Reduction of the rate of outgrowth, cell density, and cell division following removal of the apical ectodermal ridge of the chick limb-bud.
Removal of the apical ectodermal ridge causes a reduction in the rate of outgrowth of the wing-bud and the loss of distal parts. More specifically it causes a short-term increase in cell density and cell death and a decrease in the rate of cell proliferation. The evidence supports the hypothesis of density-dependent control of cell division and suggests that there may also be a mechanism regulating skeletal length at the time of differentiation. An informal model is presented to explain the observations.
D000818:Animals; D002452:Cell Count; D002470:Cell Survival; D002642:Chick Embryo; D004475:Ectoderm / Q000502:physiology; D008940:Mitotic Index; D008954:Models, Biological; D013997:Time Factors; D014921:Wings, Animal / Q000166:cytology / Q000196:embryology*