dictyNews Electronic Edition Volume 31, number 18 December 12, 2008 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 ========= Folic acid is a potent chemoattractant of free-living amoebae in a new and amazing species of a protist, Vahlkampfia Yasuo Maeda1*, Taira Mayanagi2 and Aiko Amagai3 1Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Aoba, Sendai 980-8578, Japan 2The Research Center for Child Mental Development, Osaka University Graduate School of Medicine, Yamadaoka 2-2, Suita, Osaka 565-0871, Japan 3Department of Biomolecular Science, Graduate School of Life Sciences, Tohoku University, Katahira 2-1-1, Aoba-Ku, Sendai 980-8577, Japan Zoological Science, in press Folic acid (folate; vitamin Bc) is well recognized as essential for the proper  metabolism of the essential amino acid methionine as well as for the synthesis  of adenine and thymine. A folate deficiency has been implicated in a wide  variety of disorders from Alzheimer’s disease to depression and neural tube  defects. In the cellular slime molds including Dictyostelium, vegetative  growth-phase cells are known to be chemotactically moved toward folate  that is secreted by bacterial food sources such as Escherichia coli.  Intracellular folate signal transduction including G proteins, Ca2+channels,  and PIP3 pathway has been reported in D. discoideum. To our surprise, the  genuine chemoattractant(s) of free-living protozoan amoebae have remained  to be determined, possibly because of a lack of a pertinent method for assaying  chemotaxis. We recently isolated a primitive free-living amoeba from the soil  of Costa Rica, and identified it as a new species of the genus Vahlkampfia  belonging to a subclass Gymnamoebia in which Entamoeba and Acanthamoeba  are included. The amoebae can grow and multiply quite rapidly engulfing nearby  bacteria such as E. coli. Importantly, we have demonstrated here using a quite  simple but finely designed chemotaxis assay that the Vahlkampfia amoebae  exhibit chemotaxis toward higher folate concentrations. Riboflavin and  cyanocobalamin were also found to serve as positive chemoattractants. Among these chemoattractants , folate is of particular importance because its function seems to be evolutionarily conserved as a potent chemoattractant of amoeboid cells in a wide range of organisms as well as in the Protista and cellular slime molds.  Submitted by: Yasuo Maeda [ymaeda@mail.tains.tohoku.ac.jp] -------------------------------------------------------------------------------- Analysis of cell movement by simultaneous quantification of local membrane displacement and fluorescent intensities using Quimp2. Leonard Bosgraaf *, Peter J.M. van Haastert* and Till Bretschneider # * University of Groningen, Cell Biochemistry  Department, Haren, the Netherlands # University of Warwick, Warwick Systems Biology Centre, Warwick, United Kingdom Cell Motility and the Cytoskeleton, in press The use of fluorescent markers in living cells has increased dramatically in the recent years. The quantitative analysis of the images requires specific analysis software. Previously, the program Quimp was launched for quantitating  fluorescent intensities at the membrane or the cortex of the cell. However,  Quimp it is not well suited to quantitate local membrane displacement. Here  we present Quimp2 that is capable of tracking membrane subregions in time,  which  enables the simultaneous quantification of fluorescent intensities and  membrane movement. Quimp2 has two new tools, i) conversion filters to  analyze movies obtained with fluorescent, DIC and phase contrast different  microscopes, and ii) a macro that calculates the local membrane displacement  and provides various options to display the results. Quimp2 is used here to  investigate the molecular mechanism of cell movement by correlating the  dynamics of local membrane movement with the local concentration of  myosin and F-actin.  Submitted by: Peter J.M. van Haastert [p.j.m.van.haastert@rug.nl] ============================================================== [End dictyNews, volume 31, number 18]