Today, genetics has become a frontier area for scientific research. There have been revolutionary breakthroughs in this field, that have made genetics a science with a great potential, particularly in medical sciences. Let's have a look at some famous scientists who have made an invaluable contribution to genetic research.
▸ Gregor Mendel
▸ Barbara McClintock
▸ Francis Crick
▸ Rosalind Franklin
▸ Friedrich Miescher
▸ James Watson
▸ Herbert Boyer
▸ Paul Berg
▸ Werner Arber
▸ Hamilton O. Smith
▸ Oswald Avery, Colin MacLeod, and Maclyn McCarty
Also known as the father of modern genetics, Gregor Mendel was an Augustinian monk. He was the second child of Anton and Rosine Mendel, and was born on July 22, 1822. He came from a poor farming family, and hence had to give private tuition in order to pay for his higher education. After completing his graduation, he was admitted to the University of Olmutz, in 1840, where he completed a two-year course in the fields of maths and physics. After coming back from Olmutz, he joined the monastery and gained exposure to the experimental and research facilities there. Mendel took his further education from the University of Vienna, and found a passion for teaching. However, he failed the teaching certificate exam twice and had to return to the monastery in Brunn. There, he continued his education and taught the students in the monastery.
Mendel's interest in research was based on his love for nature and interest in the field of evolution. He started his experiments on peas because they were available in many varieties and had many sets of contrasting characters, like tall and short plants, yellow and green seeds, wrinkled and smooth seeds, etc. The experiments conducted by him were simple and conclusive, the analysis of which gave him the two most important laws of inheritance; namely, the Law of Independent Assortment
and the Law of Segregation
. The former law states that, each trait is transferred independently from other traits, from the parents to the offspring. According to the latter, the traits of the offspring are not always similar to those of parent plants, as they are either separated or segregated during the formation of reproductive cells. He submitted his work to the Brunn Society of Natural Science on February 8, 1865. The paper was published in the next year, but didn't get much recognition. This happened largely because the paper had statistical data in it and did not match with popular beliefs of the time.
Biologists disregarded his work, saying that a statistician cannot give explanations for the laws in heredity. His work remained unrecognized till 1901, when three scientists Hugo de Vries, Carl Correns, and Erich von Tschermak independently discovered his work. Over time, his laws were scrutinized, and now they are considered as the fundamental laws of inheritance. However, his work saw the light of day very late, and he was not able to see its results. He was laid to rest on January 6, 1884, at the age of 62.
Barbara was an American scientist and one of the world's most distinguished cytogeneticists. She was born to Thomas Henry McClintock, a physician, and Sara Handy McClintock on June 16, 1902. She was born in Hartford, Connecticut, but in 1908, her family moved to Brooklyn, New York. She completed her secondary education in Erasmus Hall High School in Brooklyn and enrolled at the Cornell University in 1919 for further education. Barbara took a course in genetics in 1921 and received her B.S. in 1923. She got her M.A. in 1925, and a PhD in 1927. She served as a graduate assistant in the Department of Botany from 1924 to 1927.
In 1927, she was appointed as a botany instructor. In 1930, Barbara was the first person to describe the cross-shaped interaction of homologous chromosomes during meiosis. In 1931, along with a graduate student Harriet Creighton, she proved the link between chromosomal crossover during meiosis, and the recombination of genetic traits. She published the first genetic map for corn in 1931, showing the order of three genes on chromosome 9. In 1936, she accepted the position of an assistant professor in the Department of Botany, at the University of Missouri. In 1938, Barbara performed a cytogenetic analysis of the centromere, describing its organization and function. For her groundbreaking work in the field of genetics of corn, she earned a place among the leading contributors to genetics. In 1944, she became the third woman to be elected as a member of the prestigious National Academy of Sciences.
