Genetic Analysis of Phototropism of Neurospora crassa Perithecial Beaks Using White Collar and Albino Mutants

Abstract

Positive phototropism of perithecial beaks in the fungus Neurospora crassa has been demonstrated. The effect was shown to be mediated by blue light. When mutants (white collar-1 and white collar-2) which are blocked in the light induction of enzymes in the carotenoid biosynthetic pathway were used as the protoperithecial parent in crosses, the resulting perithecial beaks did not show a phototropic response. However, when wild type, albino-1, albino-2, or albino-3 strains were used as the protoperithecial parent, phototropism occurred.