Hi,

I would like to know which vendor sells DIF-1 nowadays. Thanks in advance. 

Best,
Leung Kim
Associate Professor
Florida International University
Miami, Fl USA 33199
 
On Mar 4, 2011, at 5:27 PM, dictyBase wrote:

> dictyNews
> Electronic Edition
> Volume 36, number 7
> March 4, 2011
> 
> Please submit abstracts of your papers as soon as they have been
> accepted for publication by sending them to [log in to unmask]
> 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.
> 
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> 
> 
> =========
> Abstracts
> =========
> 
> Comparative genomics of the social amoebae Dictyostelium discoideum 
> and Dictyostelium purpureum 
> 
> Richard Sucgang1*, Alan Kuo2*, Xiangjun Tian3*, William Salerno1*, Anup Parikh4, 
> Christa L. Feasley5, Eileen Dalin2, Hank Tu2, Eryong Huang4, Kerrie Barry2, 
> Erika Lindquist2, Harris Shapiro2, David Bruce2, Jeremy Schmutz2, Asaf Salamov2, 
> Petra Fey6, Pascale Gaudet6, Christophe Anjard7, M. Madan Babu8, Siddhartha Basu6, 
> Yulia Bushmanova6, Hanke van der Wel5, Mariko Katoh-Kurasawa4, Christopher Dinh1, 
> Pedro M. Coutinho9, Tamao Saito10, Marek Elias11, Pauline Schaap12, Robert R. Kay8, 
> Bernard Henrissat9, Ludwig Eichinger13, Francisco Rivero14, Nicholas H. Putnam3, 
> Christopher M. West5, William F. Loomis7, Rex L. Chisholm6, Gad Shaulsky3,4, 
> Joan E. Strassmann3, David C. Queller3, Adam Kuspa1,3,4,†, and Igor V. Grigoriev2
> 
> 1Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor 
> College of Medicine, Houston, TX 77030 
> 2U.S. Department of Energy Joint Genome Institute, Walnut Creek CA 
> 3Department of Ecology and Evolutionary Biology, Rice University, Houston, TX 77005; 
> 4Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, 
> TX 77030 
> 5Department of Biochemistry & Molecular Biology, Oklahoma Center for Medical 
> Glycobiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
> 6dictyBase, Center for Genetic Medicine, Northwestern University, 750 N Lake Shore 
> Drive, Chicago, Illinois 60611
> 7Section of Cell and Developmental Biology, Division of Biology, University of California, 
> San Diego, La Jolla, California 92093
> 8Laboratory of Molecular Biology, MRC Centre, Cambridge CB2 2QH, UK
> 9Architecture et Fonction des Macromolécules Biologiques, UMR6098, CNRS, 
> Universities of Aix-Marseille I & II, 13288 Marseille, France
> 10Department of Materials and Life Sciences, Sophia University 7-1 Kioi-Cho, 
> Chiyoda-Ku, Tokyo, Japan 102-8554
> 11Departments of Botany and Parasitology, Faculty of Science, Charles University 
> in Prague, Prague, Czech Republic
> 12College of Life Sciences, University of Dundee, DD15EH Dundee, UK
> 13Center for Molecular Medicine Cologne, University of Cologne, Joseph-Stelzmann-Str. 
> 52, 50931 Cologne, Germany
> 14Centre for Biomedical Research, The Hull York Medical School and Department of 
> Biological Sciences, University of Hull, Hull HU6 7RX, UK.
> 
> 
> Genome Biology, in press
> 
> Background:
> The social amoebae (Dictyostelia) are a diverse group of Amoebozoa that achieve 
> multicellularity by aggregation and undergo morphogenesis into fruiting bodies with 
> terminally differentiated spores and stalk cells. There are four groups of dictyostelids, 
> with the most derived being a group that contains the model species Dictyostelium 
> discoideum. 
> Results: 
> We have produced a draft genome sequence of another group Dictyostelid, Dictyostelium 
> purpureum, and compare it to the D. discoideum genome. The assembly (8.41x coverage) 
> comprises 799 scaffolds totaling 33.0 Mb, comparable to the D. discoideum genome size. 
> Sequence comparisons suggest that these two Dictyostelids shared a common ancestor 
> approximately 400 million years ago. In spite of this divergence, most orthologs reside in 
> small clusters of conserved synteny. Comparative analyses revealed a core set of 
> orthologous genes that illuminate Dictyostelid physiology, as well as differences in gene 
> family content. Interesting patterns of gene conservation and divergence are also evident 
> suggesting function differences; some protein families, such as the histidine kinases, 
> have undergone little functional change, whereas others, such as the polyketide synthases, 
> have undergone extensive diversification. The abundant amino acid homopolymers 
> encoded in both genomes are generally not found in homologous positions within proteins, 
> so they are unlikely to derive from ancestral DNA triplet repeats. Genes involved in the 
> social stage evolved more rapidly than others, consistent with either relaxed selection 
> or accelerated evolution due to social conflict.
> Conclusion:
> The findings from this new genome sequence and comparative analysis shed light on 
> the biology and evolution of the Dictyostelia.
> 
> 
> Submitted by Adam Kuspa [[log in to unmask]]
> --------------------------------------------------------------------------------
> 
> 
> Deficiency of huntingtin has pleiotropic effects in the social amoeba 
> Dictyostelium discoideum
> 
> Michael A. Myre1, Amanda L. Lumsden1, Morgan N. Thompson1, 
> Wilma Wasco2, Marcy E. MacDonald1 and James F. Gusella1
> 
> 1Molecular Neurogenetics Unit, Center for Human Genetic Research, 
> Massachusetts General Hospital, Boston MA 02114. 
> 
> 2Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative 
> Disease, Massachusetts General Hospital, Charlestown MA 02129. 
> 
> PLoS Genetics, in press
> 
