Title:

Caenorhabditis Elegans Processes Sensory Information to Choose Between Freeloading and Self-defense Strategies 

Speaker: 

Javier Apfeld, PhD

Assistant Professor

Department of Biology

Northeastern University 

Details: 

Hydrogen peroxide is the preeminent chemical weapon that organisms use for combat. Individual cells rely on conserved defenses to prevent and repair peroxide-induced damage, but whether similar defenses might be coordinated across cells in animals remains poorly understood. In this seminar, I will discuss our recent findings showing that in the nematode Caenorhabditis elegans, a neuronal circuit processes information perceived by two sensory neurons to control the induction of hydrogen-peroxide defenses in target tissues. 

We found that catalases produced by Escherichia coli, the nematode’s food source, can deplete hydrogen peroxide from the local environment and thereby protect the nematodes. In the presence of E. coli, the nematode’s neurons signal via TGFβ-insulin/IGF1 a relay to target tissues that they need not induce catalases and other hydrogen-peroxide defenses. This adaptive strategy is the first example of a multicellular organism modulating its defenses when it expects to freeload from the protection provided by molecularly orthologous defenses from another species. 

Biosketch: 

Javier Apfeld, PhD, is an assistant professor in Department of Biology at Northeastern University. The Apfeld Lab's goal is to elucidate how the brain regulates aging and resilience to oxidants, using the nematode C. elegans as a tractable model organism. His lab's work combines molecular genetics, quantitative microscopy, mathematical modeling, and engineering. 

During his PhD studies, Dr. Apfeld pioneered using genetics to study aging in Prof. Cynthia Kenyon’s lab, and discovered that intercellular communication regulates lifespan in the nematode C. elegans. He then translated this new science of aging in biotech. Returning to academia, Dr. Apfeld helped develop enabling technologies for studying C. elegans aging in collaboration with Prof. Walter Fontana, a theorist and computational scientist.