Regeneration fragmentierter, nackter Protoplasten in Hefezellen

Summary

The organism used wasSaccharomyces ellipsoideus. Exposure of yeast cells to a hypertonic strontium chloride generally does not establish typical plasmolysed cells. Rather, during a short period of exposure to plain hypertonic strontium chloride solution or to a hypertonic medium supplemented with high content of strontium chloride, the cell walls ruptured and subsequently the formation of spherical osmotically fragile bodies observed. Being associated with large droplet of protoplast together with the plasmolysed cells in the medium, abundantly small and numerous particles imperfectly for reliable counts to be made appear.

About other kinds of salts, the protoplast of the yeast cell used separated from the wall smoothly when plasmolysed with sodium chloride or potassium chloride. But calcium chloride increasingly produced the cell rupture. However subsequent successive growth of small particles of protoplast could not be observed in the medium containing calcium chloride. Despite similar results using manganese chloride or magnesium chloride, it seems to cause the damage of the sub cellular structure during prolonged incubation. Similar result was obtained, when the cells were treated in polyethyleneglycol solution.

After incubation into liquid strontium medium containing 2 mol strontium chloride, subcellular particles were isolated by the peculiar method (Fig. 6) and were incubated further. Such particles multiplicated, they being designated as K-fragment, and enlarged in size, and became K-body. The size of K-body was threefold as large as that of K-fragment. After further prolonged incubation K-body also enlarged in size, calling it K-cell. The protoplasm of K-cell was less well organized, but the early stage of the formation of daughter K-cell as revealed by microscopical observation beared resemblance to the budding found in mother yeast cell.

The findings considered in conjunction with our cytochemical studies of the action of solutions of RNase or DNase, or the stain with some basic dyes, have led us to the conclusion that macromolecular fragment and nuclear substance present in the K-fragment, K-body and K-cell, respectively. Regeneration will result in the most miniature feature of the yeas cell.