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Abstract(s)
Maximum likelihood analyses of DNA sequences from two chloroplast regions, trnL–trnF and atpB–rbcL, and the internal
transcribed spacers of 18S–5.8S–26S rRNA gene array, were performed to resolve species relationships within the moss genus
Hygroamblystegium. Constraining morphospecies to monophyly resulted in significantly less likely trees for H. tenax, but not for the
other species. The lack of support for most clades and the partial incongruence among topologies necessitated the use of another
independent, more variable region, namely the adenosine kinase gene (adk). Sequences for adk were polymorphic but were present as
multiple copies within individuals, making parology a problem for phylogenetic analyses. Adk evolution was reconstructed using a
reconciled gene tree approach in which duplications and losses were minimized in the context of an estimate of the species tree
derived from the analysis of the cp and nrDNA sequence data. Additional resolution of the species tree was then obtained by
searching for reconstructions that further reduced adk duplications and losses. All the traditionally recognized morphospecies
appeared to be polyphyletic in the resulting tree. Together with previous data from different molecular markers, the results support
the interpretation that Hygroamblystegium represents a recent radiation in which molecular and morphological evolution have been
uncoupled.
Description
Keywords
Gene trees Hygroamblystegium Adenosine kinase gene Paralogy Gene duplication
Citation
Vanderpoorten, A.; Shaw, A.J.; Cox, C.J.Evolution of multiple paralogous adenosine kinase genes in the moss genus Hygroamblystegium: Phylogenetic implications, Molecular Phylogenetics and Evolution, 31, 2, 505-516, 2004.