Coomassie Blue undergoes a visible color shift from reddish-brown to bright blue upon binding to protein. In its unstable, cationic state, Coomassie Blue has a background wavelength of 465 nm and gives off
435-736: A plasmid ( expression vector ). The plasmid vector usually has at least 3 distinctive features: an origin of replication, a multiple cloning site (MCS), and a selective marker (usually antibiotic resistance ). Additionally, upstream of the MCS are the promoter regions and the transcription start site, which regulate the expression of cloned gene. This plasmid can be inserted into either bacterial or animal cells. Introducing DNA into bacterial cells can be done by transformation via uptake of naked DNA, conjugation via cell-cell contact or by transduction via viral vector. Introducing DNA into eukaryotic cells, such as animal cells, by physical or chemical means
580-418: A ... November night was to be told by a woman to refrain from venturing an opinion about a subject for which you were not trained." Robert P. Crease remarks that "[Franklin] was close to figuring out the structure of DNA, but did not do it. The title of 'discoverer' goes to those who first fit the pieces together". Jeremy Bernstein rejects that Franklin was a "victim" and states that "[Watson and Crick] made
725-604: A Life in Science , Watson describes his academic colleagues as "dinosaurs", "deadbeats", "fossils", "has-beens", "mediocre", and "vapid". Steve Shapin in Harvard Magazine noted that Watson had written an unlikely "Book of Manners", telling about the skills needed at different times in a scientist's career; he wrote Watson was known for aggressively pursuing his own goals at the university. E. O. Wilson once described Watson as "the most unpleasant human being I had ever met", but in
870-539: A businessman descended mostly from colonial English immigrants to America. His mother's father, Lauchlin Mitchell, a tailor , was from Glasgow , Scotland, and her mother, Lizzie Gleason, was the child of parents from County Tipperary , Ireland. His mother was a modestly religious Catholic and his father an Episcopalian who had lost his belief in God. Watson was raised Catholic, but he later described himself as "an escapee from
1015-445: A density gradient, which separated the DNA molecules based on their density. The results showed that after one generation of replication in the N medium, the DNA formed a band of intermediate density between that of pure N DNA and pure N DNA. This supported the semiconservative DNA replication proposed by Watson and Crick, where each strand of the parental DNA molecule serves as a template for
1160-465: A disappointment but it is intriguing to speculate on how differently history might have unfolded had Astbury shown Beighton's image to his friend and colleague the eminent US chemist and Nobel Laureate, Linus Pauling when he visited Astbury at his home in Headingley, Leeds in 1952. Pauling was, at that time, Watson and Crick's greatest rival in trying to solve the structure of DNA and was desperate to obtain
1305-529: A faulty electrical supply and unreliable plumbing that sometimes led to flooding. To add to his woes, the Medical Research Council rejected his application for funding. Despite these set-backs, two important developments took place in Astbury's new department. The first was the elucidation of the mechanism by which thrombin acts as a protease to catalyse the formation of the major component of blood clots,
1450-445: A fibre of keratin protein in a lock of hair that was said to have come from Mozart – who was one of Astbury's favourite composers. But proteins were not the only biological fibre that Astbury studied. In 1937 Torbjörn Caspersson of Sweden sent him well prepared samples of DNA from calf thymus. The fact that DNA produced a diffraction pattern indicated that it also had a regular structure and it might be feasible to deduce it. Astbury
1595-418: A good quality X-ray diffraction image of DNA. In 1952, he had already proposed an incorrect model of DNA based on Astbury and Bell's early work but had Astbury shown Pauling these new images taken by Beighton, it might well have been Caltech, Pasadena and not Cambridge, UK that is today remembered for the discovery of the double-helix. Despite this missed opportunity, Astbury, together with Florence Bell, had made
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#17328449543721740-414: A great adventure". Astbury's enthusiasm may also account for an occasional lack of scientific caution observable in his work; Astbury could make speculative interpretations sound plausible. Astbury was an excellent writer and lecturer; his works are characterized by remarkable clarity and an easy-going, natural manner. He also enjoyed music, playing both piano and violin. Astbury met Frances Gould when he
1885-572: A helical shape could scatter X-rays to give this particular pattern. Franklin and Gosling's 'Photo 51' provided one of several important clues to Watson and Crick -but Astbury's response to Beighton's very similar X-ray images of DNA could not have been more different. He never published them in a journal or presented them at a scientific meeting. Given that Astbury was such a renowned expert in X-ray studies of biological molecules this apparent neglect of such an important clue may seem surprising. One explanation
2030-761: A hobby shared with his father, so he considered majoring in ornithology . Watson appeared on Quiz Kids , a popular radio show that challenged bright youngsters to answer questions. Thanks to the liberal policy of university president Robert Hutchins , he enrolled at the University of Chicago , where he was awarded a tuition scholarship, at the age of 15. Among his professors was Louis Leon Thurstone from whom Watson learned about factor analysis , which he would later reference on his controversial views on race . After reading Erwin Schrödinger 's book, What Is Life? in 1946, Watson changed his professional ambitions from
2175-422: A homosexual child, well, let her." The biologist Richard Dawkins wrote a letter to The Independent claiming that Watson's position was misrepresented by The Sunday Telegraph article, and that Watson would equally consider the possibility of having a heterosexual child to be just as valid as any other reason for abortion, to emphasise that Watson is in favor of allowing choice. On the issue of obesity, Watson
2320-453: A labeled complement of a sequence of interest. The results may be visualized through a variety of ways depending on the label used; however, most result in the revelation of bands representing the sizes of the RNA detected in sample. The intensity of these bands is related to the amount of the target RNA in the samples analyzed. The procedure is commonly used to study when and how much gene expression
2465-417: A later TV interview said that he considered them friends and their rivalry at Harvard "old history" (when they had competed for funding in their respective fields). In the epilogue to the memoir Avoid Boring People , Watson alternately attacks and defends former Harvard University president Lawrence Summers , who stepped down in 2006 due in part to his remarks about women and science. Watson also states in
2610-451: A major contribution by showing that the methods of X-ray crystallography could be used to reveal the regular, ordered structure of DNA. But perhaps Astbury's greatest scientific legacy was his rather unusual overcoat. In the late 1930s Astbury and his collaborators A.C. Chibnall and Kennet Bailey showed that by chemical treatment, the molecular chains of soluble seed proteins could be refolded to make them into insoluble fibres. The company ICI
2755-515: A member of the Harvard faculty until 1976, even though he took over the directorship of Cold Spring Harbor Laboratory in 1968. During his tenure at Harvard, Watson participated in a protest against the Vietnam War , leading a group of 12 biologists and biochemists calling for "the immediate withdrawal of U.S. forces from Vietnam". In 1975, on the thirtieth anniversary of the bombing of Hiroshima, Watson
