Effects of Versene-induced Calcium Deficiency in Living Neuroblasts of the Grasshopper Embryo

Abstract

1. Immersion of grasshopper embryos in various concentrations of versene solution, produces a number of well-marked changes in the mitotic cycle of the neuroblast cell.
2. Treatment with .0025 to .01M for one hour results in mitotic blockage at interphase, early prophase, late prophase and telophase stages, and mitotic delay at middle prophase and prometaphase and metaphase stages. No effect on early and middle anaphase and the later part of very late prophase is detected.
3. Treatment with cencentrations above .01M produces pronounced stickiness of chromosomes at the mid-mitotic stages and greatly increased mitotic delay, and subsequent blockage of mitosis.
4. Cleavage abnormalities are observed in the neuroblast cells when treated with concentrations above .01M for more than one hour.
5. Telophase chromosomes become highly refractile on being immersed for 30 minutes in .0025-.03M of versene. Treatment with .05M produces immediate blockage of most of the stages of mitosis. No refractile chromo-somes appear at telophase at this concentration.
6. Recovery from most of the changes induced by versene is noticed, when the cells are transferred back to normal culture solution.
7. That most of the effects of versene treatment may be due to lack of calcium ions in the cell, is indicated.