In the 1940s, Dr. Barbara first recognized jumping DNA while studying the peculiar inheritance patterns found in the colors of the Indian corn. Jumping DNA refers to certain stretches of DNA that are unstable and "transposable", meaning that they can move around, either on or between chromosomes. This theory was confirmed in the 1980s when scientists observed jumping DNA in other genomes. Almost half of the human genome is composed of transposable elements or jumping DNA. These transposons are believed to play a significant role in human evolution. In 1983, Barbara McClintock was awarded the Nobel Prize in Genetics for her work on mobile genetic elements. She also received the National Medal for Science, in 1971. Apart from this, she was the first woman to become the President of the Genetics Society of America.
She died in Huntington, New York on September 2, 1992, at the age of 90. To this day, her work is relevant despite the fact that much of it was completed over half a century ago, before the advent of the molecular era.
Francis Harry Compton Crick was born on June 8, 1916, in Northampton, England, to Harry Crick and Annie Elizabeth Wilkins. Crick received education from the Mill Hill School and Northampton Grammar School, London. He studied physics at the University College, London and obtained a Bachelor of Science in 1937. In 1949, after getting a scholarship from the Medical Research Council, he started working for the Strangeways Research Laboratory. He then moved to the Cavendish Laboratory at Cambridge, where he shifted his research on the structure of proteins.
In 1951, James Watson, an American biologist, joined the lab and both of them formed a strong working relationship. They believed that if a three-dimensional structure of the DNA could be determined, then the way the genes are passed on might also be revealed. Francis brought to the project his knowledge of X-ray diffraction, while Watson brought the knowledge of phage and bacterial genetics. They created a molecular model of DNA in 1953, which, over the next few years proved to fit all experimental evidence. This model demonstrated that DNA is a two-strand structure, and both the strands are intertwined like a twisted ladder. They published their work in the scientific journal Nature
, in 1952.
Another group of scientists of the King's College had also been studying the structure of DNA, which was led by Maurice Wilkins. Therefore, Francis, Watson, and Wilkins shared the Nobel Prize in Physiology or Medicine in 1962 for their discoveries concerning the molecular structure of nucleic acids and its significance for information transfer in living material. The trio was also presented the Lasker Foundation Award in 1960. Crick died of colon cancer on July 28, 2004, at the age of 88.
Rosalind was born on July 25, 1920 in Notting Hill, London. She was the second child of Ellis and Muriel Franklin. She did her schooling from the St. Paul's School for Girls and joined the Newnham College at the Cambridge University. She graduated in 1941, and joined BCURA (British Coal Utilisation Research Association) in 1942. For her work at BCURA, she received her PhD from the Cambridge University in 1945. She went to work as a research associate for John Randall at the King's College in London in 1951. A chemist by training, Rosalind had established herself as an expert in the structure of graphite and other carbon compounds before she moved to London. She learned many different techniques, and how to use them to extract DNA fibers and arrange them into bundles. Eventually, using this method, Rosalind discovered the key to DNA (deoxyribonucleic acid) structure. She, along with her student Raymond Gosling, made a discovery about the structure of DNA based on the pictures taken through X-ray diffraction.
Even though she had done an extensive study on the DNA structure, she did not get the credit for it, due to a conflict with another colleague Maurice Wilkins. Wilkins, without the knowledge of Franklin, took a photo taken by her and showed it to Watson and Crick. This made a crucial change in the history of DNA, as they made essential derivations from that photo and defined the structure of DNA before her. Besides other notable achievements, she was the first to produce photographs that clearly illustrated DNA's helical structure and to identify the location of phosphate sugars in DNA.
She joined the Birkbeck College in 1953, and shifted her research on the structure of coal. She also studied the tobacco mosaic virus and the structure of RNA which helped her in the further studies on viral structure. In 1956, Franklin was diagnosed with ovarian cancer. She died of the cancer on April 16, 1958, at the age of 37.
