A. subglobosum genome sequencing. Acytostelium subglobosum LB1

The social amoebae are lower eukaryotes in the soil. They are characterized by the construction of starvation-induced multicellular fruiting bodies with spore balls and supportive stalks. In most species, stalks are filled with motile stalk cells as represented by the model organism Dictyostelium discoideum whose developmental mechanisms have been well characterized. In the genus Acytostelium, however, stalks are acellular and all aggregated cells become spores. Phylogenetic analyses have shown that it is not ancestral but has lost the ability of cell differentiation. We performed the genome analysis of A. subglobosum to compare with other dictyostelid genome data available. Although A. subglobosum adopts the qualitatively different developmental program from others, the 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.