Don’t want to be all by myself BUT Don’t stand so close to me
Authors: Anne F Simon; Ryley T Yost; J Wes Robinson; Abigail T Bechard
Affiliation: University of Western Ontario
Keywords: r. circuits; s. sex-specific traits
Before engaging in complex social interactions, flies must determine their preferred social space. Indeed, all motile organisms, from bacteria to humans, including D. melanogaster, display a preferred inter-individual (or social) distance that can be affected by genetics, experience and/or the environment.
One of the focus of my lab, is to better understand the neurogenetic underpinnings of social space determination. We and others have shown that social spacing in D. melanogaster can be influenced by a variety of intrinsic and extrinsic factors, such as mating status, social enrichment, genes, and environmental conditions, and an interplay between those. A sex specific neural circuit is emerging as a modulator of social spacing: it involves dopaminergic signalling, and two major brain structures: the mushroom bodies, and protocerebral bridge.
In addition, the neural bases of social spacing are starting to be elucidated. And several of the players – from neurotransmitters to post-synaptic proteins – are conserved through evolution. At the synaptic level, we have shown that Neurobeachin (an anchor protein) and Neuroligin (a cell adhesion protein) are implicated in social space, as well. Both of those postsynaptic proteins have human homologues that are candidate genes for Autism Spectrum Disorders (ASDs).
In another type of response to social cues, flies strongly avoid the volatile substance dSO emitted by stressed flies. CO2 has been identified as one of the compounds in dSO, although other unidentified compound(s) are required to elicit the full avoidance of dSO. Because dSO is emitted by stress flies and causes a response from conspecifics, it is considered a social cue. Compared to social space, dSO avoidance requires different sensory modalities such as olfaction. Surprisingly, we found that only a very light stress is enough to elicit a strong dSO avoidance response by the flies, potentially influencing flies in all sorts of behavioural assays performed in typical Drosophila research laboratories. Furthermore, elucidating what chemical the flies are avoiding, and whether other species would avoid this chemical could open the door to pest management applications.
I will present the recent progress my research team has made in elucidating the basis underlying the decision-making process to come to around 2-body length away from another fly, and to avoid another one when an alarm signal is perceived.