Anteroposterior axis formation inXenopus limb bud recombinants: A model of pattern formation during limb regeneration

2002 ◽  
Vol 225 (3) ◽  
pp. 277-288 ◽  
Author(s):  
Hitoshi Yokoyama ◽  
Koji Tamura ◽  
Hiroyuki Ide
Development ◽  
1985 ◽  
Vol 86 (1) ◽  
pp. 169-175
Author(s):  
J. Richard Hinchliffe ◽  
Anna Sansom

The stage-21 to 22 legbud polarizing zone (ZPA) was mapped by transplanting small blocks of posterior marginal mesenchyme preaxially into stage-20 to -22 chick wing buds and assessing the degree of duplication of the wing digital skeleton produced in the host. Blocks taken from the posterior flank, from the angle between posterior flank and the proximal base of the limb bud, and from the most anterior distal position chosen (under the AER), all had very low activity. Blocks taken from the posterior margin of the legbud, plus the next distal block under the posterior part of the AER, all had high activity. We consider that barrier and amputation results on wing and legbud, when interpreted in the light of maps of the ZPA in both limb buds, are consistent with the hypothesis that both leg and wing have their growth and anteroposterior axis of pattern formation controlled by the ZPA.


Development ◽  
1981 ◽  
Vol 63 (1) ◽  
pp. 127-144
Author(s):  
J. C. Smith ◽  
L. Wolpert

A study is made of the widening of the chick limb bud that occurs after a graft of an additional polarizing region. Such buds are about 50% wider than controls, after 36 h. By contrast, growth along the proximodistal axis is unaffected. This widening is reduced by treating the host embryo with 10 Gy X-irradiation and the altered pattern of digits is consistent with a diffusible morphogen model for the specification of positional information along the anteroposterior axis.


1999 ◽  
Vol 77 (11) ◽  
pp. 1835-1837 ◽  
Author(s):  
Steven R Scadding

While the effects of exogenous retinoids on amphibian limb regeneration have been studied extensively, the role of endogenous retinoids is not clear. Hence, I wished to investigate the role of endogenous retinoic acid during axolotl limb regeneration. Citral is a known inhibitor of retinoic acid synthesis. Thus, I treated regenerating limbs of the larval axolotl Ambystoma mexicanum with citral. The result of this inhibition of retinoic acid synthesis was that limb regeneration became extremely irregular and hypomorphic, with serious pattern defects, or was inhibited altogether. I conclude that endogenous retinoic acid plays an important role in pattern formation during limb regeneration.


1998 ◽  
Vol 76 (9) ◽  
pp. 1795-1796 ◽  
Author(s):  
Steven R Scadding ◽  
Andrew Burns

The purpose of this investigation was to determine whether there were any asymmetries in the vascularization of the limb-regeneration blastema in the axolotl, Ambystoma mexicanum, that might be related to pattern formation, and to determine if retinoic acid could modify the vascular patterns of the blastema. We used acrylic casts of the vascular system of the limbs to assess the pattern of vascularization. We observed a very regular symmetrical arrangement of capillaries in the limb-regeneration blastema that did not appear to be modified by doses of retinoic acid sufficient to modify the limb pattern.


Development ◽  
1986 ◽  
Vol 94 (1) ◽  
pp. 267-275
Author(s):  
C. P. Cottrill ◽  
Paul T. Sharpe ◽  
Lewis Wolpert

A technique which identifies cells differing in surface character, aqueous two-phase partition using thin-layer countercurrent distribution (TLCCD), has been used to study differentiation and pattern formation in the developing chick limb bud. The TLCCD profiles of cell populations, derived from various regions of morphologically undifferentiated mesenchyme from three different stages of limb development, have been compared. At no stage, or location, has the population been found to be homogeneous. Cells from progress zones and more proximal regions could all be resolved into several populations. The populations from progress zones at three different developmental stages were qualitatively similar but differed in the proportions of cells in each. The most striking differences in cell populations were those obtained from the most proximal region of the limb, closest to the flank, which represents the developmentally most advanced region.


Development ◽  
1999 ◽  
Vol 126 (21) ◽  
pp. 4729-4736
Author(s):  
L. Lettice ◽  
J. Hecksher-Sorensen ◽  
R.E. Hill

Epithelial-mesenchymal interactions are essential for both limb outgrowth and pattern formation in the limb. Molecules capable of communication between these two tissues are known and include the signaling molecules SHH and FGF4, FGF8 and FGF10. Evidence suggests that the pattern and maintenance of expression of these genes are dependent on a number of factors including regulatory loops between genes expressed in the AER and those in the underlying mesenchyme. We show here that the mouse mutation dominant hemimelia (Dh) alters the pattern of gene expression in the AER such that Fgf4, which is normally expressed in a posterior domain, and Fgf8, which is expressed throughout are expressed in anterior patterns. We show that maintenance of Shh expression in the posterior mesenchyme is not dependent on either expression of Fgf4 or normal levels of Fgf8 in the overlying AER. Conversely, AER expression of Fgf4 is not directly dependent on Shh expression. Also the reciprocal regulatory loop proposed for Fgf8 in the AER and Fgf10 in the underlying mesenchyme is also uncoupled by this mutation. Early during the process of limb initiation, Dh is involved in regulating the width of the limb bud, the mutation resulting in selective loss of anterior mesenchyme. The Dh gene functions in the initial stages of limb development and we suggest that these initial roles are linked to mechanisms that pattern gene expression in the AER.


2018 ◽  
Vol 62 (9-10) ◽  
pp. 605-612 ◽  
Author(s):  
Akira Satoh ◽  
Kazumasa Mitogawa ◽  
Aki Makanae

Development ◽  
1988 ◽  
Vol 103 (2) ◽  
pp. 391-401 ◽  
Author(s):  
P. Simpson ◽  
M. El Messal ◽  
J. Moscoso del Prado ◽  
P. Ripoll

Clones of cells mutant for shaggy transform all hairs into bristles on the wing blade of Drosophila. Different types of bristles are formed at different locations. It is shown that, although shaggy cells are unable to make a correct decision between an epidermal cell pathway and that of a sensory bristle, they are nevertheless able to respond correctly to positional cues. A compilation of many clones led to the construction of a map of positional homologies in which all of the cells in any one area will produce the same kind of bristle. The result is a series of stripes oriented perpendicular to the anteroposterior axis of the wing and parallel to the dorsoventral axis. The significance of these stripes in relation to mechanisms of pattern formation is discussed.


Development ◽  
1974 ◽  
Vol 32 (1) ◽  
pp. 227-237
Author(s):  
Dennis Summerbell

The experiments examine the extent of reduplication of skeletal parts across the anteroposterior axis, following the transplantation of a zone of polarizing activity (ZPA) to the anterior margin of the limb-bud at successively later stages. Previous studies have suggested that the function of the apical ectodermal ridge (AER) is to maintain cells in a special region at the distal tip (the progress zone) labile, with respect to their positional value along the proximo-distal axis. Similarly, the results of these experiments demonstrate that cells in the progress zone are able to change their antero-posterior positional value under the influence of the grafted ZPA, while cells at more proximal levels remain unaffected. In turn, the ZPA may effect the activity of the AER and hence the progress zone.


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