Neotropical frogs as a study system for glucocorticoid regulation and a foundation for K-12 outreach

Neotropical frogs have attracted the attention of scientists, naturalists, and the general public for decades. These creatures have a rich, interdisciplinary research history, spanning behavior, physiology, development, evolution, and ecology, and serve as a captivating foundation for public engagement. In my master’s work, I took advantage of these unique animals for research and outreach. Here, I summarize my work leveraging frogs to investigate steroid hormone regulation across development and engage K-12 students in hands-on learning. Answering questions from a hormonal perspective allows biologists to conduct research that integrates multi-level biological phenomena. Glucocorticoids (GCs) are steroid hormones that are well studied for their involvement in many biological processes, especially the stress response. There are two main GCs produced by vertebrates – cortisol and corticosterone. Animals are assumed to have a primary GC that stays consistent across life stages and sampling methods, but growing evidence suggests that GC regulation is not as straightforward as we once thought. To connect previous work focused on GC abundance to specific developmental contexts, I quantified both cortisol and corticosterone across seven distinct life stages of northern glassfrogs (Hyalinobatrachium fleischmanni) using water and body sampling methods. I found that corticosterone was more abundant than cortisol, as predicted in amphibians, but the magnitude of this difference varied across life stages and depended on sampling method. Further, I found that cortisol and corticosterone and water and body hormone levels were not correlated in most life stages of H. fleischmanni. My findings address inconsistencies in our assumptions about GCs, provide interesting avenues for future research on the dynamic regulation of cortisol and corticosterone across development, and call for careful preliminary investigation of GCs across contexts in future work. The unique biology of neotropical frogs is the inspiration from which my K–12 outreach initiative “Frogs in Class” was created. Outreach in the K–12 setting is particularly important in bridging the gap between science and society. Frogs in Class addresses this gap by using poison frogs as a phenomenon through which to teach K–12 life science learning standards. The program educates participants about poison frogs and how to care for them, provides necessary supplies and support for classrooms to adopt tadpoles from the Fischer Laboratory frog colony, and presents six modules that capitalize on the current developmental stage of each classroom’s frog to engage students in learning diverse biological concepts. Each module is presented by biologists, aligned with Next Generation Science Standards (NGSS), and connects the developmental stage of each classroom’s frog to a broader biological theme. Frogs in Class allows students to experience the fascinating life-history of frogs in real time, and simultaneously leverages students’ curiosity about their frogs to engage them in broader learning objectives, including how we can utilize model systems to help us answer central questions in biology, how we can mitigate climate change, and what it means to be a scientist. Here, I share my insights following the piloting of Frogs in Class during the 2023–2024 school year. Taken together, my work demonstrates how neotropical frog development is a fascinating backdrop for investigations of GC regulation and for meaningful community outreach.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Biology

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2024

Author dc:creator

• Terrill, Emily Elizabeth

Contributors dc:contributor

• Fischer, Eva K
• Bell, Alison
• Hug, Barbara
• Delia, Jesse

• Glucocorticoids
• Glassfrogs
• Cortisol
• Corticosterone
• Amphibians
• Outreach
• Science Communication

Statement dc:rights

• Copyright 2024 Emily Terrill

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/125633

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F125633