The fusion of haploid amoebae cells with matching mating types to form a larger cell, which ingests additional amoebae and forms a cellulose wall. The resulting macrocyst undergoes recombination and meiosis followed by release of haploid amoebae. An example of this process can be found in Dictyostelium discoideum.
Source:PMID:20089169,
PMID:16592095