2900-581: A member of the Phage Group. 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. The intention was to determine whether protein or DNA was the genetic material, but upon consultation with Max Delbrück, they determined that their results were inconclusive and could not specifically identify
3045-516: A mixture of proteins. Western blots can be used to determine the size of isolated proteins, as well as to quantify their expression. In western blotting , proteins are first separated by size, in a thin gel sandwiched between two glass plates in a technique known as SDS-PAGE . The proteins in the gel are then transferred to a polyvinylidene fluoride (PVDF), nitrocellulose, nylon, or other support membrane. This membrane can then be probed with solutions of antibodies . Antibodies that specifically bind to
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#17328449543723190-527: A paper in The Lancet suggesting that biological oxidants may have a different role than is thought in diseases including diabetes, dementia, heart disease and cancer. For example, type 2 diabetes is usually thought to be caused by oxidation in the body that causes inflammation and kills off pancreatic cells. Watson thinks the root of that inflammation is different: "a lack of biological oxidants, not an excess", and discusses this in detail. One critical response
3335-578: A position in the biology department at Harvard University . His work at Harvard focused on RNA and its role in the transfer of genetic information. Watson 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 progress only once the underlying disciplines of molecular biology and biochemistry had elucidated their underpinnings, going so far as to discourage their study by students. Watson continued to be
3480-679: A post-doctoral year at the University of Copenhagen with Herman Kalckar and Ole Maaløe, Watson worked at the University of Cambridge 's Cavendish Laboratory in England, where he first met his future collaborator Francis Crick . From 1956 to 1976, Watson was on the faculty of the Harvard University Biology Department, promoting research in molecular biology. From 1968, Watson served as director of Cold Spring Harbor Laboratory (CSHL), greatly expanding its level of funding and research. At CSHL, he shifted his research emphasis to
3625-416: A question of fitting molecules or parts of molecules against another, and one of the great biological developments of our time is the realisation that probably the most fundamental interaction of all is that between the proteins and the nucleic acids." He also said that the spacing between the nucleotides and the spacing of amino acids in proteins "was not an arithmetical accident". Astbury and Bell's work
3770-433: A reddish-brown color. When Coomassie Blue binds to protein in an acidic solution, the background wavelength shifts to 595 nm and the dye gives off a bright blue color. Proteins in the assay bind Coomassie blue in about 2 minutes, and the protein-dye complex is stable for about an hour, although it is recommended that absorbance readings are taken within 5 to 20 minutes of reaction initiation. The concentration of protein in
3915-408: A single slide. Each spot has a DNA fragment molecule that is complementary to a single DNA sequence . A variation of this technique allows the gene expression of an organism at a particular stage in development to be qualified ( expression profiling ). In this technique the RNA in a tissue is isolated and converted to labeled complementary DNA (cDNA). This cDNA is then hybridized to the fragments on
4060-596: A talk at the Guy's Hospital Medical School in London on Thursday, May 14, 1953, which resulted in a May 15, 1953, article by Ritchie Calder in the London newspaper News Chronicle , entitled "Why You Are You. Nearer Secret of Life". Sydney Brenner , Jack Dunitz , Dorothy Hodgkin , Leslie Orgel , and Beryl M. Oughton were some of the first people in April 1953 to see the model of the structure of DNA , constructed by Crick and Watson; at
4205-412: A turning point in science; understanding of life was fundamentally changed and the modern era of biology began. Watson and Crick's use of DNA X-ray diffraction data collected by Rosalind Franklin and her student Raymond Gosling has attracted scrutiny. It has been argued that Watson and his colleagues did not properly acknowledge colleague Rosalind Franklin for her contributions to the discovery of
4350-461: A viewpoint on the interdisciplinary relationships between molecular biology and other related fields. While researchers practice techniques specific to molecular biology, it is common to combine these with methods from genetics and biochemistry . Much of molecular biology is quantitative, and recently a significant amount of work has been done using computer science techniques such as bioinformatics and computational biology . Molecular genetics ,
4495-538: A year of postdoctoral research, first heading to the laboratory of biochemist Herman Kalckar . Kalckar was interested in the enzymatic synthesis of nucleic acids, and he wanted to use phages as an experimental system. Watson wanted to explore the structure of DNA, and his interests did not coincide with Kalckar's. After working part of the year with Kalckar, Watson spent the remainder of his time in Copenhagen conducting experiments with microbial physiologist Ole Maaløe, then
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4640-532: Is a former member of the Board of Directors of United Biomedical, Inc., founded by Chang Yi Wang . He held the position for six years and retired from the board in 1999. 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. In March 2017, Watson was named head consultant of
4785-436: Is also a long tradition of studying biomolecules "from the ground up", or molecularly, in biophysics . Molecular cloning is used to isolate and then transfer a DNA sequence of interest into a plasmid vector. This recombinant DNA technology was first developed in the 1960s. In this technique, a DNA sequence coding for a protein of interest is cloned using polymerase chain reaction (PCR), and/or restriction enzymes , into
4930-438: Is becoming more affordable and used in many different scientific fields. This will drive the development of industries in developing nations and increase accessibility to individual researchers. Likewise, CRISPR-Cas9 gene editing experiments can now be conceived and implemented by individuals for under $ 10,000 in novel organisms, which will drive the development of industrial and medical applications. The following list describes
5075-411: Is called transfection . Several different transfection techniques are available, such as calcium phosphate transfection, electroporation , microinjection and liposome transfection . The plasmid may be integrated into the genome , resulting in a stable transfection, or may remain independent of the genome and expressed temporarily, called a transient transfection. DNA coding for a protein of interest
5220-410: Is centrifuged and the pellet which contains E.coli cells was checked and the supernatant was discarded. The E.coli cells showed radioactive phosphorus, which indicated that the transformed material was DNA not the protein coat. The transformed DNA gets attached to the DNA of E.coli and radioactivity is only seen onto the bacteriophage's DNA. This mutated DNA can be passed to the next generation and
5365-430: Is found in a cDNA library . PCR has many variations, like reverse transcription PCR ( RT-PCR ) for amplification of RNA, and, more recently, quantitative PCR which allow for quantitative measurement of DNA or RNA molecules. Gel electrophoresis is a technique which separates molecules by their size using an agarose or polyacrylamide gel. This technique is one of the principal tools of molecular biology. The basic principle
