Schizophyllum pheromones and receptors maintain their specificity in yeast. Mating was tested as in Figure 4B. Rows: the MATa mfa1 mfa2 strain (SM2331) containing either pPGK (top), pPGK-bbp2(4) (second from top), or pPGK-bbp1(1) (third from top), and the MATa MFA1 MFA2 strain (SM1058) containing pPGK (bottom). Columns: the MATα ste3 sst2 strain (SDK47) containing either pPGK (left), pPGK-bbr1 (second from left), or pPGK-bbr2 (third from left), and the MATα STE3 sst2 strain (Tn44–1B) containing pPGK (right).