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Dr. James Van Etten

Jim Van Etten was born in Cherrydale Virginia and spent most of his youth in Peoria Illinois. He received his BA degree from Carlton College in Minnesota and attended graduate school at the University of Illinois where he received both his M.S. and PhD degrees in Plant Pathology. Following graduate school he received a National Science Foundation Postdoctoral Fellowship for studies in Molecular Biology at the University of Pavia, Italy. During his studies he accepted a faculty position at the University of Nebraska, Lincoln in the Department of Plant Pathology where he has remained ever since. He is currently the William Allington Distinguished Professor of Plant Pathology and Co-Director of the Nebraska Center for Virology.

Dr. Van Etten is a worldwide leader in the field of algal virology. He began his career working on the molecular biology of fungi and subsequently became interested in bacterial viruses, specifically Φ6 that was discovered through vital contributions by Van Etten, at the University of Nebraska. The Φ6 phage was the first double-stranded RNA bacteriophage; the first phage with a split, tripartite genome; the first phage with an external lipid envelope and for several years the only member of the virus family Cystoviridae. It is a potent interferon inducer of interest to industry (patent procured) and has been used as a model system for other dsRNA viruses.

In the early 1980s he discovered the first of many viruses of algae, namely Paramecium bursaria chlorella virus 1 (PBCV-1). Since then, viruses that infect the Chlorella algal symbiont of paramecia, found naturally in most fresh-water lakes and streams, have been his major interest. His group discovered that some of these Chlorella symbionts can be grown independently of their hosts and exploited this finding to develop a plaque assay for the associated viruses. This discovery provided the foundation for studies of the biology, replication and structure of these viruses that comprised the largest viruses identified at that time. In addition, using these methods, he and others in the scientific community were able to initiate worldwide searches for these algal viruses, which have now been discovered virtually everywhere searched. Cryo-electron microscopy and 3D image reconstruction of algal viruses show complex structures including external fibers that aid in host attachment. Some of these viruses are so large; they can be seen with an ordinary light microscope. They have genome sizes ranging from 160-560 kbp, but some of the oceanic algal viruses reach genome sizes up to 1 Mbp or more. Chlorella viruses together with even larger viruses that have more recently been identified are now often collectively referred to as giruses, some of which can encode up to 900 proteins and numerous transfer RNAs. They vary greatly in morphology, lifestyle and genome structure.

Van Etten and co-workers have found that the chlorella viruses (chloroviruses) are sources of numerous biological and genetic novelties including unexpected genes encoding proteins of commercial value and a variety of small, yet functional proteins that serve as biochemical models for mechanistic and structural studies. Through such studies, he and co-workers have made numerous, significant discoveries such as: 1) The chloroviruses were the first viruses discovered that infect a green plant and that are amenable to the aforementioned plaque assay; 2) The first such virus described, PBCV-1, had the largest sequenced viral genome known for almost a decade; 3) The chloroviruses encode many novel DNA restriction and modification enzymes, some of which are commercialized and were the first discovered outside a bacterium; 4) Chloroviruses encode the smallest functional potassium ion channel protein ever described; 5) They encode the smallest chromatin remodeling enzyme described; 6) Some chloroviruses encode a hyaluronan synthetase as well as the enzymes involved in synthesizing the sugars present in hyaluronan. This was the first time that a hyaluronan synthetase gene was discovered outside of vertebrates (and a few pathogenic bacteria); 7) Glycosylation of the chlorovirus major capsid proteins differs from all other viruses and the process, which occurs in the cytoplasm, is at least partially encoded by the virus; 8) Infection of the eukaryotic algal host differs from all other viruses that infect eukaryotic hosts, but resembles that of some bacteriophages. These highlights are just a few of the many original discoveries made by Van Etten. As an indication of his impact on the field, he and his co-workers have authored over half (over 185) of the current (~375) publications on chloroviruses and their genes and gene products.

Some of the large viruses can infect bacteria, protozoa and animals. In this context, one of the algal viruses Van Etten discovered, ATCV-1, garnered widespread media attention because portions of its genomic sequence were found in brain tissue of people afflicted with certain mental disorders such as depression. Algal viral sequences have also been found in the tissues (throat swabs) of seemingly healthy humans and in swabs of some people with cognitive disorders. Mice inoculated with the virus demonstrate deficits in memory and attention while navigating mazes. Popularly referred to as the “stupidity virus”, collaborative studies are continuing to reveal the intriguingly complex biology of these algal viruses and their role, if any, in human pathologies.

Throughout his incredibly productive career, Van Etten’s work has been continuously funded by numerous agencies such as the National Science Foundation, National Institutes of Health and the Department of Energy. He has provided service in a variety of capacities including leadership roles in the International Committee on the Taxonomy of Viruses and the International Congress of Virology. His achievements have led to a large number of awards including recognition as a Fellow of the American Phytopathological Society, the American Associations for the Advancement of Science, and the American Academy of Microbiology and election as a member of the United States National Academy of Sciences. Given his remarkably productive, and continuously groundbreaking research career, he is clearly deserving of the American Phytopathological Society’s Award of Distinction.