‘Sage’: a Colour Modifier in Aspergillus nidulans

Abstract

CONIDIA of wild-type Aspergillus nidulans are green, but mutants occur with yellow and white spores. The genetical basis for these colour differences has been shown by Pontecorvo¹ to be due to two unlinked genes; one, Y, controlling spore colour and giving green spores, its mutant form y being yellow, and the other, W, controlling presence or absence of spore colour. The mutant form of this gene, w, produces a white phenotype whether Y or y is present. We have confirmed this with our material.