UNLABELLED Pseudomonas aeruginosais an opportunistic human pathogen that has long been known to chemotax. More recently, it has been established that chemotaxis is an important factor in the ability ofP. aeruginosato make biofilms. Genes that allowP. aeruginosato chemotax are homologous with genes in the paradigmatic model organism for chemotaxis,Escherichia coli However,P. aeruginosais singly ...

Chemotaxis toward different cyclic adenosine monophosphate (cAMP) concentrations was tested in Dictyostelium discoideum cell lines with deletion of specific genes together with drugs to inhibit one or all combinations of the second-messenger systems PI3-kinase, phospholipase C (PLC), phospholipase A2 (PLA2), and cytosolic Ca(2+). The results show that inhibition of either PI3-kinase or PLA2 inh...

Various Ca antagonists used in animal research, many of them known to be Ca channel blockers, inhibited Escherichia coli chemotaxis (measured as entry of cells into a capillary containing attractant). The most effective of these, acting in the nanomolar range, was v-conotoxin GVIA. The next most effective were gallopamil and verapamil. At concentrations around 100-fold higher than that needed f...

Many processes in biology involve both reactions and chemotaxis. However, to the best of our knowledge, the question of interaction between chemotaxis and reactions has not yet been addressed either analytically or numerically. We consider a model with a single density function involving diffusion, advection, chemotaxis, and absorbing reaction. The model is motivated, in particular, by studies ...

Chemotaxis is the directed movement of cells or organisms in response to gradients concentration chemical stimuli, plays essential roles various biological process. In this paper, we consider a quasilinear two-species chemotaxis-competition system with loop higher dimensions defined on smooth bounded domain homogeneous Neumann boundary conditions. With help suitable energy functional and some e...

Alveolar macrophages produce neutrophil chemoattractants; this cellular cross-talk contributes to neutrophilic airway inflammation in chronic obstructive pulmonary disease (COPD). We have investigated the chemotaxis cross-talk mechanisms between these cells using COPD alveolar macrophages. Using conditioned media from stimulated COPD alveolar macrophages, we investigated the relative contributi...

Flagellated bacteria, such as Escherichia coli, perform directed motion in gradients of concentration of attractants and repellents in a process called chemotaxis. The E. coli chemotaxis signaling pathway is a model for signal transduction, but it has unique features. We demonstrate that the need for fast signaling necessitates high abundances of the proteins involved in this pathway. We show t...

Chemotaxis-driven invasions have been proposed across a broad spectrum of biological processes, from cancer to ecology. The influential system equations introduced by Keller and Segel has proven popular choice in the modelling such phenomena, but its original form restricts homogeneous population. To account for possibility phenotypic heterogeneity, we extend case population continuously struct...

Caenorhabditis elegans changes its NaCl-associated behavior from attraction to avoidance following exposure to NaCl in the absence of food (salt chemotaxis learning). To understand the changes induced by chemotaxis learning at the neuronal network level, we modeled a neuronal network of chemotaxis and estimated the changes that occurred in the nervous system by comparing the neuronal connection...

Central to chemotaxis is the molecular mechanism by which cells exhibit directed movement in shallow gradients of a chemoattractant. We used Dictyostelium mutants to investigate the minimal requirements for chemotaxis, and identified a basal signalling module providing activation of Ras at the leading edge, which is sufficient for chemotaxis. The signalling enzymes PI3K, TorC2, PLA2 and sGC are...