Hirokazu Hotani and Hiroshi Miyamoto
1Department of Biosciences, Teikyo university, Utsunomiya, Toyosatodai, 320, Japan
2Division of Biological Chemistry, National Chemical Laboratory, Higashi, Tsukuba 300-26, Japan
(Received July 1, 1990; Accepted November 1, 1990)
Keywords: Liposome, Shape cahnge, Dark-field microscopy, Microtubules.
Abstract. Dynamic processes of morphological transformation of liposome were visualized by sensitive dark-field light microscopy, to study the formation mechanisms of vesicular cell organelles. We found that the liposomes transformed in a well-defined sequential manner through several specific transformation pathways, depending on the external conditions. A circular biconcave form, which is the initial shape of all pathways observed, transformed in to a flexible thin filament or small spheres via a variety of transient forms which possessed geometrical symmetry. Osmotic pressure was the driving force of the morphological transformation of the liposome. To study the role of cytoskeleton in morphogenesis of complex cell shapes, we made liposomes which contained the subunits of microtubules, tubulin. The liposomes were found to transform from a spherical into a dipolar shape as a result of the mechanical force generated by polymerization of microtubules in the liposome.