The Ultrastructural Observation on Dictyostelium discoideum AK127 Cells

Abstract: Dictyostelium discoideum AK127 cells are the lagC protein gene knock-out mutant strains. We studied the AK127 cells ultrastructural characteristic in the development of 14 h， 16 h and 20 h of cells with a transmission electron microscopy. The result showed that the 14 h of cells contained rich endoplasmic reticulum system. The density of cytoplasm wrapped around by the endoplasmic reticulum significantly lower than the surrounding cytoplasm. Abundant multi-membrane structure can be observed clearly. Because of inner nuclear membrane depression， some bubbly spaces containing filamentous material are produced between out nuclear membrane and inner nuclear membrane. Some spiral chromatins are suspended on inner nuclear membrane and out nuclear membrane is covered by granular materials. Development to 16 h， some membranes in the multi-membrane structure commence to disrupt and several autophagic vacuoles begin to emerge. In the developement 20h cells， a large autophagic vacuole containing several multi-membrane structures can be observed. According to this， we presumes that these multi-membrane structures may be regarded as a reserve nutrients “warehouse”， in order to maintain cell life. These results suggest that absence of gp150 have a certain relationship with bubbly nuclei， multi-membrane structure and disappearing of endoautophagy in mitochondrion. We consider that gp150 is a key factor in Dictyostelium discoideum cell differentiation and development.

CSTR: 32200.14.cjcb.2010.04.0010