dictyNews Electronic Edition Volume 27, number 13 November 10, 2006 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 ========= What can microbial genetics teach sociobiology? Kevin R. Foster1, Katie Parkinson2 and Christopher R. L. Thompson2 1. Center for Systems Biology, Harvard University, Bauer Laboratory, 7 Divinity Avenue, Cambridge, MA, 02138, USA 2. Faculty of Life Sciences, University of Manchester, Michael Smith Building, Oxford Rd, Manchester, M13 9PT, UK Correspondence to Kevin (kfoster@cgr.harvard.edu) or Chris (christopher.thompson@manchester.ac.uk) Trends in Genetics,in press The progress made in understanding sociobiology has occurred with little knowledge of the genetic mechanisms that underlie social traits. However, several recent studies have described microbial genes that affect social traits Ð bringing genetics to sociobiology. These studies confirm some key theories in social evolution, including the importance of genetic relatedness in cooperation as illustrated by cheater and social recognition genes. Furthermore, microbial genetics provides an important new perspective: the genome-to-phenome mapping of social organisms might be organized to constrain the evolution of social cheaters. This can occur both through pleiotropic genes that link cheating to a personal cost, and through the existence of phoenix genes that rescue cooperative systems from selfish and destructive strategies. These new insights demonstrate the power of studying microbes to understand the evolution of cooperation. Submitted by: Chris Thompson [christopher.thompson@man.ac.uk] ------------------------------------------------------------------------------------------------------------ A new environmentally resistant cell type from Dictyostelium Ioannis Serafimidis, Gareth Bloomfield, Jason Skelton1, Al Ivens1 and Robert R. Kay MRC Laboratory of Molecular Biology, Hills Rd, Cambridge, CB2 2QH, UK 1. The Wellcome Trust Sanger Institute, Hinxton, Cambridgeshire CB10 1SA, UK We describe the serendipitous discovery and first characterization of a new resistant cell type from Dictyostelium, which we propose to call the aspidocyte (aspida: Greek for shield). These cells are induced from amoebae by a range of toxins including heavy metals and antibiotics, and were first detected by their striking resistance to detergent lysis. Aspidocytes are separate, rounded or irregular shaped cells that are immotile but remain fully viable; once the toxic stress is removed, they revert to amoeboid cells within an hour. Induction takes a few hours and is completely blocked by the protein synthesis inhibitor cycloheximide. Aspidocytes lack a cell wall and their resistance to detergent lysis is active, requiring continued energy metabolism, and may be assisted by a complete cessation of endocytosis, as measured by uptake of the dye FM1-43. Microarray analysis shows that aspidocytes have a distinct pattern of gene expression with a number of genes up-regulated that are predicted to be involved in lipid metabolism. Aspidocytes were initially detected in a hypersensitive mutant, in which the AMP deaminase gene is disrupted, suggesting that the inductive pathway involves AMP levels or metabolism. Since aspidocytes can also be induced from wild-type cells and are much more resistant than amoebae to a membrane disrupting antibiotic, it is possible that they are an adaptation allowing Dictyostelium cells to survive a sudden onslaught of toxins in the wild. Submitted by: Rob Kay [rrk@mrc-lmb.cam.ac.uk] ============================================================= [End dictyNews, volume 27, number 13]