Both mating types in the heterothallic fungus Ophiostoma quercus contain MAT1-1 and MAT1-2 genes

In heterothallic Ascomycota, two opposite but distinct mating types control all sexual processes. Using mating crosses, mating types were assigned to ten isolates of the heterothallic fungal species Ophiostoma quercus. Primers were subsequently designed to target the MAT1-1-1, MAT1-1-3 (of the mating type 1 idiomorph), and MAT1-2-1 (of the mating type 2 idiomorph) genes in these isolates. Results showed that all isolates contained the full gene sequence for the MAT1-2-1 gene. In addition, fragments of the MAT1-1-1 and MAT1-1-3 genes were sequenced from all isolates. These results were unexpected, as each isolate from a heterothallic species would typically contain only one of the two possible MAT idiomorphs.

► Mating genes from the heterothallic Ophiostoma quercus were studied.
► The complete MAT1-2-1 gene was sequenced and represented the MAT1-2 idiomorph.
► Gene fragments of the MAT1-1-1 and MAT1-1-3 genes were sequenced.
► MAT1-1-1 and MAT1-1-3 represented the MAT1-1 idiomorph.
► Fragments of both idiomorphs were found in isolates of opposite mating type.