The ectodermal control of mesodermal patterns of differentiation in the developing chick wing.
The influence of limb ectoderm on the dorso-ventral muscle and skeletal patterns in the chick wing was studied by recombining stage 14-21 limb mesoderm with the same stage ectoderm in dorso-ventrally reversed orientation. Recombinants grafted to the flank of host embryos were allowed to develop for 10 days. Fully developed wings obtained from stage 15-21 donor embryos have at their distal half d-v polarity conforming to the reversed ectoderm and proximally polarity conforming with the mesoderm. The ectodermal effect is generally observed as a bidorsal feather pattern at the autopod and an almost complete d-v reversal of muscle and skeletal patterns. In experimental wings from donor embryos younger than stage 15, the dorso-ventral pattern conforms with the polarity of the limb mesoderm. The results suggest that control of dorso-ventral polarity resides in the mesoderm until the onset of limb development at stage 15. At this stage, the ectoderm acquires dorso-ventral information which it can impose on the mesoderm.
Geduspan
J S
JS
Department of Zoology, University of Tennessee, Knoxville 37996.
MacCabe
J A
JA
D000818:Animals; D002454:Cell Differentiation; D002642:Chick Embryo; D004475:Ectoderm / Q000502:physiology; D005241:Feathers / Q000196:embryology; D008648:Mesoderm / Q000502:physiology; D009024:Morphogenesis; D009132:Muscles / Q000196:embryology; D014921:Wings, Animal / Q000196:embryology*