Friedrich Miescher was born in 1844, in Basel, Switzerland. He had lost his hearing ability due to a severe attack of typhoid. He entered a medical school and completed his graduation by 1868. After graduating, he chose medical research as his field of further study. He pursued organic chemistry in the Felix Hoppe-Seyler's laboratory in Tubingen. At the university, he studied the composition of lymphoid cells (white blood cells), which are present in the pus at wound sites. He collected these cells from bandages found near hospitals. He isolated a new molecule from these cells and named it "nuclein", as it was isolated from the nucleus of the cell. He also stated that nuclein is composed of phosphorous, in addition to other elements like carbon, hydrogen, and nitrogen. He isolated this compound from various other types of cells, and stated that these are present in every cell and might be the basis of heredity. It was years after his death that the nucleic acids were identified, and their role in heredity was identified. Miescher died of tuberculosis in 1895.
James Watson was born in Chicago, Illinois, on April 6, 1928. He completed his schooling from Horace Mann Grammar School and South Shore High School. He won a scholarship to the University of Chicago at the age of 15, under a special scholarship program for gifted students. He completed his graduation in zoology from the same university. He received his PhD from the Indiana University in Bloomington. His PhD thesis was the study of the effect of hard X-rays on the multiplication of bacteriophage, which got him interested in the work on X-ray diffraction patterns that was being conducted at the Cambridge University. At a symposium, Watson met Maurice Wilkins, who showed him the X-ray diffraction photographs of DNA. This made him steer his study towards the structural analysis of nucleic acids and proteins. He then joined the Cavendish laboratory of the Cambridge University in 1951, and met Francis Crick. By 1953, the duo put forward a double helical model of the DNA structure, for which they won the Nobel Prize in 1962. His work in the field of science gained him the membership of the American Academy of Arts and Sciences and the National Academy of Sciences.
Herbert Boyer was born on July 10, 1936, in Derry, Pennsylvania. He earned a bachelor's of science in biology and chemistry from Saint Vincent College, in 1958. He completed his master's and doctorate from the University of Pittsburgh. In 1966, Boyer became an assistant professor at the University of California, San Francisco. During this period, he started working on the isolation of restriction enzymes from E. coli
. During a visit to a conference in Hawaii, in 1972, he met Stanley Cohen, an associate professor of medicine at Stanford. Boyer became interested in Stanley's work on plasmids and they started working on the recombinant DNA technology. Cohen had discovered a method to introduce antibiotic-carrying plasmids into certain bacteria, and Boyer had isolated a restriction enzyme from E.coli
. The collaboration of the work done by these two scientists led to the formation of the first recombinant DNA. His contribution to the field of science gained him numerous awards, like the National Medal of Science, the Albany Medical Prize in 2004, etc.
Paul Berg was born on June 30, 1926, in Brooklyn, New York. He graduated in 1943 and joined New York's City College to study chemical engineering. But the field of chemical engineering didn't interest him enough to complete the course. Hence, he enrolled in the Pennsylvania State University to study biochemistry. During this period, he also enrolled in the Navy to be a flyer, which delayed his graduation till 1946. During the last year of his graduation, he came across papers about the use of radioisotopes to trace metabolic reactions. This led him to decide to pursue his PhD in this field. He completed his PhD from the Western Reserve University in 1952, and did post doctoral research for two years under the guidance of Dr. Hermann Kalckar, Institute of Cytophysiology and Dr. Arthur Kornberg, Washington University School of Medicine, Missouri. The research that he conducted in the years after, steered him from classical biochemistry to molecular biology. His study with the Polyoma and SV40 viruses along with mammalian cells, led to the development of recombinant DNA technology. He received the 1980 Nobel Prize in Chemistry for his contribution to the field of recombinant DNA technology. Apart from this, he was also awarded the National Medal of Science in 1983.
Werner Arber was born on June 3, 1929, in Granichen, Switzerland. He studied Natural Sciences at the Swiss Polytechnical School in Zurich from 1949 to 1953. In 1953, he took an assistant-ship for electron microscopy at the Biophysical Laboratory at the University of Geneva. During this period, he developed a keen interest in bacteriophage physiology and genetics, and wrote a dissertation on the defective lambda phage mutants. He completed his PhD in 1958, from the University of Geneva. The works of Larry Morse and Esther and Joshua Lederberg inspired him, and the help of Jean Weigle and Grete Kellenberger led him to his work in molecular genetics. He returned to Geneva in the early 1960s and started working with Gunther Stent in Berkeley, Joshua Lederberg in Stanford, and Salvador Luria at MIT, Cambridge. Here, he started working on the restriction and modification mechanism of E. Coli
, and various other aspects of its enzymology and molecular mechanisms.