5510-472: Is now inside a cell, and the protein can now be expressed. A variety of systems, such as inducible promoters and specific cell-signaling factors, are available to help express the protein of interest at high levels. Large quantities of a protein can then be extracted from the bacterial or eukaryotic cell. The protein can be tested for enzymatic activity under a variety of situations, the protein may be crystallized so its tertiary structure can be studied, or, in
5655-433: Is now referred to as genetic transformation. Griffith's experiment addressed the pneumococcus bacteria, which had two different strains, one virulent and smooth and one avirulent and rough. The smooth strain had glistering appearance owing to the presence of a type of specific polysaccharide – a polymer of glucose and glucuronic acid capsule. Due to this polysaccharide layer of bacteria, a host's immune system cannot recognize
5800-454: Is occurring by measuring how much of that RNA is present in different samples, assuming that no post-transcriptional regulation occurs and that the levels of mRNA reflect proportional levels of the corresponding protein being produced. It is one of the most basic tools for determining at what time, and under what conditions, certain genes are expressed in living tissues. A western blot is a technique by which specific proteins can be detected from
5945-478: Is susceptible to influence by strong alkaline buffering agents, such as sodium dodecyl sulfate (SDS). The terms northern , western and eastern blotting are derived from what initially was a molecular biology joke that played on the term Southern blotting , after the technique described by Edwin Southern for the hybridisation of blotted DNA. Patricia Thomas, developer of the RNA blot which then became known as
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6090-399: Is that DNA fragments can be separated by applying an electric current across the gel - because the DNA backbone contains negatively charged phosphate groups, the DNA will migrate through the agarose gel towards the positive end of the current. Proteins can also be separated on the basis of size using an SDS-PAGE gel, or on the basis of size and their electric charge by using what is known as
6235-410: Is that, although Astbury recognised the importance of DNA, he did not understand that biological information was carried in the one-dimensional sequence of bases within the molecule but rather, that it resided in subtle and elaborate variations in its three-dimensional structure. Far from making his jaw drop and his pulse race, the revelation that DNA was a simple a twisting helix would therefore have been
6380-411: Is then exposed to a labeled DNA probe that has a complement base sequence to the sequence on the DNA of interest. Southern blotting is less commonly used in laboratory science due to the capacity of other techniques, such as PCR , to detect specific DNA sequences from DNA samples. These blots are still used for some applications, however, such as measuring transgene copy number in transgenic mice or in
6525-515: Is used to detect post-translational modification of proteins. Proteins blotted on to the PVDF or nitrocellulose membrane are probed for modifications using specific substrates. A DNA microarray is a collection of spots attached to a solid support such as a microscope slide where each spot contains one or more single-stranded DNA oligonucleotide fragments. Arrays make it possible to put down large quantities of very small (100 micrometre diameter) spots on
6670-634: The Davy-Faraday Laboratory at the Royal Institution in London . Fellow students included many eminent scientists, including Kathleen Lonsdale and J. D. Bernal and others. Astbury showed great enthusiasm for his studies and published papers in the journal Classic Crystallography , such as on the structure of tartaric acid . In 1928, Astbury was appointed Lecturer in Textile Physics at
6815-553: The Medical Research Council Unit, Cavendish Laboratory , were the first to describe the double helix model for the chemical structure of deoxyribonucleic acid (DNA), which is often considered a landmark event for the nascent field because it provided a physico-chemical basis by which to understand the previously nebulous idea of nucleic acids as the primary substance of biological inheritance. They proposed this structure based on previous research done by Franklin, which
6960-518: The Nobel Prize in Physiology or Medicine in 1962, along with Wilkins, for proposing a model of the structure of DNA. In 1961, it was demonstrated that when a gene encodes a protein , three sequential bases of a gene's DNA specify each successive amino acid of the protein. Thus the genetic code is a triplet code, where each triplet (called a codon ) specifies a particular amino acid. Furthermore, it
7105-512: The University of Leeds . He remained at Leeds for the remainder of his career, being appointed Reader in Textile Physics in 1937 and Professor of Biomolecular Structure in 1946. He held the chair until his death in 1961. He was elected a Fellow of the Royal Society (FRS) in 1940. He is commemorated by the Astbury Centre for Structural Molecular Biology at Leeds . In later life he
7250-457: The double helix structure of the DNA molecule . Watson, 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". Watson earned degrees at the University of Chicago ( BS , 1947) and Indiana University (PhD, 1950). Following
7395-421: The northern blot , actually did not use the term. Named after its inventor, biologist Edwin Southern , the Southern blot is a method for probing for the presence of a specific DNA sequence within a DNA sample. DNA samples before or after restriction enzyme (restriction endonuclease) digestion are separated by gel electrophoresis and then transferred to a membrane by blotting via capillary action . The membrane
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#17328449543727540-628: The Bradford assay can then be measured using a visible light spectrophotometer , and therefore does not require extensive equipment. This method was developed in 1975 by Marion M. Bradford , and has enabled significantly faster, more accurate protein quantitation compared to previous methods: the Lowry procedure and the biuret assay. Unlike the previous methods, the Bradford assay is not susceptible to interference by several non-protein molecules, including ethanol, sodium chloride, and magnesium chloride. However, it
7685-525: The Catholic religion". Watson said, "The luckiest thing that ever happened to me was that my father didn't believe in God." By age 11, Watson stopped attending mass and embraced the "pursuit of scientific and humanistic knowledge." Watson grew up on the South Side of Chicago and attended public schools, including Horace Mann Elementary School and South Shore High School . He was fascinated with bird watching,
7830-605: The Cheerland Investment Group, a Chinese investment company which sponsored his trip. Watson has also been an institute adviser for the Allen Institute for Brain Science . Watson has had disagreements with Craig Venter regarding his use of EST fragments while Venter worked at NIH . Venter went on to found Celera genomics and continued his feud with Watson. Watson was quoted as calling Venter "Hitler". In his 2007 memoir, Avoid Boring People: Lessons from
7975-454: The DNA model was Phoebus Levene , who proposed the "polynucleotide model" of DNA in 1919 as a result of his biochemical experiments on yeast. In 1950, Erwin Chargaff expanded on the work of Levene and elucidated a few critical properties of nucleic acids: first, the sequence of nucleic acids varies across species. Second, the total concentration of purines (adenine and guanine) is always equal to
