COBALT AND GLUTATHIONE IN THE PRESERVATION OF FERTILITY AND LIFE OF SAND DOLLAR EGGS

¹ Department of Biological Sciences, Northwestern University, Evanston, Illinois, and The Hopkins Marine Station, Pacific Grove, California

1. A range (M/200-M/6400) of cobaltous chloride in sea water increases the fertile life of Dendraster eggs. The most effective concentrations M/1600-M/3200) prolong fertilizability for over 168 hours in 25-30% of the eggs tested. None of the control eggs is fertile at 48 hours.

2. The exposure of unfertilized eggs for long periods or to high concentrations leads to tight fertilization membranes and gradual suppression of cytoplasmic division when the eggs are finally fertilized.

3. Glutathione (0.025%) prevented the fertility-preserving action of cobaltous chloride in lower concentrations but greatly enhanced it in higher concentrations. One mixture (50 cc. of 0.05% glutathione plus 50 cc. M/200 cobaltous chloride) preserved fertility in 50% of the eggs for 312 hours.

4. The work suggests that cobalt and cobaltous-glutathione unite with R-SH at the egg surface (each in a somewhat different manner) preventing oxidation and a deterioration of fertilizability.