Blastemal kinetics and pattern formation during amphibian limb regeneration

Development ◽  
1976 ◽  
Vol 36 (3) ◽  
pp. 561-574
Author(s):  
M. Maden

To investigate whether the uniqueness of proximal and distal limb regenerates could be attributed simply to differing blastemal growth characteristics, their increase in volume, cell number and cell-cycle times were determined. With respect to these parameters proximal and distal blastemas were identical and, furthermore, no evidence could be found for the existence of separate growth zones such as an apical proliferation centre or a progress zone within the blastema. It was therefore concluded that level-specific properties of the blastemal cells play the major role in determining the structure of the regenerate, not their growth characteristics. The only discernible difference was in the cell number within the two types of blastema at the onset of cartilage redifferentiation— proximal regenerates had 60 % more cells. Thus it seems that the larger the pattern to be regenerated (the more proximal the amputation plane), the larger the primordium within which that pattern first appears. These two conclusions are discussed in relation to current theories of pattern formation during limb regeneration and development and a new way of envisaging the regeneration of pattern is described

Development ◽  
1979 ◽  
Vol 53 (1) ◽  
pp. 269-289
Author(s):  
Jonathan Cooke

Morphological evidence is presented that definitive mesoderm formation in Xenopus is best understood as extending to the end of the neurula phase of development. A process of recruitment of cells from the deep neurectoderm layers into mesodermal position and behaviour, strictly comparable with that already agreed to occur around the internal blastoporal ‘lip’ during gastrula stages, can be shown to continue at the posterior end of the presumptive body pattern up to stage 20 (earliest tail bud). Spatial patterns of incidence of mitosis are described for the fifteen hours of development between the late gastrula and stage 20–22. These are related to the onset of new cell behaviours and overt cyto-differentiations characterizing the dorsal axial pattern,which occur in cranio-caudal and then medio-lateral spatial sequence as development proceeds. A relatively abrupt cessation of mitosis, among hitherto asynchronously cycling cells,precedes the other changes at each level in the presumptive axial pattern. The widespread incidence of cells still in DNA synthesis, anterior to the last mitoses in the posterior-to-anteriordevelopmental sequence of axial tissue, strongly suggests that cells of notochord and somites in their prolonged, non-cycling phase are G2-arrested, and thus tetraploid. This is discussed in relation to what is known of cell-cycle control in other situations. Best estimates for cell-cycle time in the still-dividing, posterior mesoderm of the neurula lie between 10 and 15 h. The supposition of continuing recruitment from neurectoderm can resolve an apparent discrepancy whereby total mesodermal cell number nevertheless contrives to double over a period of approximately 12 h during neurulation when most of the cells are leaving the cycle. Because of pre-existing evidence that cells maintain their relative positions (despite distortion)during the movements that form the mesodermal mantle, the patterns presented in this paper can be understood in two ways: as a temporal sequence of developmental events undergone by individual, posteriorly recruited cells as they achieve their final positions in the body pattern, or alternatively as a succession of wavefronts with respect to changes of cellstate, passing obliquely across the presumptive body pattern in antero-posterior direction. These concepts are discussed briefly in relation to recent ideas about pattern formation in growing systems.


1987 ◽  
Vol 65 (8) ◽  
pp. 739-749 ◽  
Author(s):  
Roy A. Tassava ◽  
David J. Goldhamer ◽  
Bruce L. Tomlinson

Data from pulse and continuous labeling with [3H]thymidine and from studies with monoclonal antibody WE3 have led to the modification of existing models and established concepts pertinent to understanding limb regeneration. Not all cells of the adult newt blastema are randomly distributed and actively progressing through the cell cycle. Instead, many cells are in a position that we have designated transient quiescence (TQ) and are not actively cycling. We postulate that cells regularly leave the TQ population and enter the actively cycling population and vice versa. The size of the TQ population may be at least partly determined by the quantity of limb innervation. Larval Ambystoma may have only a small or nonexisting TQ, thus accounting for their rapid rate of regeneration. Examination of reactivity of monoclonal antibody WE3 suggests that the early wound epithelium, which is derived from skin epidermis, is later replaced by cells from skin glands concomitant with blastema formation. WE3 provides a useful tool to further investigate the regenerate epithelium.


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.


PLoS ONE ◽  
2009 ◽  
Vol 4 (6) ◽  
pp. e5905 ◽  
Author(s):  
Minghua Nie ◽  
Yongming Xie ◽  
Joseph A. Loo ◽  
Albert J. Courey

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

1986 ◽  
Vol 86 (3) ◽  
pp. 266-270 ◽  
Author(s):  
Ole Petter Fraas Clausen ◽  
Bente Kirkhus ◽  
Erik Thorud ◽  
Aasa Schjølberg ◽  
E.v.a. Moen ◽  
...  
Keyword(s):  

2013 ◽  
Vol 70 (8) ◽  
pp. 1131-1140 ◽  
Author(s):  
Allen H. Andrews ◽  
Beverly K. Barnett ◽  
Robert J. Allman ◽  
Ryan P. Moyer ◽  
Hannah D. Trowbridge

Growth characteristics are poorly understood for speckled hind (Epinephelus drummondhayi), a tropical deep-water grouper of economic importance that is considered overfished. Age has been validated for early growth, but the validity of adult age estimates is unknown. A few studies of growth zones in otoliths have revealed maximum age estimates of 15–35 years, which have been uncritically assumed as longevity. To answer questions about adult age, bomb radiocarbon dating was used to provide validated age estimates. A novel aspect of this study was use of the postbomb radiocarbon decline period (ca. 1980–2004) to age younger fish, an approach that was validated with known-age otoliths. Bomb radiocarbon dating provided valid length-at-age estimates ranging from ∼5 years to more than 45 years. Age was unexpectedly greater than previous estimates for more than half the fish used in this study, and longevity may approach 60–80 years. This study extends the utility of bomb radiocarbon dating by more than 20 years and adds to the growing perspective that deep-water tropical fishes can be long-lived.


Development ◽  
1978 ◽  
Vol 48 (1) ◽  
pp. 169-175
Author(s):  
M. Maden

It is shown here that amputated and denervated limbs of larval axolotls dedifferentiate and a proportion of the cells released undergo DNA synthesis and mitosis. When the limb is denervated prior to amputation fewer cells go through the cell cycle, implying the existence of a pool of trophic factor in the limb. Recent work has demonstrated that denervated blastemal cells accumulate in the G1 phase of the cycle. These results strongly argue against the theory that the trophic factor controls the G2 phase. Rather, it is proposed that this factor regulates either the total number of cells cycling or the rate at which they cycle by varying the length of the G1 phase.


2020 ◽  
Vol 164 ◽  
pp. 103651
Author(s):  
Annie Espinal-Centeno ◽  
Melissa Dipp-Álvarez ◽  
Carlos Saldaña ◽  
Laszlo Bako ◽  
Alfredo Cruz-Ramírez

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