Nuclear Division in the Ameboflagellate Adelphamoeba galeacystis

Abstract

Nuclear division is synchronized cultures of the ameoboflagellate Adelphamoeba galecystis has been described. Division in this organism is typically promitotic. It occurs within an intact nuclear membrane and is characterized by the persistence of the nucleolus and its transformation into 2 polar masses. The nucleolus is stained with pyronin-Y by the methyl green pyronin-Y technic, and with Heidenhain's hematoxylin, but is unstained by the Feulgen reaction. The reaction with these stsins is removed after digestion of the nucleolus by ribonuclease. During mitosis the nucleolus undergoes an orderly series of vacuolizations before forming the polar masses. The chromatin is Feulgen positive, stains with methyl green by the methyl green pyronin-Y technic and undergoes a series of characteristic changes during the division process. Synchronizationof amebae grown on coverglasses was accomplished by transfer of cells from 30 to 38.5 C for a period of 100 min. A temporal sequence of nucleolar and chromatin participation in the nuclear division of this organism is suggested.

Promitosis and Rod Occurrence in the Limax Ameba Vahlkampfia lobospinosa*

“…Fibrous 1). 5,12). The polar masses stained densely; they were Dor crescent-shaped, with the flattened side facing the chromatin (Figs.…”

“…Rafalko (8) did not discuss vacuolations in early promitosis of Naeglaria gruberi nor did he (9) discuss them in early promitosis of Tetramitus rostratus, although he illustrated them in plates of both amebae. Considering the dynamic nature of the nucleolus, we hesitate to place as much emphasis on the vacuolations as did Napolitano & Smith ( 5 ) . They suggested that the portion of the nucleolus that is reduced during nucleolar vacuolation may participate in the synthesis of the interzonal body.…”