8120-592: The English physicist William Astbury , who described it as an approach focused on discerning the underpinnings of biological phenomena—i.e. uncovering the physical and chemical structures and properties of biological molecules, as well as their interactions with other molecules and how these interactions explain observations of so-called classical biology, which instead studies biological processes at larger scales and higher levels of organization. In 1953, Francis Crick , James Watson , Rosalind Franklin , and their colleagues at
8265-547: The Genome Project, he had stated his own 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. (The issue of the patentability of genes has since been resolved in
8410-626: The US by the US Supreme Court ; see Association for Molecular Pathology v. U.S. Patent and Trademark Office .) In 1994, Watson became president of CSHL . Francis Collins took over the role as director of the Human Genome Project. Watson was quoted in The Sunday Telegraph in 1997 as stating: "If you could find the gene which determines sexuality and a woman decides she doesn't want
8555-480: The University of Chicago to become a graduate student at Indiana University , attracted by the presence at Bloomington of the 1946 Nobel Prize winner Hermann Joseph Muller , who in crucial papers published in 1922, 1929, and in the 1930s had laid out all the basic properties of the heredity molecule that Schrödinger presented in his 1944 book. He received his PhD degree from Indiana University in 1950; Salvador Luria
8700-400: The University of Leeds in 1945 he declared that 'all biology, is now passing over into the molecular structural phase...In all branches of biology and all universities this thing must come to pass and I suggest that Leeds should be bold and help to lead the way.' Sadly, not everyone shared his dream. The University Senate allowed him to establish a new department but would not allow him to use
8845-545: The amino acid alpha helix , a result that grew out of Pauling's 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 Serum Institut (Denmark), CSHL, and the California Institute of Technology , Watson now had the desire to learn to perform X-ray diffraction experiments so he could work to determine
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#17328449543728990-437: The array and visualization of the hybridization can be done. Since multiple arrays can be made with exactly the same position of fragments, they are particularly useful for comparing the gene expression of two different tissues, such as a healthy and cancerous tissue. Also, one can measure what genes are expressed and how that expression changes with time or with other factors. There are many different ways to fabricate microarrays;
9135-426: The assembly of molecular structures. In 1928, Frederick Griffith , encountered a virulence property in pneumococcus bacteria, which was killing lab rats. According to Mendel, prevalent at that time, gene transfer could occur only from parent to daughter cells. Griffith advanced another theory, stating that gene transfer occurring in member of same generation is known as horizontal gene transfer (HGT). This phenomenon
9280-471: The atomic level. Molecular biologists today have access to increasingly affordable sequencing data at increasingly higher depths, facilitating the development of novel genetic manipulation methods in new non-model organisms. Likewise, synthetic molecular biologists will drive the industrial production of small and macro molecules through the introduction of exogenous metabolic pathways in various prokaryotic and eukaryotic cell lines. Horizontally, sequencing data
9425-484: The bacteria and it kills the host. The other, avirulent, rough strain lacks this polysaccharide capsule and has a dull, rough appearance. Presence or absence of capsule in the strain, is known to be genetically determined. Smooth and rough strains occur in several different type such as S-I, S-II, S-III, etc. and R-I, R-II, R-III, etc. respectively. All this subtypes of S and R bacteria differ with each other in antigen type they produce. The Avery–MacLeod–McCarty experiment
9570-403: The bacteriophage's protein coat with radioactive sulphur and DNA with radioactive phosphorus, into two different test tubes respectively. After mixing bacteriophage and E.coli into the test tube, the incubation period starts in which phage transforms the genetic material in the E.coli cells. Then the mixture is blended or agitated, which separates the phage from E.coli cells. The whole mixture
9715-510: The bases lay flat, stacked, 0.34 nanometres apart. At a symposium in 1938 at Cold Spring Harbor , Astbury pointed out that the 0.34 nanometre spacing was the same as amino acids in polypeptide chains. (The currently accepted value for the spacing of the bases in B-form of DNA is 0.332 nm.) In 1946 Astbury presented a paper at a symposium in Cambridge in which he said: "Biosynthesis is supremely
9860-510: The best evidence for the helical nature of DNA. Watson and Crick had three sources for Franklin's unpublished data: In a 1954 article, Watson and Crick acknowledged that, without Franklin's data, "the formulation of our structure would have been most unlikely, if not impossible". In The Double Helix , Watson later admitted that "Rosy, of course, did not directly give us her data. For that matter, no one at King's realized they were in our hands". In recent years, Watson has garnered controversy in
10005-504: The carrier of hereditary information and that DNA was a dull monotonous molecule of little interest other than perhaps as a structural component. In 1944, Astbury was one of the few scientists to recognise the importance of work done by the microbiologist Oswald Avery and his Rockefeller colleagues Maclyn McCarty and Colin Macleod. Avery and his team had shown that nucleic acid could pass on the property of virulence in pneumococcus and thus offered
10150-491: The development of new technologies and their optimization. Molecular biology has been elucidated by the work of many scientists, and thus the history of the field depends on an understanding of these scientists and their experiments. The field of genetics arose from attempts to understand the set of rules underlying reproduction and heredity , and the nature of the hypothetical units of heredity known as genes . Gregor Mendel pioneered this work in 1866, when he first described
10295-422: The diffraction of moist wool or hair fibres as they are stretched significantly (100%). The data suggested that the unstretched fibres had a coiled molecular structure with a characteristic repeat of 5.1 Å (=0.51 nm). Astbury proposed that (1) the unstretched protein molecules formed a helix (which he called the α-form); and (2) the stretching caused the helix to uncoil, forming an extended state (which he called
10440-552: 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 entitled " Molecular Structure of Nucleic Acids: A Structure for Deoxyribose Nucleic Acid " to the scientific journal Nature , which was published on April 25, 1953. Bragg gave
10585-486: The discovery. The 1953 Cold Spring Harbor Symposium was the first opportunity for many to see the model of the DNA double helix. Watson, Crick, and Wilkins were awarded the Nobel Prize in Physiology or Medicine in 1962 for their research on the structure of nucleic acids. Rosalind Franklin had died in 1958 and was therefore ineligible for nomination. The publication of the double helix structure of DNA has been described as
10730-458: The double helix structure. Robert P. Crease notes that "Such stingy behaviour may not be unknown, or even uncommon, among scientists". Franklin's high-quality X-ray diffraction patterns of DNA were unpublished results, which Watson and Crick used without her knowledge or consent in their construction of the double helix model of DNA. Franklin's results provided estimates of the water content of DNA crystals and these results were consistent with
