LS1B

Section One

Schedule

• Introductions/Attendance• Pre-lab Quiz• Section Overview/Policies• Yeast Complementation Review• Yeast Complementation Lab Work• Review Practice Problems• Mitosis Review• Mitosis Lab Work• Clean up

Yeast Complementation

What is Yeast?

Yeast Complementation

Yeast Complementation

Why? What are we trying to find out?

• For six mutant strains,which step (enzyme) in the histidine pathway is disrupted?

• Same step or different steps between the different strains?

Yeast Complementation

What do we already know?

• None of them can grow without histidine (ie they can’t make it themselves)

• They are of mating type α

Yeast Complementation

What do we have?

• Six other strains in which the histidine pathway is also disrupted but we know which step (enzyme)!

• They are of mating type a

Yeast Complementation• What to do?

• Mate the ones with unknown mutations (α) with those with known mutations (a) . Growth without Histidine• If we see growth: different genes (enzymes,

steps in the histidine pathway)• If we don’t see growth: same gene (enzyme,

step in the histidine pathway)

Yeast Complementation

• What we are going to do today• Streak out known and unknown HIS-

mutants

Why? Allow us to mate them in grid pattern next week

Schedule

• Introductions/Attendance• Pre-lab Quiz• Section Overview/Policies• Yeast Complementation Review• Yeast Complementation Lab Work• Review Practice Problems• Mitosis Review• Mitosis Lab Work• Clean up

Mitosis

InterphaseUncondensed chromosomes replicate

Mitosis

ProphaseChromosomes condense and move

towards metaphase plate

Mitosis

MetaphaseChromosomes line up on metaphase

plate

Mitosis

AnaphaseSister chromatids separate

Mitosis

TelophaseChromosomes finish moving to

opposite sites

Mitosis

Cytokinesis then Interphase

Mitosis

Mitosis

Schedule

• Introductions/Attendance• Pre-lab Quiz• Section Overview/Policies• Yeast Complementation Review• Yeast Complementation Lab Work• Review Practice Problems• Mitosis Review• Mitosis Lab Work• Clean up

Clean Up

• Gas off, Bunsen burner disconnected• All streaked plates labeled, taped, in drawer• All slides in glass disposal• Remaining tooth picks up at front on red tray• Microscopes turned off, unplugged• Cameras labeled with names and put on front desk• Stain, unused slides, unused coverslips, remaining

onion, tweezers, scissors, probe, etc at front of room on or near red tray

• Carnoy and HCL left on desk top• Desktops wiped down, chairs pushed in

THANK YOU!!