Mechanisms of elongation in embryogenesis

Keller, Ray

doi:10.1242/dev.02406

Cited by 141 publications

(108 citation statements)

References 86 publications

(82 reference statements)

Supporting

Mentioning

106

Contrasting

Order By: Relevance

“…Whether the mitosis orientations are a direct result of these cell geometries or are the consequence of morphogen gradients that trigger lamellipodium action (Keller et al 2000;Wallingford and Harland 2002;Keller 2006) is not yet clear.…”

Section: Results and Conclusionmentioning

confidence: 99%

Detection of mitoses in embryonic epithelia using motion field analysis

Siva¹,

Brodland²,

Clausi³

2009

Computer Methods in Biomechanics and Biomedical Engineering

View full text Add to dashboard Cite

Although computer simulations indicate that mitosis may be important to the mechanics of morphogenetic movements, algorithms to identify mitoses in bright field images of embryonic epithelia have not previously been available. Here, the authors present an algorithm that identifies mitoses and their orientations based on the motion field between successive images. Within this motion field, the algorithm seeks 'mitosis motion field prototypes' characterised by convergent motion in one direction and divergent motion in the orthogonal direction, the local motions produced by the division process. The algorithm uses image processing, vector field analyses and pattern recognition to identify occurrences of this prototype and to determine its orientation. When applied to time-lapse images of gastrulation and neurulation-stage amphibian (Ambystoma mexicanum) embryos, the algorithm achieves identification accuracies of 68 and 67%, respectively and angular accuracies of the order of 308, values sufficient to assess the role of mitosis in these developmental processes.

show abstract

Section: Results and Conclusionmentioning

confidence: 99%

Detection of mitoses in embryonic epithelia using motion field analysis

Siva¹,

Brodland²,

Clausi³

2009

Computer Methods in Biomechanics and Biomedical Engineering

View full text Add to dashboard Cite

show abstract

“…This regulation seems to be conserved in L. sativum and A. thaliana and points to a general underlying mechanism by which DOG1 regulates coat dormancy to define the temperature window for germination. As in embryo-related developmental processes in animals (16,18), the embryo-encasing tissue layers of the seed Fig. 6.…”

Section: Dog1 Determines the Temperature Window For Germination By Rementioning

confidence: 99%

“…The conserved DOG1-mediated coat-dormancy mechanism controls the timing of seed germination in a temperature-dependent manner. extracellular matrix sheath and its dynamic biomechanical properties (18). In the mature seed of most angiosperms the embryo is encased by two covering layers ("coats"): the living endosperm tissue and the dead testa (seed coat).…”

mentioning

confidence: 99%

DELAY OF GERMINATION 1 mediates a conserved coat-dormancy mechanism for the temperature- and gibberellin-dependent control of seed germination

Graeber

Linkies

Steinbrecher

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

170

182

View full text Add to dashboard Cite

Seed germination is an important life-cycle transition because it determines subsequent plant survival and reproductive success. To detect optimal spatiotemporal conditions for germination, seeds act as sophisticated environmental sensors integrating information such as ambient temperature. Here we show that the DELAY OF GERMI-NATION 1 (DOG1) gene, known for providing dormancy adaptation to distinct environments, determines the optimal temperature for seed germination. By reciprocal gene-swapping experiments between Brassicaceae species we show that the DOG1-mediated dormancy mechanism is conserved. Biomechanical analyses show that this mechanism regulates the material properties of the endosperm, a seed tissue layer acting as germination barrier to control coat dormancy. We found that DOG1 inhibits the expression of gibberellin (GA)-regulated genes encoding cell-wall remodeling proteins in a temperaturedependent manner. Furthermore we demonstrate that DOG1 causes temperature-dependent alterations in the seed GA metabolism. These alterations in hormone metabolism are brought about by the temperature-dependent differential expression of genes encoding key enzymes of the GA biosynthetic pathway. These effects of DOG1 lead to a temperature-dependent control of endosperm weakening and determine the optimal temperature for germination. The conserved DOG1-mediated coat-dormancy mechanism provides a highly adaptable temperature-sensing mechanism to control the timing of germination.dormancy gene DOG1 | gibberellin metabolism | germination temperature | cell-wall remodelling | Lepidium sativum

show abstract

“…2) occurs as the result of cell intercalation movements. 13,14 (see movie s1, supplemental information).…”

Section: Regional Tissue Elongation and Expansion In The Gastrulatingmentioning

confidence: 99%

Identification of emergent motion compartments in the amniote embryo

Loganathan¹,

Little²,

Joshi³

et al. 2014

Organogenesis

View full text Add to dashboard Cite

The tissue scale deformations (1mm) required to form an amniote embryo are poorly understood. Here, we studied »400 mm-sized explant units from gastrulating quail embryos. The explants deformed in a reproducible manner when grown using a novel vitelline membrane-based culture method. Time-lapse recordings of latent embryonic motion patterns were analyzed after disk-shaped tissue explants were excised from three specific regions near the primitive streak: 1) anterolateral epiblast, 2) posterolateral epiblast, and 3) the avian organizer (Hensen's node). The explants were cultured for 8 hours-an interval equivalent to gastrulation. Both the anterolateral and the posterolateral epiblastic explants engaged in concentric radial/centrifugal tissue expansion. In sharp contrast, Hensen's node explants displayed Cartesian-like, elongated, bipolar deformations-a pattern reminiscent of axis elongation. Time-lapse analysis of explant tissue motion patterns indicated that both cellular motility and extracellular matrix fiber (tissue) remodeling take place during the observed morphogenetic deformations. As expected, treatment of tissue explants with a selective Rho-Kinase (p160ROCK) signaling inhibitor, Y27632, completely arrested all morphogenetic movements. Microsurgical experiments revealed that lateral epiblastic tissue was dispensable for the generation of an elongated midline axisprovided that an intact organizer (node) is present. Our computational analyses suggest the possibility of delineating tissue-scale morphogenetic movements at anatomically discrete locations in the embryo. Further, tissue deformation patterns, as well as the mechanical state of the tissue, require normal actomyosin function. We conclude that amniote embryos contain tissue-scale, regionalized morphogenetic motion generators, which can be assessed using our novel computational time-lapse imaging approach. These data and future studies-using explants excised from overlapping anatomical positions-will contribute to understanding the emergent tissue flow that shapes the amniote embryo.

show abstract

Mechanisms of elongation in embryogenesis

Cited by 141 publications

References 86 publications

Detection of mitoses in embryonic epithelia using motion field analysis

Detection of mitoses in embryonic epithelia using motion field analysis

DELAY OF GERMINATION 1 mediates a conserved coat-dormancy mechanism for the temperature- and gibberellin-dependent control of seed germination

Identification of emergent motion compartments in the amniote embryo

Contact Info

Product

Resources

About