dictyNews Electronic Edition Volume 41, number 3 January 30, 2015 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 ========= Comparative genome and transcriptome analyses of the social amoeba Acytostelium subglobosum that accomplishes multicellular development without germ-soma differentiation. Hideko Urushihara, Hidekazu Kuwayama, Kensuke Fukuhara, Takehiko Itoh, Hiroshi Kagoshima, Tadasu Shin-I, Atsushi Toyoda, Kazuyo Ohishi, Tateaki Taniguchi, Hideki Noguchi, Yoko Kuroki, Takashi Hata, Kyoko Uchi, Kurato Mohri, Jason S. King, Robert H. Insall, Yuji Kohara, Asao Fujiyama. BMC Genomics, in press. Background: Social amoebae are lower eukaryotes that inhabit the soil. They are characterized by the construction of a starvation- induced multicellular fruiting body with a spore ball and supportive stalk. In most species, the stalk is filled with motile stalk cells, as represented by the model organism Dictyostelium discoideum, whose developmental mechanisms have been well characterized. However, in the genus Acytostelium, the stalk is acellular and all aggregated cells become spores. Phylogenetic analyses have shown that it is not an ancestral genus but has lost the ability to undergo cell differentiation. Results: We performed genome and transcriptome analyses of Acytostelium subglobosum and compared our findings to other available dictyostelid genome data. Although A. subglobosum adopts a qualitatively different developmental program from other dictyostelids, its gene repertoire was largely conserved. Yet, families of polyketide synthase and extracellular matrix proteins have not expanded and a serine protease and ABC transporter B family gene, tagA, and a few other developmental genes are missing in the A. subglobosum lineage. Temporal gene expression patterns are astonishingly dissimilar from those of D. discoideum, and only a limited fraction of the ortholog pairs shared the same expression patterns, so that some signaling cascades for development seem to be disabled in A. subglobosum. Conclusions: The absence of the ability to undergo cell differentiation in Acytostelium is accompanied by a small change in coding potential and extensive alterations in gene expression patterns. Submitted by Hideko Urushihara [hideko@biol.tsukuba.ac.jp] ---------------------------------------------------------------------- A Long-range Foresight for the Medical Application of Apoptosis Specifically Induced by Dd-MRP4, Dictyostelium Mitochondrial Ribosomal Protein S4, to Cancer Therapy Yasuo Maeda Department of Developmental Biology and Neurosciences , Graduate School of Life Sciences, Tohoku University (Emeritus), Aoba, Sendai 980-8578, Japan; E-mail: kjygy352@ybb.ne.jp Biomolecules, in press Apoptosis (programmed cell death) is regarded as ultimate differentiation of the cell. We have recently demonstrated that a targeted delivery of Dd-MRP4 (Dictyostelium mitochondrial ribosomal protein S4) suppresses specifically the proliferation of the human cancer cells, by inducing their apoptotic cell death [1]. This amazing fact was discovered, simply based on the finding that Dd-MRP4 expression is absolutely required for transition of Dictyostelium cells from growth to differentiation [2,3]. Dd-MRP4 protein has quite unique structural characters, in that it is highly basic (pI: about 11.5) and interestingly has several nuclear-localization signals within the molecule. In this review, we introduce briefly the efficacy of several apoptosis- inducing substances reported thus far for cancer therapy, and speculate the possible mechanisms, by which apoptosis is specifically induced by Dd-MRP4, on the basis of its structural uniqueness. We also discuss about several issues to be solved for the medical application of ectopically expressed Dd-MRP4 in human cancer cells. Keywords: apoptosis; cell differentiation; cancer therapy; Dd-MRP4 (Dictyostelium mitochondrial ribosomal protein S4); microRNA (miRNA); mitochondria; Dictyostelim discoideum; human cancer cells (References) 1. Chida, J.; Araki, H.; Maeda Y. Specific growth suppression of human cancer cells by targeted delivery of Dictyostelium mitochondrial ribosomal protein S4. Cancer Cell International 2014, 14:56. 2. Chida, J.; Amagai, A.; Tanaka, M.; Maeda Y. Establishment of a new method for precisely determining the functions of individual mitochondrial genes using Dictyostelium cells. BMC Genet. 2008, 9:.doi:10.1186/1471-2156-9-25. 3. Maeda, Y.; Chida, J. Control of cell differentiation by mitochondria, typically evidenced in Dictyostelium development. Biomolecules 2013, 3, 943-966; doi:10.3390/biom3040943. Submitted by Yasuo Maeda [kjygy352@ybb.ne.jp] ============================================================== [End dictyNews, volume 41, number 3]