Patterns of cell proliferation show two distinct domains around avian pharyngeal closing plates as they form, perforate and rupture. Pouch endoderm and groove ectoderm are in one domain showing 81-86% proliferation, which suggests relatively rapid growth. Cells in epithelia that comprise the pharyngeal closing plates contiguous with pouch and groove epithelia are vital but are dividing at a significantly lower percentage (62-64%). This phenomenon is similar to the lag in growth reported for cells in the oral membrane around the time of rupture (Miller and Olcott, 1989), is consistent with Waterman's suggestion that cellular reorganization, rather than massive degeneration, is a major mechanism of initial perforation (Waterman, 1985), and suggests that differential growth is a contributor to perforation and rupture of chick pharyngeal closing plates.
Anatomical Record 237:408-414 (1993)
Grant sponsor: Howard Hughes Medical Research Foundation; Grant sponsor: The Casstevens Family Fund; Grant sponsor: Hamilton College Faculty Research Funds; Grant sponsor: The Hamilton College Academic Fund for Seniors.
Last Modified: 20 September 1999