Kevin Matthew McKay Week 8

• assignment
• user:Kevin Matthew McKay
• 6b: Hour 1: x y z all black; Hour 3: x very dim red, y dim red, z very dim red; Hour 5: x black, y black/bit of green, z black/bit of red; Hour 9: x dark green, y bright green, z black/bit of red.
• 7: Hour 1 they were all transcribed equally. Hour 3, gene x and z were similarly transcribed. Hour 5, genes x and y were similarly transcribed. Hour 9, none of them were really similarly transcribed.
• 9: At the first time point, oxygen level was normal, so transcription of genes x y and z was the same, giving the yellow color. As oxygen was depleted over time, the transcription of genes x y and z differed. They responded differently to a loss of oxygen.
• 10: Over the course of the experiment, TEF4 was repressed, it went from a yellow to light green color in the microarray. This correlates with its function in the cell, translation elongation or the building of proteins. As the cell runs low on glucose, it is going to run low on energy, and will stop or lower production of proteins which involves translation and expression of TEF4.
• 11: If glucose is running out, the the yeast would want to switch to aerobic metablolism, and be more efficient with their limited glucose supply. Aerobic metablosim involves the TCA cycle, and its associated genes, many of which have common promoter sequences leading to the similar expression profile in limited glucose conditions.
• 12: To regulate expression of genes simultaneously, the genome could use a common promoter motif for a group of related genes, or use the same transcription factor.
• 13: We are going to see more red because a repressor would repress expression and getting rid of that would allow for uncontrolled expression giving the red color.
• 14: When Yap1 is overexpressed, you would see more red spots.
• 15: Yes. Loss of a repressor that repressed another repressor could cause repression of a gene and overexression of a transcription factor for a repressor gene could cause repression of another gene.
• 16: I would like to see control spots of other pathways that this gene was involved in to see repression or expression of the pathway due to deletion or overexpression of the gene of interest. I could also run a northern blot and look at differences in mRNA for the gene of interest.