10875-529: The double-helix scheme work. It is as simple as that". Matthew Cobb and Nathaniel C. Comfort write that "Franklin was no victim in how the DNA double helix was solved" but that she was "an equal contributor to the solution of the structure". A review of the correspondence from Franklin to Watson, in the archives at CSHL, revealed that the two scientists later exchanged constructive scientific correspondence. Franklin consulted with Watson on her tobacco mosaic virus RNA research. Franklin's letters were framed with
11020-400: The engineering of gene knockout embryonic stem cell lines . The northern blot is used to study the presence of specific RNA molecules as relative comparison among a set of different samples of RNA. It is essentially a combination of denaturing RNA gel electrophoresis , and a blot . In this process RNA is separated based on size and is then transferred to a membrane that is then probed with
11165-629: The epilogue, "Anyone sincerely interested in understanding the imbalance in the representation of men and women in science must reasonably be prepared at least to consider the extent to which nature may figure, even with the clear evidence that nurture is strongly implicated." At a conference in 2000, Watson suggested a link between skin color and sex drive, hypothesizing that dark-skinned people have stronger libidos . His lecture argued that extracts of melanin —which gives skin its color—had been found to boost subjects' sex drive. "That's why you have Latin lovers ", he said, according to people who attended
11310-548: The evil system." In 1990, Watson was appointed as the head of the Human Genome Project at the National Institutes of Health , a position he held until April 10, 1992. 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
11455-410: The experiment involved growing E. coli bacteria in a medium containing heavy isotope of nitrogen (N) for several generations. This caused all the newly synthesized bacterial DNA to be incorporated with the heavy isotope. After allowing the bacteria to replicate in a medium containing normal nitrogen (N), samples were taken at various time points. These samples were then subjected to centrifugation in
11600-399: The extract. They discovered that when they digested the DNA in the extract with DNase , transformation of harmless bacteria into virulent ones was lost. This provided strong evidence that DNA was the genetic material, challenging the prevailing belief that proteins were responsible. It laid the basis for the subsequent discovery of its structure by Watson and Crick. Confirmation that DNA is
11745-526: The fact that their (blacks) intelligence is the same as ours (whites) – whereas all the testing says not really ... people who have to deal with black employees find this not true." Watson has repeatedly asserted that differences in average measured IQ between blacks and whites are due to genetics. In early October 2007, he was interviewed by Charlotte Hunt-Grubbe at Cold Spring Harbor Laboratory (CSHL). He discussed his view that Africans are less intelligent than Westerners. Watson said his intention
11890-536: The feasibility of this idea, ICI made an entire overcoat from Ardil which Astbury regularly sported to lectures and in the end, although Ardil did not prove to be the salvation of the British textile industry, it did serve as a powerful illustration of Astbury's conviction that not only could we solve the structure of giant biomolecules such as proteins and DNA using X-rays, but that we might also then deliberately manipulate these structures for our own practical purposes. This
12035-470: The first strong evidence that DNA might be the hereditary material. Astbury described Avery's work as 'one of the most remarkable discoveries of our time' and it inspired him with the vision that, in the aftermath of World War 2, he would established a new department at Leeds that would become a national centre to blaze the trail for the new science of molecular biology. Writing to the Vice-Chancellor of
12180-945: The funds raised by the sale went to support scientific research. The medal sold at auction at Christie's in December 2014 for US$ 4.1 million . Watson intended to contribute the proceeds to conservation work in Long Island and to funding research at Trinity College, Dublin. He was the first living Nobel recipient to auction a medal. The medal was later returned to Watson by the purchaser, Alisher Usmanov . Several of Watson's former doctoral students subsequently became notable in their own right including, Mario Capecchi , Bob Horvitz , Peter B. Moore and Joan Steitz . Besides numerous PhD students, Watson also supervised postdoctoral researchers and other interns including Ewan Birney , Ronald W. Davis , Phillip Allen Sharp (postdoc), John Tooze (postdoc) and Richard J. Roberts (postdoc). Watson
12325-453: The genetic basis of cancer." In a retrospective summary of Watson's accomplishments there, Bruce Stillman , the laboratory's president, said, "Jim Watson created a research environment that is unparalleled in the world of science." In 2007, Watson said, "I turned against the left wing because they don't like genetics, because genetics implies that sometimes in life we fail because we have bad genes. They want all failure in life to be due to
12470-526: The genetic material which is cause of infection came from the Hershey–Chase experiment . They used E.coli and bacteriophage for the experiment. This experiment is also known as blender experiment, as kitchen blender was used as a major piece of apparatus. Alfred Hershey and Martha Chase demonstrated that the DNA injected by a phage particle into a bacterium contains all information required to synthesize progeny phage particles. They used radioactivity to tag
12615-506: The helix backbones had to be on the outside. From a 2003 piece by Brenda Maddox in Nature : Other comments dismissive of "Rosy" in Watson's book caught the attention of the emerging women's movement in the late 1960s. "Clearly Rosy had to go or be put in her place ... Unfortunately Maurice could not see any decent way to give Rosy the boot". And, "Certainly a bad way to go out into the foulness of
12760-460: The insoluble protein fibrin, from its soluble precursor fibrinogen by Laszlo Lorand, a young PhD student who had fled his native Hungary to join Astbury. Lorand's work was a major discovery in our understanding of the process by which blood clots form. The second development was a series of new X-ray photographs of B-form DNA taken in 1951 by Astbury's research assistant Elwyn Beighton which the historian of science, Professor Robert Olby has since said
12905-431: The laws of inheritance he observed in his studies of mating crosses in pea plants. One such law of genetic inheritance is the law of segregation , which states that diploid individuals with two alleles for a particular gene will pass one of these alleles to their offspring. Because of his critical work, the study of genetic inheritance is commonly referred to as Mendelian genetics . A major milestone in molecular biology
13050-536: 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 PhD research in Luria's laboratory at Indiana University. That spring, he met Delbrück first in Luria's apartment and again that summer during Watson's first trip to the Cold Spring Harbor Laboratory (CSHL). The Phage Group
13195-478: The lecture. "You've never heard of an English lover. Only an English Patient ." He has also said that stereotypes associated with racial and ethnic groups have a genetic basis: Jews being intelligent, Chinese being intelligent but not creative because of selection for conformity, and Indians being servile because of selection under caste endogamy. Regarding intelligence differences between blacks and whites, Watson has asserted that "all our social policies are based on
13340-475: The model of the structure of DNA. The Cambridge University student newspaper Varsity 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 and Crick paper in Nature . Many at the meeting had not yet heard of
