We hypothesized that none of the fertilized frog eggs placed in a solution containing cytochalasin B would complete cleavage while most of the fertilized frog eggs which placed in a solution that did not contain cytochalasin B would undergo complete cleavage.
Cleavage is the first few mitotic divisions of the fertilized egg.
It is thought that actin microfilaments are involved in the formation of the contractile ring. As the microfilaments contract, the cell surface is constricted until the cell finally divides into two cells. Cytochalasin B is a drug that is known to bind to the fast growing end of actin microfilamnets thus preventing their growth. If cleavage does involve actin microfilaments, we would expect that in the presence of cytochalasin B, fertilized frog eggs would be unable to complete cleavage due to the binding of cytochalasin B. Furthermore, we would expect fertilized frog eggs that were not placed in cytochalasin B to undergo complete cleavage. It contained 1.9 mL of 0.1 Ringer's solution.