The cell cycle and sorting behaviour in Dictyostelium discoideum

Area of Science:

• Cell Biology
• Developmental Biology
• Biophysics

Background:

• Cell sorting is crucial for multicellular development.
• The role of cell cycle progression in Dictyostelium discoideum cell sorting is not fully understood.
• Differential adhesion is a proposed mechanism for cell sorting.

Purpose of the Study:

• To investigate the influence of cell cycle phase on cell sorting behavior in Dictyostelium discoideum.
• To determine if specific cell cycle stages exhibit preferential localization during aggregation and slug formation.
• To explore the potential role of cell-cycle-dependent adhesion in Dictyostelium discoideum morphogenesis.

Main Methods:

• Synchronized Dictyostelium discoideum cell populations were generated using mitotic wash-off.
• Cell cycle progression was monitored using cell counts and DNA synthesis assays.
• Cells in distinct cell cycle phases (S-phase, G2) were fluorescently labeled and mixed with unlabeled asynchronous cells.
• Cell sorting and localization within developing slugs were observed and analyzed.

Main Results:

• A high degree of cell cycle synchrony was achieved and confirmed.
• Cells in S-phase and very early G2 phases exhibited a strong tendency to sort to the anterior (tip) of the developing slugs.
• This preferential sorting occurred at the onset of starvation-induced aggregation and morphogenesis.

Conclusions:

• Cell cycle phase significantly influences cell sorting behavior in Dictyostelium discoideum.
• S-phase and early G2 cells display unique sorting properties, potentially mediated by differential adhesion.
• These findings suggest that cell-cycle-related adhesion differences play a role in the morphogenetic processes of cellular slime molds.