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Tatum was a biochemist who shared the 1958 Nobel Prize for Medicine for discovering how genes regulate biochemical events in cells. This was based on some experiments he carried out with colleagues at Stanford University in 1941 which involved crossing normal strains of the pink bread mould, Neurospora crassa, with another strain of the mould they had exposed to X-rays to induce genetic mutations. The offspring were found to inherit the mutation which manifested itself as metabolic defect. This led them to conclude that there was a direct link between genes and enzymatic reactions.
14 Dec 1909
Edward L Tatum was born in Boulder CO, USA
Stanford University, Yale University
Thomas Hunt Morgan, American evolutionary biologist, links the inheritance of a specific trait with a particular chromosome in fruit flies (Drosophila).
Chromosomes linked with hereditary traits
van Beneden was a Belgian cytologist and embryologist. He worked out how chromosomes divide during cell meiosis. Based on studies of an intestinal worm found in horses, he also showed that fertilisation involves the union of two half-nuclei, one form the male sperm cell and one from the female egg, each containing half the the number of chromosomes found in all cells. He later demonstrated that the chromosome number is constant for every body cell in each species. 1910-04-28T00:00:00+0000
Fraenkel-Conrat was a biochemist who discovered that RNA is pivotal to the genetic control of viral reproduction and that it is carried in the nucelic core of each virus. This indicated that the viral infectivity resides in the nucleic acid part of the virus.
He made this finding in 1955 during experiments with the tobacco mosaic virus. By 1960 he had determined the complete sequence of the 159 amino acids in the virus. His work demonstrated that virus molecules that retain viral life can be reconstituted from its separate protein and RNA. 1910-07-29T00:00:00+0000
29 Jul 1910
Heinz Ludwig Fraenkel-Conrat was born in Breslau, German Empire
(now Wroclaw, Poland)
University of California Berkeley
Galton is best known for having ignited the debate about 'Nature versus Nurture' in 1869 and coined the term 'Eugenics' in 1883. Inspired by his cousin Charles Darwin's work, he developed a programme of research to understand human variation, looking at their differences in mental capabilities and height to facial characteristics and fingerprint patterns. He pioneered the use of statistical methods to determine human differences and how intelligence and physical traits are passed down through families. 1911-01-17T00:00:00+0000
17 Jan 1911
Francis Galton died
University College London
Stevens was an American biologist who was one of the first scientists to describe the importance of the Y chromosome for determining the sex of some species, and to recognise that females have two X chromosomes. This she determined after noting male beetles produced two kinds of sperm: each with different sized chromosomes. In 1905 she was awarded $1000 for the best scientific paper written by a woman. Five years later she was listed as one of America's leading 1000 scientists by The New York Times. 1912-05-04T00:00:00+0000
4 May 1912
Nettie Maria Stevens died
Bryn Mawr College, Carnegie Institute
Luria was a microbiologist who made his name in 1943 when he demonstrated, with Max Delbruck, that viruses undergo permanent changes in their hereditary material. The same year he and Delbruck showed phage-resistant bacteria resulted from spontaneous mutations rather than as a direct response to environmental changes. Their work helped explain how bacteria develop antibiotic resistance. Luria had landed up working with Delbruck in the US because he was banned from academic research fellowships in Italy under Mussolini's Italian fascist regime because of his Jewish background. In 1969 Luria was awarded the Nobel Prize for Medicine for helping to discover the replication mechanism and the genetic structure of viruses.
13 Aug 1912
Salvador E Luria was born in Torino, Italy
Massachusetts Institute of Technology
Mazia was a cell biologist whose passion was to understand how cells reproduce. As a doctoral researcher he was one of the first to establish the role of calcium in egg activation in the process of fertilisation. Following this, he worked on the process of cell division, structure and division. He is best known for the work he did in 1931 which helped identify the cell structure responsible for mitosis, the process when a eukaryotic cell divides chromosomes into two identical daughter cells. Mazia also determined how the nucleus and chromosomes change during the cell cycle.1912-12-18T00:00:00+0000
18 Dec 1912
Daniel Mazia was born Scranton, PA, USA
University of California Berkeley
Cell, Genetics, Reproduction
Dulbecco was a virologist who in the 1950s helped to pioneer the growth of animal viruses in culture and work out how certain viruses cause tumours in the cells they infect. He and his colleagues demonstrated that the virus inserted DNA into the DNA of the host cell and this cell transformed into a cancer cell which reproduced the viral DNA along with its own thereby producing more cancer cell. This work not only aided better understanding of how viruses cause cancer, but also HIV. Dulbecco shared the 1975 Nobel Prize for Medicine for his 'discoveries concerning the interaction between tumour viruses and the genetic material of the cell.'1914-02-22T00:00:00+0000
22 Feb 1914
Renato Dulbecco was born in Catanzaro, Italy
Imperial Cancer Research Fund Laboratory
Genetics, Virology, Oncology
Crick is best known for the work he did with James Watson that identified the double-helix structure of DNA in 1953, for which he shared the Nobel Prize for Medicine in 1962. He also developed the central dogma of molecular biology which explained how genetic information flowed within a biological system, moving from DNA to RNA and then protein. His subsequent work looked at the way in which the brain works and the nature of consciousness. 1916-06-08T00:00:00+0000
An American geneticist and physician, Sutton is famous for putting forward the theory that chromosomes are the carriers of genetic material. He developed the idea in 1902-1903 based on his work with grasshoppers. This research demonstrated there to be matched pairs of maternal and paternal chromosomes and that these separated during meiosis. 1916-11-10T00:00:00+0000
10 Nov 1916
Walter S Sutton died
Wilkins was a biophysicist whose development of x-ray diffraction techniques helped determine the structure of DNA. He obtained the first x-ray patterns on DNA in 1950. This work led to his winning the Nobel Prize in 1962. Following his work on DNA, Wilkins directed his attention to studying the structure of various forms of RNA and a wide group of genetic problems, like ageing. In his younger years, Wilkins was recruited to work on the Manhattan atomic bomb project during the war. Wilkins became profoundly disillusioned with nuclear weapons after the bombing of Japan and was the president of the British Society for Social Responsibility in Science from 1969 to 1991.
