Cell migration occurs through the protrusion of the actin-enriched lamella. Here, we investigated the effects of RNAi depletion of approximately 90 proteins implicated in actin function on lamella formation in Drosophila S2 cells. Similar to in vitro reconstitution studies of actin-based Listeria movement, we find that lamellae formation requires a relatively small set of proteins that particip...

Approaches with high spatial and temporal resolution are required to understand the regulation of nonmuscle myosin II in vivo. Using fluorescence resonance energy transfer we have produced a novel biosensor allowing simultaneous determination of myosin light chain kinase (MLCK) localization and its [Ca2+]4/calmodulin-binding state in living cells. We observe transient recruitment of diffuse MLC...

Lyotropic liquid crystals formed in 3-dodecyloxy-2-hydroxypropyltrimethyl ammonium bromide (a new surfactant)n-butanol-11-decane-water system have been studied. Pseudo-ternary phase diagrams have been drawn based on experimental data at 298.2 K, and the speci fi c regions in which a single type of liquid crystal existing or diffe rent types of liquid crystal s coexisting have been determined in...

Vessels White oak cell types, fibers, rays, and vessels, were isolated from high-yield chemimechanical, neutral Rays sulphite semichemical (NSSC), and kraft pulps. Milled wood lignins (MWL) from NSSC fiber and ray Fibers cell fractions analyzed by ultraviolet and infrared spectroscopy were found to have similar syringyl/ Cell wall guaiacyl ratios. Methoxyl analyses of MWL’s were also similar an...

This paper describes electron microscopic studies on the distribution of pectin within young plant cells. Dark-grown onion roots, from 1 to 3 mm. in length, were used. In order to make the pectic substances selectively dense to electrons, they were first reacted with basic hydroxylamine. This treatment produces pectic hydroxamic acids, which in turn were treated with ferric ion to form insolubl...

Photoactivation and photobleaching of fluorescence were used to determine the mechanism by which microtubules (MTs) are remodeled in PtK2 cells during fibroblast-like motility in response to hepatocyte growth factor (HGF). The data show that MTs are transported during cell motility in an actomyosin-dependent manner, and that the direction of transport depends on the dominant force in the region...

This paper proposes a multi-level hierarchical model for the Tokay gecko (Gekko gecko) adhesive system and analyses the digital behaviour of the G. gecko under macro/meso-level scale. The model describes the structures of G. gecko’s adhesive system from the nano-level spatulae to the sub-millimetre-level lamella. The G. gecko’s seta is modelled using inextensible fibril based on Euler’s elastic...

The pecten oculi is a structure peculiar to the avian eye. Three morphological types of pecten oculi are recognized: conical type, vaned type and pleated type. The pleated type has been well studied. However, there exists only scanty data on the morphology of the latter two types of pectens. The structure of the vaned type of pecten of the ostrich, Struthio camelus was investigated with light a...

THE connective-tissue sheath around the nervous system of insects began to attract attention after Hoyle (1953) had shown that it was essential for the normal functioning of the nervous system in Locusta migratoria. The sheath, which consists of two layers, the neural lamella and the sheath cells, controls the passage of ions from the haemolymph into the nervous system. In electron-microscope s...

Productive protrusions allowing motile cells to sense and migrate toward a chemotactic gradient of reactive oxygen species (ROS) require a tight control of the actin cytoskeleton. However, the mechanisms of how ROS affect cell protrusion and actin dynamics are not well elucidated yet. We show here that ROS induce the formation of a persistent protrusion. In migrating epithelial cells, protrusio...