Endomixis is an interesting phenomenon involving a total internal nuclear reorganization, without amphimixis, within a single individual in a culture of a pedigreed race of Paramecium, taking place in the absence of conjugation. Woodruff and Erdmann reported endomixis in the bimicronucleated species, P.Aurelia, occurring periodically at regular intervals of about 30 days, and in P.caudatum, of about 60 days. It occurs as follows in P.Aurelia.
The macronucleus disintegrated and disappears. The two micronuclei divide twice forming eight daughter nuclei of which six degenerated. The Paramecium also divides, each daughter cell getting one micronucleus; which divides twice forming four nuclei. Two nuclei become macronuclei and two micronuclei. The micronuclei again divide with binary fission of the Paramecium forming two daughter cells, each with one macronucleus and two micronuclei. In the end four daughter cells are formed from a single individual. Endomixis is believed to revitalize the paramecia. Diller does not believe in the validity of the process. Sonneborn also failed to get any cytological or genetically evidence for endomixis in Paramecium.
The macronucleus disintegrated and disappears. The two micronuclei divide twice forming eight daughter nuclei of which six degenerated. The Paramecium also divides, each daughter cell getting one micronucleus; which divides twice forming four nuclei. Two nuclei become macronuclei and two micronuclei. The micronuclei again divide with binary fission of the Paramecium forming two daughter cells, each with one macronucleus and two micronuclei. In the end four daughter cells are formed from a single individual. Endomixis is believed to revitalize the paramecia. Diller does not believe in the validity of the process. Sonneborn also failed to get any cytological or genetically evidence for endomixis in Paramecium.
