Phylogeny-wide analysis of social amoeba genomes highlights ancient origins for complex intercellular communication
- Andrew Heidel1,
- Hajara Lawal2,
- Marius Felder1,
- Christina Schilde2,
- Nicholas Helps2,
- Budi Tunggal3,
- Francisco Rivero4,
- Uwe John5,
- Michael Schleicher6,
- Ludwig Eichinger3,
- Matthias Platzer1,
- Angelika Noegel3,
- Pauline Schaap2 and
- Gernot Glöckner7,8
- 1 FLI Jena;
- 2 University of Dundee;
- 3 University of Cologne;
- 4 Hull University;
- 5 AWI Bremerhaven;
- 6 LMU Munich;
- 7 Institute for Freshwater Ecology and Inland Fisheries
- ↵* Corresponding author; email: gloeckner{at}igb-berlin.de
Abstract
Dictyostelium discoideum (DD), an extensively studied model organism for cell and developmental biology, belongs to the most derived group 4 of social amoebas, a clade of altruistic multicellular organisms. To understand genome evolution over long time periods and the genetic basis of social evolution, we sequenced the genomes of Dictyostelium fasciculatum (DF) and Polysphondylium pallidum (PP), that represent the early diverging groups 1 and 2, respectively. In contrast to DD, PP and DF have conventional telomere organisation and strongly reduced numbers of transposable elements. The number of protein coding genes is similar between species, but only half of them comprise an identifiable set of orthologous genes. In general, genes involved in primary metabolism, cytoskeletal functions and signal transduction are conserved, while genes involved in secondary metabolism, export and signal perception underwent large differential gene family expansions. This most likely signifies involvement of the conserved set in core cell and developmental mechanisms, and of the diverged set in niche- and species-specific adaptations for defence and food, mate and kin selection. Phylogenetic dating using a concatenated data set and extensive loss of synteny indicate that DF, PP and DD split from their last common ancestor at least 0.6 billion years ago.
- Received January 20, 2011.
- Accepted July 11, 2011.
- Copyright © 2011, Cold Spring Harbor Laboratory Press
