Expression of a cell surface antigen in Dictyostelium discoideum in relation to the cell cycle.
We have previously shown binding of a monoclonal antibody MUD 9 to the cell surface of Dictyostelium discoideum amoebae and slug cells. In the slug stage the prestalk region was predominantly labelled, while vegetative amoebae showed a great heterogeneity in binding. In the present paper it is shown that the heterogeneous label of vegetative amoebae is due to differences in MUD 9 binding by cells in different cell cycle phases. Cells were synchronized by dilution from stationary phase and the level of MUD 9 binding was determined. Synchrony was determined by investigating increase in cell number and changes in the volume distribution of the cells, and by estimating the number of cells in S phase by monitoring bromodeoxyuridine (BUdR) incorporation. Simultaneously the amount of MUD 9 binding was determined by quantitative microscopy and flow cytometry. The amount of MUD 9 label varies during the cell cycle. The highest amount of label is found on cells early in the cell cycle, i.e. S-phase. These results support the finding that the developmental fate of Dictyostelium discoideum cells depends among other things on the cell cycle position of the cells at the moment of starvation.
Krefft
M
M
Bergische Universität, Gesamthochschule Wuppertal, Biochemie, Wuppertal, FRG.
Weijer
C J
CJ
D000911:Antibodies, Monoclonal; D000946:Antigens, Fungal / Q000032:analysis*; D000954:Antigens, Surface / Q000032:analysis*; D001973:Bromodeoxyuridine; D002453:Cell Cycle; D004271:DNA, Fungal / Q000096:biosynthesis; D004023:Dictyostelium / Q000166:cytology* / Q000254:growth & development; D005434:Flow Cytometry; D007700:Kinetics; D013997:Time Factors
D000911:Antibodies, Monoclonal; D000946:Antigens, Fungal; D000954:Antigens, Surface; D004271:DNA, Fungal; D001973:Bromodeoxyuridine