The root of the dictyostelid tree
2011 (English)Conference paper, Poster (Other academic)
The root represents the oldest point in a phylogeny, and determining it gives evolution a time arrow. The first molecular treatment of the social amoebae (Dictyostelia) was carried out with small subunit ribosomal DNA (SSU rDNA) data in 2006, and from this four major dictyostelid groups were defined. However, the relationships among them, i.e. the root of the tree, could not be confidently determined. In this study, a new protein data set – eukaryotic release factor 3 (eRF3) – was developed for deep dictyostelid phylogeny. This was accomplished by designing degenerate PCR primers, developing PCR strategies, generating sequences from seven new species and assembling currently available dictyostelid data sets. Phylogenetic reconstruction according to a strict total evidence approach supports the earlier SSU rDNA root, placing group 1 as the most basal divergence. However, an alternative root lying between group 1 + 2 and group 3 + 4 has substantial support, especially from protein coding sequences. In addition, the analyses confidently place Dictyostelium purpureum as the earliest branch in group 4. This result questions the age of group 4 and the calibration of the whole dictyostelid phylogeny.
Place, publisher, year, edition, pages
IdentifiersURN: urn:nbn:se:uu:diva-166554OAI: oai:DiVA.org:uu-166554DiVA: diva2:476830
XVIII International Botanical Congress, Melbourne, Australia, 23-30 July, 2011