A5026841023- Cellular Mechanics and Interactions
- Developmental Biology and Gene Regulation
- Wnt/β-catenin signaling in development and cancer
- 3D Printing in Biomedical Research
- Cell Adhesion Molecules Research
- Hippo pathway signaling and YAP/TAZ
- Axon Guidance and Neuronal Signaling
- Pluripotent Stem Cells Research
- Zebrafish Biomedical Research Applications
- Congenital heart defects research
- Neurobiology and Insect Physiology Research
- RNA Research and Splicing
- Cancer Cells and Metastasis
- Microtubule and mitosis dynamics
- Marine Biology and Environmental Chemistry
- Protist diversity and phylogeny
- Marine Ecology and Invasive Species
- Silk-based biomaterials and applications
- Microfluidic and Bio-sensing Technologies
- Tissue Engineering and Regenerative Medicine
- Proteoglycans and glycosaminoglycans research
- Advanced Materials and Mechanics
- Bone Tissue Engineering Materials
- Protease and Inhibitor Mechanisms
- MicroRNA in disease regulation
University of Toronto
2015-2024
National Institutes of Health
2011
Max Planck Society
1985-2001
University of Cologne
1994-2001
Max Planck Institute for Developmental Biology
1985-2001
University of California, Berkeley
1990-1996
Max Planck Institute for Biology
1983
Tissue boundary formation in the early vertebrate embryo involves cycles of cell attachment and detachment at boundary, contact-dependent signaling by membrane-bound EphB receptors ephrinB ligands.
Morphogenetic processes often involve the rapid rearrangement of cells held together by mutual adhesion. The dynamic nature this adhesion endows tissues with liquid-like properties, such that large-scale shape changes appear as tissue flows. Generally, resistance to flow (tissue viscosity) is expected depend on cohesion a (how strongly its adhere each other), but exact relationship between these parameters not known. Here, we analyse link and viscosity uncover basic mechanical principles...
Adhesion differences between cell populations are in principle a source of strong morphogenetic forces promoting sorting, boundary formation and tissue positioning, cadherins main mediators adhesion. However, direct link cadherin expression, differential adhesion, morphogenesis has not yet been determined for specific process vivo. To provide such connection, we modulated the expression C-cadherin Xenopus gastrula, combined this with measurements adhesion-related parameters. Our results show...
Vertebrate embryonic cells recognize self from non-self, thus restricting repulsion at tissue boundaries, through a combination of multiple ephrins and Eph receptors, simply based on binding selectivity asymmetric expression.
Abstract A main achievement of gastrulation is the movement endoderm and mesoderm from surface embryo to interior. Despite its fundamental importance, this internalization process not well understood in amphibians. We show that Xenopus, an active distortion vegetal cell mass, rotation, leads a dramatic expansion blastocoel floor concomitant turning around marginal zone which constitutes first major step involution. This vigorous inward surging region into can be analyzed explanted slices...
In vertebrates, PDGFA and its receptor, PDGFRalpha, are expressed in the early embryo. Impairing their function causes an array of developmental defects, but underlying target processes that directly controlled by these factors not well known. We show Xenopus gastrula, PDGFA/PDGFRalpha signaling is required for directional migration mesodermal cells on extracellular matrix blastocoel roof. Blocking PDGFRalpha mesoderm does inhibit per se, results movement randomized no longer directed...
Epithelia are planar tissues that undergo major morphogenetic movements during development. These must work in the context of mechanical properties epithelia. Surprisingly little is known about these at time and length scales processes. We show a scale hours, Xenopus gastrula ectodermal epithelium mimics an elastic solid when stretched isometrically; strikingly, its area increases twofold embryo by such pseudoelastic expansion. At same time, basal side behaves like liquid exhibits tissue...
Abstract Cilia are hair-like cellular protrusions important in many aspects of eukaryotic biology. For instance, motile cilia enable fluid movement over epithelial surfaces, while primary (sensory) play roles signalling. The molecular events underlying dynamics, and particularly their disassembly, not well understood. Phosphatase tensin homologue (PTEN) is an extensively studied tumour suppressor, thought to primarily act by antagonizing PI3-kinase Here we demonstrate that PTEN plays role...
Abstract In the Xenopus gastrula, mesoderm moves as a coherent cell aggregate across blastocoel roof toward animal pole. We show that cohesion of is not only mechanically necessary, but formation has profound effects on migratory behavior cells. Whereas isolated cells are bi‐ or multipolar, move stepwise and change their direction movement frequently, aggregated migrating in vivo substrate appear unipolar continuously persistently. Moreover, aggregates, single cells, can follow guidance cues...
Radial intercalation is a common, yet poorly understood, morphogenetic process in the developing embryo. By analyzing cell rearrangement prechordal mesoderm during Xenopus gastrulation, we have identified mechanism for radial intercalation. It involves orientation response to long-range signal mediated by platelet-derived growth factor (PDGF-A) and directional intercellular migration. When PDGF-A signaling inhibited, cells fail orient towards ectoderm, endogenous source of PDGF-A, no longer...
During amphibian gastrulation, presumptive endoderm is internalised as part of vegetal rotation, a large-scale movement that encompasses the whole half embryo. It has been considered gastrulation process unique to amphibians, but we show at cell level, internalisation exhibits characteristics reminiscent bottle formation and ingression, known mechanisms germ layer internalisation. ingression proper, cells leave single-layered epithelium. In occurs in multilayered mass; refer it...
-Catenin-independent Wnt signaling pathways have been implicated in the regulation of planar cell polarity (PCP) and convergent extension (CE) movements.Prickle, one core proteins these pathways, is known to asymmetrically localize proximally at adherens junction Drosophila melanogaster wing cells locally accumulate within plasma membrane subdomains undergoing CE movements during vertebrate development.Using mass spectrometry, we identified Ste20 kinase Mink1 as a Prickle-associated protein...
The morphogenic process of convergent thickening (CT) was originally described as the mediolateral convergence and radial explanted ventral involuting marginal zone (IMZ)