Role for differential cell proliferation in perforation and rupture of chick pharyngeal closing plates

1993 ◽  
Vol 237 (3) ◽  
pp. 408-414 ◽  
Author(s):  
Sue Ann Miller ◽  
Alicia M. Favale ◽  
Stephen J. Knohl
2018 ◽  
Vol 3 (5) ◽  
pp. 1700391 ◽  
Author(s):  
Yongmin Jeon ◽  
Hye-Ryung Choi ◽  
Myungsub Lim ◽  
Seungyeop Choi ◽  
Hyuncheol Kim ◽  
...  

2019 ◽  
Vol 98 (11) ◽  
pp. 1253-1261 ◽  
Author(s):  
S. Yamada ◽  
R. Lav ◽  
J. Li ◽  
A.S. Tucker ◽  
J.B.A. Green

Tooth germs undergo a series of dynamic morphologic changes through bud, cap, and bell stages, in which odontogenic epithelium continuously extends into the underlying mesenchyme. During the transition from the bud stage to the cap stage, the base of the bud flattens and then bends into a cap shape whose edges are referred to as “cervical loops.” Although genetic mechanisms for cap formation have been well described, little is understood about the morphogenetic mechanisms. Computer modeling and cell trajectory tracking have suggested that the epithelial bending is driven purely by differential cell proliferation and adhesion in different parts of the tooth germ. Here, we show that, unexpectedly, inhibition of cell proliferation did not prevent bud-to-cap morphogenesis. We quantified cell shapes and actin and myosin distributions in different parts of the tooth epithelium at the critical stages and found that these are consistent with basal relaxation in the forming cervical loops and basal constriction around enamel knot at the center of the cap. Inhibition of focal adhesion kinase, which is required for basal constriction in other systems, arrested the molar explant morphogenesis at the bud stage. Together, these results show that the bud-to-cap transition is largely proliferation independent, and we propose that it is driven by classic actomyosin-driven cell shape–dependent mechanisms. We discuss how these results can be reconciled with the previous models and data.


Development ◽  
1996 ◽  
Vol 122 (6) ◽  
pp. 1759-1767 ◽  
Author(s):  
L. Schuger ◽  
G.R. Johnson ◽  
K. Gilbride ◽  
G.D. Plowman ◽  
R. Mandel

Epithelial and mesenchymal cells isolated from mouse embryonic lungs synthesized and responded to amphiregulin (AR) in a different fashion. Mesenchymal cells produced and deposited 3- to 4-fold more AR than epithelial cells, proliferated in the presence of exogenous AR, and their spontaneous growth was blocked by up to 85% by anti-AR antibodies. In contrast, epithelial cells exhibited a broad response to this growth regulator factor depending on whether they were supplemented with extracellular matrix (ECM) and whether this ECM was of epithelial or mesenchymal origin. AR-treated epithelial cells proliferated by up to 3-fold in the presence of mesenchymal-deposited ECM, remained unchanged in the presence of epithelial-deposited ECM, and decreased in their proliferation rate below controls in the absence of ECM supplementation. This effect was abolished by treatment with the glycosaminoglycan-degrading enzymes heparinase and heparitinase suggesting the specific involvement of heparan sulfate proteoglycan (HSPG) in AR-mediated cell proliferation. In whole lung explants, branching morphogenesis was inhibited by antibodies against the AR heparan sulfate binding site and stimulated by exogenous AR. Since during development, epithelial cells are in contact with mesenchymal ECM at the tips of the growing buds and alongside the basement membrane, focal variations in the proportion of epithelial and mesenchymal HSPG will focally affect epithelial proliferation rates. Therefore, AR-HSPG interaction may underlie the process of branching morphogenesis by inducing differential cell proliferation.


1998 ◽  
Vol 211 (4) ◽  
pp. 382-389 ◽  
Author(s):  
Marian C.E. Peeters ◽  
Bert Schutte ◽  
Marie-Hélène J.N. Lenders ◽  
Johan W.M. Hekking ◽  
Jan Drukker ◽  
...  

Glia ◽  
2012 ◽  
Vol 60 (4) ◽  
pp. 615-629 ◽  
Author(s):  
Willem Kamphuis ◽  
Marie Orre ◽  
Lieneke Kooijman ◽  
Maurice Dahmen ◽  
Elly M. Hol

1999 ◽  
Vol 216 (4/5) ◽  
pp. 398-410 ◽  
Author(s):  
Sue Ann Miller ◽  
Michael Adornato ◽  
Ailish Briglin ◽  
Megan Cavanaugh ◽  
Todd Christian ◽  
...  

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