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 during our centenary year but also the huge variety of animals and physiological systems that are essential for the ‘comparative’ approach. David Matthews is an author on ‘ Locomotor effects of a fibrosis-based immune response in stickleback fish’, published in JEB. David conducted the research described in this article while a Graduate student in Dr George Lauder's lab at the Department of Organismic and Evolutionary Biology, Harvard University, USA. He is now a postdoc in the lab of Dr Craig Albertson at the Department of Biology, University of Massachusetts Amherst, USA, investigating the mechanisms by which genetic changes are translated into functional and fitness differences between individuals.

David Matthews

Describe your scientific journey and your current research focus

I began my research career as an undergrad studying the biomechanics of mantis shrimp predatory appendages. Although I was lucky to be exposed to several other fields through classes and internships, my research interests always came back to biomechanics. In my undergraduate thesis with Dr Craig Albertson, I was able to integrate these interests with genetics to address broader evolutionary questions, and through this experience discovered my career path. In grad school, I worked with Dr George Lauder to hone my understanding of the conceptual basis of biomechanics and the accompanying methodologies. I recently started a postdoc, again working with Dr Craig Albertson, to combine my biomechanical experience with his expertise in the genetic architecture of adaptation. I'm excited to take this next step in my research career that will hopefully be the culmination of my longstanding research goals to better understand the microevolutionary mechanisms of adaptation.

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

Wild freshwater stickleback fish are often infected with a tapeworm parasite that in the worst cases can kill the fish host. Unsurprisingly, many stickleback are capable of mounting an immune response to minimize the effects of the parasite. However, some populations of stickleback have actively suppressed this immune response, leaving themselves highly vulnerable to infection. This led us to ask whether the immune response itself carries negative effects that could cause the stickleback to prefer infection. Specifically, we asked whether the stiff (fibrotic) tissue that is deposited in the fish's body to help it fight infection might inhibit the fish's ability to escape predators. Surprisingly, we found that the immune response actually increased the speed at which stickleback swim away from a potential predator, indicating increased escape performance. This was exactly the opposite of what we expected, meaning that the reasons why some fish choose to suppress their immune system in the face of a deadly threat are still a mystery.

What are the potential implications of this finding for your field of research?

I think that one of the most important lessons of this work is that adaptation is extremely complex and can only be understood through a comprehensive, integrative and collaborative research program. In this case, we would expect that there must be severe and wide-reaching negative effects of the stickleback's immune response; why else would they suppress it when it could save their lives? However, in the realm of swimming performance, we found a positive impact of immunity. If the suppression of this immune response is adaptive in any way, we will only be able to understand it by studying the many possible impacts that it could have in all aspects of the fish's physiology, behavior and ecology.

Which part of this research project was the most rewarding/challenging?

The most challenging part of this project was that we had to measure so many phenotypes on the same fish in order to connect a fish's immune state to its swimming performance. This meant that my collaborators and I had to induce the immune response without using a parasite (to avoid confounding effects), measure the strength of the response, measure body stiffness in the fish, measure their behavior, and measure swimming performance. Many of these methods were new to me and required us to build custom experimental rigs, such as our fish bending apparatus that measured body stiffness. However, this challenge was also one of the rewarding aspects of the project because it taught me so much about how to address a novel research question and create the implements that you need to gather the necessary data.

Stickleback fish were placed into a custom three-point bending apparatus to measure their flexural stiffness in the presence and absence of a fibrosis immune response.

Stickleback fish were placed into a custom three-point bending apparatus to measure their flexural stiffness in the presence and absence of a fibrosis immune response.

Why did you choose JEB to publish your paper?

JEB was the first journal that I published in (though not as a first author), so I have always been aware of the scope and the rigorous nature of the journal. When it came time to submit this work for publication, I knew that it would fit in well with the scope of this journal and that the review process would be thorough and highly beneficial to the final published paper.

Are there any modern-day JEB papers that you think will be the classic papers of 2123?

One hundred years is a long time and it's hard to imagine what human knowledge will even look like at that point. However, I think that the scientific process is timeless. That's why I hope that ‘The best predictions in experimental biology are critical and persuasive’ by Douglas Fudge and Andy Turko (2020; doi:10.1242/jeb.231894) is considered a classic paper. Although this is a Commentary rather than a Research Article, I think it is an incredibly helpful guide for scientists at any career stage to learn how to make an effective hypothesis. It's easy to forget how much the exact wording of a hypothesis shapes the scientific process, and this paper serves as both a reminder of this fact and a guide on how to formulate a hypothesis to make our scientific work as rigorous as possible.

If you had unlimited funding, what question in your research field would you most like to address?

It has long been recognized that in order to understand natural selection we need to understand how differences in organisms affect their ability to perform in their environment, and in turn how this impacts that organism's fitness. However, the link between form and function has often been an endeavor best approached in the lab, while fitness can only be truly understood in the field. As each of these types of research is highly demanding independently of each other, few research groups have been able to effectively combine them. With unlimited funding, I would love to create a highly collaborative group of scientists with diverse backgrounds that could properly integrate these two worlds of research.

What changes do you think could improve the lives of early-career researchers, and what would make you want to continue in a research career?

I think one thing that could make a huge difference for both early-career researchers and for the field of biology as a whole is to reduce the importance of ‘impact factor’ in career advancement. It seems as though everyone recognizes that scientific merit is only a minor part of acceptance into the most prestigious journals, and that connections, ego and the current popularity of an individual's exact field are much larger indicators of acceptance. Despite this, common knowledge suggests that it is almost necessary to have a paper published in a high-impact journal to get many academic jobs. I think that this creates a huge amount of stress for early-career researchers and encourages them to decrease the rigor of their work to try to sell it. It would only be good for the people and for the field to move away from this model of evaluation.

David Matthews's contact details: Department of Biology, University of Massachusetts Amherst, Amherst, MA 01003, USA.

E-mail: [email protected]

Matthews
,
D. G.
,
Maciejewski
,
M. F.
,
Wong
,
G. A.
,
Lauder
,
G. V.
and
Bolnick
,
D. I.
(
2023
).
Locomotor effects of a fibrosis-based immune response in stickleback fish
.
J. Exp. Biol.
226
,
jeb246684
.