Biology subjects

Dukas, R.

Publications and source records attributed to Dukas, R..

2 recordsLinked to original sources

bioRxiv2024

The role of resource defensibility in facilitating sexually-selected weapon evolution: An experimental evolution test

Animal weapons have evolved multiple times primarily for battling for access to mates. Despite intra-sexual selection being common, weapon evolution has evolved relatively rarely. So why do weapons not evolve more commonly? It has been hypothesized that three precursors are necessary for the initiation of weapon evolution: high variance in reproductive success, patchy high-value resources, and spatial environments conducive to one-on-one competition. Here, we test this hypothesis by performing experimental evolution in Drosophila melanogaster, utilizing heterogeneous environments where conditions facilitating territorial defense and opportunities for competitive interactions vary. We examine changes in sexually dimorphic morphology and male aggression that are predicted to occur, based on this model. We also examine whether condition dependence for sexual dimorphism has evolved after 35 and 75 generations of experimental evolution. Aggression did increase, albeit modestly, in environments that facilitate resource defense. Morphological changes are modest although with some trait specific changes to allometry, generally in the opposite direction of our predictions. Condition dependence trends in the opposite direction from those predicted by our hypothesis as well. We discuss our results in the context of the necessary conditions for the evolution of weapons, and if, and when condition dependence of trait exaggeration may evolve.

evolutionary biology↗

bioRxiv2023

Recovery from social isolation requires dopamine in males, but not the autism-related gene nlg3 in either sex

Social isolation causes profound changes in social behaviour in a variety of species including humans, monkeys, mice, bees, and vinegar flies. However, the genetic and molecular mechanisms modulating behavioural responses to both social isolation and social recovery remain to be elucidated. In this study, we quantified the behavioural response of vinegar flies to social isolation through the use of two distinct protocols, one involving flies social space preference and the other assessing flies sociability, defined as their spontaneous tendencies to form groups. We found that social isolation increased social space and reduced sociability. These effects of social isolation, however, were reversible and could be reduced after 3 days of group housing. Flies with a loss of function of neuroligin3 (ortholog of autism-related neuroligin genes) with known increased social space in a socially enriched environment, were still able to recover from social isolation. Using a UAS-TH-RNAi driven in all neurons, we show that dopamine is important for a response to social isolation and recovery in males but not in females. Furthermore, only in males, dopamine levels are reduced after isolation and are not recovered after group housing. Finally, in socially enriched flies with a loss of function of neuroligin3, dopamine levels are reduced in males, but not in females. We propose a model to explain how dopamine and neuroligin3 are involved in the behavioural response to social isolation and its recovery in a dynamic and sex-specific manner.

neuroscience↗