Drosophila melanogaster Pupae Orientation in Several Culture Conditions

Abstract

Environmental conditions are indicated to affect pupal orientation in Drosophila melanogaster. The aim of this study was to analyze the differences in the number of upright, tilted, and flat pupae under 4 experimental conditions: uncontaminated conditions (condition 1), contaminated conditions for one generation (condition 2), contaminated conditions for two generations (condition 3), and the condition in which the contamination has been removed by five generations (condition 4). Each experiment involved 72 experimental units and each experimental unit consisting of one fruit fly culture. Each culture was derived from five pairs of wildtype fruit flies. The Kruskal-Wallis H Test was used as a hypothesis test while the Games-Howell was used for the post hoc test. The results of the analysis indicated that the pupal orientation was always significantly different in the four experimental conditions: condition 1 (χ2(2)=51.769, p<0.001), condition 2 (χ2(2)=47.543, p<0.001), condition 3 (χ2(2))=48.835, p<0.001), and condition 4 (χ2(2)=49.972, p<0.001). The number of pupae in the tilted orientation was always significantly higher than the other two orientations. On the other hand, the number of pupae in the upright orientation was not significantly different from the flat orientation in the four experimental conditions. The findings obtained in this study can be used as a basis for studying the behavior of fruit fly larvae under certain disease or environmental conditions, especially during the pupal formation stage.