During vertebrate gastrulation, highly coordinated cellular rearrangements lead to the formation of the three germ layers, ectoderm, mesoderm and endoderm. In zebrafish, silberblick (slb)/wnt11 regulates normal gastrulation movements by activating a signalling pathway similar to the Frizzled-signalling pathway, which establishes epithelial planar cell polarity (PCP) in Drosophila. However, the ...

The existence of contact inhibition of nuclear overlapping (monolayering) has previously been interpreted to mean that intercellular contact locally inhibits the cell's locomotory apparatus and hence that cells in a confluent monolayer should be immobilized. Garrod & Steinberg, however, observed gross movements and exchanging of nuclear nearest neighbour relationships in a confluent monolayer o...

Members of the Wnt family have been implicated in a variety of developmental processes including axis formation, patterning of the central nervous system and tissue morphogenesis. Recent studies have shown that a Wnt signalling pathway similar to that involved in the establishment of planar cell polarity in Drosophila regulates convergent extension movements during zebrafish and Xenopus gastrul...

Coordinated morphogenetic cell movements during gastrulation are crucial for establishing embryonic axes in animals. Most recently, the non-canonical Wnt signaling cascade (PCP pathway) has been shown to regulate convergent extension movements in Xenopus and zebrafish. Heparan sulfate proteoglycans (HSPGs) are known as modulators of intercellular signaling, and are required for gastrulation mov...

A closed form three-dimensional solution is presented for determination of the local buckling (cell buckling) load of the nanosheets. Moreover, an expression is proposed for the effective 2D Young’s modulus of the unit cell of the nanosheet. In this regard, a three-dimensional efficient space-frame-like geometrical model with angular and extensional compliances is considered to investigate stab...

While gastrulation movements offer mechanistic paradigms for how collective cellular movements shape developing embryos, far less is known about coordinated cellular movements that occur later in development. Studying eyelid closure, we explore a case where an epithelium locally reshapes, expands, and moves over another epithelium. Live imaging, gene targeting, and cell-cycle inhibitors reveal ...

While most models of visual word identification and reading posit that a word's visual codes are rapidly transformed onto case-invariant representations (i.e., table and TABLE would equally activate the word unit corresponding to "table"), a number of experiments have shown a lowercase advantage in various word identification and reading tasks. In the present experiment, we examined the locus o...

Epithelial cells use a striking array of morphogenetic behaviors to sculpt organs and body plans during development. Although it is clear that epithelial morphogenesis is largely driven by cytoskeletal rearrangements and changes in cell adhesion, little is known about how these processes are coordinated to construct complex biological structures from simple sheets of cells. The follicle cell ep...

The movement of pro-apoptotic factors of the Bcl2-family from the cytosol to the mitochondria and the consequent permeabilization of the mitochondrial outer membrane to release cytochrome c and Smac from the mitochondrial intermembrane space into the cytosol or AIF to the nucleus are now well characterized steps in programmed cell death (Figure 1). However, there are concurrent movements of oth...