Nuclear degeneration during spore formation in the true slime mold, Didymium nigripes.

Stages in degeneration of nuclei in developing sporangia of the true slime mold, Didymium nigripes , are described. Certain nuclei within the forming sporangium become incorporated into vesicles and then disintegrate. The contents of these autophagic vesicles become part of a large central vacuole present in the spore. Other structures, such as mitochondria, are also found in the central vacuole. It is suggested that these nuclei and assorted cell organelles serve as a source of nucleic acid and protein to be utilized by the myxamoeba at the time of spore germination.