The Structure of the Centrioles and Spindle Body as Observed Under the Electron and Phase Contrast Microscope S-A New Extension-fiber Theory Concerning Mitotic Mechanism in Animal Cells

Abstract

PrefaceThe genetical purpose of the mitosis is in the division of chromatid substances and genetic factors into two equal parts for the daughter cells . Therefore, the mitotic organella (so-called mitotic apparatus) should have a suitable clear-cut structure for the performance of this essential purpose , probably without any wider variations through the biological world.The present paper deals with the various morphological observations on mitotic apparatus made in our laboratory with the aids of electron and phase contrast microscopes and gives a systematic explanation of mitosis based on the new knowledges.In an opportunity to observe cellular organella, especially the Golgi body and centrioles under phase contrast microscope in our laboratory (Hanaoka 1954), it was affirmed that the classical Golgi net-work, the filaments con sisting of the Golgi externum, is also observable in living cells. At the same time, under the same condition, the centrioles were remarked in the central region of this Golgi sphere without exception. Therefore, work hypothesis was offered by us that the centrioles which locate to the centers of the spindle body, also produce the Golgi filaments during the interkinetic stage of the cells.The present electron microscopic observations particularly concerning to the centrioles, proved the reality of my presumption and, furthermore, gave an opportunity to make a revision of my precedent theoretical understanding for the fundamental structure of the spindle fiber (the extension-fiber theory in mitotic mechanism 1953), resulting a pretty modification in it.Here I would like to propose a new extension-fiber theory basing on our new morphological data. This new view point enables us to give a dif ferentiation between the animal and plant cells referring to the attitude of the nuclear division. Material and methodsThe materials and methods referring to this report were mostly described in our paper published previously dealing with each organella such as cen Cytologia 22, 1957 13

Phase microscopic observations in the golgi apparatus in the living cultivated cells.

“…This series of ob servation shows that no such intimate relation is maintained between the Golgi apparatus and centrosomes during the process of cell division as has been suggested by Macdougald (1937) and Amano (1957). Fragmentation of the Golgi apparatus was followed by dissolution in the ground cytoplasm .…”

Fine Structure of Centrioles of the Grasshoppers, <i>Acrida turrita</i> Linné and <i>Atractomorpha bedeli</i> Bolivar

“…?_ een suggested from electron microscope studies that the latter may form a crown _? ?_ round the centriole (Amano, 1957, Yamada 1956, Freeman 1964. In the present materials, the distal half of the centriole is surrounded by _?…”

An Ultrastructural Study of Plant Spermatogenesis

“…A number of investigators (de Harven and Bernhard, 1956;Amano, 1957;Bessis, 1957; Bernhard and de Harven, 1960;Gall, 1961;Andr6 and Bernhard, 1964;Fawcett, 1966) have reported on the fine structure of the typical animal centriole. The paired centrioles of most animal cells undergo replication at a specific time during division and apparently play a role in the architecture of the spindle (Amano, 1957;Inout, 1964;Roth and Shigenaka, 1964;Krishan and Buck, 1965;Murray et al, 1965).…”