The proliferative capacity of gland cells in Hydra attenuata was investigated. The results
indicate that both gland cell proliferation and interstitial cell differentiation to gland cells
contribute to the maintenance of the whole population. On the basis of [3H]thymidine incorporation
and nuclear DNA measurements, gland cells consist of at least three different
populations. One population consists of rapidly proliferating cells with a cell cycle of about 72 h.
These cells are distributed throughout the body column. In the lower gastric region there is a
population of non-cycling cells in G2 while in the upper gastric region there is a population of noncycling
cells in G1. About half the G1 population becomes a new antigen, SEC 1, which is typical of
mucus cells