dictyNews Electronic Edition Volume 32, number 6 March 6, 2009 Please submit abstracts of your papers as soon as they have been accepted for publication by sending them to dicty@northwestern.edu or by using the form at http://dictybase.org/db/cgi-bin/dictyBase/abstract_submit. Back issues of dictyNews, the Dicty Reference database and other useful information is available at dictyBase - http://dictybase.org. ========= Abstracts ========= Review: Eukaryotic Chemotaxis Wouter-Jan Rappel and William F. Loomis Departments of Physics and Biology, University of California, San Diego Wiley Interdisciplinary Reviews: Systems Biology and Medicine, in press During eukaryotic chemotaxis, external chemical gradients guide the crawling motion of cells. This process plays an important role in a large variety of biological systems and has wide ranging medical implications. New experimental techniques including confocal microscopy and microfluidics have advanced our understanding of chemotaxis while numerical modeling efforts are beginning to offer critical insights. In this short review, we survey the current experimental status of the field by dividing chemotaxis into three distinct 'modules': directional sensing, polarity and motility. For each module, we attempt to point out potential new directions of research and discuss how modeling studies interact with experimental investigations. Submitted by: Bill Loomis [wloomis@ucsd.edu] -------------------------------------------------------------------------------- Filopodia: Complex models for simple rods Jan Faix (1), Dennis Breitsprecher (1), Theresia E.B. Stradal (2) and Klemens Rottner (2). (1) Inst. for Biophysical Chemistry, Hannover Medical School, Germany. (2) Helmholz Center for Infection Research, Braunschweig, Germany. International Journal of Biochemistry & Cell Biology, in press. Filopodia are prominent cell surface projections filled with bundles of linear actin filaments that drive their protrusion. These structures are considered important sensory organelles, for instance in neuronal growth cones or during the fusion of sheets of epithelial tissues. In addition, they can serve a precursor function in adhesion site or stress fibre formation. Actin filament assembly is essential for filopodia formation and turnover, yet the precise molecular mechanisms of filament nucleation and/or elongation are controversial. Indeed, conflicting reports on the molecular requirements of filopodia initiation have prompted researchers to propose different types and/or alternative or redundant mechanisms mediating this process. However, recent data shed new light on these questions, and they indicate that the balance of a limited set of biochemical activities can determine the structural outcome of a given filopodium. Here we focus on discussing our current view of the relevance of these activities, and attempt to propose a molecular mechanism of filopodia assembly based on a single core machinery. Submitted by: Hans Faix [faix@bpc.mh-hannover.de] ============================================================== [End dictyNews, volume 32, number 6]