Name: Barbara McClintock Born: Hartford, Connecticut, June 16, 1902 Secondary Education: Erasmus Hall High School, Brooklyn, N.Y. harned Degrees: B.S., Cornell University, 1923 M.A., " " 1925 Ph.D., " " 1927 Honorary Doctor of Science: University of Rochester, 1947 Western College, 1949 Smith College, 1957 University of Missouri, 1968 Awards: Achievement Award, Association of University Women, 1947 Merit Award, Botanical Society of America, 1957 Kimber Medal, National Academy of Sciences, 1967 National Medal of Science, 1970 Positions Held: Instructor in Botany, Cornell University, 1927-1931 Fellow, National Research Council, 1931-1933 Fellow, Guggenheim Foundation, 1933-1934 Research Associate, Cornell University, 1934~1936 Assistant Professor, University of Missouri, 1936-1941 Staff Member, Carnegie Institution of Washington, 1941-1967 Distinguished Service Member, Carnegie Institution of Washington, 1967 to present. Andrew D. White Professor-at-Large, Cornell University, 1965 to present. Professional Societies: AAAS (Fellow) American Academy of Arts and Sciences American Philosophical Society American Society of Naturalists Botanical Society of America Genetics Society of America (Vice-President, 1939; President, 1945) National Academy of Sciences Sigma Xi abe BARBARA MeCLINTOCK: STATERUT OF ACHIEVES When Barbara McClintock began her graduate work at Cornell in the middle 1920's the foundations of maize genetics hed been firmly laid but comparatively little cytological work had been done. Maize was considered to be so poorly suited for cytological study that the heed of a fanous genetics laboratory forsook maize for Nicotiana in the mistaken belie? that the latter wes more favorable material for genetic research. McClintock arrived in the scientific arena at e propitious time. The carmine smear technique, which greatly faciliteted cytological studies, had just been developed by Belling. She quickly found that carmine smears of maize sporocytes et nidprophase of melosis yielded preparations of extraordinary beauty and clarity. Maise could now be used for detailed cytogenetic analyses of a kind heretofore izmossible with any organisn ena McClintock in the succeeding years published a series of renarkeble papers which clearly established her as the foremost investigator in cytogenetics. Eer first major contribution was the cgenonstration that the chromosomes were indivicually recognizable by their relative lengths end arm ratios, distinctive chrononmere patterns, and deep~ staining knobs in characteristic positions. ‘This ves folloved by such significant stucies as the analysis of translocation heterozygotes, the correlation of cytological and genetical crossing over, the assisment of linkage groups to specific chrososomes, the physical location of gene loci by deficiencies, the forustion of dicentric bridges end acentric fragnents as e result of crossing over in inversion heterozygotes, the somatic and melotic behavior of unsteble ring chromosomes, the occurrence of nonhomolesous pairings, the structure and function of the nucleoler organizing region, the production of viable homozygous Geficiencies that simulated gene mutation and formed 2 pseudoallelic series, and the genetic and cytological consequences of the bridzge~breakare-fusion cycle. Her current studies on the evolutionary history of races of maize as disclosed by the number and location of specific chromosome knobs have been conducted with typical precision end elegance. Among McClintock's outstanding contributions is her analysis of the control of gene action in maize and the discovery of the two-unit interacting system. This concept wes the precursor of the regulator-operon theory of gene resulation that won for its pronulga- tors, Jacob and Monod, the ijobel Prize in 1965. Her finding that the trans- position of controlling elements from one chromosomal location to another was accompanied by a change in gene action afforded a new and revolutionary insight into chromosome structure and genic expression, - Genetics would not occupy its present high estate were it not for her magnificent end pioneering contributions. | Her consummate skill and versatility as a cytologist are perhaps best evidenced by the fact that in the few weeks she devoted to tieurospora there resulted what remains more than tyventy years later as the definitive paper on the melotic chranosones of this fungus. So difficult cytolozically is Neurospora thet not even the correct chromosome nuxber vas known prior to her studies, An indication of the significance of her contributions to the present fabric of genetic theory may be hed from the number of tines her discoveries are specifically mentioned in several recent general texts. As a rule, in such books only the pioneering, the truly significant and illuminating Ciscoveries - the milestones - are cited. The record shows that her work is discussed 15 times in Strickberger, 26 times in Swenson, 10 tines in HWerskowitz, 8 tines in Srb, Owen and Edgar, and 18 tines in Levis end John, One of the remarkable things about Berbara HeClintock's surpassingly beautiful investigations is that they cane solely from ker own labors. Without technical help of any kind she has by virtue of her boundless energy, her complete cevotion to science, her originality and ingenuity, and her quick and high intelligence made a series of sipmificant discoveries unparalleled in the history of cytogenetics. A skilled experimentalist, a master at interpreting cytological detail, a brilliant theoretician, she has had an illuminating end pervasive role in the developrent of eytolosy and genetics. Biography of Barbara MeClintock ' America's most distinguished cytogeneticist, Barbara McClintock, was born in Hartford, Connecticut on June 16, 1902. After attending hish school in Hew York City, she enrolled at Cornell University in 1919 and from this institution received the 3. S. degree in 1923, the M. A. in 1925, and the Ph. D. in 1927. Ske served as a graduate assistant in the Department of Botany from 192h-27 and in 1927, following completion of her graduate studies, was appointed an Instructor, a post she held until 1931. Dr. McClintock was awarded a. National Research Council fellowship in 1931 and spent two years as a fellow at the California Institute of Technology. In 1933 she received a Guggenhein Fellowship which enabled her to spend a year abroad at Freiburg. She returned to the _ States and to the Department of Plant Breeding at Cornell in 1934. She left Cornell in 1936 to accept an Assistant Professorship in the Department of Botany at the University of Missouri. In 191 she Joined the staff of the Carnegie Institution of Washington, and began a heppy and fruitful association which has continued to the present time. She is currently a Staff Member of the Carnegie's Genetics Research Unit at Cold Spring Harbor, Long Island, New York. MeClintock was appointed Andrew D. White professor-at-larze at Cornell in 1965, a fitting recognition by her Alna Mater of the great distinction she has achieved as a scientist and scholar, . Barbara McClintock was awarded the honorary Doctor of Science degree by the University of Rochester in 1947, by Western College in 1949, and by Smith College in 1958. She was the recipient in 1947 of the Achievement Award of the Americen Association of University Wonen, was given the Avard of Merit by the Botanical Society of America in 1957 and most recently (1967) was selected by the tiational Acadeny of Sciences for the Kimber Award in Genetics. McClintock has been for many years a member of the Hatlonal Acadeny of Sciences and of the Arerican Prilosophical Society, as well a3 @ member of numerous professional organizations. She wes elected Vice President of the Genetics Society of America in 1939 and President in 1945. As Special Consultant to the Rockefeller Foundation she has in recent years been instrumental in advancing the training of geneticists in several Latin American ¢ountries. Selected List of Publications of Barbara MeClintock Beadle, G. W. and B. McClintock. A genic disturbance of meiosis in Zea nays. Science 68: 433. 1928. HeClintock, B. A cytological and genetical study of triploid maize. Genetics Lb: 160-222, 1929. McClintock, B. Chromosome uorphology in Zea mays. Seience 69: 629. 1929, McClintock, B.