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Biochemistry and Molecular Biology

The 24th Annual Larry Ewing Lectureship

September 15, 2014


ewingDr. Ewing joined the School of Public Health in 1972 and over his time here his lab developed a method for the isolation of highly purified, steroidogenically active Leydig cells that is now used around the world.

He was the founder and later president of the Society for the Study of Reproduction, had over 130 major publications and held a patent on the sustained release of steroids for male contraception. Dr. Ewing had a significant impact on Reproductive Biology at Johns Hopkins University and we continue to build on his science today.


"The Role of Somatic Genome Instability during Oogenesis"
By Dr. Allan Spradling of The Carnegie Institution


ewing3Allan Spradling is the Twenty-Fourth Annual Larry L. Ewing Lecturer. Allan was born and raised in Kalamazoo, Michigan. He earned his bachelor’s degree in mathematics and physics from the University of Chicago and was awarded a Ph.D. in biology from MIT in 1975. It was as a graduate student that he began his life-long fascination with Drosophila and their use to study gene regulation and its consequences to cell function and fate and organismal development.



As a postdoctoral fellow at the University of Indiana, (1976-1979) Allan initiated his studies of the Drosophila ovary. There he discovered that eggshell genes undergo amplification during follicle development. In 1980 he began his distinguished career as a faculty member at the Carnegie Institution of Washington. Two years later, he and his colleague at the Carnegie, Gerry Rubin, demonstrated that transposable elements could be used to introduce DNA into the Drosophila genome.  This discovery revolutionized the genetic and molecular analysis of this complex organism.


At the Carnegie his laboratory has developed many lines of flies with transposable element-induced mutations and has made these lines available to the entire Drosophila research community.   His interest in oogenesis has led him to make fundamental discoveries about the mechanisms regulating oogonial stem cells of Drosophila. Those studies have highlighted the critical importance to germ line stem cell maintenance and differentiation of a specialized microenvironment, the stem cell niche. His laboratory has also identified intriguing similarities between mice and flies in early oocyte development.  

Allan Spradling is widely recognized for this scientific accomplishments and leadership. Allan was appointed as Investigator of the Howard Hughes Medical Institute in 1988 and Director of the Carnegie Institution of Washington in 1994. He was elected to the National Academy of Sciences and the American Academy of Arts and Sciences and is a Fellow of the American Association for the Advancement of Science. His awards include the National Academy of Sciences Molecular Biology Award, the George W. Beadle Medal, the E.F. Conklin Medal and the Gruber Foundation Medal in Genetics.