Sociability in Fruit Flies: Genetic Variation, Heritability and Plasticity

Abstract

Sociability, defined as individuals' propensity to participate in non-aggressive activities with conspecifics, is a fundamental feature of behavior in many animals including humans. However, we still have a limited knowledge of the mechanisms and evolutionary biology of sociability. To enhance our understanding, we developed a new protocol to quantify sociability in fruit flies (Drosophila melanogaster). In a series of experiments with 59 F1 hybrids derived from inbred lines, we documented, first, significant genetic variation in sociability in both males and females, with broad-sense heritabilities of 0.24 and 0.21 respectively. Second, we observed little genetic correlation in sociability between the sexes. Third, we found genetic variation in social plasticity among the hybrids, with a broad-sense heritability of ~0.24. That is, genotypes differed in the degree of sociability after experiencing the same relevant social experience. Our data pave the way for further research on the mechanisms that underlie sociability as well as its ecological and evolutionary consequences.

Social behavior and aging: A fly model

“…Social isolation has the same effect on sociability as on social space: the flies are less close, and less social (lower sociability score). 252 We thus speculate that sociability is a behavior related to social space, and would also be affected by aging, probably with lower levels of sociability in very old flies.…”

“…252 Sociability has been scored in flies as the likelihood of flies being together vs in separate quadrants of a divided arena 252 Sociability scores were found to be genetically inherited, and sometimes sexspecific within a given genetic background. 252 Sociability has been scored in flies as the likelihood of flies being together vs in separate quadrants of a divided arena 252 Sociability scores were found to be genetically inherited, and sometimes sexspecific within a given genetic background.…”

“…Sociability is non-aggressive interactions with conspecific individuals. 252 Sociability has been scored in flies as the likelihood of flies being together vs in separate quadrants of a divided arena 252 Sociability scores were found to be genetically inherited, and sometimes sexspecific within a given genetic background. Social isolation has the same effect on sociability as on social space: the flies are less close, and less social (lower sociability score).…”

Abnormal Social Interactions in a Drosophila Mutant of an Autism Candidate Gene: Neuroligin 3

“…Recently, social space has been used as an effective assay to study social interactions with others in a group to identify neural circuitry, underlying mechanisms, and functional changes within the fly brain that modulate these interactions [ 2 ]. Other social behaviors, including courtship, aggression, sociability, and Drosophila Stress Odorant (dSO) avoidance, are also used to examine the underlying mechanisms of social behavior in Drosophila [ 9 , 10 , 11 , 12 , 13 ].…”

“…In this study, we investigated the role of nlg3 in Drosophila social behavior using several assays to assess social interactions in groups of flies: social space [ 35 ] and sociability [ 11 ]. We compared these assays to the response of flies in other social contexts, including aggression [ 36 ] and dSO avoidance [ 37 ].…”