Barbara McClintock was an American scientist and cytogeneticist who was awarded the 1983 Nobel Prize in Physiology or Medicine. McClintock received her PhD in botany from Cornell University in 1927. There she started her career as the leader of the development of maize cytogenetics, the focus of her research for the rest of her life. From the late 1920s, McClintock studied chromosomes and how they change during reproduction in maize. She developed the technique for visualizing maize chromosomes and used microscopic analysis to demonstrate many fundamental genetic ideas. One of those ideas was the notion of genetic recombination by crossing-over during meiosis—a mechanism by which chromosomes exchange information. She produced the first genetic map for maize, linking regions of the chromosome to physical traits. She demonstrated the role of the telomere and centromere, regions of the chromosome that are important in the conservation of genetic information. She was recognized as among the best in the field, awarded prestigious fellowships, and elected a member of the National Academy of Sciences in 1944.
Genetic recombination is the exchange of genetic material between different organisms which leads to production of offspring with combinations of traits that differ from those found in either parent. In eukaryotes, genetic recombination during meiosis can lead to a novel set of genetic information that can be further passed on from parents to offspring. Most recombination occurs naturally and can be classified into two types: (1) interchromosomal recombination, occurring through independent assortment of alleles whose loci are on different but homologous chromosomes ; & (2) intrachromosomal recombination, occurring through crossing over.
Calvin Blackman Bridges was an American scientist known for his contributions to the field of genetics. Along with Alfred Sturtevant and H.J. Muller, Bridges was part of Thomas Hunt Morgan's famous "Fly Room" at Columbia University.
A couple of homologous chromosomes, or homologs, are a set of one maternal and one paternal chromosome that pair up with each other inside a cell during fertilization. Homologs have the same genes in the same loci where they provide points along each chromosome which enable a pair of chromosomes to align correctly with each other before separating during meiosis. This is the basis for Mendelian inheritance which characterizes inheritance patterns of genetic material from an organism to its offspring parent developmental cell at the given time and area.
Mosaicism or genetic mosaicism is a condition in multicellular organisms in which a single organism possesses more than one genetic line as the result of genetic mutation. This means that various genetic lines resulted from a single fertilized egg. Mosaicism is one of several possible causes of chimerism, wherein a single organism is composed of cells with more than one distinct genotype.
Obaid Siddiqi FRS was an Indian National Research Professor and the Founder-Director of the Tata Institute of Fundamental Research (TIFR) National Center for Biological Sciences. He made seminal contributions to the field of behavioural neurogenetics using the genetics and neurobiology of Drosophila.
Alfred Henry Sturtevant was an American geneticist. Sturtevant constructed the first genetic map of a chromosome in 1911. Throughout his career he worked on the organism Drosophila melanogaster with Thomas Hunt Morgan. By watching the development of flies in which the earliest cell division produced two different genomes, he measured the embryonic distance between organs in a unit which is called the sturt in his honor. In 1967, Sturtevant received the National Medal of Science.
Brian Charlesworth is a British evolutionary biologist at the University of Edinburgh, and editor of Biology Letters. Since 1997, he has been Royal Society Research Professor at the Institute of Evolutionary Biology (IEB) in Edinburgh. He has been married since 1967 to the British evolutionary biologist Deborah Charlesworth.
Curt Stern was a German-born American geneticist.
Mitotic recombination is a type of genetic recombination that may occur in somatic cells during their preparation for mitosis in both sexual and asexual organisms. In asexual organisms, the study of mitotic recombination is one way to understand genetic linkage because it is the only source of recombination within an individual. Additionally, mitotic recombination can result in the expression of recessive genes in an otherwise heterozygous individual. This expression has important implications for the study of tumorigenesis and lethal recessive genes. Mitotic homologous recombination occurs mainly between sister chromatids subsequent to replication. Inter-sister homologous recombination is ordinarily genetically silent. During mitosis the incidence of recombination between non-sister homologous chromatids is only about 1% of that between sister chromatids.
Lilian Vaughan Morgan was an American experimental biologist who made seminal contributions to the genetics of the fruit fly, Drosophila melanogaster, which cemented its status as one of the most powerful model systems in biology. In addition to her scientific career, she was involved in science education and was one of the founders of the Children's School of Science in Woods Hole, Massachusetts.
