Effect of light wavelength on the phototaxis response of wild-type Oregon-R and mutant ort1 Drosophila melanogaster

Abstract

Drosophila melanogaster, whose common name is “fruitfly”, is a universally accepted model organism in biological research. In comparison to the wild-type strain Oregon-R, the mutant ort¹ Drosophila melanogaster has a decreased phototaxis response in green (visible) light as well as in the ultraviolet region. Previous research has tested the behavior of D. melanogaster under light intensity and wavelength, from visible to ultraviolet light. However, the focus of this experiment is to observe and compare the effect of green light on the two strains: mutant ort¹ and wild-type Oregon-R. We used three different light treatments, testing the effect of green, red, and white filters; we used 20 wild-type and 20 mutant replicates for each of these treatments and recorded the time it took for the specimen to reach the indicated marker. White light was the intended negative control to determine whether negative geotaxis or phototaxis was the dominant response for both the mutant and wild-type strains. In green light, the mean phototaxis response time was 38 seconds for wild-type D. melanogaster compared with 10 seconds for mutant ort¹. This difference was statistically significant (p- < 0.05).