dictyNews Electronic Edition Volume 36, number 6 Feb 25, 2011 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 ========= dictyNews Electronic Edition Volume 36, number 6 Feb 25, 2011 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 ========= Protein Kinase B Homologue pkbR1 Performs One of Its Roles at First Finger Stage of Dictyostelium Hiroshi Ochiai,a,b,c,1 Kosuke Takeda,a  Masashi Fukuzawa,d Atsushi Kato,a,e,f Shigeharu Takiya,c,e,f Tetsuo Ohmachi, b a Division of Biological Sciences, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan; b Department of Biochemistry and Molecular Biology, Faculty of Agriculture & Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosaki 036-8561, Japan; c Division of Genome Dynamics, Creative Research Initiative ÓSouseiÓ, Hokkaido University, Sapporo 060-0810, Japan; d Department of Biology, Faculty of Agriculture & Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosaki 036-8561, Japan; e Division of Functional Genome Science, Department of Biological Sciences, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan; f Department of Biological Sciences, Faculty of Science, Hokkaido University, S apporo 060-0810, Japan   The present address: Section of Cell and Developmental Biology, Division of Biological Sciences and Center for Molecular Genetics, University of California, San Diego, La Jolla, California 92093-0380. 1 Corresponding author Eukaryotic Cell, in press Dictyostelium discoideum has protein kinases AKT/PKBA and PKBR1 that belong to the AGC family of kinases. The protein kinase B related kinase (PKBR1) has been studied with emphasis on its role in chemotaxis, but its roles in late development remained so far obscure. The pkbR1 null mutant stays in the first finger stage for about 16 hr and longer. Only a few aggregates continue to the migrating slugs stage, however, the slugs immediately go back probably to the previous first finger stage, and stay there for approximately 37 hr. Finally the mutant fingers diversify into various multicellular bodies. Expression of the pkbR1 finger protein is probably required for development to the slug stage and to express ecmB which is first observed in migrating slugs. The mutant also showed no ST-lacZ expression, which is of the earliest step in differentiation to one of the stalk cell sub-types. The pkbR1 null mutant forms a small number of aberrant fruiting bodies but in the presence of 10% of wild-type amoebae the mutant preferentially forms viable spores, driving the wild type to form non-viable stalk cells. These results suggest that the mutant has defects in a system that changes the physiological dynamics in the prestalk cell region of a finger. We suggest that the arrest of its development is due to loss of the second wave of expression of a protein kinase A catalytic subunit gene (pkaC) only in the prestalk region of the pkbR1 null mutant. Submitted by Hiroshi Ochiai [hochiai@sci.hokudai.ac.jp] -------------------------------------------------------------------------------- Kin discrimination and possible cryptic species in the social amoeba Polysphondylium violaceum Sara E Kalla, David C Queller, Andrea Lasagni, and Joan E Strassmann BMC Evolutionary Biology 2011, 11:31 Background The genetic diversity of many protists is unknown. The differences that result from this diversity can be important in interactions among individuals. The social amoeba Polysphondylium violaceum, which is a member of the Dictyostelia, has a social stage where individual amoebae aggregate together to form a multicellular fruiting body with dead stalk cells and live spores. Individuals can either cooperate with amoebae from the same clone, or sort to form clonal fruiting bodies. In this study we look at genetic diversity in P. violaceum and at how this diversity impacts social behavior. Results The phylogeny of the ribosomal DNA sequence (17S to 5.8S region) shows that P. violaceum is made up of at least two groups. Mating compatibility is more common between clones from the same phylogenetic group, though matings between clones from different phylogenetic groups sometimes occurred. P. violaceum clones are more likely to form clonal fruiting bodies when they are mixed with clones from a different group than when they are mixed with a clone of the same group. Conclusion Both the phylogenetic and mating analyses suggest the possibility of cryptic species in P. violaceum. The level of divergence found within P. violaceum is comparable to the divergence between sibling species in other dictyostelids. Both major groups A/B and C/D/E/F show kin discrimination, which elevates relatedness within fruiting bodies but not to the level of clonality. The diminished cooperation in mixes between groups suggests that the level of genetic variation between individuals influences the extent of their cooperation. Submitted by: Sara Kalla [sekalla@gmail.com] ============================================================== [End dictyNews, volume 36, number 6]