Giovanni Bosco, PhD
Oscar M. Cohn Professor
Department of Molecular and Systems Biology
Dartmouth Geisel School of Medicine
(September 13, 2016)
Social Learning and Trans-Generational Inheritance of Behavior in Drosophila: Revisiting Darwin’s “Gemmule” Hypothesis
Survival of the fittest depends not just on strength, but also on cunning. How do smaller animals learn to recognize and avoid predators over generations? Dr. Bosco’s work focuses on the learning and inheritance of avoidance behaviors in the fruit fly. He and his lab have shown that fruit flies exposed to a predator (a parasitic wasp) are able to not only teach other flies about the threat, but also to pass this information epigenetically to future generations. Female fruit flies exposed to a wasp show genetic changes that help future generations avoid the predator. These genetic changes are also evident in the eggs of this female. Future work in Dr. Bosco’s lab will focus on exactly how this process works.
We have started a new project in which we have developed a novel paradigm for studying long-term memory in Drosophila. This project has three components to it: First, although most other Drosophila learning and memory assays use classical conditioning to elicit an associative memory, our new method uses an innate non-associative response to an ecologically-relevant stimulus (a predatory wasp). Second, flies exposed to predators engage in social interactions, whereby naive flies learn and remember as if they had seen the predator. To our knowledge, this is the first example of fly-to-fly communication about a specific environmental threat that is strictly communicated via visual cues. We wish to further develop this approach to understand the genetic basis of memory formation and maintenance. Third, we have discovered that brain activity elicited by this predator can change germline physiology and reprogramming of epigenetic germline information. Exposure of females to predators induces epigenetic reprogramming of eggs and leads to the inheritance of specific behaviors that help subsequent generations to avoid predation by this same predatory wasp. Inheritance of this behavior persists for five generations and acts through a novel (and yet to be described) mechanism. Current work in the Bosco Lab seeks to understand how brain activity changes germline information, and how this information can be passed down from one generation to the next.