Studies during the last 25 years have provided increasing evidence for the ability of plants to support the cell-to-cell and systemic transport of RNA molecules and that this process plays a role in plant development and in the systemic orchestration of cellular responses against pathogens and other environmental challenges. Since RNA viruses exploit the cellular RNA transport machineries for s...

To adapt to plants as hosts, plant viruses have evolutionally needed the capacity to modify the host plasmodesmata (PD) that connect adjacent cells. Plant viruses have acquired one or more genes that encode movement proteins (MPs), which facilitate the cell-to-cell movement of infectious virus entities through PD to adjacent cells. Because of the diversity in their genome organization and in th...

The cell-to-cell movement of the GUS-tagged potato virus X (PVX) coat protein (CP) movement-deficient mutant was restored by potyviral CPs of potato virus A (PVA) and potato virus Y (PVY) in Nicotiana benthamiana leaves in transient cobombardment experiments. Viral cell-to-cell movement of PVX CP mutant was complemented in Nicotiana tabacum cv. SR1 transgenic plants expressing PVY CP: PVX RNA a...

Migration and behaviour of Dictyostelium slugs results from coordinated movement of its constituent cells. It has been proposed that cell movement is controlled by propagating waves of cAMP as during aggregation and in the mound. We report the existence of optical density waves in slugs; they are initiated in the tip and propagate backwards. The waves reflect periodic cell movement and are medi...

Transport of viruses from cell to cell in plants typically involves one or more viral proteins that supply dedicated movement functions. Transport from leaf to leaf through phloem, or long-distance transport, is a poorly understood process with requirements differing from those of cell-to-cell movement. Through genetic analysis of tobacco etch virus (TEV; potyvirus group), a novel long-distance...

Reticulocytosis was induced in rabbits with phenylhydrazine. The accumulation of a small part of (59)Fe in blood cells of these animals was inhibited by ouabain and related to changes in extracellular sodium and potassium concentrations. Sodium increases movement from the cell surface into the cell, whereas potassium and ouabain decrease this movement. (59)Fe movement was found to be temperatur...

To shape a developing animal, individual cell movements must be coordinated over long distances. Two recent studies help show how this is achieved during convergence and extension of the Drosophila germ-band, where polarity within the plane of the embryonic epithelium biases junction remodeling to polarize cell intercalation.

Invasive bacteria actively induce their own uptake by phagocytosis in normally nonphagocytic cells and then either establish a protected niche within which they survive and replicate, or disseminate from cell to cell by means of an actin-based motility process. The mechanisms underlying bacterial entry, phagosome maturation, and dissemination reveal common strategies as well as unique tactics e...

The neural basis of the internal models used in sensorimotor transformations is beginning to be uncovered. Sensorimotor learning involves the modification of such models. Different stages of sensory-motor processing have been explored with a continuum of experimental tasks, from learning arbitrary associations of sensory cues to movements, to adapting to altered kinematic and dynamic environmen...

Biomechanical and environmental constraints limit body movements and tool use actions. However, in the case of tool use, such constraints can often be overcome by adjusting a tool’s tool transformation to the requirements of the intended tool use action. The research presented here examined whether participants grasped a lever at different positions, thus modifying the lever’s tool transformati...