Sameshima M, Kishi Y, Osumi M, Mahadeo D, Cotter D A
Electron Microscopy Center, The Tokyo Metropolitan Institute of Medical Science, Japan.
Cell Struct Funct. 2000 Oct;25(5):291-5. doi: 10.1247/csf.25.291.
In spores of Dictyostelium discoideum three actin filaments are bundled to form a novel tubular structure and the tubules are then organized into rods. These tubular structures we will term actin tubules. Actin tubules are reconstructed from the supernatant of spore homogenates, while the usual actin filaments were bundled after incubation of supernatants from growing cells. Alpha-actinin, ABP-120 and EF-1alpha are not essential for rod formation. Cofilin is a component of the cytoplasmic rods but few cofilin molecules are included in the nuclear rods. The viability of spores lacking actin rods is very low, and the spore shape is round instead of capsular. The rods can be fragmented by pressure, indicating that the rods may be effective in absorbing physical pressure. The complex organization of actin filaments, actin tubules and rods may be required for spores to achieve complete dormancy and maintain viability.
在盘基网柄菌的孢子中，三根肌动蛋白丝束在一起形成一种新型管状结构，然后这些小管被组织成杆状。我们将这些管状结构称为肌动蛋白小管。肌动蛋白小管是从孢子匀浆的上清液中重建的，而通常的肌动蛋白丝是在生长细胞的上清液孵育后束在一起的。α-辅肌动蛋白、ABP-120和EF-1α对于杆状结构的形成不是必需的。丝切蛋白是细胞质杆状结构的一个组成部分，但核杆状结构中包含的丝切蛋白分子很少。缺乏肌动蛋白杆的孢子活力非常低，孢子形状是圆形而不是囊状。这些杆状结构可以被压力破碎，表明这些杆状结构可能在吸收物理压力方面有效。肌动蛋白丝、肌动蛋白小管和杆状结构的复杂组织可能是孢子实现完全休眠并维持活力所必需的。