15 Dec 1916
Maurice H F Wilkins was born in Pongaroa, New Zealand
A geneticist by training, Sager enjoyed two careers. She first made her mark in the 1950s and 1950s when she discovered the transmission of genetic traits through chloroplast DNA. This was the first example of genetics not involving the cell nucleus. Later on, in the early 1970s, she became a major pioneer in cancer genetics. She was one of the first to propose and investigate the function of tumour suppressor genes. 1918-02-07T00:00:00+0000
7 Feb 1918
Ruth Sager was born in Brookline, Massachusetts, USA
Kornberg was a biochemist renowned for his research on enzymes which create DNA. In 1956 he and his team isolated the first enzyme known to be involved in the replication of DNA. It would be called DNA polymerase I. For this work Kornberg shared the 1959 Nobel Prize for Medicine. The Prize was given for the discovery of the 'mechanisms in the biological synthesis of ribonucleic acid and deoxyribonucleic acid.'1918-03-03T00:00:00+0000
Lewis was a developmental geneticist who shared the 1995 Nobel Prize for Medicine for discoveries concerning the genetic control of early embryonic development. He made these discoveries based on the fruit fly. By crossbreeding thousands of flies he demonstrated that genes were arranged on the chromosome in the same order as their body segments, whereby the first set of genes controls the development of the head and thorax, the middle set the abdomen, and the final set the hind parts. He also discovered that the genetic regulatory functions could overlap. A fly with a defective gene in the thoracic region could develop an extra set of wings. His work helped explain the causes of congenital deformities.
20 May 1918
Edward B Lewis was born in Wilkes-Barre, PA, USA
California Institute of Technology
Monod was a biochemist who, together with Francois Jacob, worked out the genetic control of enzyme and virus synthesis based on their experiments with Escherichia coli in the early 1960s. They proposed that a messenger molecule in cells carries codes from the DNA in the cell nucleus to the site of protein synthesis in the cell's cytoplasm. This molecule was later called messenger RNA which is now the basis of COVID-19 vaccines. Based on his work Monrod was awarded a Nobel Prize for Medicine in 1965.
7 Jun 1920
Jacques Monod was born in Nancy, France
Jacob was a French biologist who on the back of experiments in bacteria with Jacques Monod provided the first evidence of the existence and role of an intermediary molecule, now known as messenger RNA, which carries genetic information from genes to the cell's protein factories for the production of specific proteins. He shared the Nobel Prize in 1965 for 'discoveries concerning genetic control of enzyme and virus synthesis.'1920-06-17T00:00:00+0000
17 Jun 1920
Francois Jacob was born in Nancy, France
Witkin is best known for her work on DNA mutagenesis and DNA repair. She helped elucidate the first co-ordinated stress response. This she did by studying the response of bacteria to UV radiation. Witkins was one of the first few women to be elected to the US National Academy of Sciences, in 1977. She was also awarded the National Medal of Science in 2002. 1921-03-09T00:00:00+0000
The son of Jewish Polish immigrants, Benzer was a molecular biologist who proved that genetic mutations were caused by changes in the DNA sequence. This was based on some experiments he pursued with mutant T4 bacteriophages, known as r mutants. In 1952 he spotted abnormal behaviour in one mutant strain and a year later devised a technique to measure the recombination frequency between different r mutant strains to map the substructure of a single gene. His work laid the path to determining the detailed structure of viral genes. Benzer also coined the term cistron to denote functional subunits of genes. Together with Ronald Konopka, his student, Benzer also discovered the first gene to control an organism's sense of time, in 1971. 1921-10-15T00:00:00+0000
15 Oct 1921
Seymour Benzer was born in Brooklyn, NY, USA
Purdue University, California Institute of Technology
Khorana was a chemist who shared the 1968 Nobel Prize for Medicine for the elucidation of the genetic code and its function in protein synthesis. He helped demonstrate that the chemical composition and function of a new cell is determined by four nucleotides in DNA and that the nucleotide code is transmitted in groups of three, called codons, and these codons instruct the cell to start and stop the production of proteins. His work also laid the foundation for the development of polymerase chain reaction (PCR), a technique that makes it possible to make billions of copies of small fragments of DNA.
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