Professor of Biochemistry

University of Iowa

I grew up on a farm in Iowa. After obtaining a B.Sc. degree in biophysics, I wasn’t sure what I wanted to do for a career, so I joined the American Peace Corps and was assigned to be a science and math teacher in Ghana, West Africa. My two years as a Peace Corps Volunteer were a fantastic experience. I taught in the 6^th-form (equivalent to American junior college) at a boarding school in Dormaa Ahenkro, an up-country town on the Ivory Coast border. I taught calculus, physics, organic & physical chemistry, and other subjects I myself had taken in college only a year or two before. The students were bright & highly motivated, knowing that education was their only way out of poverty. To this day, I have fond memories of Ghanaian people and their culture.

The students and townspeople in that part of Ghana were always battling infectious diseases, often coming down with malaria & schistosomiasis and occasionally getting African sleeping sickness or river blindness. Their only real medical help came from a poorly supplied mission hospital. At the time, I did not think I was interested in medicine. The school subscribed to Scientific American, which came by sea freight 8-10 months late, and I realized from reading it that a revolution was going on in molecular biology that I decided to participate in. So, I returned to the United States as a graduate student at Cornell University in upstate New York, and for the next nearly 10 years did not think much about the parasitic diseases I had seen in Ghana. I obtained a Ph.D. in biochemistry and did post-doctoral stints at the MRC Laboratory for Molecular Biology, in Cambridge, England, with Fred Sanger, who was soon to receive his second Nobel Prize, and at Stanford University with David Hogness in a Drosophila lab. I had the good fortune in Cambridge of helping to develop DNA sequencing techniques and at Stanford of contributing to the new recombinant DNA techniques. I became an Assistant Professor of Biochemistry at the University of Iowa and my first independent research projects were on yeast and Drosophila.

One evening at a party I had a chance conversation with George Cain, a parasitologist in the Biology Department at Iowa, who pointed out I should apply my molecular biology skills to studying the parasites that cause the tropical diseases I had seen in Ghana. As I thought about it, I was delighted to see a link between African diseases and the emerging power of molecular biology research. In 1980 I took a year’s sabbatical leave to work at an internationally funded laboratory in Nairobi, Kenya, East Africa, then called the International Laboratory for Research on Animal Diseases (ILRAD). ILRAD was a vibrant place and I learned to work in the laboratory on African trypanosomes, which cause African sleeping sickness. That was a watershed year for me. When I returned, I was no longer interested in model organisms such as yeast and Drosophila. Instead, I was committed to working on the parasites causing the diseases I had seen years earlier in Ghana. My laboratory’s first contribution in this area was to determine the sequences of two 1-kb minicircles of Trypanosoma brucei, at a time when DNA sequencing was still in its infancy. We went on to investigate the molecular basis of antigenic variation in T. brucei and other features of this continually fascinating protozoan organism. We also established long-term collaborations with two other faculty members at the University of Iowa, Mary Wilson and Vaughn Kirchhoff, on the study of Leishmania chagasi and Trypanosoma cruzi, which cause visceral leishmaniasis and Chagas disease, respectively, in Latin America. For a number of years we also studied Onchocerca volvulus, the worm that causes river blindness.

In the late 1980s and early 90s I participated for several years in the summer course on molecular parasitology at the Marine Biological Laboratory in Woods Hole, Mass. I had never taken a course in parasitology, so most of the basic parasitology I know was acquired by teaching and participating in this course. I thoroughly enjoyed the course and the stimulating scientific environment of Woods Hole.

The field of molecular parasitology has advanced and expanded enormously since I entered it a quarter century ago – to the point where we now know the entire genomic sequences of several tropical parasites. An awkward reality is that all of this increased knowledge has not translated into elimination, or even better management, of most of the tropical diseases I first saw in Ghana. Nevertheless, it often takes 25 years or more for basic science discoveries to be converted into practical applications. The next 25 years of molecular parasitology research should be as interesting and exciting as the past 25, and I am confident it will provide some real prospects to eliminate or better deal with parasitic infections in developing countries.