1. Chapter 14 Gene Control in Development
Thu Fenno

2. Pheromone-Stimulated Gene Expression
Upon completion of this lesson the students will be able to:
Identify Yeast (Review)
Identify Cell Types in Yeast
Identify Regulating Pheromone

3. Yeast (Review) Unicellular Eukaryote Divides by budding
Exist as haploid or diploid cells
Undergo aerobic or anaerobic respiration
Saccharomyces cerevisiae

4. Morphology of Yeast Cell Type

5. Cell Types in S. cerevisiae

6. Pheromone-Stimulated Gene Expression
Haploid yeast cells produce pheromones and pheromone receptors

8. Eukaryotic Cell Cycle

9. Conclusion
S. cerevisiae expresses three different cell types: the two haploid cell types (a and a cells), and the diploid a/a cells.
Haploid cells produce pheromones and pheromone receptors.
Binding of the pheromones to their receptors on cells of the opposite type leads to gene activation and arrest in the G1 phase of the cell cycle.
Fusion of the haploid cells form diploid cells.
In the presence of sufficient nutrients, these cells will grow as diploids. Starvation induces diploid cells to undergo meiosis and form four haploid spores.