Chapter 20, Problem 13P

Concerning the Tools of Genetics Box Analysis of Cell-Cycle Mutants in Yeast:

a.	Describe how you would use replica plating of mutagenized, haploid yeast cells to identify temperature-sensitive (ts) mutations in essential genes needed for yeast growth and survival.
b.	Among the many ts mutations you found in part (a), how would you distinguish mutations in genes needed for cell-cycle progression from those in genes needed for other aspects of the life of yeasts?
c.	If you had a large collection of yeast cell-cycle mutants, how would you determine which of the mutations are in the same gene and which are in different genes?
d.	Figures A and B in the Tools of Genetics Box show a culture of a single yeast ts cell-cycle mutant. The two figures show the same petri plate of cells examined at different times: Fig. A before the shift to restrictive temperature, and Fig. B after the temperature shift. Cells with small buds in Fig. A arrest as a single large budded cell in Fig. B (the yellow arrows point to an example). In contrast, cells with large buds in Fig. A arrest as two large-budded cells in Fig. B (red arrows). What do these observations tell you about when during the cell cycle the protein product of the gene in question normally functions?
e.	Describe in detail an experiment to show that the human gene for the cyclin-dependent kinase CDK1 can replace the function of the homologous gene in yeast.