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Discovery of DNA Structure and Function: Watson and Crick By: Leslie A
01/08/2018 Discovery of DNA Double Helix: Watson and Crick | Learn Science at Scitable NUCLEIC ACID STRUCTURE AND FUNCTION | Lead Editor: Bob Moss Discovery of DNA Structure and Function: Watson and Crick By: Leslie A. Pray, Ph.D. © 2008 Nature Education Citation: Pray, L. (2008) Discovery of DNA structure and function: Watson and Crick. Nature Education 1(1):100 The landmark ideas of Watson and Crick relied heavily on the work of other scientists. What did the duo actually discover? Aa Aa Aa Many people believe that American biologist James Watson and English physicist Francis Crick discovered DNA in the 1950s. In reality, this is not the case. Rather, DNA was first identified in the late 1860s by Swiss chemist Friedrich Miescher. Then, in the decades following Miescher's discovery, other scientists--notably, Phoebus Levene and Erwin Chargaff--carried out a series of research efforts that revealed additional details about the DNA molecule, including its primary chemical components and the ways in which they joined with one another. Without the scientific foundation provided by these pioneers, Watson and Crick may never have reached their groundbreaking conclusion of 1953: that the DNA molecule exists in the form of a three-dimensional double helix. The First Piece of the Puzzle: Miescher Discovers DNA Although few people realize it, 1869 was a landmark year in genetic research, because it was the year in which Swiss physiological chemist Friedrich Miescher first identified what he called "nuclein" inside the nuclei of human white blood cells. (The term "nuclein" was later changed to "nucleic acid" and eventually to "deoxyribonucleic acid," or "DNA.") Miescher's plan was to isolate and characterize not the nuclein (which nobody at that time realized existed) but instead the protein components of leukocytes (white blood cells). -
Barbara Mcclintock's World
Barbara McClintock’s World Timeline adapted from Dolan DNA Learning Center exhibition 1902-1908 Barbara McClintock is born in Hartford, Connecticut, the third of four children of Sarah and Thomas Henry McClintock, a physician. She spends periods of her childhood in Massachusetts with her paternal aunt and uncle. Barbara at about age five. This prim and proper picture betrays the fact that she was, in fact, a self-reliant tomboy. Barbara’s individualism and self-sufficiency was apparent even in infancy. When Barbara was four months old, her parents changed her birth name, Eleanor, which they considered too delicate and feminine for such a rugged child. In grade school, Barbara persuaded her mother to have matching bloomers (shorts) made for her dresses – so she could more easily join her brother Tom in tree climbing, baseball, volleyball, My father tells me that at the and football. age of five I asked for a set of tools. He My mother used to did not get me the tools that you get for an adult; he put a pillow on the floor and give got me tools that would fit in my hands, and I didn’t me one toy and just leave me there. think they were adequate. Though I didn’t want to tell She said I didn’t cry, didn’t call for him that, they were not the tools I wanted. I wanted anything. real tools not tools for children. 1908-1918 McClintock’s family moves to Brooklyn in 1908, where she attends elementary and secondary school. In 1918, she graduates one semester early from Erasmus Hall High School in Brooklyn. -
Jewels in the Crown
Jewels in the crown CSHL’s 8 Nobel laureates Eight scientists who have worked at Cold Max Delbrück and Salvador Luria Spring Harbor Laboratory over its first 125 years have earned the ultimate Beginning in 1941, two scientists, both refugees of European honor, the Nobel Prize for Physiology fascism, began spending their summers doing research at Cold or Medicine. Some have been full- Spring Harbor. In this idyllic setting, the pair—who had full-time time faculty members; others came appointments elsewhere—explored the deep mystery of genetics to the Lab to do summer research by exploiting the simplicity of tiny viruses called bacteriophages, or a postdoctoral fellowship. Two, or phages, which infect bacteria. Max Delbrück and Salvador who performed experiments at Luria, original protagonists in what came to be called the Phage the Lab as part of the historic Group, were at the center of a movement whose members made Phage Group, later served as seminal discoveries that launched the revolutionary field of mo- Directors. lecular genetics. Their distinctive math- and physics-oriented ap- Peter Tarr proach to biology, partly a reflection of Delbrück’s physics train- ing, was propagated far and wide via the famous Phage Course that Delbrück first taught in 1945. The famous Luria-Delbrück experiment of 1943 showed that genetic mutations occur ran- domly in bacteria, not necessarily in response to selection. The pair also showed that resistance was a heritable trait in the tiny organisms. Delbrück and Luria, along with Alfred Hershey, were awarded a Nobel Prize in 1969 “for their discoveries concerning the replication mechanism and the genetic structure of viruses.” Barbara McClintock Alfred Hershey Today we know that “jumping genes”—transposable elements (TEs)—are littered everywhere, like so much Alfred Hershey first came to Cold Spring Harbor to participate in Phage Group wreckage, in the chromosomes of every organism. -
