Does DNA exert an active role in generating cell-sized spheres in an aqueous solution with a crowding binary polymer?

Area of Science:

• Biophysics
• Origin of Life Research
• Polymer Science

Background:

• Understanding the spontaneous formation of protocells is crucial for origin of life studies.
• Aqueous two-phase systems (ATPS) offer a tunable environment for studying compartmentalization.
• The role of polymers and nucleic acids in early cellular organization is an active research area.

Purpose of the Study:

• To investigate the spontaneous generation of cell-like structures in a crowded polymer environment.
• To determine the localization of DNA within phase-separated micro-droplets.
• To explore the manipulation and dynamics of these DNA-containing micro-droplets.

Main Methods:

• Utilized an aqueous two-phase system (ATPS) composed of dextran and polyethylene glycol (PEG).
• Incorporated DNA into the ATPS near the critical condition for phase-segregation.
• Employed optical tweezers for micro-droplet manipulation and observation of dynamic fusion.

Main Results:

• Observed spontaneous generation of cell-like morphology in dextran-rich micro-droplets.
• Demonstrated selective localization of DNA within the interior of these micro-droplets.
• Showcased dynamic fusion of droplets via laser manipulation, resembling reversed cell division.

Conclusions:

• The study demonstrates a method for creating DNA-containing protocell models in vitro.
• The findings provide insights into potential mechanisms for early cellular compartmentalization and organization.
• The controlled fusion dynamics offer a model for primitive cellular processes.