Genetic and Epigenetic Factors Involved in the Excretion of Naphthoquinone Pigments into the Culture Medium by Nectria haematococca

Abstract

The production by the fungus Nectria haematococca of antibiotic pigments related to fusarubin can be increased by (i) culture conditions unfavourable for good growth, (ii) multiplication of two cytoplasmic factors of unknown molecular nature, and (iii) mutation of nuclear genes. Six nuclear genes involved in the regulation of naphthoquinone release have been characterized and mapped. Some have three allelic forms: the wild allele, one or several mutated alleles determining the hyperproduction of pigments, and one or several intragenic suppressors of the latter mutations. These genes also seem to be involved in developmental events, especially in sexual reproduction.