A novel form of self-fertility evolved in Cryptococcus depauperatus, a close relative to the human pathogenic Cryptococcus species, in which sexual development is attained by self-signaling of a cognate pheromone and pheromone-receptor pair.

Mating phenotypes are diverse in Schizosaccharomyces pombe and the natural variation can impact the spread of wtf meiotic drivers.

Selection for asymmetric signalling between gametes explains the very origins of sexual asymmetry as seen in mating-types with morphologically similar but self-incompatible gametes.