BIOL 2104
Lab 2: Allozyme Analysis Using Electrophoresis
Introduction
This experiment involves allozyme analysis, a technique that reveals the genetic variation that exists within a wide range of organisms (Gómez, 1998). Allozymes are different forms of an enzyme expressed by alternative alleles on the same gene locus (Micales & Bonde, 1995).
Analysis of these allozymes can be done by protein electrophoresis, a technique used in this experiment. Protein electrophoresis involves the movement of proteins within an electric field with mobility being dependent on factors such as the size and shape (secondary and tertiary structure), as well as the charge of the protein (due to primary structure). Electric-field strength, matrix pH, and ionic buffer strength of the electric field are also factors that can affect mobility (McGill University). Because there are so many factors involved in analyzing proteins during electrophoresis, it is unusual for two different proteins to have the same relative mobility (Gómez, 1998).
In this experiment, Drosophila melanogaster, Drosophila virilis, as well as a marker strain (mutant strain of D. melanogaster) were used to examine this relationship. After electrophoresis and a staining method take place, this reaction will cause the enzymes, aldehyde oxidase, alcohol dehydrogenase, and malate dehydrogenase, to become visible, appearing as a set of different banding patterns. These banding patterns will be dependent on the molecular form of the enzyme, indicating the genetic variation that can exist between strains (Carleton University, 2009).
In this experiment, I hypothesize that since morphological differences exist within these three strains, they will also be different at the biochemical level. To test this hypothesis, my testable prediction is that different banding patterns will exist between the strains.
Materials and Methods
Refer to Experiment 2 of the Introductory Genetics laboratory...