A Conversation with Dr. Astrid Deryckere, Winner of the 2024 Charles H. Turner Award

This year’s winner of the Charles H. Turner Award, Dr. Astrid Deryckere, has long been drawn to understanding how nervous systems evolve over time and what factors shape the birth of neurons. As a postdoctoral researcher in the Tosches Lab, Deryckere uses a type of salamander—the Iberian ribbed newt, Pleurodeles waltl—to explore the evolution of neural circuits. We recently had the opportunity to tour the Tosches Lab salamander facility and talk with Deryckere about her research. 

On an unseasonably warm spring day, Deryckere swiped us into the restricted access room, a space that we walk by every day curious about the goings on inside. Following her in, we first came across two large tanks gurgling and circulating with pink microscopic shrimp, the primary food source for the salamanders she studies. Guiding us through another locked door, Deryckere ushered us into a room we had been excitedly anticipating for years–the salamander room. Here, small fish tanks line the shelves. We see tanks filled with water and the dark brown and green speckled salamanders swimming about. Deryckere showed us a range of Pleurodeles waltl life stages, from larvae the size of a quarter with feathery, external gills that mimic those of axolotls to adults that have undergone the water-to-land transition, a process that involves reduction of the gills, as well as regression of the tail fin. Thrilled by this glimpse of the creatures she studies, we sat down with Deryckere to discuss the Turner award, her path to basic research, and her postdoctoral work. 

Deryckere grew up watching nature documentaries about how animal behavior is regulated by the nervous system. “I was quite naturally drawn to the brain and trying to figure out how each animal does what it does,” she says. In spite of her early inclination towards neuroscience, Deryckere did not always see herself as having a direct impact on the field. “For me [mentorship] has been the making or breaking point of being a scientist,” she explains. “I had never heard about a PhD before I started university.” 

Deryckere credits her introduction to the career path of a researcher to PhD course assistants at KU Leuven, where she did her bachelor’s degree. With their encouragement, Deryckere began working with Dr. Eve Seuntjens, who later became the supervisor for her PhD work on neurogenesis in the developing octopus embryo. “I got paired with the best mentor ever. I'm really grateful for that and that she made me see what I could do.”

After completing her PhD, Deryckere started her postdoctoral work on vertebrate brain development in Dr. Maria Tosches lab at Columbia University. “The octopus was awesome, but it’s really like an alien in the animal kingdom,” Deryckere explained about her transition to salamanders. “I got more and more interested in how brains evolve along the evolutionary tree. [The Tosches] lab uses amphibians to connect more and more branches of the tree.”

Here at Columbia, she feels herself lucky to have found another great mentor. “Maria [Tosches] really cares about you as a person. I'm just grateful for the microenvironment that I ended up in,” said Deryckere, referring specifically to Quad Group, a monthly intradepartmental meeting of the newest labs in the Biological Sciences department at Columbia, led by Dr. Laura Duvall, Dr. Erin Barnhart, Dr. Ishmail Abdus-Saboor, and Dr. Maria Tosches. “Our lab and my colleagues are great.” 

Deryckere now studies the development of the brain in salamanders. Specifically, she’s interested in how the stem cells of the brain “give birth” to the different types of neurons over time. Her work, which has been published in Science and Brain, Behavior and Evolution and is currently pre-print on bioRxiv, relies on a technique known as birth dating, where she administers a compound that incorporates into the DNA of a dividing cell and labels that cell along with the cell’s progeny. By administering this compound at different times during development, she is able to identify which neuron types are born at what time. Astrid also optimized injecting and electroporating a green fluorescent protein (GFP) plasmid into the brain of developing salamanders, enabling her to visualize neural architecture in live animals.

Additionally, Deryckere is using single cell RNA sequencing to identify all the different cell types in the salamander brain. This technique allows her to compare salamanders with reptiles (turtles and lizards) and mammals (mice) to see which neuron types are conserved. Astrid found that there are two major types of neurons organized into molecularly distinct layers in the salamander brain. She is now using comparative analyses to understand what is necessary to build layers in vertebrate brains. “By studying the salamander brain and comparing it to amniotes [of other species], we can uncover how their ancestors would have looked and how brains evolved,” explains Deryckere. “The salamander and other amphibians have a peculiar spot in the evolutionary tree, bridging aquatic fish to terrestrial reptiles, birds and mammals. This water to land transition came with a lot of innovations in the brain.”

In addition to offering insights into brain evolution, Astrid’s work is poised to compare stem cell development to tissue regeneration. Salamanders are celebrated for their exceptional regenerative prowess, demonstrating an impressive capability to redevelop even complete body segments like limbs. They offer a model into understanding how cells, tissues, and organs regenerate after injury. 

“There's an idea in the field that regeneration might be a recapitulation of development and that some organisms are able to kind of go back in time and create this more embryonic state or an embryonic stem cell that can generate back all the neurons that are necessary,” said Deryckere. “But, in order to prove or disprove that hypothesis, we need to understand development.”

Dr. Astrid Deryckere’s work is supported by the European Molecular Biology Organization (Long-Term Fellowship ALTF 874-2021).