The Contributions of George Beadle and Edward Tatum
| PERSPECTIVES Biochemical Genetics and Molecular Biology: The Contributions of George Beadle and Edward Tatum Bernard S. Strauss1 Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois 60637 KEYWORDS George Beadle; Edward Tatum; Boris Ephrussi; gene action; history It will concern us particularly to take note of those cases in Genetics in the Early 1940s which men not only solved a problem but had to alter their mentality in the process, or at least discovered afterwards By the end of the 1930s, geneticists had developed a sophis- that the solution involved a change in their mental approach ticated, self-contained science. In particular, they were able (Butterfield 1962). to predict the patterns of inheritance of a variety of charac- teristics, most morphological in nature, in a variety of or- EVENTY-FIVE years ago, George Beadle and Edward ganisms although the favorites at the time were clearly Tatum published their method for producing nutritional S Drosophila andcorn(Zea mays). These characteristics were mutants in Neurospora crassa. Their study signaled the start of determined by mysterious entities known as “genes,” known a new era in experimental biology, but its significance is to be located at particular positions on the chromosomes. generally misunderstood today. The importance of the work Furthermore, a variety of peculiar patterns of inheritance is usually summarized as providing support for the “one gene– could be accounted for by alteration in chromosome struc- one enzyme” hypothesis, but its major value actually lay both ture and number with predictions as to inheritance pattern in providing a general methodology for the investigation of being quantitative and statistical. -
Genes, Genomes and Genetic Analysis
© Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION UNIT 1 © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FORDefining SALE OR DISTRIBUTION and WorkingNOT FOR SALE OR DISTRIBUTION with Genes © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Chapter 1 Genes, Genomes, and Genetic Analysis Chapter 2 DNA Structure and Genetic Variation © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Molekuul/Science Photo Library/Getty Images. © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC. NOT FOR SALE OR DISTRIBUTION 9781284136609_CH01_Hartl.indd 1 08/11/17 8:50 am © Jones & Bartlett Learning, LLC -
DNA the Central Dogma 3.4: Genes, Central Dogma • 3.5: Cell Division-Mitosis and Meiosis, • 3.6: Chromosomal Involvement, DNA Level of Involvement
U3 DNA the Central Dogma 3.4: Genes, Central Dogma • 3.5: Cell Division-Mitosis and Meiosis, • 3.6: Chromosomal involvement, DNA level of involvement. CENTRAL DOGMA • What is the central dogma of DNA? • The central dogma of molecular biology describes the two-step process, transcription and translation, by which the information in genes flows into proteins: DNA → RNA → protein. Transcription is the synthesis of an RNA copy of a segment of DNA. • Transcription is the synthesis of an RNA copy of a segment of DNA. RNA is synthesized by the enzyme RNA polymerase. Genes Are Located on Chromosomes (1910 – 1920s) Thomas Hunt Morgan discovers that genes are located on chromosomes. Working on fruit flies, he concludes that certain traits are linked to gender and that those traits are probably carried on one of the sex chromosomes (X or Y). He hypothesizes that other genes are also carried on specific chromosomes. Using chromosome recombination, he and his students map the locations of genes on chromosomes. Morgan and his students write the seminal book “The Mechanism of Mendelian Heredity”. Genes Control Biochemical Events George Beadle and Edward Tatum (1930) discover through experiments on neurospora, a bread mold, that genes are responsible for the production of enzymes. Their report is the genesis of the "one gene-one enzyme" concept. DNA Is the Genetic Material (1928, 1944, 1952) ◊ Several scientists prove that DNA is the chemical basis of genetic information. ◊ Oswald Avery proves that DNA carries genetic information. ◊ Linus Pauling discovers that many proteins take the shape of a spiral, like a spring coil. -
MCDB 5220 Methods and Logics April 21 2015 Marcelo Bassalo