13485-440: The modern α-helix. In 1931, Astbury was also the first to propose that mainchain-mainchain hydrogen bonds (i.e., hydrogen bonds between the backbone amide groups ) contributed to stabilizing protein structures . His initial insight was taken up enthusiastically by several researchers, including Linus Pauling . Astbury's work moved on to include X-ray studies of many proteins (including myosin , epidermin and fibrin ) and he
13630-411: The most common are silicon chips, microscope slides with spots of ~100 micrometre diameter, custom arrays, and arrays with larger spots on porous membranes (macroarrays). There can be anywhere from 100 spots to more than 10,000 on a given array. Arrays can also be made with molecules other than DNA. Allele-specific oligonucleotide (ASO) is a technique that allows detection of single base mutations without
13775-406: The most important photographs in the world'. This is because the image shows a striking cross-shaped pattern of black spots made by X-rays as they are scattered by the DNA fibre and when James Watson was first shown Franklin and Gosling's picture, this cross-shaped pattern made him so excited that he said 'my mouth fell open and my pulse began to race', because he knew that only a molecule coiled into
13920-399: The need for PCR or gel electrophoresis. Short (20–25 nucleotides in length), labeled probes are exposed to the non-fragmented target DNA, hybridization occurs with high specificity due to the short length of the probes and even a single base change will hinder hybridization. The target DNA is then washed and the unhybridized probes are removed. The target DNA is then analyzed for the presence of
14065-503: The newly labeled molecules as DNA. 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 X-ray diffraction data for DNA. Watson was now certain that DNA had a definite molecular structure that could be elucidated. In 1951, the chemist Linus Pauling in California published his model of
14210-837: The normal and unremarkable forms of address, beginning with "Dear Jim", and concluding with "Best Wishes, Yours, Rosalind". 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); Wilkins M. H. F., Stokes A. R. & Wilson H. R. "Molecular Structure of Deoxypentose Nucleic Acids". Nature 171, 738–740 (1953); Franklin R. and Gosling R. G. "Molecular Configuration in Sodium Thymonucleate". Nature 171, 740–741 (1953). In 1956, Watson accepted
14355-669: The only local scholarship available and went up to Jesus College, Cambridge . After two terms at Cambridge, his studies were interrupted by service during the First World War . A poor medical rating following appendectomy resulted in his posting in 1917 to Cork , Ireland with the Royal Army Medical Corps . He later returned to Cambridge and finished his last year with a specialization in physics . After graduating from Cambridge, Astbury worked with William Bragg , first at University College London and then, in 1923, at
14500-462: The pharmaceutical industry, the activity of new drugs against the protein can be studied. Polymerase chain reaction (PCR) is an extremely versatile technique for copying DNA. In brief, PCR allows a specific DNA sequence to be copied or modified in predetermined ways. The reaction is extremely powerful and under perfect conditions could amplify one DNA molecule to become 1.07 billion molecules in less than two hours. PCR has many applications, including
14645-488: The phrase 'molecular biology' in the title due to opposition from senior biologists who felt that, as a physicist, Astbury was encroaching without invitation on intellectual territory that they rightfully considered to be their own. The Senate also granted him premises but these were a far cry from what he had hoped for. His new department was housed in a Victorian terraced house that required substantial conversion, with uneven floors that made delicate scientific equipment wobble,
14790-462: The popular and scientific press for his "misogynist treatment" of Franklin and his failure to properly attribute her work on DNA. According to one critic, Watson's portrayal of Franklin in The Double Helix was negative, giving the impression that she was Wilkins' assistant and was unable to interpret her own DNA data. Watson's accusation was indefensible since Franklin told Crick and Watson that
14935-403: The probe via radioactivity or fluorescence. In this experiment, as in most molecular biology techniques, a control must be used to ensure successful experimentation. In molecular biology, procedures and technologies are continually being developed and older technologies abandoned. For example, before the advent of DNA gel electrophoresis ( agarose or polyacrylamide ), the size of DNA molecules
15080-470: The project and the book was commercially published. In an interview with Anne Sayre for her book, Rosalind Franklin and DNA (published in 1975 and reissued in 2000), Francis Crick said that he regarded Watson's book as a "contemptible pack of damned nonsense". In 1968, Watson became the director of the Cold Spring Harbor Laboratory (CSHL). Between 1970 and 1972, the Watsons' two sons were born, and by 1974,
15225-528: The protein of interest can then be visualized by a variety of techniques, including colored products, chemiluminescence , or autoradiography . Often, the antibodies are labeled with enzymes. When a chemiluminescent substrate is exposed to the enzyme it allows detection. Using western blotting techniques allows not only detection but also quantitative analysis. Analogous methods to western blotting can be used to directly stain specific proteins in live cells or tissue sections. The eastern blotting technique
15370-630: The second person 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 . Watson was quoted as saying, "I am putting my genome sequence on line to encourage the development of an era of personalized medicine , in which information contained in our genomes can be used to identify and prevent disease and to create individualized medical therapies". In 2014, Watson published
15515-549: The story of the discovery of the structure of DNA, as well as the personalities, conflicts and controversy surrounding their work, and includes many of his private emotional impressions at the time. Watson's original title was to have been "Honest Jim". Controversy surrounded the publication of the book. Watson's book was originally to be published by the Harvard University Press , but Francis Crick and Maurice Wilkins, among others, objected. Watson's home university dropped
15660-607: The structure of DNA. That summer, Luria met John Kendrew , and he arranged for a new postdoctoral research project for Watson in England. In 1951 Watson visited the Stazione Zoologica 'Anton Dohrn' in Naples . In mid-March 1953, Watson and Crick deduced the double helix structure of DNA. Crucial to their discovery were the experimental data collected at King's College London —mainly by Rosalind Franklin for which they did not provide proper attribution. Sir Lawrence Bragg ,
15805-540: The study of cancer, along with making it a world-leading research center in molecular biology. In 1994, he started as president and served for 10 years. He was then appointed chancellor, serving until he resigned in 2007 after making comments claiming that there is a genetic link between intelligence and race . In 2019, following the broadcast of a documentary in which Watson reiterated these views on race and genetics, CSHL revoked his honorary titles and severed all ties with him. Watson has written many science books, including
15950-420: The study of gene expression, the detection of pathogenic microorganisms, the detection of genetic mutations, and the introduction of mutations to DNA. The PCR technique can be used to introduce restriction enzyme sites to ends of DNA molecules, or to mutate particular bases of DNA, the latter is a method referred to as site-directed mutagenesis . PCR can also be used to determine whether a particular DNA fragment
