Katsuto Takakura

Preparation of BODIPY probes for multicolor fluorescence imaging studies of membrane dynamics

Three different colored fluorescent fatty acids containing BODIPY with extremely high fluorescence quantum yields have been synthesized as probes for investigating the dynamics of membranes. Colored vesicles containing each probe, which were located in the interior of the bilayer membranes, were distinguished from each other by fluorescence microscopy.

Population study of sizes and components of self-reproducing giant multilamellar vesicles.

Population analysis of a system of self-reproducing giant multilamellar vesicles (GMVs) was carried out by means of flow cytometry. The multidimensional distribution of forward light scattering (FS), side light scattering (SS), and fluorescence (FL) intensities originating from each GMV provided information about changes in a population composed of 104 vesicles. FS-FL dot plots indicated that, after the addition of the membrane precursor, the size distribution of the newly generated vesicles was nearly the same as that of the original, but the catalyst content was reduced. This result can be interpreted as evidence for the occurrence of the self-reproduction of GMVs. Moreover, the new GMVs recovered the amount of catalyst to the initial value, keeping their size distribution constant, when a solution of the catalyst was added to the new GMVs. These results are the first experimental evidence for a novel phenomenon on GMV size distribution during their self-reproducing cycle.

Cell-sorting of robust self-reproducing giant vesicles tolerant to a highly ionic medium

We constructed a robust giant vesicular system that underwent self-reproduction in a highly ionic medium, and we elucidated the self-reproduction dynamics of the giant vesicles by using flow cytometry and a cell-sorting technique for population analysis.