From a to ? is a short supplemental textbook that uses control of yeast mating type as a model for many aspects of cell determination in general. Topics covered include gene silencing; genetic recombination; differentiation; combinatorial gene regulation; mRNA transport to establish asymmetric cell division; signal transduction; evolution of genetic networks; and various aspects of cell biology, including action of cytoskeleton and bud site selection. The book includes a foreword by Mark Ptashne, author of A Genetic Switch.

Foreword, M. Ptashne 1. Why Read a Book about Yeast? 2. Yeast Cell Types 3. Master Regulatory Transcription Factors Control Cell Type 4. Making and Secreting Cell Type-specific Signals 5. Detecting and Responding to a Signal 6. How Division of a Single Cell Can Produce Two Cell Types 7. Gene Silencing in the Control of Cell Type 8. Controlling Cell Polarity 9. Evolution of Cell Type Determination Index