ECR Spotlight – Angus Thies Free

Angus Thies

How did you become interested in biology?

My love of the natural world, especially marine life, grew from spending my childhood summers finding horseshoe crabs on the tidal beaches of Cape Cod, digging razor clams along the North Shore, and scrutinizing grocery store lobsters in my home state of Massachusetts. The existence of alien-looking life beneath the waves has held my fascination ever since. I badgered my parents into trips to the New England Aquarium, where I spent hours following fish through their tanks and pestering patient volunteers with endless questions about how fish breathe water and how anemones move without skeletons. In middle school, I started keeping freshwater aquariums, breeding fish and invertebrates, and collecting local species from vernal pools in the woods. My obsession with marine biology only intensified in high school, when I learned how to SCUBA dive; I was even fortunate enough to make several trips to the Caribbean and see coral reefs firsthand. Those transformative dives will forever be enshrined in my memory and my fascination with otherworldly marine life evolved into questions of form and function: how do these animals work at the cellular and sub-cellular level? I decided to pursue an education in marine biology to find answers.

Describe your scientific journey and your current research focus

I attended the University of California, San Diego, for my undergraduate education specifically because it hosts Scripps Institution of Oceanography (SIO), a world-leader in marine and climate science research. As a Marine Biology major, I immediately began exploring volunteer research opportunities at SIO and over 4 years worked in developmental biology, paleoclimate, bioacoustics and physiology labs. I spent time working in the Caribbean at the School for Field Studies, where I focused on coral reef ecology, in Boston at the New England Aquarium as an animal husbandry intern, and in Oregon at the Environmental Protection Agency, where I tracked fecal microbe populations in estuarian aquaculture facilities. The single most impactful of these opportunities was my time volunteering in Martin Tresguerres' Comparative Marine Physiology Lab at SIO, where I was introduced to coral symbiosis research for the first time. My experience in the Tresguerres Lab inspired me to complete a joint BS/MS degree, during which I produced a thesis focused on characterizing a protein that orchestrates nutrient exchange between the coral host and its symbiotic algal partner. After a year working as an industry consultant to develop confocal microscopy platforms, I returned to the Tresguerres Lab as a PhD student funded by a National Science Foundation Graduate Research Fellowship. My research efforts focused on identifying mechanisms of nutrient exchange in intracellular invertebrate–algal symbioses including those of corals, anemones, jellyfish and sea slugs. I also worked on numerous projects concerning acid–base (pH) regulation in marine animals, establishment of symbiotic microbial relationships, biomineralization mechanisms and developing immunoassays. After my PhD, I completed a brief postdoc in the Tresguerres Lab before transitioning to an industry role as a Field Application Scientist for Meso Scale Discovery, the global leader for developing ultra-sensitive, multiplexed immunoassays for the detection of protein biomarkers. In this role, I partner with numerous academic and industry groups to develop custom immunoassays for detecting novel biomarkers relevant for life science, drug development and clinical research.

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

Many marine invertebrate animals, including corals and some jellyfishes, retain single-celled algae in their cells, forming symbiotic relationships: algae gain access to the carbon dioxide waste produced by the animal host and transform it via photosynthesis into energy-rich sugars and oxygen that satisfy the majority of the host's nutritional demands. Corals and jellyfish host similar algae but independently evolved symbiosis, resulting in two separate lineages of host cells. In coral host cells, algae are held in specialized intracellular spaces, called symbiosomes, that are modified to concentrate carbon dioxide and promote algal photosynthesis, thereby increasing sugar and oxygen production, which benefits the coral as a whole. Two proteins, the vacuolar-type H⁺-ATPase (VHA) and carbonic anhydrase (CA), support this carbon concentrating mechanism (CCM). Jellyfish host cells, called amoebocytes, also retain symbionts in symbiosomes, but display two major differences from coral host cells: (1) they host 3 to 6 times as many algae per cell and (2) they are highly mobile, roaming the greatly expanded connective tissues of jellyfishes. Given the independent evolutionary origin of jellyfish symbiosis and stark differences in development, morphology and motility of amoebocytes, we explored whether the amoebocytes of the upside-down jellyfish employ a similar VHA–CA-coupled CCM. We found that amoebocytes contain both VHA and CA at high abundance and closely associated with the symbiosome, and that VHA and CA activities enhance photosynthetic oxygen production. This indicates that while jellyfishes and corals independently evolved symbiosis, they employ the same cellular machinery to promote algal photosynthesis. These results establish links between food digestion, innate immunity and intracellular symbiosis that may broadly apply to invertebrate–algal and invertebrate–microbial symbioses.

Why did you choose JEB to publish your paper?

We chose to pursue publication in JEB because of its long history of hosting influential studies in experimental biology, making it an ideal platform for research on animal physiology, symbiosis and evolutionary biology. JEB reaches a broad audience of experimental biologists and prioritizes well-conceived, rigorously tested mechanistic studies aiming to uncover underlying biological processes. We additionally find the peer-review process at JEB to be timely, rigorous and constructive: both reviewers and editors provide thoughtful consideration, critiques and suggestions which strengthened this study and past submissions. Finally, we prioritize publishing in journals that have Open Access agreements with our host institution to ensure broad visibility of publicly funded research.

What is your favourite animal, and why?

My favorite animal is the upside-down jellyfish, Cassiopea! Besides being visually striking and pulsing hypnotically, their biology is fascinating. These soft-bodied invertebrates host photosynthetically active plants inside their cells and use them to recycle their metabolic waste products into fixed sugars and oxygen. Unlike other jellies that spend their lives swimming in the water column, Cassiopea rest tentacles-up on the bottom of shallow lagoons and reefs, trying to maximize their exposure to sunlight. Cassiopea still capture planktonic prey but meet most of their energy budget through symbiont photosynthesis. This symbiotic relationship is so essential to Cassiopea that baby jellyfish polyps won't develop into adult medusae unless they have an established population of symbionts. How cool is that?!

What do you like to do in your free time?

Living in San Diego, I try to spend most of my free time outdoors enjoying the wonderful year-round sunshine. I'm an avid rock climber, mountaineer, runner, spearfisher and freediver. Rock climbing and mountaineering hold special places in my heart: I began learning technical climbing skills at the very end of my undergraduate career and since then have made many pilgrimages to Yosemite and Joshua Tree National Parks, the High Sierras, and Potrero Chico National Park in Mexico to climb. I love climbing because it has taught me to trust myself in dangerous situations, pushes me to explore the more remote corners of nature, and allows me to participate in a supportive and highly driven community focused on environmental preservation and friendship.

What's next for you?

I recently transitioned from an academic postdoc to a Field Application Scientist position at Meso Scale Discovery, where I'm applying my biochemistry skills to develop novel immunoassays for academic research and clinical applications. I've found this role to be an excellent opportunity to broaden my education and gain experience in the fields of neurobiology, immunology and oncology.