Glucose starvation induces same-sex mating in <i>C</i>. <i>albicans</i>.

(A) Same-sex mating between two “a” strains (GH1013 and GH1350a). 1 × 107 cells of each strain were mixed and cultured on YPD-K and YP-K media at 25°C. After three days of growth, the mating mixture was replated onto SCD-Arg, SCD-His, and SCD-Arg-His dropout plates to assess mating efficiency. The middle panel (up) indicates that two “a” cells underwent cell fusion and a daughter cell grew out from the conjunction tube. Scale bar, 10 μm. (B) PCR verification of the MTL types. Strains used: lane 1, SN152 (a/α); 2, GH1350 (α/α); 3, GH1350a (a/a); 4, GH1013 (a/a); 5–7, progeny strains of the GH1350a × GH1013a cross. (C) FACS analysis of the DNA content of parental and progeny strains. Parental diploids have the standard G1 and G2 cell cycle peaks representing 2C and 4C DNA levels. Mating progeny contain DNA content corresponding to 4C and 8C peaks, confirming their tetraploid nature. Arg, arginine; d, daughter cell; FACS, fluorescence-activated cell sorting; His, histidine; M, DNA ladder; MTL, Mating type locus; p, mating projection; SCD, synthetic complete medium; YPD-K, yeast extract-peptone-glucose-K2HPO4; YP-K, yeast extract-peptone-K2HPO4.