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Alfred D. Hershey in 1953
Alfred Day Hershey
December 4, 1908
|Died||May 22, 1997 88) (aged|
|Alma mater||Michigan State University|
|Known for||Proof of DNA as genetic material of life|
|Awards|| Albert Lasker Award for Basic Medical Research (1958)|
Nobel Prize in Physiology or Medicine (1969)
|Fields||Bacteriology, genetics, DNA|
|Institutions||Washington University Medical School|
Alfred Day Hershey (December 4, 1908 – May 22, 1997) was an American Nobel Prize–winning bacteriologist and geneticist.
He was born in Owosso, Michigan and received his B.S. in chemistry at Michigan State University in 1930 and his Ph.D. in bacteriology in 1934, taking a position shortly thereafter at the Department of Bacteriology at Washington University in St. Louis.
He began performing experiments with bacteriophages with Italian-American Salvador Luria, German Max Delbrück, Indian-Canadian Adam Hasnain, and Serbian Mila Huhtala in 1940, and observed that when two different strains of bacteriophage have infected the same bacteria, the two viruses may exchange genetic information.
He moved with his research partner Martha Chase to Laurel Hollow, New York, in 1950 to join the Carnegie Institution of Washington's Department of Genetics, where he and Martha Chase performed the famous Hershey–Chase experiment in 1952. This experiment provided additional evidence that DNA, not protein, was the genetic material of life. Notable post-doctoral fellows in Hershey's lab include Anna Marie Skalka.
He became director of the Carnegie Institution in 1962 and was awarded the Nobel Prize in Physiology or Medicine in 1969, shared with Salvador Luria and Max Delbrück for their discovery on the replication of viruses and their genetic structure.
In 1981, Hershey became a founding member of the World Cultural Council.
Hershey had one child, Peter Manning Hershey (1956-1999) with his wife Harriet (often called Jill) (1918-2000). The family was active in the social network of Cold Spring Harbor Laboratories and regularly enjoyed the beach in season. Hershey was a Christian.
After Hershey died, another phage worker, Frank Stahl, wrote: "The Phage Church, as we were sometimes called (see Phage group), was led by the Trinity of Delbrück, Luria, and Hershey. Delbrück's status as founder and his ex cathedra manner made him the pope, of course, and Luria was the hard-working, socially sensitive priest-confessor. And Al (Hershey) was the saint."
A bacteriophage, also known informally as a phage, is a virus that infects and replicates within bacteria and archaea. The term was derived from "bacteria" and the Greek φαγεῖν, meaning "to devour". Bacteriophages are composed of proteins that encapsulate a DNA or RNA genome, and may have structures that are either simple or elaborate. Their genomes may encode as few as four genes and as many as hundreds of genes. Phages replicate within the bacterium following the injection of their genome into its cytoplasm.
The Hershey–Chase experiments were a series of experiments conducted in 1952 by Alfred Hershey and Martha Chase that helped to confirm that DNA is genetic material. While DNA had been known to biologists since 1869, many scientists still assumed at the time that proteins carried the information for inheritance because DNA appeared to be an inert molecule, and, since it is located in the nucleus, its role was considered to be phosphorus storage. In their experiments, Hershey and Chase showed that when bacteriophages, which are composed of DNA and protein, infect bacteria, their DNA enters the host bacterial cell, but most of their protein does not. Hershey and Chase and subsequent discoveries all served to prove that DNA is the hereditary material.
Max Ludwig Henning Delbrück, a German–American biophysicist, helped launch the molecular biology research program in the late 1930s. He stimulated physical scientists' interest into biology, especially as to basic research to physically explain genes, mysterious at the time. Formed in 1945 and led by Delbrück along with Salvador Luria and Alfred Hershey, the Phage Group made substantial headway unraveling important aspects of genetics. The three shared the 1969 Nobel Prize in Physiology or Medicine "for their discoveries concerning the replication mechanism and the genetic structure of viruses". He was the first physicist to predict what is now called Delbrück scattering.
Salvador Edward Luria was an Italian microbiologist, later a naturalized U.S. citizen. He won the Nobel Prize in Physiology or Medicine in 1969, with Max Delbrück and Alfred Hershey, for their discoveries on the replication mechanism and the genetic structure of viruses. Salvador Luria also showed that bacterial resistance to viruses (phages) is genetically inherited.
