Neurospora crassa
The adaptive function of mating type in the ascomycete "Neurospora crassa" is discussed in the article "Neurospora crassa". That matings in "N. crassa" are restricted to interaction of strains of opposite mating type may be an adaptation to promote some degree of outcrossing. Outcrossing, through complementation, could provide the benefit of masking recessive deleterious mutations in genes that function in the dikaryon and/or diploid stage of the life cycle.