macrocyst

{{for|a large cyst in medicine|Cyst#Terminology}}

{{for|the enlarged red blood cell|Macrocyte}}

A macrocyst is an aggregate of cells of Dictyostelids formed during sexual reproduction enclosed in a cellulose wall.{{cite book |author = Brock|title = Biology of Microorganisms|edition = 11th|publisher = Prentice Hall|year = 2006|isbn = 9780131443297|editor-last = Madigan|editor-first = Michael T.|editor-last2 = Martinko|editor-first2 = John M|first = T|page = 468}}{{rp|468}}

If two amoebae of different mating types are present in a dark and wet environment, they can fuse during aggregation to form a giant cell. The giant cell will then engulf the other cells in the aggregate and encase the whole aggregate in a thick, cellulose wall to protect it. This is known as a macrocyst. Inside the macrocyst, the giant cell divides first through meiosis, then through mitosis to produce many haploid amoebae that will be released to feed as normal amoebae would.