1 2 3 4 5

Results
The embryos were observed after a 24 hours time period. There was strong evidence to show the calcium is a major contributor in the development of the sea urchin embryos. The control embryos developed normally and at time of observation were performing gastrulation (See
Figure 1). The embryos, which were placed in calcium-free sea water immediately following fertilization, began development normally and were similar to the control embryos at the 7-hour stage (See Figure 2 and 3). But when they were observed at the 20-hour stage the embryos had not continued through gastrulation (See Figure 4). The embryos appeared to stop development soon after the 7-hour stage. The embryos, which were placed in calcium-free sea water after 7 hours of development, showed very different results (See Figure 5). The embryos had died and no longer maintained their shape. It appeared as if the cells were no longer adhered together. Based on these results, major events during development are dependent on the presence of calcium. In the future, further developments can be made involving the importance of cadherin molecules in embryogenesis.

© 2001 Cebra-Thomas

Last Modified: 26 April, 2001


[Lab Protocols | Students | Cebra-Thomas | Course | Links ]