Model Organisms for Biomedical Research
Dictyostelium discoideum

The soil-dwelling amoeba Dictyostelium discoideum is best known for its remarkable life cycle, consisting of a unicellular and multicellular phase. The unicellular phase consists of solitary amoeba feeding on bacteria and reproducing by binary fission. When challenged by starvation, the amoeba collect into aggregates and develop into multicellular fruiting bodies. This complex life cycle makes Dictyostelium an ideal model organism with which to study a range of biological problems, including signal transduction, chemotaxis, disease, phagocytosis and cellular differentiation. The 34 Mb genome sequence contains six chromosomes with sizes ranging from 4 to 7 Mb, a multicopy 90 kb extrachromosomal element that harbors the rRNA genes, and the 55 kb mitochondrial genome. The number of protein coding genes in the genome is approximately 12,000 and many of the known genes show a high degree of sequence similarity to genes in vertebrate species. Additional information about Dictyostelium discoideum can be found by visiting these websites:

image of a bullet http://dictybase.org/tutorial/
Image of a bullet http://dictybase.org/genomeseq.htm

Major Resources
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dictyBase - An Online Informatics Resource for Dictyostelium dictyBase (http://dictybase.org) provides a single access point for information about the social amoeba Dictyostelium discoideum, including overviews of Dictyostelium biology, investigators involved in Dictyostelium research, genome and functional annotations, and curated Dictyostelium literature including Gene Ontology annotations. The Genome Browser allows display of the entire genome, and includes RNAseq expression data for individual genes. Additional dictyBase tools include BLAST for discovering homology and functional relationships.

The Dicty Stock Center serves as a central repository for thousands of Dictyostelium strains and plasmids. These are freely available and serve as a vital resource for the research community. Strains are curated using controlled vocabularies and include phenotypes when available.

The addition of three Dictyostelid species to dictyBase is the first step toward becoming a web portal for amoebal genomes, and provides an opportunity for direct comparison between the genomes. The additional genomes are available at:

Dictyostelium purpureum
Polysphondylium pallidum
Dictyostelium fasciculatum

For more information, please contact dictyBase.
Image of a bullet dictyExpress - dictyExpress is an interactive web application for retrieval and analysis of gene expression profiles from over 1,000 different D. discoideum experiments. These are linked to dictyBase gene pages and allow the user to perform a variety of analyses and comparisons with the expression data.
Image of a bullet cDNA Project- Several Japanese universities are involved in a cDNA project. These institutions are: University of Tsukuba, Hokkaido University, Kinki University and Osaka University. The goal of this project is to structurally and functionally analyze whole expressed genes in developing Dictyostelium discoideum cells.
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NBRP nenkin- The National Bioresource Project for Cellular Slime Molds is a collaboration between the University of Tsukuba and National Institute of Advanced Industrial Science and Technology. Its purpose is to store and distribute strains and cDNA from the social amoebae within Japan.

Image of a bullet Genome Project - The Dictyostelium discoideum genome project was an international collaboration which completed the genome sequence in 2005. The major collaborators were the  Institut Pasteur in Paris and the  Wellcome Trust Sanger Institute in Hinxton; the University of Cologne and the  Institute of Molecular Biotechnology in Jena; and Baylor College of Medicine in Houston.
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IC Contact
 

Stefan Maas, Ph.D.
Division of Genetics and Developmental Biology
NIGMS, National Institutes of Health
45 Center Drive, Room 2As.25B
Bethesda, MD 20892-6200

TEL: (301) 594-0943
E-MAIL:  stefan.maas@nih.gov
Home Page URL:  http://www.nigms.nih.gov/About/maas.htm