Strobilation in the chesapeake bay sea nettle, Chrysaora quinquecirrha—II. Partial characterization of the neck-inducing factor from strobilating polyps

Abstract

1. 1. A neck-inducing factor (NIF) is involved in initiation of strobilation in Chrysaora quinquecirrha polyps. NIF induces formation of a neck under the tentacles, evidence that strobilation has begun. 2. 2. NIF is detected in the medium approximately 2 hr after chilled polyps are stimulated to strobilate by raising their temperature; no NIF is detected 5 hr after the temperature change. 3. 3. NIF is heat stable at pH 8–10, water soluble and of high molecular weight. 4. 4. Partially purified NIF can be detected using the Lowry et al. technique for protein. NIF is inactivated by pronase and chymotrypsin. The author suggests that NIF is a protein or polypeptide.