> Huntingtin is a large HEAT repeat protein first identified in humans, where a polyglutamine 
> tract expansion near the amino terminus causes a gain-of-function mechanism that leads 
> to selective neuronal loss in Huntington’s disease (HD). Genetic evidence in humans and 
> knock-in mouse models suggests that this gain-of-function involves an increase or 
> deregulation of some aspect of huntingtin’s normal function(s), which remains poorly 
> understood. As huntingtin shows evolutionary conservation, a powerful approach to 
> discovering its normal biochemical role(s) is to study the effects caused by its deficiency 
> in a model organism with a short life-cycle that comprises both cellular and multicellular 
> developmental stages. To facilitate studies aimed at detailed knowledge of huntingtin’s 
> normal function(s), we generated a null mutant of hd, the HD ortholog in Dictyostelium 
> discoideum. Dictyostelium cells lacking endogenous huntingtin were viable but during 
> development did not exhibit the typical polarized morphology of Dictyostelium cells, 
> streamed poorly to form aggregates by accretion rather than chemotaxis, showed 
> disorganized F-actin staining, exhibited extreme sensitivity to hypoosmotic stress, 
> and failed to form EDTA-resistant cell-cell contacts. Surprisingly, chemotactic 
> streaming could be rescued in the presence of the bivalent cations Ca2+ or Mg2+ 
> but not pulses of cAMP. Although hd- cells completed development, it was delayed 
> and proceeded asynchronously, producing small fruiting bodies with round, defective 
> spores that germinated spontaneously within a glassy sorus. When developed as 
> chimeras with wild-type cells, hd- cells failed to populate the pre-spore region of the 
> slug. In Dictyostelium, huntingtin deficiency is compatible with survival of the organism 
> but renders cells sensitive to low osmolarity which produces pleiotropic cell autonomous 
> defects that affect cAMP signaling, and as a consequence development. Thus, 
> Dictyostelium provides a novel haploid organism model for genetic, cell biological 
> and biochemical studies to delineate the functions of the HD protein.
> 
> 
> 
> Submitted by Michael Myre [[log in to unmask]]
> --------------------------------------------------------------------------------
> 
> A Dictyostelium SH2 adaptor protein required for correct DIF-1 signaling and 
> pattern formation
> 
> 
> Christopher Sugden1, Susan Ross1, Sarah J. Annesley4, Christian Cole1, 
> Gareth Bloomfield3, Alasdair Ivens2 Jason Skelton2, Paul R. Fisher4, 
> Geoffrey Barton1 and Jeffrey G. Williams1*
> 
> 1School of Life Sciences, University of Dundee, Dow St., Dundee, DD1 5EH UK
> 2Wellcome Trust Sanger Institute, Hinxton, CB10 1SA UK
> 3MRC Laboratory of Molecular Biology, Hills Road, Cambridge, CB2 2QH UK
> 4Department of Microbiology, La Trobe University, Bundoora, Victoria 3086, Australia
> * Corresponding Author
> [log in to unmask]
> tel 44 1382 385220, 
> fax 44-1382 34421
> 
> 
> Dev. Biol., in press
> 
> Dictyostelium is the only non-metazoan with functionally analysed SH2 domains
> and studying them can give insights into their evolution and wider potential. LrrB 
> has a novel domain configuration with leucine-rich repeat, 14-3-3 and SH2 
> protein-protein interaction modules. It is required for the correct expression of 
> several specific genes in early development and here we characterize its role in 
> later, multicellular development. During development in the light, slug formation 
> in LrrB null (lrrB-) mutants is delayed relative to the parental strain, and the slugs 
> are highly defective in phototaxis and thermotaxis. In the dark the mutant arrests 
> development as an elongated mound, in a hitherto unreported process we term 
> dark stalling. The developmental and phototaxis defects are cell autonomous and 
> marker analysis shows that the pstO prestalk sub-region of the slug is aberrant in 
> the lrrB- mutant. Expression profiling, by parallel micro-array and deep RNA 
> sequence analyses, reveals many other alterations in prestalk-specific gene 
> expression in lrrB- slugs, including reduced expression of the ecmB gene and 
> elevated expression of ampA. During culmination ampA is ectopically expressed 
> in the stalk, there is no expression of ampA and ecmB in the lower cup and the 
> mutant fruiting bodies lack a basal disc. The basal disc cup derives from the pstB 
> cells and this population is greatly reduced in the lrrB- mutant. This anatomical 
> feature is a hallmark of mutants aberrant in signalling by DIF-1, the polyketide 
> that induces prestalk and stalk cell differentiation. In a DIF-1 induction assay 
> the lrrB- mutant is profoundly defective in ecmB activation but only marginally 
> defective in ecmA induction. Thus the mutation partially uncouples these two 
> inductive events. In early development LrrB interacts physically and functionally 
> with CldA, another SH2 domain containing protein. However, the CldA null 
> mutant does not phenocopy the lrrB- in its aberrant multicellular development 
> or phototaxis defect, implying that the early and late functions of LrrB are 
> effected in different ways. These observations, coupled with its domain 
> structure, suggest that LrrB is an SH2 adaptor protein active in diverse 
> developmental signaling pathways. 
> 
> 
> Submitted by: Jeff Williams [[log in to unmask]]
> ==============================================================
> [End dictyNews, volume 36, number 7]