Edward B. Lewis
|Born||Edward Butts Lewis
May 20, 1918
|Died||July 21, 2004 (aged 86)
|Known for||Research into genetics of the common fruit fly|
|Thesis||A genetic and cytological analysis of a tandem duplication and its included loci in Drosophila melanogaster (1942)|
|Doctoral advisor||Alfred Sturtevant|
|Doctoral students||Mark M. Davis|
After serving as a meteorologist in the U.S. Air Force in World War II, Lewis joined the Caltech faculty in 1946 as an instructor. In 1956 he was appointed Professor of Biology, and in 1966 the Thomas Hunt Morgan Professor of Biology.
His Nobel Prize winning studies with Drosophila founded the field of developmental genetics and laid the groundwork for our current understanding of the universal, evolutionarily conserved strategies controlling animal development.
Effects of radiation[change | change source]
During the 1950s, Lewis studied the effects of radiation from X-rays, nuclear fallout and other sources as possible causes of cancer. He reviewed medical records from survivors of the atomic bombings of Hiroshima and Nagasaki, as well as radiologists and patients exposed to X-rays. Lewis concluded that "health risks from radiation had been underestimated". Lewis published articles in Science and other journals and made a presentation to a Congressional committee on atomic energy in 1957.
At the scientific level of the debate, the crucial question was whether the "threshold theory" was valid or whether, as Lewis insisted, the effects of radioactivity were "linear with no threshold", where every exposure to radiation had a long-term cumulative effect.
Genes regulating development[change | change source]
In a series of experiments with the fruit-fly Drosophila, Lewis was able to identify a complex of genes whose proteins bind to the regulatory regions of target genes. The latter then activate or repress cell processes which direct the final development of the organism.
Furthermore, the sequence of these control genes show co-linearity: the order of the loci in the chromosome parallels the order in which the loci are expressed in segments along the body. Not only that, but this cluster of master control genes programs the development of all higher organisms.
In his Nobel lecture, Lewis said "Ultimately, comparisons of the [control complexes] throughout the animal kingdom should provide a picture of how the organisms, as well as the [control genes] have evolved".
References[change | change source]
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- Davis, Mark Morris (1981). Programmed DNA rearrangements during differentiation : immunoglobulin class switching (PhD thesis). California Institute of Technology. OCLC 436997013.
- Scott, Matthew P; Lawrence, Peter A (2004), "Obituary: Edward B. Lewis (1918-2004).", Nature (published 2004 Sep 9), 431 (7005), p. 143, doi:10.1038/431143a, PMID 15356617 Check date values in:
- Crow, James F; Bender, Welcome (2004), "Edward B. Lewis, 1918-2004.", Genetics (published 2004 Dec), 168 (4), pp. 1773–83, PMC , PMID 15611154 Check date values in:
- Lipshitz H.D. 2004. Genes, development, and cancer: the life and work of Edward B. Lewis. Kluwer Academic, Boston.
- Edward Lewis, Nobelist who studied fly DNA, dies at 86
- Gerald H. Clarfield and William M. Wiecek 1984. Nuclear America: military and civilian nuclear power in the United States 1940-1980, Harper & Row, New York. p225
- Lewis E.B. 1995. The bithorax complex: the first fifty years. Nobel Prize lecture. Repr. in Ringertz N. (ed) 1997. Nobel lectures, Physiology or Medicine. World Scientific, Singapore.
- Lawrence P. 1992. The making of a fly. Blackwell, Oxford.
- Duncan I. 1987. The bithorax complex. Ann. Rev. Genetics 21, 285–319.
- Lewis E.B. 1992. Clusters of master control genes regulate the development of higher organisms. J. Am. Medical Assoc. 267, 1524–1531.
- McGinnis W. et al. 1984. A conserved DNA sequence in homeotic genes of the Drosophila antennipedia and bithorax complexes. Nature 308, 428–433.
- Scott M.P. and Weiner A.J. 1984. Structural relationships among genes that control developmental sequence homology between the antennipedia, ultrabithorax and fushi tarazu loci of Drosophila. PNAS USA 81, 4115.
- Gehring W. 1999. Master control systems in development and evolution: the homeobox story. Yale.
- Duncan I. and G. Montgomery 2002. E.B. Lewis and the bithorax complex. Part I. Genetics 160: 1265–1272. PMC free article:  Duncan I. and G. Montgomery 2002. E.B. Lewis and the bithorax complex. Part II. Genetics 161: 1–10. PMC free article