A molecular phylogenetic framework for the phylum Ctenophora using 18S rRNA genes

Citation
M. Podar et al., A molecular phylogenetic framework for the phylum Ctenophora using 18S rRNA genes, MOL PHYL EV, 21(2), 2001, pp. 218-230
Citations number
39
Categorie Soggetti
Biology,"Experimental Biology
Journal title
MOLECULAR PHYLOGENETICS AND EVOLUTION
ISSN journal
10557903 → ACNP
Volume
21
Issue
2
Year of publication
2001
Pages
218 - 230
Database
ISI
SICI code
1055-7903(200111)21:2<218:AMPFFT>2.0.ZU;2-S
Abstract
This paper presents the first molecular phylogenetic analysis of the phylum Ctenophora, by use of 18S ribosomal RNA sequences from most of the major t axa. The ctenophores form a distinct monophyletic group that, based on this gene phylogeny, is most closely related to the cnidarians. Our results sug gest that the ancestral ctenophore was tentaculate and cydippid-like and th at the presently recognized order Cydippida forms a polyphyletic group. The other ctenophore orders that we studied (Lobata, Beroida, and Platyctenida ) are secondarily derived from cydippid-like ancestors, a conclusion that i s also supported by developmental and morphological data. The very short ev olutionary distances between characterized ctenophore 18S rRNA gene sequenc es suggests that extant ctenophores are derived from a recent common ancest or. This has import-ant consequences for future studies and for an understa nding of the evolution of the metazoans. (C) 2001 Academic Press.