Automated identification of social interaction criteria in Drosophila melanogaster

Abstract

The study of social behaviour within groups has relied on fixed definitions of an 'interaction'. Criteria used in these definitions often involve a subjectively defined cut-off value for proximity, orientation and time (e.g. courtship, aggression and social interaction networks) and the same numerical values for these criteria are applied to all of the treatment groups within an experiment. One universal definition of an interaction could misidentify interactions within groups that differ in life histories, study treatments and/or genetic mutations. Here, we present an automated method for determining the values of interaction criteria using a pre-defined rule set rather than pre-defined values. We use this approach and show changing social behaviours in different manipulations of Drosophila melanogaster. We also show that chemosensory cues are an important modality of social spacing and interaction. This method will allow a more robust analysis of the properties of interacting groups, while helping us understand how specific groups regulate their social interaction space.

Social behavior and aging: A fly model

“…Factors that contribute to social spacing will depend on the nature of the interaction between individuals and the group. 27,118,160,170,173,[189][190][191][192][193][194][195] Social experience was shown to affect social space, as socially isolated flies were more distal and therefore less social. 178 Social spacing and social avoidance may be emergent behaviors that arise in groups when individuals try to avoid others in the same group.…”

“…For example, in herd immunity, individuals who are not infected would be closer to the group while others may be isolated or even quarantined when infected. 189 Olfaction thus might be important in how flies establish their preferred social distance, through social interactions, but not in what is their preferred social distance. 185,186 Oftentimes, the measure of distance is reported in terms of body-length units.…”

“…187 In D. melanogaster, social spacing can be easily quantified with the social space assay, 188 that allows measuring the distance of one fly to its nearest neighbor, a variable recently used in several studies. 27,118,160,170,173,[189][190][191][192][193][194][195] Social experience was shown to affect social space, as socially isolated flies were more distal and therefore less social. This effect was more pronounced in females than in males.…”

The neurogenetics of group behavior inDrosophila melanogaster

“…1B,C). Although these criteria were determined empirically, new approaches can perform this task in an automated manner (Schneider and Levine, 2014). Schneider et al (2012b) then recorded these interactions over 30 min.…”

Social structure and indirect genetic effects: genetics of social behaviour

“…Recently, the first hurdle (recording the history of interactions) has been successfully addressed with the ability to record identities faithfully in extended videos, as well as automated methods of detecting social behaviours within a group (Branson et al, 2009;Dankert et al, 2009;Kabra et al, 2013;Schneider & Levine, 2014). The ability to monitor regulation of genes has also progressed, as we can now monitor several genes in vivo (Ardekani et al, 2012) and restrained individuals can be monitored for physiological changes while exposed to stimuli (Maimon, Straw & Dickinson, 2010).…”