Meeting Abstract
Previous studies have shown that the fruit fly Drosophila melanogaster can orient using Earth-strength magnetic fields, but the orientation behavior is not consistent across studies. Using a wild-caught population of Drosophila, we are attempting to use artificial selection to generate two strains of Drosophila that have robust, predictable behaviors which can be used to investigate the underlying mechanisms of magnetoreception. We used a sequential Y-maze to identify both north-seeking and south-seeking flies. After the flies completed the maze, we collected and bred the top 20% of north- and south-seeking flies, then repeated the protocol for 15 generations. As a positive control, we also performed a similar set of selection experiments to breed a population of positive phototaxic and negative phototaxic flies. We have now begun testing whether the generation 15 flies have developed directional preferences. We have so far completed 4 replicates with each line of Drosophila. As of May, 2016, our preliminary results (n = 4) indicate that Drosophila show positive phototaxis and that our light-selected flies have a significantly stronger preference for light than our dark-selected flies (p < 0.05). Our results also indicate that our north-selected and south-selected Drosophila do not have different directional preferences based on Earth-strength magnetic fields (p = 0.26). We will present our updated results and ultimately plan to continue our experiments through 10 replicates with each line of flies. If we find that we have in fact created two lines of Drosophila with different magnetic field directional preferences, we will begin experiments to identify the genetic basis of the directional preferences. If we have not created flies with distinct directional preferences, we plan to continue our selection experiments for another 15 generations.
