What is it about?
Biomolecular condensates are micrometer-sized, membraned-less cellular compartments whose structures exhibit a wide range of material properties. These properties, which often also change over time, are important for various biological functions. In this work, we generate microdroplets by mixing two types of polymers, polyethylene glycol and dextran. The droplets encapsulating large-sized DNA serve as a model system for biomolecular condensates. We observe a non-monotonic dependence of the physical properties of the droplets on the imposed ionic conditions. Our analysis suggests that this reflects the formation of a DNA network by trivalent ions, which affects the viscoelastic properties of the droplets.
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Why is it important?
We have developed a simple and cheap model system for biomolecular condensates based on an aqueous two-phase system by polyethylene glycol and dextran. This system allows us to obtain dextran microdroplets that encapsulate large-sized DNA by merely mechanically mixing all materials. Remarkably, the mechanical properties of the droplets can be controlled by the ionic conditions of the solution.
Perspectives
Overall, our findings were obtained from droplet fusion measurements and single particle tracking, by microscopic observation, which allowed us to extract all relevant material properties of the droplets. We expect that this simple model system will serve as a platform to test ideas on biomolecular condensates that play a crucial role in the phase behavior in biological cells.
Takashi Nishio
National Institute of Advanced Industrial Science and Technology
Read the Original
This page is a summary of: Coalescence of liquid or gel-like DNA-encapsulating microdroplets, The Journal of Chemical Physics, October 2024, American Institute of Physics,
DOI: 10.1063/5.0223951.
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