Origin and evolution of the slime molds (Mycetozoa)

Abstract

The Mycetozoa include the cellular (dictyostelid), acellular (myxogastrid), and protostelid slime molds. However, available molecular data are in disagreement on both the monophyly and phylogenetic position of the group. Ribosomal RNA trees show the myxogastrid and dictyostelid slime molds as unrelated early branching lineages, but actin and ␤-tubulin trees place them together as a single coherent (monophyletic) group, closely related to the animal-fungal clade. We have sequenced the elongation factor-1␣ genes from one member of each division of the Mycetozoa, including Dictyostelium discoideum, for which cDNA sequences were previously available. Phylogenetic analyses of these sequences strongly support a monophyletic Mycetozoa, with the myxogastrid and dictyostelid slime molds most closely related to each other. All phylogenetic methods used also place this coherent Mycetozoan assemblage as emerging among the multicellular eukaryotes, tentatively supported as more closely related to animals ؉ fungi than are green plants. With our data there are now three proteins that consistently support a monophyletic Mycetozoa and at least four that place these taxa within the ''crown'' of the eukaryote tree. We suggest that ribosomal RNA data should be more closely examined with regard to these questions, and we emphasize the importance of developing multiple sequence data sets.

Large-scale phylogenomic analysis reveals the phylogenetic position of the problematic taxon Protocruzia and unravels the deep phylogenetic affinities of the ciliate lineages

“…This is in agreement with numerous studies on morphological characters as well as with the results of several previously published works based on single gene phylogenies (Baldauf and Doolittle, 1997;Barroin et al, 1988;BaroinTourancheau et al, 1998;Bernhard et al, 1995;Budin and Philippe, 1998;Bütschli, 1887Bütschli, -1889Lwoff, 1935a, 1935b;Elwood et al, 1985;Fauré-Fremiet, 1950;von Gelei, 1932von Gelei, , 1934Greenwood et al, 1991;Hammerschmidt et al, 1996;Hirt et al, 1995;Israel et al, 2002;Jankowski, 1967Jankowski, , 1973Katz et al, 2004;Klein, 1928Klein, , 1929Leander and Keeling, 2003;Leipe et al, 1994;Lynn and Sogin, 1988;Philippe and Adoutte, 1998;Sogin and Elwood, 1986).…”

Global characterization of the Dicer-like protein DrnB roles in miRNA biogenesis in the social amoeba Dictyostelium discoideum

“…D. discoideum has a fascinating life-cycle where growing single cells, upon starvation, are reprogrammed to enter multicellular development where up to 100 000 cells aggregate, differentiate, and finally form a fruiting body consisting of a stalk topped by a ball of spores [24]. Phylogenetically, D. discoideum belongs to the supergroup Amoebozoa, which branched out after plants but before fungi and animals [25,26]. …”

Classification and Phylogenetic Analysis of the cAMP-Dependent Protein Kinase Regulatory Subunit Family

“…Most phylogenetic analysis based on rRNA (McCarrol et al 1983;Hasegawa et al 1985;Herzog and Maroteaux 1986;Hendricks et al 1991;Douglas et al 1991) and some based on protein sequence analysis (Kuma et al 1995;Baldauf and Doolittle 1997;Baldauf et al 2000) place Dictyostelium as outgroup to Fungi and Animals. Conversely, other models based on protein sequence analysis suggest that Fungi diverged from the line leading to Animals before the divergence of Dictyostelium and Animals Smith 1990, 1995;Roger et al 1996;Kalhor et al 1999;Norian et al 1999;Swigart et al 2000).…”