Nuclear membrane fusion in electrofused mammalian cells

Area of Science:

• Cell Biology
• Biophysics

Background:

• Cell fusion is a critical process in biology.
• Electrofusion offers a method to induce cell-cell and nucleus-nucleus fusion.

Purpose of the Study:

• To investigate the mechanisms and frequency of nuclear fusion during electrofusion.
• To identify factors influencing electrofusion efficiency.

Main Methods:

• Electrofusion of various cell types (Ehrlich ascites tumor cells, Muntjac cells, V79-S181 cells).
• Staining procedures and DNA flow cytometry for analysis.
• Manipulation of electrical field frequency and ATP levels.

Main Results:

• Nuclear membrane fusion occurred frequently (up to 50%) under optimal electrofusion conditions.
• Intracellular dielectrophoresis at specific frequencies (1-4 MHz) facilitated nuclear repositioning and fusion.
• Exponentially growing cells and G1 phase cells exhibited higher fusion rates than plateau phase cells.
• External ATP addition increased fusion in plateau cells, suggesting an energy-dependent mechanism.
• Cell fusion in dielectrophoretically aligned chains followed a probabilistic law, favoring two-cell fusion.

Conclusions:

• Electrofusion is an effective method for achieving high rates of nuclear fusion.
• Intracellular dielectrophoresis is a key mechanism driving nuclear fusion post-plasma membrane fusion.
• Cellular energy status and cell cycle progression significantly impact electrofusion efficiency.