Fig. 7.

Model proposed to explain the evolution of MAT loci and breeding systems in Aspergillus species from a heterothallic ancestor (not to scale). Adapted in part from Dyer (2007). Mating-type genes are shown in colour: MAT1-1-1 family α-domain in red, MAT1-2-1 HMG family in green, and MAT1-2-4 family in blue. Note that gene nomenclature varies between heterothallic and homothallic species due to presence of idiomorphs only in the former species. Flanking genes (SLA2 and APN2) are shown by diagonal hatching. Dotted lines indicate idiomorph region; heavy bold lines indicate conserved sequence flanking the idiomorph region; suffix ‘d’ indicates disabled pseudogene (Rydholm et al. 2007). Note that the illustration does not show all genes present in the flanking regions (e.g. an APC gene is also present in some species, but syntenic order varies according to species). Furthermore, only limited sequence is available from the A. pseudoglaucus MAT1-1 gene region, as indicated by question marks.