FINE STRUCTURAL STUDIES OF APOLAR MITOSIS

A fine structural analysis of apolar mitosis induced by chloral hydrate was made on Haemanthus katherinaeBak. endosperm. Under the influence of chloral hydrate MTs disappear initially and then are formed de novo. Kinetochore fibers grow away from kinetochores and their formation is asynchronous for all chromosomes in the set and also for sister kinetochores. Bundles of MTs forming kinetochore fibers converge toward one of the poorly defined polar regions during formation of kinetochore fibers (metaphase) and in motionless kinetochores. Such MTs increasingly diverge when kinetochores move during anaphase. The relation of ER to formation of MTs is evident and briefly discussed. A continuous transition exists between NE and ER during formation and disintegration of the NE. Some theoretical aspects of these problems were also discussed. © 1969 Springer-Verlag.