Chromatography Experiment of the Drosophila Eye Pigmentation Pathway Introduction:
How can the use of chromatography help explain single gene mutations of the drosophila melanogaster bio-synthetic pigment pathway? This experiment was meant to help connect the mode of inheritance with different eye color mutations and pinpoint where they occur in the pigment pathway. The drosophila eye color is a result of two bio-synthetic eye color pathways, this is expressed as a trait or phenotype, a multigene trait. There is the ommochrome pathway that produces a brown pigment and the drosopterin pathway that results in the bright red pig mention due to many pigments blended together. The initial substrates or precursors begin with the amino acid tryptophan into ommochrome and guanine into the pterin pathway is an enzymatic pathway is allowed to continue creating one enzymatic reaction after another, resulting in the end color produced. Together if these two pathways have no mutations, this results in the wildtype eye color that is brick red. Wildtype color is the dominant eye color for the fruit fly or what is normally seen in the population. If the eye color is other than wildtype this indicates that there is a mutation in either pathway that produces pigmentation’s. This means there is a defect in the gene that encodes for an enzyme in either pathway or it may mean that there is a mutated gene that codes for the pigment transport system that affects the overall eye color. (Bio 2.1 lab manual pg. 133.)
The molecular biology class of Santa Rosa Junior college have been undergoing experiments using chromatography to further study eye pigment mutations of the drosophilia, knowing that there are two different pathways linked to the different colors. Five different colors were studied; wildtype, scarlet, brown, sepia, and white. Hypothesis of how these colors are linked to the enzymatic pigment pathways went as follows: the wildtype had both functional bio-synthetic...
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