Document of bibliographic reference 294745

BibliographicReference record

Type

Bibliographic resource

Type of document

Journal article

BibLvlCode

AS

Title

A phylogenomic framework and timescale for comparative studies of tunicates

Abstract

Tunicates are the closest relatives of vertebrates and are widely used as models to study the evolutionary developmental biology of chordates. Their phylogeny, however, remains poorly understood, and to date, only the 18S rRNA nuclear gene and mitogenomes have been used to delineate the major groups of tunicates. To resolve their evolutionary relationships and provide a first estimate of their divergence times, we used a transcriptomic approach to build a phylogenomic dataset including all major tunicate lineages, consisting of 258 evolutionarily conserved orthologous genes from representative species. Results: Phylogenetic analyses using site-heterogeneous CAT mixture models of amino acid sequence evolution resulted in a strongly supported tree topology resolving the relationships among four major tunicate clades: (1) Appendicularia, (2) Thaliacea + Phlebobranchia + Aplousobranchia, (3) Molgulidae, and (4) Styelidae + Pyuridae. Notably, the morphologically derived Thaliacea are confirmed as the sister group of the clade uniting Phlebobranchia + Aplousobranchia within which the precise position of the model ascidian genus Ciona remains uncertain. Relaxed molecular clock analyses accommodating the accelerated evolutionary rate of tunicates reveal ancient diversification (~ 450–350 million years ago) among the major groups and allow one to compare their evolutionary age with respect to the major vertebrate model lineages. Conclusions: Our study represents the most comprehensive phylogenomic dataset for the main tunicate lineages. It offers a reference phylogenetic framework and first tentative timescale for tunicates, allowing a direct comparison with vertebrate model species in comparative genomics and evolutionary developmental biology studies.

WebOfScience code

https://www.webofscience.com/wos/woscc/full-record/WOS:000429988000001

Bibliographic citation

Delsuc, F.; Philippe, H.; Tsagkogeorga, G.; Simion, P.; Tilak, M.-K.; Turon, X.; López-Legentil, S.; Piette, J.; Lemaire, P.; Douzery, E.J.P. (2018). A phylogenomic framework and timescale for comparative studies of tunicates. BMC Biology 16(1): 39 [1-14]. https://dx.doi.org/10.1186/s12915-018-0499-2

Is peer reviewed

true

Access rights

open access

Is accessible for free

true