Ultrastructural changes in the distal wing bud of the chick embryo after removal of the apical ectodermal ridge

1979 ◽  
Vol 185 (4) ◽  
pp. 333-346 ◽  
Author(s):  
Eero A. Kaprio
Keyword(s):  
Chick Embryo ◽  
Apical Ectodermal Ridge ◽  
Ultrastructural Changes ◽  
Wing Bud

The differentiation of prospective thigh mesoderm grafted beneath the apical ectodermal ridge of the wing bud in the chick embryo

1959 ◽  
Vol 1 (3) ◽  
pp. 281-301 ◽  
Author(s):  
John W. Saunders ◽  
Mary T. Gasseling ◽  
John M. Cairns
Keyword(s):  
Chick Embryo ◽  
Apical Ectodermal Ridge ◽  
Wing Bud

Transfilter evidence for a zone of polarizing activity participating in limb morphogenesis

Development ◽  
1981 ◽  
Vol 65 (1) ◽  
pp. 185-197
Author(s):  
Eero A. Kaprio
Keyword(s):  
Chick Embryo ◽  
Apical Ectodermal Ridge ◽  
Cell Contact ◽  
Diffusion Cell ◽  
Cell Penetration ◽  
Cell Contacts ◽  
Limb Morphogenesis ◽  
Filter Insertion ◽  
Wing Bud ◽  
Zone Of Polarizing Activity

Barriers were inserted into stage-20 HH chick embryo wing buds to separate the zone of polarizing activity from the anterior two-thirds of the wing bud with its overlying apical ectodermal ridge. Half of the barrier length projected out of the wing bud at insertion. Sham-operated wing buds developed only occasionally into wings with cartilage deletions. After insertion of an impermeable membrane (Cellophane), the typical wing skeleton contained only a humerus and a radius. In order to differentiate between diffusion, cell contact and cell penetration, Nuclepore filters with pore sizes of 0·05 μm, 1·0 μm and 8·0 μm, respectively, were inserted. The typical wing skeleton after Nuclepore filter insertion was one with post-axial deletions. None, however, developed with complete distal deletions as after Cellophane. Deletions in the wing skeletons after Nuclepore insertion were the least with 1·0 μm filters and the most with 8·0 μm filteis. Elevation of the apical ectodermal ridge was noted until 18 h after the insertions. In none of the groups did the ridge flatten. The results suggest that the zone of polarizing activity does have a role in normal limb morphogenesis. The mechanism by which its morphogen spreads is diffusion rather than being mediated via cell contacts.

Fate of brachial muscles of the chick embryo innervated by inappropriate nerves: structural, functional and histochemical analyses

Development ◽  
1986 ◽  
Vol 95 (1) ◽  
pp. 147-168
Author(s):  
Jane Butler ◽  
Peter Cauwenbergs ◽  
Ethel Cosmos
Keyword(s):  
Chick Embryo ◽  
Muscle Growth ◽  
Extended Period ◽  
Differential Rate ◽  
Innervation Pattern ◽  
In Ovo ◽  
Intramuscular Nerve ◽  
Quantitative Analyses ◽  
Wing Bud ◽  
Actual Loss

The extent of interaction between brachial muscles and foreign (thoracic) nerves of the chick embryo was determined during an extended period of development in ovo from the perspectives of innervation pattern, function (motility analyses), muscle growth (quantitative analyses of muscle volume) and fibre-type expression (myosin-ATPase profiles). Results indicated that according to all parameters analysed, initially a compatible union existed between the foreign nerves and their muscle targets. During subsequent stages of development, deterioration of the once compatible relationship emerged, until eventually denervation of muscles, i.e. an actual loss of intramuscular nerve branches, was observed. The process of denervation, which proceeded at a differential rate among individual muscles, however was restricted to brachial muscles derived from the premuscle masses of the wing bud. In contrast, brachial muscles of myotomal origin were spared the fate of wing-bud-derived muscles and maintained a successful union with the foreign nerves.

Myogenic cell movement in the developing avian limb bud in presence and absence of the apical ectodermal ridge (AER)

Development ◽  
1984 ◽  
Vol 80 (1) ◽  
pp. 105-125
Author(s):  
Madeleine Gumpel-Pinot ◽  
D. A. Ede ◽  
O. P. Flint
Keyword(s):  
Cell Migration ◽  
Cell Movement ◽  
Host Tissue ◽  
Apical Ectodermal Ridge ◽  
Limb Bud ◽  
Myogenic Cell ◽  
Myogenic Cells ◽  
Apical Direction ◽  
Wing Bud ◽  
Presence And Absence

Fragments of quail wing bud containing myogenic cells of somitic origin and fragments of quail sphlanchopleural tissue were introduced into the interior of the wing bud of fowl embryo hosts. No movement of graft into host tissue occurred in the control, but myogenic cells from the quail wing bud fragments underwent long migrations in an apical direction to become incorporated in the developing musculature of the host. When the apical ectodermal ridge (AER), together with some subridge mesenchyme, was removed at the time of grafting, no such cell migration occurred. The capacity of grafted myogenic cells to migrate in the presence of AER persists to H.H. stage 25, when myogenesis has begun, but premyogenic cells in the somites, which normally migrate out into the early limb bud, do not migrate when somite fragments are grafted into the wing bud. Coelomic grafts of apical and proximal wing fragments showed that apical sections of quail wing buds become invaded by myogenic cells of the host, but grafts from proximal wing bud regions do not.

Inductive and axial properties of prospective wing-bud mesoderm in the chick embryo

1974 ◽  
Vol 38 (1) ◽  
pp. 41-50 ◽  
Author(s):  
John W. Saunders ◽  
Cecelia Reuss
Keyword(s):  
Chick Embryo ◽  
Wing Bud

Reduction of the rate of outgrowth, cell density, and cell division following removal of the apical ectodermal ridge of the chick limb-bud

Development ◽  
1977 ◽  
Vol 40 (1) ◽  
pp. 1-21
Author(s):  
Dennis Summerbell
Keyword(s):  
Cell Proliferation ◽  
Cell Death ◽  
Cell Division ◽  
Cell Density ◽  
Apical Ectodermal Ridge ◽  
Limb Bud ◽  
Short Term ◽  
Density Dependent ◽  
Wing 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.

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