Martha Cowles Chase, also known as Martha C. Epstein, was an American geneticist who in 1952, with Alfred Hershey, experimentally helped to confirm that DNA rather than protein is the genetic material of life.
Cold Spring Harbor Laboratory (CSHL) is a private, non-profit institution with research programs focusing on cancer, neuroscience, plant biology, genomics, and quantitative biology.
Werner Arber is a Swiss microbiologist and geneticist. Along with American researchers Hamilton Smith and Daniel Nathans, Werner Arber shared the 1978 Nobel Prize in Physiology or Medicine for the discovery of restriction endonucleases. Their work would lead to the development of recombinant DNA technology.
Escherichia virus T4 is a species of bacteriophages that infect Escherichia coli bacteria. It is a member of virus subfamily Tevenvirinae and includes among other strains Enterobacteria phage T2, Enterobacteria phage T4 and Enterobacteria phage T6. T4 is capable of undergoing only a lytic lifecycle and not the lysogenic lifecycle.
Richard Johann Kuhn was an Austrian-German biochemist who was awarded the Nobel Prize in Chemistry in 1938 "for his work on carotenoids and vitamins".
Seymour Benzer was an American physicist, molecular biologist and behavioral geneticist. His career began during the molecular biology revolution of the 1950s, and he eventually rose to prominence in the fields of molecular and behavioral genetics. He led a productive genetics research lab both at Purdue University and as the James G. Boswell Professor of Neuroscience, Emeritus, at the California Institute of Technology.
Hamilton Othanel Smith is an American microbiologist and Nobel laureate.
The Luria–Delbrück experiment (1943) demonstrates that in bacteria, genetic mutations arise in the absence of selection, rather than being a response to selection. Therefore, Darwin's theory of natural selection acting on random mutations applies to bacteria as well as to more complex organisms. Max Delbrück and Salvador Luria won the 1969 Nobel Prize in Physiology or Medicine in part for this work.
The history of genetics dates from the classical era with contributions by Pythagoras, Hippocrates, Aristotle, Epicurus, and others. Modern genetics began with the work of the Augustinian friar Gregor Johann Mendel. His work on pea plants, published in 1866, established the theory of Mendelian inheritance.
Allan M. Campbell was an American microbiologist and geneticist whose pioneering work on Lambda phage has helped advance molecular biology in the late 20th century.
René Thomas (14 May 1928 - 9 January 2017 was a Belgian scientist. His research included DNA biochemistry and biophysics, genetics, mathematical biology, and finally dynamical systems. He devoted his life to the deciphering of key logical principles at the basis of the behaviour of biological systems, and more generally to the generation of complex dynamical behaviour. He was professor and laboratory head at the Université Libre de Bruxelles, and taught and inspired several generations of researchers.
The phage group was an informal network of biologists centered on Max Delbrück that contributed heavily to bacterial genetics and the origins of molecular biology in the mid-20th century. The phage group takes its name from bacteriophages, the bacteria-infecting viruses that the group used as experimental model organisms. In addition to Delbrück, important scientists associated with the phage group include: Salvador Luria, Alfred Hershey, Seymour Benzer, Gunther Stent, James D. Watson, Frank Stahl, and Renato Dulbecco.
Jean-Jacques Weigle was a Swiss molecular biologist at Caltech and formerly a physicist at the University of Geneva from 1931 to 1948. He is known for his major contributions on field of bacteriophage λ research, focused on the interactions between those viruses and their E. coli hosts.
Gisela Mosig was a German-American molecular biologist best known for her work with enterobacteria phage T4. She was among the first investigators to recognize the importance of recombination intermediates in establishing new DNA replication forks, a fundamental process in DNA replication.
Charles “Charley” M. Steinberg was an immunobiologist and permanent member of the Basel Institute for Immunology. He was a former student of Max Delbrück. Notably he hosted Richard Feynman at Caltech when the physicist studied molecular biology, leading Feynman to remark that Charlie was “...the smartest guy I know”. He was instrumental in the discovery of V(D)J recombination, bacteriophage genetics as part of the phage group and co-discoverer of the amber-mutant of the T4 bacteriophage that led to the recognition of stop codons.