Fruit Fly Genetics: Dihybrid Cross
Vestigial and ebony are two commonly studied mutations in fruit flies. Studies of these mutations have even been correlated with reproduction. In this study, a dihybrid cross is conducted between heterozygous vestigial and ebony flies in order to determine the acceptance of the nine to three to three to one ratio. If the results of this experiment come out as what is expected, about nineteen percent of the filial two generation should be vestigial and another nineteen percent should be ebony. Introduction
The vestigial and ebony mutations in fruit flies are both common studies of genetics. Vestigial winged flies have wings which appear crinkled and uneven in contrast to those of wildtype flies, and ebony flies have a dark body that strongly differs from the brown body of wildtype flies. A study by J.M Rendel provided some evidence of both of these mutations affecting the reproduction patterns of the mutated flies. In his study he concluded that ebony flies reproduced much more thoroughly if they remained in the dark throughout their lifespan. They still reproduced in the light, but the number of offspring produced was significantly lower. Rendel also discovered a possible preference of ebony flies over vestigial flies when wildtype flies mate; however, he does not have a hypothesis for why this might be (Rendell). Some scientists believe the reason could be due to vestigial wings affecting the flight of the flies, which other flies might find “unattractive” (Plunkett). In this study, a dihybrid cross was completed between homozygous wildtype, heterozygous vestigial, heterozygous ebony, and heterozygous vestigial and ebony flies. Due to the testing of more than one trait and the use of a dihybrid cross, the offspring is expected to result in a nine to three to three to one ratio, according to Mendel’s law of independent assortment. Materials and Methods
In this experiment, a dihybrid...