The effect of different light colours on the phototaxis response of wild-type and <i>ort</i>1 mutant <i>Drosophila melanogaster</i>


  • Julia Johnson
  • Ori Nevares
  • Manmeet Sandhu
  • Rikul Thapar


Drosophila melanogaster is a small organism commonly known as the fruit fly. Little research has been carried out on the effect of ort1 mutations, which are known to cause defects in synaptic transmission of the R7 and R8 photoreceptors in D. melanogaster.  These photoreceptors are normally sensitive to blue and green light, and therefore ort1 mutants have impaired vision for these colours of light. The objective of this study was to observe the effect of the ort1 mutation and light colour on the phototaxis response in mutant and wild-type Oregon-R strains of D. melanogaster. This was tested by administering each D. melanogaster into a T-shaped test tube apparatus, which had a coloured filter at the top and a clear area at the bottom. The time each replicate spent in the top or bottom of the apparatus was recorded.  Mutant and wild-type were tested in blue, green, and white (control) light treatments.  Although it was found that the wild-type D. melanogaster spent more time in the coloured area as compared to ort1 mutants, the results were not statistically significant (p>0.05). However, the proportion of time spent in each colour was significantly different between each colour treatment (p<0.05).