In search of mitochondrial markers for resolving the phylogeny of cyclophyllidean tapeworms (Platyhelminthes, Cestoda) — a test study with Davaineidae
- 1 January 2008
- journal article
- Published by Walter de Gruyter GmbH in Acta Parasitologica
- Vol. 53 (2)
- https://doi.org/10.2478/s11686-008-0029-4
Abstract
The most species rich order of tapeworms is the Cyclophyllidea and prior to wide-scale sampling of these worms for phylogenetics, we wished to develop reliable PCR primers that would capture fragments of mitochondrial (mt) DNA with phylogenetic utility across the order. Nuclear ribosomal RNA gene sequences are well-established and valuable markers for resolving flatworm interrelationships spanning a wide range of taxonomic divergences, but fail to provide resolution amongst recently diverged lineages. Entire mt genomes of selected cyclophyllidean tapeworms are available on GenBank, and we used these to design PCR primers to amplify mtDNA from cox1, rrnL and nad1 for a range of cyclophyllideans (7 davaineids, 1 hymenolepidid and 1 dilepidid) and selected outgroups (Tetrabothrius sp. and Mesocestoides sp.). A combined nuclear and mt gene data set was used to estimate a reference phylogeny and the performance of the individual genes was compared to this. Although nuclear and mt genes each contributed to the structure and stability of the phylogenetic estimate, strongest nodal support was provided by nuclear data amongst the basal lineages and by mt data amongst the most recently diverged lineages. The apparent complementarity afforded by combining nuclear and mt data was compromised by these data partitions providing conflicting signal at poorly supported nodes. Nevertheless, we argue for a combined evidence approach. PCR primers that amplify rrnL were designed and tested successfully against a diversity of cyclophyllideans; rrnL and nad1 appeared to be more informative than the fragment of cox1. The genus Raillietina was not supported by molecular evidence. The new primers will likely provide considerable resolution to estimates of cyclophyllidean interrelationships in future studies.Keywords
This publication has 10 references indexed in Scilit:
- MRBAYES: Bayesian inference of phylogenetic treesBioinformatics, 2001
- Failure of the ILD to Determine Data Combinability for Slow Loris PhylogenySystematic Biology, 2001
- Contributions to the Phylogeny of the Cyclophyllidea (Cestoda) Inferred from Mitochondrial 12S rDNAJournal of Molecular Evolution, 1999
- Phylogenetic analysis among the families of the Cyclophyllidea (Eucestoda) based on comparative morphology, with new hypotheses for co-evolution in vertebratesSystematic Parasitology, 1999
- MODELTEST: testing the model of DNA substitution.Bioinformatics, 1998
- The CLUSTAL_X windows interface: flexible strategies for multiple sequence alignment aided by quality analysis toolsNucleic Acids Research, 1997
- Can three incongruence tests predict when data should be combined?Molecular Biology and Evolution, 1997
- tRNAscan-SE: A Program for Improved Detection of Transfer RNA Genes in Genomic SequenceNucleic Acids Research, 1997
- TESTING SIGNIFICANCE OF INCONGRUENCECladistics, 1994
- Structure of the large ribosomal subunit RNA of Phytophthora megasperma, and phylogeny of the oomycetesFEBS Letters, 1994