A simple assay to study social behavior inDrosophila: measurement of social space within a group¹

Abstract

We have established a new simple behavioral paradigm in Drosophila melanogaster to determine how genes and the environment influence the behavior of flies within a social group. Specifically, we measure social space as the distance between two flies. The majority of Canton-s flies, regardless of their gender, are within two-body lengths from each other. Their social experience affects this behavior, with social isolation reducing and mating enhancing social space respectively, in both males and females. Unlike several other social behaviors in the fly, including the formation of social groups themselves (a well described behavior - Bartelt et al., 1985, De Gee et al., 2008, Lof et al., 2008, Lof et al., 2009), social space does not require the perception of the previously identified aggregation pheromone cis-Vaccenyl Acetate (Bartelt et al., 1985). Conversely, performance of the assay in darkness or mutations in the eye pigmentation gene white increased social space. Our results establish a new assay for the genetic dissection of a fundamental mode of social interaction.

Automated identification of social interaction criteria in Drosophila melanogaster

“…Auditory treatments show clustering within the PCA separate from controls ( figure 2d), yet all variables have overlapping CIs (table 1), which illustrates a multivariate aspect of interaction values. Unlike Simon et al [4], our analysis method detected a significantly close social distance phenotype in olfactory-deficient mutants Orco 2 compared to its controls (non-overlapping CIs; table 1). In addition to a close social distance, the interaction space of these homozygous mutants appears disrupted (to visual inspection) with a discontinuous pattern between the antennae (electronic supplementary material, figure S11D versus figure 1d and electronic supplementary material, figure S10D) and show limited evidence of actively regulating interaction duration frequencies (electronic supplementary material figure S11E versus figure 1e and electronic supplementary material, figure S10E).…”

The neurogenetics of group behavior inDrosophila melanogaster

“…On shorter time scales, individuals may be sexually attracted to one another, or to environmental resources such as food patches (Ramos-Fernández et al, 2006). Individuals may also avoid one another because of social or sexual competition, or to maintain a comfortable distance from their neighbors (Simon et al, 2011). The process of satisfying these opposing forces gives rise to a dynamic group-level structure called a social network (Kossinets and Watts, 2006).…”

Collective selection of food patches in Drosophila

“…For testing adults, we set 2 ml of diet in 55 mm Petri dishes. Because aggregated flies typically maintain an average inter-individual distance of 2.5 mm (Simon et al, 2012), each food patch could hold more than 200 adults. For testing larvae, we set 1.2 ml of diet in 22 mm circular wells cut from an 8 ml layer of agar-gelled water (30 g l −1 ) in an 85 mm Petri dish.…”