Metabolism detective

How metabolic pathways change with time and circumstances fascinate Jason Tennessen.
March 25, 2024

Growing up on a dairy farm in eastern Wisconsin, Jason Tennessen (Ph.D., 2007) wondered why calves stop growing when they become adults. “Why don’t they all end up like Babe the Blue Ox?” he asked himself. Ditto for pigs and other farm animals that were part of his daily life. What secret signals inside an organism, he wondered, change over the course of its development?

It's been a bit of a winding road from those early-life musings to his current work studying metabolic pathways in fruit flies. But through it all, he has kept his mind fixed on improving understanding of the internal chemical transformations that regulate life.

Though an interest in biology can take many directions, Tennessen has had his eyes set on an academic career since he participated in an Upward Bound program for high school students at the University of Wisconsin-Green Bay. 

“That was the first time I realized you could get paid to be a scientist,” he says, “I just fell in love with it.” 

After earning his undergraduate degree in biology at Lawrence University, he began searching for a graduate program that could carry him forward on that path. Among the labs he visited was that of GCD professor Ann Rougvie, who was using C. elegans to investigate just the kinds of questions that intrigued him back on that Wisconsin farm.

“That’s why I came to Minnesota,” he says. “This lab was in the thick of the revolution around how genes are regulated in the context of growth and maturation and how they make the decisions to go from juvenile stage to the adult stage.”

Tennessen spent the next six years exploring the role of factors like stress and dietary nutrients in maturation. “I feel very lucky to have been in the Ph.D. program at Minnesota, in Ann’s lab. That was a very nurturing environment,” he says. “It’s clear the faculty really cared about us.”

After completing his Ph.D., he went on to a postdoctoral position at the University of Utah. Originally planning to study how steroid hormones regulate maturation in fruit flies, he ended up shifting his focus to metabolism. That in turn led him to his current role as associate professor and associate chair for research and facilities in the Department of Biology at Indiana University. Today he not only conducts his own research but also is one of the people in charge of the world’s largest Drosophila stock center.

With a focus on how an animal’s metabolism changes in response to environmental stimuli, Tennessen’s current investigations have numerous implications for human well-being. One major project he leads is investigating how herbicides and other chemicals alter metabolic pathways. Another is exploring how sugar metabolism changes as an organism matures – a key factor in the development of Type 2 diabetes. 

Advice to today’s students pondering their next steps? 

“First of all, you have to find something you love, a problem you truly find interesting,” he says. “Second is to look for problems that are not necessarily popular: If you find something you love but half the world is working on it, you’re going to have a hard time getting funding and showing employers and funding agencies that you should be doing the work.

“And the last thing is, follow where the science takes you. Explore new techniques. Enter new fields.” 

Most of all, Tennessen advises, avoid the temptation to go it alone. “Don’t be afraid to collaborate,” he says. “You can do much more exciting science if you’re collaborating.” — Mary Hoff