Sensory Integration Regulating Male Courtship Behavior in Drosophila

Abstract

The courtship behavior of Drosophila melanogaster serves as an excellent model system to study how complex innate behaviors are controlled by the nervous system. To understand how the underlying neural network controls this behavior, it is not sufficient to unravel its architecture, but also crucial to decipher its logic. By systematic analysis of how variations in sensory inputs alter the courtship behavior of a naïve male in the single-choice courtship paradigm, we derive a model describing the logic of the network that integrates the various sensory stimuli and elicits this complex innate behavior. This approach and the model derived from it distinguish (i) between initiation and maintenance of courtship, (ii) between courtship in daylight and in the dark, where the male uses a scanning strategy to retrieve the decamping female, and (iii) between courtship towards receptive virgin females and mature males. The last distinction demonstrates that sexual orientation of the courting male, in the absence of discriminatory visual cues, depends on the integration of gustatory and behavioral feedback inputs, but not on olfactory signals from the courted animal. The model will complement studies on the connectivity and intrinsic properties of the neurons forming the circuitry that regulates male courtship behavior.

Visually induced initiation of Drosophila innate courtship-like following pursuit is mediated by central excitatory state

“…However, if a moving female abdomen is presented in front of the male, then the tethered male will exhibit sustained courtship-like pursuit until the target female stops 'moving' 8 . These results indicate that the courtship-like pursuit is visually guided 4,8 . In the present experiments, we found that a tethered male displayed sustained courtship-like pursuit even when the target female was replaced with a moving squareshaped light spot displayed on a screen (Fig.…”

“…Visual motion typically results in orienting and chasing behaviours, which are often accompanied by unilateral wing extension and vibration, two hallmarks of courtship behaviour [1][2][3][4] . However, such courtshiplike behaviour quickly wanes unless the moving object is a female [1][2][3][4] .…”

“…Visual motion typically results in orienting and chasing behaviours, which are often accompanied by unilateral wing extension and vibration, two hallmarks of courtship behaviour [1][2][3][4] . However, such courtshiplike behaviour quickly wanes unless the moving object is a female [1][2][3][4] . Using an actuated magnet as a dummy, Agrawal et al 5 succeeded in inducing courtship pursuit in a freely moving male fly that persisted longer when the dummy was perfumed with a pheromone blend, that is, hexane extracts of cuticular hydrocarbons, from the body of a conspecific female.…”

Social structures depend on innate determinants and chemosensory processing inDrosophila

“…Inspection of video sequences indicated that these classes of behaviors often involve physical contact between the fore-and middle legs of the interacting flies, and these were scored to evaluate their relative frequency of occurrence (Table S1). Drosophila legs harbor both touch-and tastesensitive sensillae (13), suggesting that flies might exchange somatosensory and gustatory information during these interactions.…”

“…The gustatory mutant poxn ΔXBs6 has a deletion of the poxn gene with a partial transgenic rescue that effectively transforms gustatory sensillae, including those on the forelegs, into mechanosensory sensillae (13). The control Canton-S and Oregon-R females formed interactions at a significantly higher rate than males (P < 0.001), and Canton-S flies made interactions more frequently than Oregon-R flies (P < 0.001).…”