Analysis of morphogenetic movements in the neural plate of the newt Taricha torosa

Burnside, M.Beth; Jacobson, Antone G.

doi:10.1016/0012-1606(68)90025-0

Cited by 112 publications

(56 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…When lamellipodia act successively at many different locations throughout the tissue, the cumulative effect, which might be considered a superposition of these local disturbances, results in a CE pattern (Fig. 3B) similar to that observed in real embryos (Burnside and Jacobson, 1968;Jacobson and Lofberg, 1969).…”

Section: A B C Results and Discussionsupporting

confidence: 56%

Do lamellipodia have the mechanical capacity to drive convergent extension?

Brodland¹

2006

Int. J. Dev. Biol.

View full text Add to dashboard Cite

Convergent extension (CE), a kinematic motif associated with several important morphogenetic movements in embryos, entails narrowing of a tissue in one in-plane direction and elongation in the other. Although the cell elongation and intercalation which accompany this process have been investigated and relevant genes and biochemical pathways have been studied in multiple organisms, a fundamental question that has not yet been answered is "Do the lamellipodia thought to drive these motions actually have the mechanical capacity to do so?" Here, we address this and a number of related issues using a state-of-the-art computational model which can replicate cell motions, changes in cell shape and tissue deformations. The model is based on the cell-level finite element approach of Chen and Brodland, but has additional features which allow it to model lamellipodium formation and contraction. In studying CE, computational models provide an important complement to molecular approaches because they reveal the "mechanical pathways" through which gene products must ultimately act in order to produce physical movements. The model shows that lamellipodia can drive CE, that they do so through cell intercalations and that the elongated cells characteristic of CE arise only when adjacent tissues resist convergence, a result which we confirm experimentally.

show abstract

Section: A B C Results and Discussionsupporting

confidence: 56%

Do lamellipodia have the mechanical capacity to drive convergent extension?

Brodland¹

2006

Int. J. Dev. Biol.

View full text Add to dashboard Cite

show abstract

“…Such tissue movements are driven by a variety of morphogenetic engines, including cell rearrangements, oriented cell divisions and changes in cell shape. Cell shape changes are of particular importance during the morphogenesis of epithelial sheets, in which bending is facilitated by the specific constriction of the apical surfaces of cells (Burnside and Jacobson, 1968;Jacobson and Gordon, 1976;Leptin and Grunewald, 1990;Schoenwolf, 1988). Interestingly, cells undergoing such apical constriction are almost universally characterized by elongation along their apicobasal axis (Burnside, 1973;Sweeton et al, 1991;Viamontes and Kirk, 1977).…”

Section: Introductionmentioning

confidence: 99%

Direct activation of Shroom3 transcription by Pitx proteins drives epithelial morphogenesis in the developing gut

et al. 2010

View full text Add to dashboard Cite

SUMMARYIndividual cell shape changes are essential for epithelial morphogenesis. A transcriptional network for epithelial cell shape change is emerging in Drosophila, but this area remains largely unexplored in vertebrates. The distinction is important as so far, key downstream effectors of cell shape change in Drosophila appear not to be conserved. Rather, Shroom3 has emerged as a central effector of epithelial morphogenesis in vertebrates, driving both actin-and microtubule-based cell shape changes. To date, the morphogenetic role of Shroom3 has been explored only in the neural epithelium, so the broad expression of this gene raises two important questions: what are the requirements for Shroom3 in non-neural tissues and what factors control Shroom3 transcription? Here, we show in Xenopus that Shroom3 is essential for cell shape changes and morphogenesis in the developing vertebrate gut and that Shroom3 transcription in the gut requires the Pitx1 transcription factor. Moreover, we show that Pitx proteins directly activate Shroom3 transcription, and we identify Pitx-responsive regulatory elements in the genomic DNA upstream of Shroom3. Finally, we show that ectopic expression of Pitx proteins is sufficient to induce Shroom3-dependent cytoskeletal reorganization and epithelial cell shape change. These data demonstrate new breadth to the requirements for Shroom3 in morphogenesis, and they also provide a cell-biological basis for the role of Pitx transcription factors in morphogenesis. More generally, these results provide a foundation for deciphering the transcriptional network that underlies epithelial cell shape change in developing vertebrates.

