dictyNews Electronic Edition Volume 34, number 16 May 28, 2010 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. Follow dictyBase on twitter: http://twitter.com/dictybase ========= Abstracts ========= Dictyostelium amoebae and neutrophils can swim by Nicholas P. Barry and Mark S. Bretscher MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, England PNAS, in press Animal cells migrating over a substratum crawl in amoeboid fashion; how the force against the substratum is achieved remains uncertain. We find that amoebae and neutrophils, cells traditionally used to study cell migration on a solid surface, move towards a chemotactic source whilst suspended in solution. They can swim and do so with speeds similar to those on a solid substrate. Based on the surprisingly rapidly changing shape of amoebae as they swim and earlier theoretical schemes for how suspended microorganisms can migrate (Purcell EM (1977) Life at low Reynolds number. Am. J. Phys. 45:3-11), we suggest the general features these cells employ to gain traction with the medium. This requires either the movement of the cell’s surface from the cell’s front towards its rear, or protrusions which move down the length of the elongated cell. Our results indicate that a solid substratum is not a prerequisite for these cells to produce a forward thrust during movement and suggest that crawling and swimming are similar processes, a comparison we think is helpful in understanding how cells migrate. Submitted by Mark Bretscher [msb@mrc-lmb.cam.ac.uk] -------------------------------------------------------------------------------- Autophagy in Dictyostelium: genes and pathways, cell death and infection Javier Calvo-Garrido, Sergio Carilla-Latorre, Yuzuru Kubohara, Natalia Santos-Rodrigo, Ana Mesquita, Thierry Soldati, Pierre Golstein and Ricardo Escalante Autophagy, in press The use of simple organisms to understand the molecular and cellular function of complex processes is instrumental for the rapid development of biomedical research. A remarkable example has been the discovery in S. cerevisiae of a group of proteins involved in the pathways of autophagy. Orthologues of these proteins have been identified in humans and experimental model organisms. Interestingly, some mammalian autophagy proteins do not seem to have homologues in yeast but are present in Dictyostelium, a social amoeba with two distinctive life styles, a unicellular stage in nutrient-rich conditions that differentiates upon starvation into a multicellular stage that depends on autophagy. This review focuses on the identification and annotation of the putative Dictyostelium autophagy genes and on the role of autophagy in development, cell death and infection by bacterial pathogens. Submitted by Ricardo Escalante [rescalante@iib.uam.es] ============================================================== [End dictyNews, volume 34, number 16]