Balancer chromosomes are a type of genetically engineered chromosome used in laboratory biology for the maintenance of recessive lethal mutations within living organisms without interference from natural selection. Since such mutations are viable only in heterozygotes, they cannot be stably maintained through successive generations and therefore continually lead to production of wild-type organisms, which can be prevented by replacing the homologous wild-type chromosome with a balancer. In this capacity, balancers are crucial for genetics research on model organisms such as Drosophila melanogaster, the common fruit fly, for which stocks cannot be archived. They can also be used in forward genetics screens to specifically identify recessive lethal mutations. For that reason, balancers are also used in other model organisms, most notably the nematode worm Caenorhabditis elegans and the mouse.
A recombinant inbred strain or recombinant inbred line (RIL) is an organism with chromosomes that incorporate an essentially permanent set of recombination events between chromosomes inherited from two or more inbred strains. F1 and F2 generations are produced by intercrossing the inbred strains; pairs of the F2 progeny are then mated to establish inbred strains through long-term inbreeding.
Laurence Marvin Sandler (1929–1987) was a "leading Drosophila geneticist", active during the mid-20th century. Sandler is best known for his work establishing and elucidating the phenomenon of meiotic drive.
Margaret Gale Kidwell is a British American evolutionary biologist and Regents’ Professor Emerita at the University of Arizona, Tucson. She grew up on a farm in the English Midlands during World War II. After graduating from the University of Nottingham in 1953, she worked in the British Civil Service as an Agricultural Advisory Officer from 1955-1960. She moved to the US in 1960 under the auspices of a Kellogg Foundation Fellowship to study Genetics and Statistics at Iowa State University. She married quantitative geneticist James F. Kidwell in 1961, obtained her MS degree in 1962 and moved with her husband to Brown University in 1963. She received her PhD from Brown University in 1973 under the guidance of Masatoshi Nei. From 1973 to 1984 she pursued independent research into a number of anomalous genetic phenomena in Drosophila which later lead to collaborative studies resulting in the discovery of hybrid dysgenesis and the isolation of transposable P elements. After appointment as Professor of Biology at Brown University in 1984 she moved to the University of Arizona in 1985 as Professor of Ecology and Evolutionary Biology. Additional positions included Chair of the Interdisciplinary Genetics Program from 1988-1991 and Head of the Department of Ecology and Evolutionary Biology from 1992-1997. Research at the University of Arizona has increasingly focused on the evolutionary significance of transposable genetic elements. In 1996, she was the first woman from Arizona to be elected to the United States National Academy of Sciences
Sarah Craven Bedichek Pipkin (1913–1977) was an American geneticist.
Abraham Bentsionovich Korol is a professor in the Institute of Evolution at the University of Haifa. He is a prominent Israeli geneticist and evolutionary biologist known for his work on the evolution of sex and recombination, genome mapping and the genetics of complex traits. Korol was born in Bendery city, Moldavia, then part of the Soviet Union, and immigrated to Israel in 1991. Before immigrating to Israel, Korol was appointed in 1981 as a senior researcher and was awarded the degree of Doctor of Science by the Presidium of Academy of Science USSR in 1988, and became a full professor in 1991. After immigrating to Israel in 1991, Korol has established and headed the Laboratory of Population Genetics and Computational Biology in the Institute of Evolution at the University of Haifa. He became full professor there in 1996 and served as the director of the Institute of Evolution between 2008-2013. Since 1994, Korol has filled many scholarly positions including member of the steering committee of Israeli Gene Bank; member of the Human Genome Organization; member of the European Society of Evolutionary Biology; a member of the Coordinating Committee of the International Wheat Genome Sequencing Consortium; member of the Infrastructure Steering Committee of the Israeli Ministry of Science; representative of Haifa University in the Kamea program steering committee ; member of the Advisory Committee of Absorption in Science of the Israeli Ministry of Absorption.
Helen Slizynska (1908-1977) was a geneticist at the University of Edinburgh who conducted important work on the fruit fly Drosophila.
R. Scott Hawley is an American geneticist and investigator at the Stowers Institute for Medical Research in Kansas City, Missouri, a member of the US National Academy of sciences and fellow of the American Association for the Advancement of Science. He has been President of the Genetics Society of America, and leads a research team focused on the molecular mechanisms that regulate chromosome behavior during meiosis.
Thomas Charles Kaufman is an American geneticist. He is known for his work on the zeste-white region of the Drosophila X chromosome. He is currently a Distinguished Professor of biology at Indiana University, where he conducts his current research on Homeotic Genes in evolution and development.
