Snell (Snell), George D.( The American geneticist, Nobel Prize in Physiology or Medicine, 1980)
Comments for Snell (Snell), George D.
Biography Snell (Snell), George D.
genus. December 19, 1903
. American geneticist George Davis Snell was born in Bradford (Massachusetts), . Family Catherine Snell (Davis), and Cullen Bryant Snell, . former secretary of the local Christian Youth Association and the inventor, . developed a method of winding induction coils,
. The family had three children, George was the youngest of them. When he was four years old, the family moved to Brooklyn. Tam C. enrolled in public school, where he showed his special interest in mathematics and science. In his youth with. loved to read books on astronomy and physics, as well as playing soccer with friends.
In 1922, Mr.. S. enrolled at Dartmouth College. Initially, his favorite subjects were mathematics and physics, but in the future, wrote S., 'genetics course, read to us by Professor John Dzherouldom turned out to be surprisingly exciting, and that's what determined the choice of my way'. In 1926, Mr.. S. received a bachelor of science degree at Dartmouth College and on the advice Dzheroulda began studying genetics at Harvard University. Here he worked under the direction of William Castle, the first American biologist, has applied Mendel's laws of heredity genetics mammals. Student research with. studied the coupling of two or more genes in the chromosome, restricting or eliminating their independent inheritance. This phenomenon, discovered in 1910. Thomas Hunt Morgan, was the subject of his doctoral dissertation S., which he defended in 1930
After obtaining his doctoral degree with. within two years he taught zoology, first in Dartmouth College, and then at Brown University. Then C. received a grant of the National Research Council, which gave him the opportunity to work within two years the University of Texas under the leadership of Hermann Muller. By studying the genetic effects of X-ray irradiation of mice with. first established that the exposure caused mutations in mammals. In 1933. S. became an assistant professor at Washington University in St. Louis (Missouri). But C. knew that going to do is not taught as a science, and so in 1935. became a member of Jacksonian laboratory.
Jackson Laboratory was established in Bar Harbor (Maine) in 1929. Clarence Cook Little, a former student of William Castle. This laboratory was to be the center of mammalian genetics research. Despite the fact that in 1935, when C. started working here Fellow, the laboratory was still small, it was already known thanks to the work of scientists on the genetics of mice. Under natural conditions it is impossible to find two species of mammals, with identical genes. However, Little and his colleagues conducted akin to mating (inbreeding) of individuals of many generations of mice, and the result of genetically homogeneous lines, all specimens were similar to each other as identical twins.
. During the first years of work in the laboratory with Jacksonian
. continued to study mutations caused by radiation exposure. In the late 30-ies., Completing the study, C. began to think about new research projects, in t.ch. concerning the genetic aspects of transplantation. By this time it was already known that organs transplanted from genetically different individuals, rejected. And while Little has found that this process is controlled not by one but by several genes, he could not show the separate influence of each of these genes. S. Similar genetic factors called genes histocompatibility. Based on his early work on the linked genes, he came to the conclusion that a particular gene or locus, which plays a critical role in prizhivanii or transplant rejection.
In 1937, Mr.. researcher at the London Hospital Guy Peter Gorer found that the reaction of graft rejection in mice involved tissue protein, which he called antigen II. In 1946, Mr.. Gorer moved to Jackson Laboratory, to work together with C. Scientists have found that antigen Gorera and histocompatibility locus Snell identical, so they are combining terms that have entered a new - H-2 gene (from the English word Hictocompatibility - histocompatibility). However, their investigation hampered by the fact that we compare the mouse lines differed not only in the presence of these genes, but also many other features.
With. had the idea that derived through inbreeding of laboratory mice can be used to select genes responsible for graft rejection. To this end, he crossed mice of two inbred lines - A and B fabrics are mutually do not take root. From the hybrid offspring of these mice, he chose those who reject tissue of mice of strain A, and crossed them with mice of strain A. After several generations through a number of genes in the genotype of these animals gradually increased, though still had little detached tissue of mice of strain A, ie. possessing genes histocompatibility Line In. After about 20 generations. received a line of mice, identical mice A, but capable of taking grafts from mice and in mice from rejecting A.
In 1946, Mr.. S. proceeded to the removal of such 'resistant mice with reciprocal gene', but the next year in Jacksonian laboratory fire occurred, the first received line were destroyed, and C. was forced to start work first. By the mid 50-ies. He received a number of lines of mice with reciprocal gene and proceeded to the comparison of selected genes histocompatibility. 'We found a group of approximately 10 loci responsible for the rejection of the transplant - he wrote later. - One of these loci quite clearly stood out among others in its influence on the reaction of rejection '. This gene locus was H-2. By this time, C. Gorer and have already established that H-2 - this is not a separate gene, and a group of genes located in close proximity to each other in the same chromosome. In this regard, the locus of H-2 and several are located next to the genes were identified primarily histocompatibility complex - MHC (Major Histocompatibility Complex), then C. called it supergene.
In 1957. S. became a senior research fellow Jacksonian laboratory. Research RENAMO, which were often used inbred lines of mice bred to. and his colleagues have become particularly common place in the late 50's., after Jean Jean Dausset identified the first protein of human histocompatibility. In 1965, Mr.. Dosse hypothesized, . according to which many described by the time of histocompatibility rights are derived from one set of MHC genes (later he was named human leukocyte locus A, . or HLA), . similar to the system of H-2 mice,
. His assumption proved correct, the similarities between these systems in mice and humans has been thoroughly established.
With. pointed out that 'influence on the graft, apparently, has no relation to the true function of genes MNF'. An important step in studying this function was made by Baruch Benacerraf, who in 1969. found that the genes of the MHC complex depends on the protective immune reaction to some foreign bodies. In the mid 70-ies. number of researchers, . including Benacerraf, . working lesson regardless of each other, . set, . that proteins, . encoded complex MHC (these proteins are always on the surface of cells), . can play the role of those same 'key', . with which certain types of white blood cells (T cells) recognize the normal cells of the body (the so-called samoraspoznavanie) and distinguish them from the abnormal and foreign cells.,
. In 1980
. S., Doss, and Benacerraf was awarded the Nobel Prize in Physiology or Medicine "for their discoveries concerning genetically determined structures located on the surface of cells and regulating immune responses'. Researcher at the Karolinska Institute, George Klein, a congratulatory speech said: 'The complex MNF - this is an extremely sensitive surveillance system, revealing cells with changes in membrane. Furthermore, this set makes possible a mechanism for cell destruction, which, for one reason or another have foreign steel. This rejection of alien transplants - is just side effects'. Finally, Klein called the work of the laureates 'one of the most important links in the complex chain of modern biology'.
In other studies conducted in the laboratory Jacksonian, C. studied the genes that influence the reaction of graft rejection, but not members of the MHC complex, the genes of this complex is not responsible for tissue compatibility, and other aspects of prizhivaniya and transplant rejection.
In 1937, Mr.. S. married Rode Carson, in the family they have three sons. In 1969. S. left his job in the Jacksonian laboratory and retired, he currently lives and works in Bar Harbor, maintaining communication with researchers from around the world. S. - An avid gardener, he devotes a lot of time and his vegetable garden.
With. been awarded many prizes, t.ch. Osborne and Mendel Award of the American Institute of Nutrition (1951), Gregor Mendel medal of the Czechoslovak Academy of Sciences (1967), an international award Gardner Fund (1976) and Wolff Prize in Medicine Israel Fund Wolff (1978). He is a member of the National Academy of Sciences of the USA, Society of Transplantation and the American Society of geneticists.