show abstract

“…These movements occur ubiquitously in metazoan development and probably account for more tissue distortion in embryogenesis than any other single process (Keller 1987;Keller et al 1991b). Examples include archenteron elongation in echinoderms (Ettensohn 1985;Hardin & Cheng 1986), germ band extension (Irvine & Wieschaus 1994) and imaginal leg disc evagination in Drosophila (see Condic et al 1991), Hydra regeneration (Bode & Bode 1984), nematode body axis elongation (Priess & Hirsh 1986;Williams-Masson et al 1997), and elongation of dorsal axial embryonic tissues of ascidians (Cloney 1964;Miyamoto & Crowther 1985), ¢shes (Warga & Kimmel 1990;Kimmel et al 1994;Concha & Adams 1998), birds (Schoenwolf & Alvarez 1989), mammals (Sausedo & Schoenwolf 1994), and amphibians (Vogt 1929;Schechtman 1942;Burnside & Jacobson 1968;Keller 1984;Keller et al 1991a,b). Convergence can be coupled directly to extension with conservation of tissue volume, the decrease in width accounted for by a proportional increase in length (¢gure 1a).…”

Section: Introductionmentioning

confidence: 99%

“…Convergence and extension have been studied most in situations where tissue volume changes due to cell growth does not occur at all or is insigni¢cant, such as in the early development of sea urchins (Hardin & Cheng 1986), amphibians (Burnside & Jacobson 1968;Keller 1986), and £ies (Condic et al 1991). However, these movements also occur in embryos that grow dramatically in early development, such as those of the mouse (Snow 1977), and in these cases, tissue volume changes may also come into play.…”

Section: Introductionmentioning

confidence: 99%

Mechanisms of convergence and extension by cell intercalation

Keller

Davidson

Edlund

et al. 2000

Phil. Trans. R. Soc. Lond. B

472

401

View full text Add to dashboard Cite

The cells of many embryonic tissues actively narrow in one dimension (convergence) and lengthen in the perpendicular dimension (extension). Convergence and extension are ubiquitous and important tissue movements in metazoan morphogenesis. In vertebrates, the dorsal axial and paraxial mesodermal tissues, the notochordal and somitic mesoderm, converge and extend. In amphibians as well as a number of other organisms where these movements appear, they occur by mediolateral cell intercalation, the rearrangement of cells along the mediolateral axis to produce an array that is narrower in this axis and longer in the anteroposterior axis. In amphibians, mesodermal cell intercalation is driven by bipolar, mediolaterally directed protrusive activity, which appears to exert traction on adjacent cells and pulls the cells between one another. In addition, the notochordal^somitic boundary functions in convergence and extension bỳ capturing' notochordal cells as they contact the boundary, thus elongating the boundary. The prospective neural tissue also actively converges and extends parallel with the mesoderm. In contrast to the mesoderm, cell intercalation in the neural plate normally occurs by monopolar protrusive activity directed medially, towards the midline notoplate^£oor-plate region. In contrast, the notoplate^£oor-plate region appears to converge and extend by adhering to and being towed by or perhaps migrating on the underlying notochord. Converging and extending mesoderm sti¡ens by a factor of three or four and exerts up to 0.6 m N force. Therefore, active, force-producing convergent extension, the mechanism of cell intercalation, requires a mechanism to actively pull cells between one another while maintaining a tissue sti¡ness su¤cient to push with a substantial force. Based on the evidence thus far, a cell^cell traction model of intercalation is described. The essential elements of such a morphogenic machine appear to be (i) bipolar, mediolaterally orientated or monopolar, medially directed protrusive activity; (ii) this protrusive activity results in mediolaterally orientated or medially directed traction of cells on one another; (iii) tractive protrusions are con¢ned to the ends of the cells; (iv) a mechanically stable cell cortex over the bulk of the cell body which serves as a movable substratum for the orientated or directed cell traction. The implications of this model for cell adhesion, regulation of cell motility and cell polarity, and cell and tissue biomechanics are discussed.

show abstract

Analysis of morphogenetic movements in the neural plate of the newt Taricha torosa

Cited by 112 publications

References 3 publications

Do lamellipodia have the mechanical capacity to drive convergent extension?

Do lamellipodia have the mechanical capacity to drive convergent extension?

Direct activation of Shroom3 transcription by Pitx proteins drives epithelial morphogenesis in the developing gut

Mechanisms of convergence and extension by cell intercalation

Contact Info

Product

Resources

About