Cracking the Genetic Code MCDB 5220 Methods and Logics April 21 2015 Marcelo Bassalo The DNA Saga… so far Important contributions for cracking the genetic code: • The “transforming principle” (1928) Frederick Griffith The DNA Saga… so far Important contributions for cracking the genetic code: • The “transforming principle” (1928) • The nature of the transforming principle: DNA (1944 - 1952) Oswald Avery Alfred Hershey Martha Chase The DNA Saga… so far Important contributions for cracking the genetic code: • The “transforming principle” (1928) • The nature of the transforming principle: DNA (1944 - 1952) • X-ray diffraction and the structure of proteins (1951) Linus Carl Pauling The DNA Saga… so far Important contributions for cracking the genetic code: • The “transforming principle” (1928) • The nature of the transforming principle: DNA (1944 - 1952) • X-ray diffraction and the structure of proteins (1951) • The structure of DNA (1953) James Watson and Francis Crick The DNA Saga… so far Important contributions for cracking the genetic code: • The “transforming principle” (1928) • The nature of the transforming principle: DNA (1944 - 1952) • X-ray diffraction and the structure of proteins (1951) • The structure of DNA (1953) How is DNA (4 nucleotides) the genetic material while proteins (20 amino acids) are the building blocks? ? DNA Protein ? The Coding Craze ? DNA Protein What was already known? • DNA resides inside the nucleus - DNA is not the carrier • Protein synthesis occur in the cytoplasm through ribosomes {• Only RNA is associated with ribosomes (no DNA) - rRNA is not the carrier { • Ribosomal RNA (rRNA) was a homogeneous population The “messenger RNA” hypothesis François Jacob Jacques Monod The Coding Craze ? DNA RNA Protein RNA Tie Club Table from Wikipedia The Coding Craze Who won the race Marshall Nirenberg J. -
In 1953 in England James Watson and Francis Crick Discovered the Structure of DNA in the Now-Famous Scientific Narrative Known As the “Race Towards the Double Helix”
THE NARRATIVES OF SCIENCE: LITERARY THEORY AND DISCOVERY IN MOLECULAR BIOLOGY PRIYA VENKATESAN In 1953 in England James Watson and Francis Crick discovered the structure of DNA in the now-famous scientific narrative known as the “race towards the double helix”. Meanwhile in France, Roland Barthes published his first book, Writing Degree Zero, on literary theory, which became the intellectual precursor for the new human sciences that were developing based on Saussurean linguistics. The discovery by Watson and Crick of the double helix marked a definitive turning point in the development of the life sciences, paving the way for the articulation of the genetic code and the emergence of molecular biology. The publication by Barthes was no less significant, since it served as an exemplar for elucidating how literary narratives are structured and for formulating how textual material is constructed. As Françoise Dosse notes, Writing Degree Zero “received unanimous acclaim and quickly became a symptom of new literary demands, a break with tradition”.1 Both the work of Roland Barthes and Watson and Crick served as paradigms in their respective fields. Semiotics, the field of textual analysis as developed by Barthes in Writing Degree Zero, offered a new direction in the structuring of narrative whereby each distinct unit in a story formed a “code” or “isotopy” that categorizes the formal elements of the story. The historical concurrence of the discovery of the double helix and the publication of Writing Degree Zero may be mere coincidence, but this essay is an exploration of the intellectual influence that both events may have had on each other, since both the discovery of the double helix and Barthes’ publication gave expression to the new forms of knowledge 1 Françoise Dosse, History of Structuralism: The Rising Sign, 1945-1966, trans. -
James Watson and Francis Crick
James Watson and Francis Crick https://www.ducksters.com/biography/scientists/watson_and_crick.php biographyjameswatsonandfranciscrick.mp3 Occupation: Molecular biologists Born: Crick: June 8, 1916 Watson: April 6, 1928 Died: Crick: July 28, 2004 Watson: Still alive Best known for: Discovering the structure of DNA Biography: James Watson James Watson was born on April 6, 1928 in Chicago, Illinois. He was a very intelligent child. He graduated high school early and attended the University of Chicago at the age of fifteen. James loved birds and initially studied ornithology (the study of birds) at college. He later changed his specialty to genetics. In 1950, at the age of 22, Watson received his PhD in zoology from the University of Indiana. James Watson and Francis Crick https://www.ducksters.com/biography/scientists/watson_and_crick.php James D. Watson. Source: National Institutes of Health In 1951, Watson went to Cambridge, England to work in the Cavendish Laboratory in order to study the structure of DNA. There he met another scientist named Francis Crick. Watson and Crick found they had the same interests. They began working together. In 1953 they published the structure of the DNA molecule. This discovery became one of the most important scientific discoveries of the 20th century. Watson (along with Francis Crick, Rosalind Franklin, and Maurice Wilkins) was awarded the Nobel Prize in Physiology or Medicine in 1962 for the discovery of the DNA structure. He continued his research into genetics writing several textbooks as well as the bestselling book The Double Helix which chronicled the famous discovery. Watson later served as director of the Cold Spring Harbor Lab in New York where he led groundbreaking research into cancer. -
A Giant of Genetics Cornell University As a Graduate Student to Work on the Cytogenetics of George Beadle, an Uncommon Maize
