|
|
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died and no longer maintained their shape.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.
|
|
|