Measuring behaviour in Drosophila

Behavioural genetics · Shao lab, University of Delaware · 2023–2024

Courtship in Drosophila is a fixed sequence. The male orients toward the female, taps her, extends one wing and vibrates it into a song, licks, and attempts to copulate. How long that sequence takes to start and how long it runs are the numbers a behavioural study is built on, and for decades they were obtained by a person watching video and pressing a key. A trained scorer manages a handful of pairs per hour, so the size of a study is set by how much of a person's time it can buy rather than by the biology. I built the computer vision that reads the same events off the video directly.

Because the tracker already knew where every fly was in every frame, the same videos could also answer a second question. A fly in an open arena tends to hug the wall and avoid the middle, and how much it avoids the middle is the standard read-out for anxiety-like behaviour, so I asked whether mating changes that and whether Corazonin, a neuropeptide tied to the stress response, is involved. Before mating the Corazonin mutants spent at least as much time in the centre as wild-type flies did, but after mating the two went in opposite directions, with wild-type flies spending more time in the centre while the mutants, the females most of all, almost stopped entering it.

Presentations

High-Throughput Behavioral Assay Unveils Female Courtship in Drosophila. R. Oliver, S. Yamali, S. Knox, T. Dadyala, L. Shao. International Behavioral and Neural Genetics Society, Western University, London, ON, Canada, 2024.
High-Throughput Behavioral Assay Unveils Female Courtship in Drosophila. R. Oliver, S. Yamali, S. Knox, T. Dadyala, L. Shao. Sexually Dimorphic Circuits and Behaviors, Janelia Research Campus, HHMI, Ashburn, VA, 2024.

Files

[Poster](/work/centrophobism-poster.pdf), PDF · 1 page · 2.3 MB The poster version of the study, with the full design, the statistics and the conclusions on one sheet.
[Code](https://github.com/Srujyama/FlyFlirt)

Figures

Four box plots of the percent of time spent in the centre of the arena, Corazonin mutants (CRZ) against wild-type (CS): females before mating (a), males before mating (b), females after mating (c) and males after mating (d). In panel c the CRZ females spend almost no time in the centre. — **Figure 1.** Percent of time spent in the centre of the arena, for wild-type (CS) and Corazonin-mutant (CRZ) flies, before mating (a, b) and after (c, d). A fly that avoids the open middle is showing centrophobism, which is the standard read-out for anxiety-like behaviour in the assay. The CRZ post-mating drop in panel c is the result the study is about.

Two scatter plots of mating latency against percent of time in the centre while mating, each with a regression line: flat for wild-type CS pairs (a) and falling for CRZ mutant pairs (b). — **Figure 2.** How long a pair took to begin mating, plotted against the percent of the mating itself that the pair spent in the centre of the arena. The regression line is flat for wild-type (CS) pairs and falls for the Corazonin mutants (CRZ).