dictyNews Electronic Edition Volume 27, number 17 December 22, 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 ========= cAMP production by adenylyl cyclase G induces prespore differentiation in Dictyostelium slugs Elisa Alvarez-Curto, Shweta Saran, Marcel Meima, Jenny Zobel, Claire Scott and Pauline Schaap* Division of Cell and Developmental Biology, College of Life Sciences, University of Dundee, Dundee, Angus DD1 5EH, UK Development, in press Encystation and sporulation are crucial developmental transitions for solitary and social amoebas, respectively. While little is known of encystation, sporulation requires both extra- and intracellular cAMP. After aggregation of social amoebas, extracellular cAMP binding to surface receptors and intracellular cAMP binding to cAMP dependent protein kinase (PKA) act together to induce prespore differentiation. Later, a second episode of PKA activation triggers spore maturation. Adenylyl cyclase B (ACB) produces cAMP for maturation, but the cAMP source for prespore induction is unknown. We show that adenylyl cyclase G (ACG) protein is upregulated in prespore tissue after aggregation. acg null mutants show reduced prespore differentiation, which becomes very severe when ACB is also deleted. ACB is normally expressed in prestalk cells, but is upregulated in the prespore region of acg null structures. These data show that ACG induces prespore differentiation in wild-type cells, with ACB capable of partially taking over this function in its absence. Submitted by Pauline Schaap [p.schaap@dundee.ac.uk] -------------------------------------------------------------------------------- Treasure hunt in an amoeba: non-coding RNAs in Dictyostelium discoideum Andrea Hinas and Fredrik Soderbom Department of Molecular Biology, Biomedical Center, Swedish University of Agricultural Sciences, Box 590, 75124 Uppsala, Sweden Current Genetics, in press Review Article Abstract The traditional view of RNA being merely an intermediate in the transfer of genetic information, as mRNA, spliceosomal RNA, tRNA, and rRNA, has become outdated. The recent discovery of numerous regulatory RNAs with a plethora of functions in biological processes has truly revolutionized our understanding of gene regulation. Tiny RNAs such as microRNAs and small interfering RNAs play vital roles at different levels of gene control. Small nucleolar RNAs are much more abundant than previously recognized, and new functions beyond processing and modification of rRNA have recently emerged. Longer non-coding RNAs (ncRNAs) can also have important regulatory roles in the cell, e.g., antisense RNAs that control their target mRNAs. The majority of these i mportant findings arose from analyses in various model organisms. In this review, we focus on ncRNAs in the social amoeba Dictyostelium discoideum. This important genetically tractable model organism has recently received renewed attention in terms of discovery, regulation and functional studies of ncRNAs. Old and recent findings are discussed and put in context of what we today know about ncRNAs in other organisms. Submitted by: Fredrik Soderbom [fredde@xray.bmc.uu.se] -------------------------------------------------------------------------------- Dictyostelium Myb transcription factors function at culmination as activators of ancillary stalk differentiation Masatsune Tsujioka*, Natasha Zhukovskaya*, Yoko Yamada, Masashi Fukuzawa, Susan Ross and Jeffrey G. Williams *contributed equally University of Dundee MSI/WTB Complex Dow Street Dundee DD1 5EH UK Eukaryotic Cell in press ecmB and mrrA are expressed in the cups that cradle Dictyostelium spore-heads and MybE is necessary for their expression in lower but not upper cup cells. A Myb site within the mrrA promoter is necessary for expression in both cups. Thus multiple Myb proteins are required for ancillary stalk differentiation. Submitted by: Jeff Williams [j.g.williams@dundee.ac.uk] ============================================================ [End dictyNews, volume 27, number 17]