A Study of Mitosis in the Mold Blastocladiella with a Ribonuclease-aceto-orcein Staining Technique

Abstract

By combining a ribonuclease digestion of the basophilic constituents in the persistent nucleolus with a subsequent aceto-orcein staining, the mitotic evolution of chromatin in vegetative cells of Blastocladiella was studied.
The following sequence of stages was described: a beaded, chromatin ring, succeded by a “prophase-metaphase” chromatic crescent (both around a spherical nucleolus); and then an anaphase-like figure, followed by a “telophase” arrangement (around an elongating and a constricted, spindle-shaped nucleolus, respectively).
Neither metaphase plates nor individually recognizable chromosomes were observed. The suggestion was made that endomitotic reproduction of the hereditary material in this fungus is normally, but not necessarily, followed by pseudo-amitotic, intranuclear division.