Learning of pathogenic bacteria in adult C. elegans bidirectionally regulates pathogen response in the progeny

Summary

Date: 
March 6, 2019 - 12:00pm
Location: 
Northwest Building, Room 243
About the Speaker
Name: 
Ana Pimenta Goncalves Pereira
Speaker Title: 
Postdoctoral Fellow
Speaker Affiliation: 
Zhang Lab

Food choices, which are strongly driven by olfactory preferences, significantly impact the fitness of an animal. While food preferences are at least in part genetically determined, a growing body of behavioral studies in many species shows that they are also regulated by in utero exposure to certain foods. However, it is still virtually unknown how embryonic exposure to certain foods regulates the development and the function of the nervous system.

In order to address this question, we probed the olfactory-driven food choices of C. elegans progeny whose mothers were fed with different bacteria, their natural food source. Previous studies from our lab show that the adult C. elegans learns to avoid the smell of pathogenic bacteria, such as the Pseudomonas aeruginosa strain PA14, after feeding on the pathogen for a few hours. In the present work we test how the exposure to this pathogen during embryonic development regulates the olfactory preference of the progeny when they reach adulthood. We found that the olfactory preference for the pathogen in these progeny is linearly correlated with the learned avoidance of PA14 in their mothers. If the mothers show strong learning of the pathogen, their progeny avoid PA14; intriguingly, if the mothers show weak learning of PA14, the progeny prefers PA14. Animals mutated for the RRF-3/RNA-directed RNA polymerase, a master regulator for the synthesis of the small interfering RNAs that are maternally inherited or in the soma, are defective in regulating the olfactory response to PA14 in their progeny. Our results characterize an intergenerational effect that allows the progeny to rapidly adapt to an environmental condition that is critical for survival.