image: In August, University of Houston biologist Molly Albecker received a $2.16 million federal grant to study salt tolerance in frogs.
Credit: University of Houston
A University of Houston biologist has received a $2.16 million federal grant to study how some coastal frogs survive in salty environments, which could shed light on how cells, including those in humans, cope with salt stress.
The five-year grant, awarded Aug. 6 by the National Institute of General Medical Sciences, supports the work of Molly Albecker, principal investigator and assistant professor of biology in UH’s College of Natural Sciences and Mathematics. Her team will explore how salt affects frogs at multiple biological levels, offering insights into the evolutionary and physiological mechanisms driving salt tolerance in freshwater organisms.
It all started with the American green treefrog (Hyla cinerea), once believed to be unable to survive in saltwater ecosystems. In 2014, Albecker — then a doctoral student — discovered these small amphibians in the brackish, coastal marshes on North Carolina’s Outer Banks.
“It wasn't just one frog; it was hundreds of frogs that lived in this particular wetland,” Albecker said. “The fact that I made that observation pivoted my research, and it took a more evolutionary focus of: ‘Can some species evolve to handle salt?’”
This finding spurred Albecker’s 2021 research, which revealed that coastal frogs may produce higher amounts of an enzyme called glycerol phosphate dehydrogenase (gpd1). This enzyme helps generate glycerol, a molecule that can safely accumulate within a cell that helps buffer against salt stress.
The new National Institutes of Health funding will allow Albecker’s team to expand this work by examining how salt exposure affects frogs and tadpoles across multiple life stages and biological levels — from cellular to whole-body physiology. Field sites will stretch from coastal wetlands along the Gulf and Atlantic coasts to inland environments.
“When an adaptation allows an individual to tolerate some kind of stressor, there could be a downstream cost to that adaptation,” Albecker said. “So, we’ll also be looking at the ways that adaptive evolution is compensating and mitigating these long-term costs of dealing with elevated salinities.”
While the research focuses on frogs, the findings could extend to humans. By revealing how different frog species from different environments adapt to salt, scientists could better understand the health risks of salt-heavy diets in humans as well.
Understanding how chronic salt exposure affects organs may highlight novel mechanisms and pathways that inspire medical or therapeutic interventions for health impacts of chronic, high salt diets, Albecker said.