Relative quantity of the mRNA steady-state level determined by qRT-PCR of the polyketide gene orsA (AN7909) and the corresponding HPLC profiles of supernatants of cultures. Relative quantity is given as the log2 of −ΔΔCt. Constitutive expression of the β-actin gene (AN6542) was used as an internal control. I: Control, A. nidulans. II: Cocultivation of A. nidulans and S. hygroscopicus, inoculation with 1/20 volume of S. hygroscopicus culture. III: A. nidulans culture, inoculation with 1/20 volume of filtered S. hygroscopicus culture supernatant. IV: Cocultivation of A. nidulans and S. hygroscopicus, inoculation with 1/100 volume of S. hygroscopicus culture. V: Cocultivation of A. nidulans and S. hygroscopicus (1/100 volume of S. hygroscopicus culture) separated by a dialysis bag. VI: Cultivation of A. nidulans, inoculation with 1/20 volume culture supernatant of a coculture of A. nidulans WT and S. hygroscopicus. VII: Cultivation of A. nidulans with 1/20 volume culture supernatant of a coculture of A. nidulans ΔorsA (ΔAN7909) strain and S. hygroscopicus.