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

Tsumoto K, Arai M, Nakatani N, Watanabe SN, Yoshikawa K - Life (Basel) (2015)

Bottom Line: DNA molecules were selectively located in the interior of dextran-rich micro-droplets, when the composition of an aqueous two-phase system (ATPS) was near the critical condition of phase-segregation.The resulting micro-droplets could be controlled by the use of optical tweezers.A hypothetical scenario for the emergence of a primitive cell with DNA is briefly discussed.

View Article: PubMed Central - PubMed

Affiliation: Graduate School of Engineering, Mie University, Mie, 514-8507, Japan. tsumoto@chem.mie-u.ac.jp.

ABSTRACT
We report the spontaneous generation of a cell-like morphology in an environment crowded with the polymers dextran and polyethylene glycol (PEG) in the presence of DNA. DNA molecules were selectively located in the interior of dextran-rich micro-droplets, when the composition of an aqueous two-phase system (ATPS) was near the critical condition of phase-segregation. The resulting micro-droplets could be controlled by the use of optical tweezers. As an example of laser manipulation, the dynamic fusion of two droplets is reported, which resembles the process of cell division in time-reverse. A hypothetical scenario for the emergence of a primitive cell with DNA is briefly discussed.

No MeSH data available.


Transport and fusion of DNA-containing dextran-rich microspheres using optical tweezers. (a) The target microsphere could be transferred while it entrapped DNA aggregates. (b) A DNA aggregate trapped by a laser could not be moved across the interface between a dextran microsphere and the outer PEG solution. The focus point of the laser is marked by crosses as a guide. (c) Two DNA-entrapping microspheres spontaneously fused with each other. The first photograph of this series is the same as that in Figure 2b. In (a) and (b), the numbers in the upper right are the time after trapping; in (c), the numbers simply indicate the order in which images were captured. Dextran and PEG are 1.5% and 7% PEG, respectively. Bar: 10 µm.
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life-05-00459-f004: Transport and fusion of DNA-containing dextran-rich microspheres using optical tweezers. (a) The target microsphere could be transferred while it entrapped DNA aggregates. (b) A DNA aggregate trapped by a laser could not be moved across the interface between a dextran microsphere and the outer PEG solution. The focus point of the laser is marked by crosses as a guide. (c) Two DNA-entrapping microspheres spontaneously fused with each other. The first photograph of this series is the same as that in Figure 2b. In (a) and (b), the numbers in the upper right are the time after trapping; in (c), the numbers simply indicate the order in which images were captured. Dextran and PEG are 1.5% and 7% PEG, respectively. Bar: 10 µm.

Mentions: Both microspheres and DNA aggregates can be trapped using a laser. Therefore, encapsulated DNA aggregates could be transported by applying optical tweezers to the target dextran microspheres (Figure 4a). Due to the apparently strong associations between DNA and dextran droplets, DNA aggregates that had been trapped under a laser focus could not be extracted from the microsphere (Figure 4b). Interestingly, we observed that a single DNA-trapping microsphere was trapped and moved to be juxtaposed to another DNA-trapping microsphere, leading to their spontaneous fusion into a larger droplet containing two DNA aggregates (Figure 4c).


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

Tsumoto K, Arai M, Nakatani N, Watanabe SN, Yoshikawa K - Life (Basel) (2015)

Transport and fusion of DNA-containing dextran-rich microspheres using optical tweezers. (a) The target microsphere could be transferred while it entrapped DNA aggregates. (b) A DNA aggregate trapped by a laser could not be moved across the interface between a dextran microsphere and the outer PEG solution. The focus point of the laser is marked by crosses as a guide. (c) Two DNA-entrapping microspheres spontaneously fused with each other. The first photograph of this series is the same as that in Figure 2b. In (a) and (b), the numbers in the upper right are the time after trapping; in (c), the numbers simply indicate the order in which images were captured. Dextran and PEG are 1.5% and 7% PEG, respectively. Bar: 10 µm.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4390863&req=5

life-05-00459-f004: Transport and fusion of DNA-containing dextran-rich microspheres using optical tweezers. (a) The target microsphere could be transferred while it entrapped DNA aggregates. (b) A DNA aggregate trapped by a laser could not be moved across the interface between a dextran microsphere and the outer PEG solution. The focus point of the laser is marked by crosses as a guide. (c) Two DNA-entrapping microspheres spontaneously fused with each other. The first photograph of this series is the same as that in Figure 2b. In (a) and (b), the numbers in the upper right are the time after trapping; in (c), the numbers simply indicate the order in which images were captured. Dextran and PEG are 1.5% and 7% PEG, respectively. Bar: 10 µm.
Mentions: Both microspheres and DNA aggregates can be trapped using a laser. Therefore, encapsulated DNA aggregates could be transported by applying optical tweezers to the target dextran microspheres (Figure 4a). Due to the apparently strong associations between DNA and dextran droplets, DNA aggregates that had been trapped under a laser focus could not be extracted from the microsphere (Figure 4b). Interestingly, we observed that a single DNA-trapping microsphere was trapped and moved to be juxtaposed to another DNA-trapping microsphere, leading to their spontaneous fusion into a larger droplet containing two DNA aggregates (Figure 4c).

Bottom Line: DNA molecules were selectively located in the interior of dextran-rich micro-droplets, when the composition of an aqueous two-phase system (ATPS) was near the critical condition of phase-segregation.The resulting micro-droplets could be controlled by the use of optical tweezers.A hypothetical scenario for the emergence of a primitive cell with DNA is briefly discussed.

View Article: PubMed Central - PubMed

Affiliation: Graduate School of Engineering, Mie University, Mie, 514-8507, Japan. tsumoto@chem.mie-u.ac.jp.

ABSTRACT
We report the spontaneous generation of a cell-like morphology in an environment crowded with the polymers dextran and polyethylene glycol (PEG) in the presence of DNA. DNA molecules were selectively located in the interior of dextran-rich micro-droplets, when the composition of an aqueous two-phase system (ATPS) was near the critical condition of phase-segregation. The resulting micro-droplets could be controlled by the use of optical tweezers. As an example of laser manipulation, the dynamic fusion of two droplets is reported, which resembles the process of cell division in time-reverse. A hypothetical scenario for the emergence of a primitive cell with DNA is briefly discussed.

No MeSH data available.