1. Cell Communication Lab Saccharomyces cereisiae up close

2. Mating Types • Both alpha and a mating types undergo the same asexual reproduction in the absence of the opposite “sex” • They form single and budding haploid cells by undergoing mitosis. • If mixed, they undergo sexual reproduction • form shmoos, diploid zygotes, budding zygotes and sometimes asci if nutrients are limited.

3. “alpha” and “a” type haploid vs. budding Budding haploid cell Single haploid cell

5. Shmoos

6. Budding Diploid Zygotes

7. Budding diploid zygote Budding diploid zygote Diploid zygote Diploid zygote Diploid zygote Diploid zygote Diploid zygote Budding diploid zygote

8. Ascus

9. Life Cycle Overview A: single haploid and Budding zygotes B: Haploid zygotes, Shmoos, diploid zygote C: Budding diploid Zygotes D: Haploid daughter cells, E: asci (these form if nutrients Are sparse)

10. Wet mount • Place a few drops of water on the slide • Take a colony from the petri dish with a toothpick • Place the toothpick in the drop of water and gently mix the yeast cells in the water • Place a cover slip over the specimen at a 45 degree angle.