Ernest everett just lecture, 1999. The value of mentoring in the career of a young scientist

Abstract

It is with humility and pride that I accept the E.E. Just award, and it is a privilege to present the Just Lecture for 1999. Just was a brilliant scientist in his time—rubbing shoulders with the geniuses of the time, including Loeb and Lillie, and walking in the shadows of Conklin and other developmental biologists. Just’s tenets are today’s paradigms for cell and developmental biology and the neurosciences. Just has a special significance to me because he founded the Department of Zoology at Howard University. Looking back, Just would be proud to know that since its inception his department has graduated more than 5000 Bachelor of Science degree students. Just also developed the Masters program in Zoology at Howard University, the first at an HBCU. He also produced approximately 15 Masters students who went on to complete the doctorate degree, including Geraldine Pittman-Woods and Louis Hansborough. Just’s department has produced more than 200 Master of Science degrees, and the department evolved to produce approximately 12% of the nation’s African-American Ph.D.s in the biological sciences. Just indeed left massive footprints in the halls of academe—footprints that are difficult to fill but footprints and a career that are worthy of emulation. I am an alumnus of Just’s department where two University of Wisconsin‐trained scientists served as my mentors: one was Charles Brown, a cell biologist; the other Harold Finley, an eminent protozoologist. They pushed and guided me toward a career in the biomedical sciences. They knew that at that time it was in my best interest not to get three degrees from the same institution, but that I should go away for further graduate studies. Leaving Howard for Brown University represented a major change in my life. There I was confronted by a group of bright, well-prepared, and highly competitive graduate students. All 11 incoming students had the same schedule, interacting with each other and from two to four faculty in the same classroom daily for 1 year. Paul Weiss had just revised his textbook of biology, and we all had to assist in his undergraduate laboratories. We were privileged to be taught by brilliant developmental biologists like Mac V. Edds, Richard Goss, and then a young Paul Gross; cell biologists like J. Walter Wilson, Elizabeth Leduc, and Richard Ellis; and geneticists like Lederberg, Herman Chase, and Stanley Zimmering, and we had exposure to several bright young men and women like the Colemans, Gauthier, and Quevedo in the areas of cell and developmental biology. Consider the national environment during this period— the ASCB was only 2 years old, and the founders, including Fawcett, Palade, Porter, and Swift, ruled supreme. We were all caught up in this national enthusiasm and as cell biologists considered ourselves “cytonauts”— exploring the cell— discovering and defining, rediscovering, and redefining the structure and functions of organelles. We benefited from two technical advances: the first was that the epoxy resins replaced the methacrylates, and aldehydes like glutaraldehyde replaced the formalin fixatives for electron microscopy. Everything was new—and surprising, and scientists like Ledbetter and Porter were defining the structure and functions of microtubules in plant and animal cells. We too presented information on microtrubule structure and function, showing their association with compensatory hypertrophy of kidney cells after unilateral nephrectomy, and described subplasmalemmal microtubules involved in motility of trypanosomes, which a year earlier appeared as solid filaments in methacrylate-embeded material, which we called subpellicular filaments. With Dick Ellis and Anne Weissman, a bright undergraduate student, we wrote a paper on microtubules involved in sequestering 6 of more than 50 mitochondria to form the middle piece of some invertebrate spermatozoa and described the manchette microtubules associated with nuclei of spermatids differentiating to form spermatozoa. In 1962‐1963 Lehninger too had just published his book on the mitochondrion, with little mention of mitochondrial DNA. At the same time, Ris, Piko, and Steinert and others were pioneering research on DNA in mitochondria; that same year we presented information on the greatest mitochondrial DNA repository, which was located in the kinetoplast of the trypanosome. We were busily developing techniques to better visualize DNA in intact mitochondria in germinal cells and corpus luteal cells and to later visualize DNA circles with Lloyd Matsumoto on cytochrome c