BOOK REVIEW farm after obtaining his baccalaureate at Nebraska Ag, he went to A giant of genetics Cornell University as a graduate student to work on the cytogenetics of George Beadle, An Uncommon maize. On receiving his Ph.D. from Cornell in 1931, Beadle was awarded a National Research Council fellowship to do postdoctoral work in T. H. Farmer: The Emergence of Genetics th Morgan’s Division of Biology at Caltech, where the fruit fly, Drosophila, in the 20 Century was then being developed as the premier experimental object of van- By Paul Berg & Maxine Singer guard genetics. On encountering Boris Ephrussi—a visiting geneticist from Paris— Cold Spring Harbor Laboratory Press, at Caltech, Beadle began his work on the mechanism of gene action. 2003 383 pp. hardcover, $35, He and Ephrussi studied certain mutants of Drosophila whose eye ISBN 0-87969-688-5 color differed in various ways from the red hue characteristic of the wild-type fly. They inferred from these results that the embryonic Reviewed by Gunther S Stent development of animals consists of a series of chemical reactions, each step of which is catalyzed by a specific enzyme, whose formation is, in http://www.nature.com/naturegenetics turn, controlled by a specific gene. This inference provided the germ for Beadle’s one-gene-one-enzyme doctrine. To Beadle and Ephrussi’s “Isaac Newton’s famous phrase reminds us that major advances in disappointment, however, a group of German biochemists beat them science are made ‘on the shoulders of giants’. Too often, however, the to the identification of the actual chemical intermediates in the ‘giants’ in our field are unknown to many colleagues and biosynthesis of the Drosophila eye color pigments. -
From Controlling Elements to Transposons: Barbara Mcclintock and the Nobel Prize Nathaniel C
454 Forum TRENDS in Biochemical Sciences Vol.26 No.7 July 2001 Historical Perspective From controlling elements to transposons: Barbara McClintock and the Nobel Prize Nathaniel C. Comfort Why did it take so long for Barbara correspondence. From these and other to prevent her controlling elements from McClintock (Fig. 1) to win the Nobel Prize? materials, we can reconstruct the events moving because their effects were difficult In the mid-1940s, McClintock discovered leading up to the 1983 prize*. to study when they jumped around. She genetic transposition in maize. She What today are known as transposable never had any inclination to pursue the published her results over several years elements, McClintock called ‘controlling biochemistry of transposition. and, in 1951, gave a famous presentation elements’. During the years 1945–1946, at Current understanding of how gene at the Cold Spring Harbor Symposium, the Carnegie Dept of Genetics, Cold activity is regulated, of course, springs yet it took until 1983 for her to win a Nobel Spring Harbor, McClintock discovered a from the operon, François Jacob and Prize. The delay is widely attributed to a pair of genetic loci in maize that seemed to Jacques Monod’s 1960 model of a block of combination of gender bias and gendered trigger spontaneous and reversible structural genes under the control of an science. McClintock’s results were not mutations in what had been ordinary, adjacent set of regulatory genes (Fig. 2). accepted, the story goes, because women stable alleles. In the term of the day, they Though subsequent studies revealed in science are marginalized, because the made stable alleles into ‘mutable’ ones. -
Joshua Lederberg – in Memoriam
ARTICLE-IN-A-BOX Joshua Lederberg – In Memoriam The foundations of the young science of molecular biology were laid towards the middle of the last century, primarily resting on a series of outstanding discoveries where microorganisms played a significant role. The exploitation of bacteria to address fundamental questions related to the nature of genes and how they function unleashed a steady stream of path-breaking discoveries during the 1940s and 50s. This was rather ironic since the term bacterial genetics would have been considered an oxymoron only a few years ago as the idea of bacteria possessing genes was alien to most geneticists who were busy working with plants, flies, and fungi. Joshua Lederberg, who passed away in February 2008, was one of the undisputed leaders of this molecular biology revolution. Lederberg’s work led to the discovery of two forms of genetic exchange in bacteria – conjugation and transduction. These discoveries had an enormous impact in opening up the genetic analysis of bacteria that resulted in other major breakthroughs such as the elucidation of the mechanism of gene regulation. For his contribu- tions to microbial genetics, Lederberg shared the 1958 Nobel Prize for Physiology or Medicine with Edward Tatum and George Beadle. Lederberg’s contributions however did not confine only to the field of bacterial genetics. He was keenly interested in exotic areas such as artificial intelligence, extra-terrestrial life (exobiology) and space exploration and made significant contributions to these fields too. He also championed the cause of disarmament and elimination of biological weapons. In a sense, he was also a science journalist as he regularly contributed articles dealing with science and public issues in the Washington Post and The Chronicle.