Mating starts by gametogenesis. This produces small, mobile gametes that fuse to form a small binucleate cell. The volume of the binucleate cell then increases to produce a giant binuclear cell. As growth proceeds, the nuclei swell, and then fuse forming a true diploid zygote giant cell. As this is occurring, amoebae undergo chemotaxis towards the giant cell surface. The zygote giant cell ingests the surrounding amoebae, and digests them. Next the zygote forms a macrocyst which stays dormant for a time before germination occurs. When the macrocyst germinates it releases many haploid amoeboid cells.