Chapter 13, Problem 51P

While most animals cannot tolerate polyploidy, some mollusks, such as oysters, can. Although wild oysters are diploid, farmed oysters are often made triploid. The advantage of triploidy is that the oysters are sterile, so they expend the energy that would otherwise be used to make unappetizing gametes in the production of delicious muscle. These meaty triploid oysters are more valuable commercially than diploids.

a.	To make triploid oysters, researchers used cytochalasin B, a chemical that can inhibit cell division in either meiosis I or meiosis II during oogenesis. This drug does not interfere with chromosome replication. Explain how triploid oysters could be generated using cytochalasin B.
b.	Cytochalasin B is toxic to humans, so oyster farmers cannot use this drug. Can you think of an alternate method that might enable oyster farmers to produce large numbers of triploid oysters?