ECR Spotlight is a series of interviews with early-career authors from a selection of papers published in Journal of Experimental Biology and aims to promote not only the diversity of early-career researchers (ECRs) working in experimental biology but also the huge variety of animals and physiological systems that are essential for the ‘comparative’ approach. Jason Dallas is an author on ‘ Cross-species gut microbiota transplantation predictably affects host heat tolerance’, published in JEB. Jason conducted the research described in this article while a PhD student in Dr Robin Warne's lab at Southern Illinois University, USA. He is now a postdoctoral research assistant in the lab of Dr Donald Walker at Middle Tennessee State University, USA, investigating herpetofauna ecophysiology including thermal biology, host microbiome and responses to human activity.

Jason Dallas

How did you become interested in biology?

As with many researchers who ultimately enter the field of biology, I was always interested in animals when I was young, ranging from whales to insects, which represented a large amount of my bedroom's bookshelf. Yet, I always had a particular fascination with amphibians and reptiles, which ultimately led to me nearly being left behind in the Philadelphia Zoo reptile house on an elementary school field trip. Nonetheless, I showed little interest in biology throughout the remainder of my pre-collegiate education, focusing on other topics including engineering and computer programming. It was not until I was selecting an undergraduate university that I shifted my focus to environmental science, because I had developed interest in climate change and the widescale effects humans were having on the planet. This ultimately led me to choose Rider University as my undergraduate institution, where I reignited my passion in herpetology.

Describe your scientific journey and your current research focus

I joined a neurobiology lab during my freshman year at Rider University, USA, focused on studying the circadian rhythm of mice and how the inclusion of a shelter would influence their response to shifting light–dark cycles. This experience offered me the opportunity to gain experience in designing an experiment while also working with animals in a research laboratory setting. It also taught me that I was definitely not a neurobiologist as I then moved to Daniel Druckenbrod's lab studying dendrochronology and examined many tree cores from Monticello, Thomas Jefferson's home. Later, I was offered the opportunity to conduct research on freshwater turtles during my undergraduate program as part of a larger project focusing on how urbanization affects their population structure. This was my first foray into research on herpetofauna and I found it incredibly rewarding. It also showed me that I had the chance to make a career out of researching herpetofauna. With this experience, I then pursued a master's degree at Shippensburg University working with northern black racers and their effects on the local snake community in Pablo Delis's lab. During this time, I gained substantial field experience handling a wide diversity of herpetofauna, which only further piqued my research interests in a PhD program at Southern Illinois University in Robin Warne's lab. My PhD research covered a variety of topics ranging from the cloacal microbiome of snakes to the thermal physiology of an exotic gecko species and manipulating the gut microbiota of larval wood frogs. The wood frog research resulted in my shift towards focusing on the gut microbiota of herpetofauna, a topic that is only beginning to receive greater attention. My current position as a postdoctoral researcher in Donald Walker's lab at Middle Tennessee State University is building upon this by examining bacterial-fungal interactions in herpetofauna with particular focus on the Basidiobolus and Ophidiomyces fungi.

How would you explain the main findings of your paper to a member of the public?

All multicellular organisms harbor a complex and diverse community of microorganisms, such as bacteria, fungi, and viruses, which are referred to as the host microbiome. The microbiome assists its hosts with a variety of functions ranging from enhancing the energy acquisition from their diet to modulating the immune system and, ultimately, maintaining host health and performance. Additionally, due to the unique nature of the microbiome being a dynamic community, experimental manipulation of the microbiome can result in diverging host phenotypes allowing researchers to link the microbiome community to host biology. This includes the transplantation of the microbiome community which has been shown to reverse gastrointestinal disorders in humans. As climate change is driving an increase in global temperatures and extreme heat events, many ectothermic animals will face a greater risk of heat stress. Resultantly, increases in heat tolerance levels will promote survival under predicted warming. My research identified that transplanting the gut microbiome from a heat tolerant frog species to a more heat sensitive species resulted in increased heat tolerance in the recipients. This result suggests that cross-species microbiome transplants may be a potential tool in protecting heat sensitive species from the ever-growing threat of climate change.

Why did you choose JEB to publish your paper?

JEB promotes research on the cutting edge of manipulative experiments examining animal physiology to a broad reader base and has been doing so for a century. This enables researchers across the globe to read novel results and think about how to integrate the methods in upcoming studies or address questions that arose from the published papers. Furthermore, it allows for reaching out to other researchers and the promotion of collaborative opportunities. I have great interest in and respect for the experimental studies that JEB publishes, and I wanted to offer my own research to this journal so that other researchers could see the unique results I observed.

A hot-water bath with flasks containing larval wood frogs to record their heat tolerance. Photo credit: Jason Dallas.

A hot-water bath with flasks containing larval wood frogs to record their heat tolerance. Photo credit: Jason Dallas.

What do you enjoy most about research, and why?

I greatly enjoy the general scientific process of being able to ask questions about phenomena in nature and designing hypotheses and experiments to best address these questions. Reading literature on the diverse methods that researchers have used to address similar questions also enables me to greatly expand my knowledge base when it comes to experimental design and statistical analyses. Also, the never-ending branching tree of science makes it so unique to me. The idea that you design a research study to answer specific questions that results in the formation of even more questions to pursue is incredibly interesting because it allows me to follow a branch of research in greater detail beyond my current project.

What is the hardest challenge you have faced in the course of your research and how did you overcome it?

For this particular study, it was the on-the-fly change that needed to be made in the experimental design due to a limitation in our equipment. The initial study design involved examining both heat and cold tolerance with respect to the different microbiome treatments. However, after a successful pilot study examining both heat and cold tolerance in larval wood frogs, the initial cold tolerance trial of the experimental animals did not yield useable results as I could not reach temperatures low enough to reach their cold tolerance. This resulted in a very stressful morning as I had to quickly shift the entire study design to solely focus on heat tolerance. In the end, this was the correct move and provided greater details on how the microbiome treatment influenced host thermal physiology.

What is the most important lesson that you have learned from your career so far?

Developing a strong plan/outline. Experimental projects are complex and can involve multiple people, laboratories, and a large number of study groups/animals. Prior to working in such research settings, much of my work was limited to field studies that often involved me working by myself, which made planning relatively easy. Once I began delving more into experimental projects, I realized my prior planning efforts would not suffice, so I had to spend significantly more time developing proper experimental methods and sample sizes.

Do you have a top tip for others just starting out at your career stage?

Get experience working in an undergraduate research lab. First, spend some time looking at the research the professors at your institution are conducting. If you find something that interests you, reach out to them asking if they would be willing to offer you the opportunity to work in their lab. Gaining this experience will enable you to see if (1) you like the research they are conducting and (2) you could see yourself continuing to do research in the future. Also, try to get your feet wet by dipping into the scientific literature pool. As it is a vast pool, having a professor to help you by sending particularly relevant papers that you can read and discuss with the professor or graduate students would enable the students to ask questions and discuss. This is an essential skill all scientists need to develop.

Jason Dallas's contact details: Middle Tennessee State University, Department of Biology, 440 Friendship St., Murfreesboro, TN 37132, USA.


J. W.
S. T. M.
R. W.
Cross-species gut microbiota transplantation predictably affects host heat tolerance
J. Exp. Biol.