 A very fine hypha, called trichogyne emerges from one gametangium, the "ascogonium", and merges with a gametangium (the "antheridium") of the other fungal isolate.The nuclei in the antheridium then migrate into the ascogonium, and plasmogamy—the mixing of the cytoplasm—occurs.Unlike in animals and plants, plasmogamy is not immediately followed by the merging of the nuclei (called "karyogamy").