16095-532: The study of gene structure and function, has been among the most prominent sub-fields of molecular biology since the early 2000s. Other branches of biology are informed by molecular biology, by either directly studying the interactions of molecules in their own right such as in cell biology and developmental biology , or indirectly, where molecular techniques are used to infer historical attributes of populations or species , as in fields in evolutionary biology such as population genetics and phylogenetics . There
16240-464: The study of ornithology to genetics . Watson earned his BS degree in zoology from the University of Chicago in 1947. In his autobiography, Avoid Boring People , Watson described 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 later experiences. In 1947 Watson left
16385-554: The synthesis of a new complementary strand, resulting in two daughter DNA molecules, each consisting of one parental and one newly synthesized strand. The Meselson-Stahl experiment provided compelling evidence for the semiconservative replication of DNA, which is fundamental to the understanding of genetics and molecular biology. In the early 2020s, molecular biology entered a golden age defined by both vertical and horizontal technical development. Vertically, novel technologies are allowing for real-time monitoring of biological processes at
16530-512: The textbook Molecular Biology of the Gene (1965) and his bestselling book The Double Helix (1968). Between 1988 and 1992, Watson was associated with the National Institutes of Health , helping to establish the Human Genome Project , which completed the task of mapping the human genome in 2003. Watson was born in Chicago on April 6, 1928, as the only son of Jean ( née Mitchell) and James D. Watson,
16675-481: The theory of Transduction came into existence. Transduction is a process in which the bacterial DNA carry the fragment of bacteriophages and pass it on the next generation. This is also a type of horizontal gene transfer. The Meselson-Stahl experiment was a landmark experiment in molecular biology that provided evidence for the semiconservative replication of DNA. Conducted in 1958 by Matthew Meselson and Franklin Stahl ,
16820-492: The time, they were working at Oxford University 's chemistry department. All were impressed by the new DNA model, especially Brenner, who subsequently worked with Crick at Cambridge in the Cavendish Laboratory and the new Laboratory of Molecular Biology . According to the late Beryl Oughton, later Rimmer, they all travelled together in two cars once Dorothy Hodgkin announced to them that they were off to Cambridge to see
16965-513: The total concentration of pyrimidines (cysteine and thymine). This is now known as Chargaff's rule. In 1953, James Watson and Francis Crick published the double helical structure of DNA, based on the X-ray crystallography work done by Rosalind Franklin which was conveyed to them by Maurice Wilkins and Max Perutz . Watson and Crick described the structure of DNA and conjectured about the implications of this unique structure for possible mechanisms of DNA replication. Watson and Crick were awarded
17110-468: The two sugar-phosphate backbones being on the outside of the molecule. Franklin told Crick and Watson that the backbones had to be on the outside; before then, Linus Pauling and Watson and Crick had erroneous models with the chains inside and the bases pointing outwards. 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
17255-484: The understanding and ability to diagnose and treat cancers, neurological diseases, and other causes of human suffering." CSHL substantially expanded both its research and its science educational programs under Watson's direction. He is credited with "transforming a small facility into one of the world's great education and research institutions. Initiating a program to study the cause of human cancer, scientists under his direction have made major contributions to understanding
17400-440: The use of molecular biology or molecular cell biology in medicine is now referred to as molecular medicine . Molecular biology sits at the intersection of biochemistry and genetics ; as these scientific disciplines emerged and evolved in the 20th century, it became clear that they both sought to determine the molecular mechanisms which underlie vital cellular functions. Advances in molecular biology have been closely related to
17545-404: The young family made Cold Spring 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 and then chancellor emeritus. In his roles as director, president, and chancellor, Watson led CSHL to articulate its present-day mission, "dedication to exploring molecular biology and genetics in order to advance
17690-584: The β-form). Although incorrect in their details, Astbury's models were correct in essence and correspond to modern elements of secondary structure , the α-helix and the β-strand (Astbury's nomenclature was kept), which were developed twenty years later by Linus Pauling and Robert Corey in 1951. Hans Neurath was the first to show that Astbury's models could not be correct in detail, because they involved clashes of atoms. Neurath's paper and Astbury's data inspired H. S. Taylor (1941,1942) and Maurice Huggins (1943) to propose models of keratin that are very close to
17835-527: Was Molecular Biology of the Cell , in which he coordinated the work of a group of scientist-writers. His third was Recombinant DNA , which described the ways in which genetic engineering has brought new information about how organisms function. In 1968, Watson wrote The Double Helix , listed by the board of the Modern Library as number seven in their list of 100 Best Nonfiction books. The book details
17980-446: Was 'clearly the famous B-pattern found by Rosalind Franklin and R. Gosling'. Olby was referring to an X-ray image of B-form DNA that was taken a year later by Rosalind Franklin and her PhD student Raymond Gosling at King's College a year later which came to be known as 'Photo 51' Despite its modest name this image was to play an important role in the story of DNA and a plaque on the wall outside King's College, London hails it as 'one of
18125-511: Was a potter and provided comfortably for his family. Astbury also had a younger brother, Norman, with whom he shared a love of music. Astbury might well have become a potter but, luckily, won a scholarship to Longton High School , where his interests were shaped by the Headmaster and second master, both chemists . After becoming head boy and winning the Duke of Sutherland 's gold medal, Astbury won
18270-467: Was a landmark study conducted in 1944 that demonstrated that DNA, not protein as previously thought, carries genetic information in bacteria. Oswald Avery , Colin Munro MacLeod , and Maclyn McCarty used an extract from a strain of pneumococcus that could cause pneumonia in mice. They showed that genetic transformation in the bacteria could be accomplished by injecting them with purified DNA from
18415-720: Was able to deduce from their diffraction patterns that the molecules of these substances were coiled and folded . This work led him to the conviction that the best way to understand the complexity of living systems was through studying the shape of the giant macromolecules from which they are made – an approach which he popularised with passion as 'molecular biology'. His other great passion was classical music and once said that protein fibres such as keratin in wool were 'the chosen instruments on which nature has played so many incomparable themes, and countless variations and harmonies' These two passions converged when in 1960 he presented an X-ray image taken by his research assistant Elwyn Beighton of
