Automated Quantification of Locomotion, Social Interaction, and Mate Preference in Drosophila Mutants

Abstract

Automated tracking methods facilitate screening for and characterization of abnormal locomotion or more complex behaviors in Drosophila. We developed the Iowa Fly Locomotion and Interaction Tracker (IowaFLI Tracker), a MATLAB-based video analysis system, to identify and track multiple flies in a small arena. We report altered motor activity in the K⁺ and Na⁺ channel mutants, Hk1 and parats1, which had previously been shown to display abnormal larval locomotion. Environmental factors influencing individual behavior, such as available “social space,” were studied by using IowaFLI Tracker to simultaneously track multiple flies in the same arena. We found that crowding levels affect individual fly activity, with the total movement of individual flies attenuated around a particular density. This observation may have important implications in the design of activity chambers for studying particular kinds of social interactions. IowaFLI Tracker also directly quantifies social interactions by tracking the amount of time individuals are in proximity to one another—visualized as an “interactogram.” This feature enables the development of a “target-preference” assay to study male courtship behavior where males are presented with a choice between two immobilized, decapitated females, and their locomotion and interactions quantified. We used this assay to study the chemosensory mutants olf D (paraolf D, sbl 2) and Gr32a and their preferences towards virgin or mated females. Male olf D flies showed reduced courtship levels, with no clear preference towards either, whereas Gr32a males preferentially courted with virgin females over mated females in this assay. These initial results demonstrate that IowaFLI Tracker can be employed to explore motor coordination and social interaction phenomena in behavioral mutants of Drosophila.

Keywords::

• crowding
• courtship
• DIAS
• Gr32a
• Hk
• IowaFLI Tracker
• “Interactogram,”
• ion channels
• olfD
• para
• pheromone receptor,
• “Target-Preference” assay

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Correction

ACKNOWLEDGMENTS

We would like to thank Dr. Toshi Kitamoto and Mr. Ryan Jewell for their input during early stages of this work, members of the Wu Lab for their critical reading of the manuscript, and Dr. Hubert Amerin for his generous gift of Gr32a stocks.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

This research was supported by NIH grants GM88804 and GM80255 to C.F.W. J.I. was a recipient of an Iowa Center for Research by Undergraduates award and a Carver College of Medicine Research Fellowship.

IowaFLI Tracker is intended for research and educational use, and is openly available under a Creative Commons, Attribution, Non-commercial, ShareAlike 3.0 Unported license (CC BY-NC-SA; http://creativecommons.org/licenses/by-nc-sa/3.0/) from the Web site: www.journalofneurogenetics.org. Subsequent reports utilizing IowaFLI Tracker must refer to it as “IowaFLI Tracker,” and should cite this article as:

Iyengar, A., Imoehl, J., Ueda, A., Nirschl, J., & Wu, C.-F. (2012). Automated quantification of locomotion, social interaction and mate preference in Drosophila mutants. J Neurogenet, 26, 306-316.