Stephen Louie Week 7

Introduction to Microarrays

• 6b.

gene x: 1.0 (Black), 2.2 (Dim Red), 1.0 (Black), .15 (Medium Green)
gene y: 1.0 (Black), 4.5 (Medium Red), .95 (Black), .05 (Bright Green)
gene z: 1.0 (Black), 1.5 (Dim Red), 2.0 (Dim Red), 2.0 (Dim Red)

• 7.

Gene X and Gene Y were transcribed similarly.

• 9.

At the first point, most of the genes have not been acted upon.  Since they have neither been repressed or induced, the mRNA quantity is normal.  The red and green 1:1 ration is thus represented by yellow.

• 10.

TEF4 was repressed in this experiment.  When there is a lack of glucose, the cell has less fuel to convert to energy that is used to power activities.  Thus, the cell is forced to decrease its activity and repress the gene in order to conserve its limited supply of fuel.

• 11.

TCA genes are repressed to prevent the cell from starving itself.

• 12.

• 13.

You would see the color red.

• 14.

You can expect to see red spots.

• 15

• 16

To be able to accurately tell if a gene is over-expressed or repressed, you should use a gene that is already repressed or over-expressed as the control.  This way a change in color will certainly stand out.