Biology 2581B Study Guide - Gap Gene, Zygote, Repressor
3 Mar 2014
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Document Summary
In order to find how one gene affects the expression of another (determining a pathway), we can follow expression patterns. For example, in the imaginal discs (area which develops into wings) of drosophila, the expression of two proteins, wingless protein and vestigial protein, determines either a wild-type or mutant phenotype. The expression of vestigial protein, which is not produced in many cells in the wild-type, is affected by wingless protein, which must be present in neighbouring cells for vestigial protein to be expressed. We can also thus, determine pathways by analyzing double mutants for genes that could be in epistasis (the ability of the activity of one gene to mask the activity of another gene). If gene a and b act independently, the double mutant could have mutant phenotypes for both genes a and b. If mutations in one gene are counteracted by mutations in a second suppressor gene, the double mutants would have a phenotype closer to the wild-type.
