Common Fruit Fly Lab Report

Introduction
The common fruit fly, Drosophila melanogaster, has played an impactful role over the century as a model organism used for its versatility in biochemical research and the study of human genetics. This multicellular insect became an ideal organism to study due to its inexpensiveness, small size, short life cycle, genetic variability and low maintenance in laboratory settings. It was first introduced in publications during the 1900s where genetic analyses of mutations were studied to see how they would affect development in their behavioral processes. (Roberts 2006). The advent of Thomas Morgan’s discovery and extensive scientific contributions of the spontaneous white-eyed mutant prompted the discovery of various other eye pigment mutations in the flies. Since

Heterozygous bwD flies contain eye cells that are only 5% pigmented and phenotypically display a white eye with scattering clusters of reddish spots (Schneiderman et al.,2010). This mutation is located on chromosome 2 and is associated with a lesion that includes an addition of heterochromatin on its chromosome (Talbet et al. 1994). Evidence of the allele’s mutations indicates that the allele completely lacks function. This eye pigmentation varies with age and shows nearly 100-fold reductions in pteridine levels. The reduction in pterdine levels indicates that this mutation lacks much of the red pigmentation found in the eye.

Molecular characteristics of the gene and gene product The variations of pigmentation between alleles of the brown gene are likely to be caused by repressing pteridines in the pigment cells. Mutations in the brown (bw) gene result in a modification of pigmentation in the eye color. The reduction of screening pigments in primary pigment cells of the ommatidium, consisting of brown ommochromes and red pteridines, cause variations of darker or lighter shades of