A Passion for Parasites [Microbiology]

October 23rd, 2014 by Englund, P. T.

I knew nothing, and had thought nothing, about parasites until 1971. In fact, if you had asked me before then, I might have commented that parasites were rather disgusting. I had been at Johns Hopkins for 3 years, and I was on the lookout for a new project. In 1971, I came across a paper in Journal of Molecular Biology by Larry Simpson, a classmate of mine in graduate school. Larry's paper described a remarkable DNA structure known as kinetoplast DNA (kDNA), isolated from a parasite. kDNA, the mitochondrial genome of trypanosomatids, is a DNA network composed of several thousand interlocked DNA rings. Almost nothing was known about it. I was looking for a project on DNA replication, and I wanted it to be both challenging and important. I had no doubt that working with kDNA would be a challenge as I would be exploring uncharted territory. I was also sure that the project would be important when I learned that parasites with kDNA threaten huge populations in underdeveloped tropical countries. Looking again at Larry's paper, I found the electron micrographs of the kDNA networks to be rather beautiful. I decided to take a chance on kDNA. Little did I know then that I would devote the next 40 years of my life to studying kDNA replication.