Cell proliferation in the developing wing-bud of normal and talpid3 mutant chick embryos.
Previous measurements on mitotic division rate or cell cycle time have been made on samples from a few discrete limb regions or by continuous sampling, but only down a unidimensional limb axis, disregarding morphological discontinuities such as the presence or absence of cartilage. This study presents a new analysis on normal and talpid3 mutant chick embryos, measuring mitotic rate and also cell density through the central proximo-distal axis and at the limb periphery, taking into account the development of cartilage regions. Differentiation of cartilage is correlated with a marked drop in mitotic rate, accounting for a proximo-distal gradient of mitosis in central counts which was not observed at the limb periphery. Talpid3 limbs at an early stage show a central mitotic gradient, but the reverse of that observed in normal limbs.
D000818:Animals; D002356:Cartilage / Q000196:embryology / Q000502:physiology; D002452:Cell Count; D002454:Cell Differentiation; D002642:Chick Embryo; D008938:Mitosis; D009024:Morphogenesis; D009154:Mutation; D014921:Wings, Animal / Q000166:cytology / Q000196:embryology*