Important role of melanin for fertility in the fungus Podospora anserina

Abstract

Melanins are pigments used by fungi to withstand various stresses and to strengthen vegetative and reproductive structures. In Sordariales fungi, their biosynthesis starts with a condensation step catalyzed by an evolutionary-conserved polyketide synthase. Here we show that complete Inactivation of this enzyme in the model ascomycete Podospora anserina through targeted deletion of the PaPks1 gene results in reduced female fertility, in contrast to a previously analyzed nonsense mutation in the same gene that retains full fertility. We also show the utility of PaPks1 mutants for detecting rare genetic events in P. anserina, such as parasexuality and possible fertilization and/or apomixis of nuclei devoid of mating type gene.

GUN Mutants: New Weapons To Unravel Ascospore Germination Regulation in the Model Fungus Podospora anserina

“…As in other fungi, melanin in P. anserina is synthesized through an enzymatic cascade, starting with the PaPKS1 polyketide synthase. Inactivation of this key enzyme results in total inability to produce melanin in hyphae, perithecia, and ascospores, as observed in the Papks1 193 and the Δpapks1 null mutants ( 23 – 25 ). Remarkably, nonmelanized ascospores in the Papks1 193 mutant escape dormancy and germinate spontaneously.…”

The GUN mutants: new weapons to unravel ascospore germination regulation in the model fungus Podospora anserina

“…As in other fungi, melanin in P. anserina is synthesized through an enzymatic cascade, starting with the PaPks1 Polyketide Synthase. Inactivation of this key enzyme results in total inability to produce melanin in hyphae, perithecia and ascospores, as observed in the PaPks1 193 and the ΔPaPks1 null mutants (Coppin and Silar, 2007;Gautier et al, 2021;Langfelder et al, 2003). Remarkably, nonmelanized ascospores in the PaPks1 193 mutant escape from dormancy and germinate spontaneously.…”