18560-418: Was able to obtain some external funding and he employed the crystallographer Florence Bell . She recognised that the "beginnings of life [were] clearly associated with the interaction of proteins and nucleic acids". Bell and Astbury published an X-ray study on DNA in 1938, describing the nucleotides as a "Pile of Pennies". Astbury and Bell reported that DNA's structure repeated every 2.7 nanometres and that
18705-500: Was an English physicist and molecular biologist who made pioneering X-ray diffraction studies of biological molecules . His work on keratin provided the foundation for Linus Pauling 's discovery of the alpha helix . He also studied the structure for DNA in 1937 and made the first step in the elucidation of its structure . Astbury was the fourth child of seven, born in Longton, Stoke-on-Trent . His father, William Edwin Astbury,
18850-551: Was an idea which truly came of age in the mid- to late 1970s with the rise of recombinant DNA technology by which time Astbury was dead but as his friend and colleague, J.D.Bernal wrote in an obituary to him, 'His monument will be found in the whole of molecular biology'. Astbury was known for his unfailing cheerfulness , idealism , imagination and enthusiasm . He foresaw correctly the tremendous impact of molecular biology and transmitted his vision to his students, "his euphoric evangelizing zeal transforming laboratory routine into
18995-491: Was conveyed to them by Maurice Wilkins and Max Perutz . Their work led to the discovery of DNA in other microorganisms, plants, and animals. The field of molecular biology includes techniques which enable scientists to learn about molecular processes. These techniques are used to efficiently target new drugs, diagnose disease, and better understand cell physiology. Some clinical research and medical therapies arising from molecular biology are covered under gene therapy , whereas
19140-429: Was given many awards and honorary degrees. At Leeds Astbury studied the properties of fibrous substances such as keratin and collagen with funding from the textile industry . ( Wool consists of keratin.) These substances did not produce sharp patterns of spots like crystals , but the patterns provided physical limits on any proposed structures. In the early 1930s, Astbury showed that there were drastic changes in
19285-510: Was his doctoral advisor. Originally, Watson was drawn into molecular biology by the work of Salvador Luria . Luria eventually shared the 1969 Nobel Prize in Physiology or Medicine for his work on the Luria–Delbrück experiment , which concerned the nature of genetic mutations . He was part of a distributed group of researchers who were making use of the viruses that infect bacteria , called bacteriophages . He and Max Delbrück were among
19430-445: Was one of over 2000 scientists and engineers who spoke out against nuclear proliferation to President Gerald Ford , arguing that there was no proven method for the safe disposal of radioactive waste, and that nuclear plants were a security threat due to the possibility of terrorist theft of plutonium. Watson's first textbook, The Molecular Biology of the Gene , used the concept of heads—brief declarative subheadings. His next textbook
19575-541: Was quoted in 2000, saying: "Whenever you interview fat people, you feel bad, because you know you're not going to hire them." Watson has repeatedly supported genetic screening and genetic engineering in public lectures and interviews, arguing that stupidity is a disease and the "really stupid" bottom 10% of people should be cured. He has also suggested that beauty could be genetically engineered, saying in 2003, "People say it would be terrible if we made all girls pretty. I think it would be great." In 2007, Watson became
19720-434: Was shown that the codons do not overlap with each other in the DNA sequence encoding a protein, and that each sequence is read from a fixed starting point. During 1962–1964, through the use of conditional lethal mutants of a bacterial virus, fundamental advances were made in our understanding of the functions and interactions of the proteins employed in the machinery of DNA replication , DNA repair , DNA recombination , and in
19865-432: Was significant for two reasons. Firstly they showed that X-ray crystallography could be used to reveal the regular, ordered structure of DNA – an insight which laid the foundations for the later work of Maurice Wilkins and Rosalind Franklin , after which the structure of DNA was identified by Francis Crick and James D. Watson in 1953. Secondly, they did this work at a time when most scientists thought that proteins were
20010-456: Was so interested in this idea that they built a pilot production plant in Scotland to a new textile fibre called 'Ardil' that was produced by deliberately altering the molecular structure of the main soluble protein component of monkeynuts to refold it into an insoluble fibre in the hope of using this as a cheap and abundant substitute for wool as a raw material in the textile industry. To demonstrate
20155-472: Was stationed in Cork, Ireland with the Royal Army Medical Corps during World War I . They married in 1922 and had a son, Bill, and a daughter, Maureen. James Watson This is an accepted version of this page James Dewey Watson (born April 6, 1928) is an American molecular biologist , geneticist , and zoologist . In 1953, he co-authored with Francis Crick the academic paper in Nature proposing
20300-474: Was that the idea was neither new nor worthy of merit, and that The Lancet published Watson's paper only because of his name. Other scientists have expressed their support for his hypothesis and have proposed that it can also be expanded to why a lack of oxidants can result in cancer and its progression. In 2014, Watson sold his Nobel Prize medal to raise money after complaining of being made an "unperson" following controversial statements he had made. Part of
20445-412: Was the discovery of the structure of DNA . This work began in 1869 by Friedrich Miescher , a Swiss biochemist who first proposed a structure called nuclein , which we now know to be (deoxyribonucleic acid), or DNA. He discovered this unique substance by studying the components of pus-filled bandages, and noting the unique properties of the "phosphorus-containing substances". Another notable contributor to
20590-418: Was the intellectual medium where Watson became a working scientist. Importantly, the members of the Phage Group sensed 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 genes were proteins and able to replicate themselves. The other major molecular component of chromosomes , DNA,
20735-540: Was to promote science, not racism, but some UK venues canceled his appearances, and he canceled the rest of his tour. An editorial in Nature said that his remarks were "beyond the pale" but expressed a wish that the tour had not been canceled so that Watson would have had to face his critics in person, encouraging scientific discussion on the matter. Because of the controversy, the board of trustees at Cold Spring Harbor Laboratory suspended Watson's administrative responsibilities. Watson issued an apology, then retired at
20880-486: Was typically determined by rate sedimentation in sucrose gradients , a slow and labor-intensive technique requiring expensive instrumentation; prior to sucrose gradients, viscometry was used. Aside from their historical interest, it is often worth knowing about older technology, as it is occasionally useful to solve another new problem for which the newer technique is inappropriate. William Astbury William Thomas Astbury FRS (25 February 1898 – 4 June 1961)
21025-556: Was widely considered to be a "stupid tetranucleotide", serving only a structural role to support the proteins. Even at this early time, Watson, under the influence of the Phage Group, was aware of the Avery–MacLeod–McCarty experiment , which suggested that DNA was the genetic molecule. Watson's research project involved using X-rays to inactivate bacterial viruses. Watson then went to Copenhagen University in September 1950 for
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