The phylogeny of extant starfish (Asteroidea: Echinodermata) including Xyloplax, based on comparative transcriptomics.

Autor: Linchangco GV Jr; Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, NC, USA. Electronic address: glinchan@uncc.edu., Foltz DW; Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA., Reid R; Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, NC, USA., Williams J; Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, NC, USA., Nodzak C; Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, NC, USA., Kerr AM; Marine Laboratory, University of Guam, Mangilao, GU, USA., Miller AK; Marine Laboratory, University of Guam, Mangilao, GU, USA., Hunter R; Department of Biology, Abilene Christian University, Abilene, TX, USA., Wilson NG; Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA; Western Australian Museum, Locked Bag 49, Welshpool DC, Western Australia 6986, Australia., Nielsen WJ; Department of Biology and Center for Genomic and Computational Biology, Duke University, Durham, NC, USA., Mah CL; Department of Invertebrate Zoology, Smithsonian Institution, Washington, District of Columbia, USA., Rouse GW; Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA., Wray GA; Department of Biology and Center for Genomic and Computational Biology, Duke University, Durham, NC, USA., Janies DA; Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, NC, USA. Electronic address: djanies@uncc.edu.
Jazyk: angličtina
Zdroj: Molecular phylogenetics and evolution [Mol Phylogenet Evol] 2017 Oct; Vol. 115, pp. 161-170. Date of Electronic Publication: 2017 Jul 27.
DOI: 10.1016/j.ympev.2017.07.022
Abstrakt: Multi-locus phylogenetic studies of echinoderms based on Sanger and RNA-seq technologies and the fossil record have provided evidence for the Asterozoa-Echinozoa hypothesis. This hypothesis posits a sister relationship between asterozoan classes (Asteroidea and Ophiuroidea) and a similar relationship between echinozoan classes (Echinoidea and Holothuroidea). Despite this consensus around Asterozoa-Echinozoa, phylogenetic relationships within the class Asteroidea (sea stars or starfish) have been controversial for over a century. Open questions include relationships within asteroids and the status of the enigmatic taxon Xyloplax. Xyloplax is thought by some to represent a newly discovered sixth class of echinoderms - and by others to be an asteroid. To address these questions, we applied a novel workflow to a large RNA-seq dataset that encompassed a broad taxonomic and genomic sample. This study included 15 species sampled from all extant orders and 13 families, plus four ophiuroid species as an outgroup. To expand the taxonomic coverage, the study also incorporated five previously published transcriptomes and one previously published expressed sequence tags (EST) dataset. We developed and applied methods that used a range of alignment parameters with increasing permissiveness in terms of gap characters present within an alignment. This procedure facilitated the selection of phylogenomic data subsets from large amounts of transcriptome data. The results included 19 nested data subsets that ranged from 37 to 4,281loci. Tree searches on all data subsets reconstructed Xyloplax as a velatid asteroid rather than a new class. This result implies that asteroid morphology remains labile well beyond the establishment of the body plan of the group. In the phylogenetic tree with the highest average asteroid nodal support several monophyletic groups were recovered. In this tree, Forcipulatida and Velatida are monophyletic and form a clade that includes Brisingida as sister to Forcipulatida. Xyloplax is consistently recovered as sister to Pteraster. Paxillosida and Spinulosida are each monophyletic, with Notomyotida as sister to the Paxillosida. Valvatida is recovered as paraphyletic. The results from other data subsets are largely consistent with these results. Our results support the hypothesis that the earliest divergence event among extant asteroids separated Velatida and Forcipulatacea from Valvatacea and Spinulosida.
(Copyright © 2017 Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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