Cetiedil is a potential antisickling agent whose major effect appears to be at the erythrocyte membrane. To test the hypothesis that cetiedil alters cation transport, we studied the effect of the drug in promoting changes in cell water (Wc), cell sodium (Nac), and cell potassium (Kc). Results are quite different depending on the presence or near absence of intracellular ATP. With fresh cells, 1...

Recent data have reinforced the fundamental role of regulated cell adhesion as a force that drives morphogenesis during gastrulation. As we discuss, cell adhesion is required for all modes of gastrulation movements in all organisms. It can even be instructive in nature, but it must be tightly and dynamically regulated. The picture that emerges from the recent findings that we review here is tha...

Gastrulation is a fundamental process in early development that results in the formation of three primary germ layers. During avian gastrulation, presumptive mesodermal cells in the dorsal epiblast ingress through a furrow called the primitive streak (PS), and subsequently move away from the PS and form adult tissues. The biophysical mechanisms driving mesodermal cell movements during gastrulat...

During vertebrate gastrulation, convergence and extension movements elongate embryonic tissues anteroposteriorly and narrow them mediolaterally. Planar cell polarity (PCP) signaling is essential for mediolateral cell elongation underlying these movements, but how this polarity arises is poorly understood. We analyzed the elongation, orientation and migration behaviors of lateral mesodermal cell...

Life is intimately related to movement on many different time and length scales, from molecular movements to the motility of cells and organisms. One type of movement which is ubiquitous on the molecular and cellular scale, although not specific to the organic world, is Brownian motion or passive diffusion: Biomolecules, vesicles, organelles, and other subcellular particles constantly undergo r...

Polarization of early embryos along cell contact patterns--referred to in this paper as radial polarization--provides a foundation for the initial cell fate decisions and morphogenetic movements of embryogenesis. Although polarity can be established through distinct upstream mechanisms in Caenorhabditis elegans, Xenopus laevis, and mouse embryos, in each species, it results in the restriction o...

A new vital marking procedure was devised, studied, and applied to the phenomenon of hydra column tissue movements. The method involves injecting colloidal carbon (India ink) into the ectodermal epithelium of hydra. The carbon is taken up specifically by epithelial cells and packed into lysosome residual bodies. Each marked cell is then identifiable by its aggregated carbon particle, which appe...

The generation of four-dimensional (4D) confocal datasets; consisting of 3D image sequences over time; provides an excellent methodology to capture cellular behaviors involved in developmental processes.  The ability to track and follow cell movements is limited by sample movements that occur due to drift of the sample or, in some cases, growth during image acquisition. Tracking cells in datase...

lation. Recent studies show that signaling through integrin As a first step in describing the nature of the crosstalk receptors is required for normal cell movements durbetween integrin and C-cadherin, Marsden and DeSiing Xenopus gastrulation. Integrins function in this mone present evidence that integrin-mediated homoprocess by modulating the activity of cadherin adhetypic cell binding in diff...

Recent data have reinforced the fundamental role of regulated cell adhesion as a force that drives morphogenesis during gastrulation. As we discuss, cell adhesion is required for all modes of gastrulation movements in all organisms. It can even be instructive in nature, but it must be tightly and dynamically regulated. The picture that emerges from the recent findings that we review here is tha...