Regulation of purine nucleotide metabolism in sporulating cells. Concentrations of (a, d) adenosine nucleotides, (b, e) purine salvage metabolites, and (c, f) their sum in sporulating SK1 MAT a/α cells and sporulation-deficient SK1 MATα/α cells after transfer to sporulation medium. Concentrations of (g) adenosine and (h) guanosine nucleotides in diploid wild-type, amd1- and isn1-mutant cells at 4 h after transfer to sporulation medium. (i) Expression of genes implicated in purine nucleotide synthesis and salvage in (left panel) sporulating and (middle panel) sporulation-deficient cells. Significance levels of differences in genes expression between both strains are shown in the right panel. Data were treated and presented as in Figure 1b and c. (j) Time course of chromosome segregation and spore formation in diploid wild-type, amd1- and isn1-mutant cells. (k) DNA content of diploid isn1- and amd1-mutant cells after transfer sporulation medium. (Abbreviations: AXP = [ATP] + [ADP] + [AMP]; Hypo = hypoxanthine; MI and MII denote the first and the second meiotic division, respectively; N2 and N4 denote diploid and tetraploid chromosome sets, respectively).