Wild-type and mutant ort1 Drosophila melanogaster travel varying distances in response to different light intensity gradients

Abstract

The objective of our study was to investigate whether different light intensity gradients had an effect on the movement of wild-type and ort¹ mutant Drosophila melanogaster. It has been found that R1-R6 and R7-R8 photoreceptors, which are commonly found in wild-type D. melanogaster, are missing or are defective in the ort¹ mutant D. melanogaster. This leads to a decreased ability to detect light and lowers phototactic response of the mutant D. melanogaster. We hypothesized: 1) light intensity gradients have an effect on the distance travelled towards light, 2) the presence of a mutation has an effect on the distance travelled, and 3) the effect of the light intensity gradients is different in wild-type and mutant D. melanogaster. We tested 36 mutant and 36 wild-type D. melanogaster at light intensity gradients of 0 lux, 0-500 lux, and 0-1000 lux, and measured the distances travelled toward the light source within a large test tube. We found that the wild type moved more in the 0 lux and 0-500 lux treatments, while the ort¹mutants moved more in the 0-1000 lux treatment. We conducted a two-way ANOVA and obtained p-values of H_O1:0.06, H_O2:0.17, H_O3:0. Although we observed similar trends as seen in the literature, due to these p-values, we failed to reject all three of our null hypotheses.