Analysis of elongating morphogenesis of quail anterior submaxillary gland: absence of localized cell proliferation.
Quail anterior submaxillary glands elongated extensively without branching (more than sevenfold) from 8 to 10 incubation days. Investigation of mitotic activity of the rudiments in vivo showed no localized cell proliferation throughout the rudiments, and recombination experiments in vitro to examine regional differences in mitogenic activity of the surrounding mesenchyme also showed that no mesenchymal region specifically stimulates the epithelial cell proliferation. Histological observation of the rudiments showed that epithelial cells did not lengthen in a parallel direction to the long axis of the rudiment, and that mesenchymal cells encircled the epithelial cord perpendicularly to its axis. The basement membrane was obscure in the distal end of the rudiments, while it was easily detected in the other part of the rudiments. These results suggest that the elongating morphogenesis of the anterior submaxillary rudiments is not achieved by localized cell proliferation but by almost uniformly distributed cell proliferation, and mesenchymal cells surrounding the rudiment or the basement membrane may be involved in the controlling mechanisms of the elongating morphogenesis.
D000818:Animals; D001485:Basement Membrane / Q000166:cytology / Q000196:embryology; D002455:Cell Division; D003370:Coturnix / Q000196:embryology*; D004847:Epithelial Cells; D004848:Epithelium / Q000196:embryology; D008940:Mitotic Index; D009024:Morphogenesis; D011784:Quail / Q000196:embryology*; D013363:Submandibular Gland / Q000166:cytology / Q000196:embryology*