He was appointed as Extraordinary Professor for Molecular Genetics at the University of Geneva in 1965. He shifted to Basel in 1971 and started research in the newly constructed Biozentrum, which was an interdisciplinary research laboratory. He received the 1978 Nobel Prize for his outstanding work in the discovery of restriction enzymes present in E. Coli
. He was elected as a fellow of the American Academy of Arts and Sciences in 1984, and is a member of the Pontifical Academy of Sciences since 1981.
Hamilton O. Smith
Hamilton Othanel Smith shared the 1978 Nobel Prize in physiology with Werner Arber and Daniel Nathans. He was born on August 23, 1931 in New York City. He graduated in mathematics from the University of California, Berkeley in 1952, and obtained a medical degree from the Johns Hopkins University in 1956. During the period between 1956 and 1962, he did clinical work in medicine at various places like the Washington University in St. Louis and the Henry Ford Hospital in Detroit. During this period, he gained knowledge in the fields of genetics and molecular biology and joined the University of Michigan for postdoctoral work, which was funded by the National Institute of Health. He returned to the Johns Hopkins University in 1965 and was a professor of microbiology in 1973. He joined the microbiology department of Johns Hopkins in 1967 and started working on the Haemophilus influenzae
virus. He discovered Hind II (a type of restriction enzyme) and also identified its cleavage site in 1968. This enzyme is still used as an invaluable tool in the field of genetic engineering.
In 1965, Smith collaborated with J. Craig at the Institute for Genomic Research (TIGR) and sequenced the whole genome of the H. influenzae
virus. In 1998, he joined Celera Genomics and helped in the sequencing of human and drosophila genome. Currently, he is working with Synthetic Genomics to produce biofuel from recombinant algae.
Oswald Avery, Colin MacLeod, and Maclyn McCarty
Oswald Avery was born on October 21, 1877, in Halifax, Nova Scotia. He was very good at playing the cornet, which gained him a scholarship at the National Conservatory of Music. He joined the Colgate University in 1893 and passed with a B.A. After graduating, he joined the College of Physicians and Surgeons in New York, and earned a medical degree in 1904. In 1917, he joined the Rockefeller Institute and started with his research on Pneumococcus
Colin MacLeod was born on January 28, 1909, in Port Hastings, Canada. He joined the MacGill University at the age of 16, and completed his medical degree by 23.
Maclyn McCarty was born on June 9, 1911, in South Bend, Indiana, U.S. He did his premed training in 1929 from Stanford University, and completed his medical degree from Johns Hopkins University. In 1942, he was awarded a scholarship from the National Institute of Health, and he chose to join Avery's lab at the Rockefeller Institute.
In 1934, Colin MacLeod joined Avery's lab at the Rockefeller, and in 1941, Maclyn McCarty joined them. The trio started working on the transformation principle together. In 1944, they published their work on the transforming principle, which stated that a nucleic acid was the chemical basis for heritable transformations in bacteria.
Another honorable name in this field is that of Charles Darwin. He is well-known for his contribution to evolutionary biology, but his contribution to genetics is less known. His main contribution to the field was his collection of tremendous genetic data, and his attempt to provide enough evidence for his interpretations. He described many genetic phenomena and formulated the developmental theory of genetics, which is known as pangenesis
. This theory influenced many subsequent theories, and is supported by various recent evidences.
This was information on some of the most famous scientists in genetic research and their contribution to this field. Their work in genetics led to some groundbreaking discoveries pertaining to genetic variations across populations, inheritance of traits, diversity in the characteristics of living beings, and evolution of life.