Schematic illustration of the mating-type (mat) chromosomes of the three N. tetrasperma lineages included in the study.

Regions of elevated intra-lineage divergence and introgression are defined based on genome divergence estimates. Genes positioned below the chromosomes were used for the phylogenetic and Bayesian concordance analyses. In bold are genes for which representatives of all known heterothallic species and subgroups of Neurospora were included in the phylogenetic analyses. The figure is drawn to scale.