Genetic Basis and Function of Mating-Type Genes in Aspergillus cristatus

Abstract

Aspergillus cristatus is a homothallic fungus, the genome of which contains two mating-type (MAT) genes, MAT1-1-1 and MAT1-2-1. Previous studies showed that the origin of MAT loci in this species differs from that of other fungi, and their functions have never been described. In this study, MAT1-1-1 and MAT1-2-1 were individually deleted by gene replacement, confirming that these genes regulate the sexual development of Aspergillus cristatus, with the two single-deletion mutants showing similar phenotypes. To explain this phenomenon, the evolutionary relationships of the core domains from high-mobility-group box (HMGB) domain, high-mobility-group (HMG) domain, and alpha 1 (α1) domain were investigated, with the findings indicating that α1 domain and HMG domain have a close evolutionary relationship. Transcriptomic analyses indicated that mating-type genes regulate the sexual development of Aspergillus cristatus by controlling the expression levels of pheromone precursor and receptor genes. This paper presents the first systemic investigation of the function of MAT genes from Aspergillus cristatus.