title: ITS-2 and 18S rRNA gene phylogeny of Aplysinidae (Verongida, Demospongiae).
abstract: 18S ribosomal DNA and internal transcribed spacer 2 (ITS-2) full-length sequences, each of which was sequenced three times, were used to construct phylogenetic trees with alignments based on secondary structures, in order to elucidate genealogical relationships within the Aplysinidae (Verongida). The first poriferan ITS-2 secondary structures are reported. Altogether 11 Aplysina sponges and 3 additional sponges (Verongula gigantea, Aiolochroia crassa, Smenospongia aurea) from tropical and subtropical oceans were analyzed. Based on these molecular studies, S. aurea, which is currently affiliated with the Dictyoceratida, should be reclassified to the Verongida. Aplysina appears as monophyletic. A soft form of Aplysina lacunosa was separated from other Aplysina and stands at a basal position in both 18S and ITS-2 trees. Based on ITS-2 sequence information, the Aplysina sponges could be distinguished into a single Caribbean-Eastern Pacific cluster and a Mediterranean cluster. The species concept for Aplysina sponges as well as a phylogenetic history with a possibly Tethyan origin is discussed.
authors.affiliation: Research Center for Infectious Diseases, University of Würzburg, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Schmitt
authors.forename: Ute
authors.initials: U
authors.lastname: Hentschel
authors.forename: Sven
authors.initials: S
authors.lastname: Zea
authors.forename: Thomas
authors.initials: T
authors.lastname: Dandekar
authors.forename: Matthias
authors.initials: M
authors.lastname: Wolf
mesh_terms: D000818:Animals; D020029:Base Pairing / Q000235:genetics*; D001483:Base Sequence; D017931:DNA Primers; D021903:DNA, Ribosomal Spacer / Q000235:genetics*; D016013:Likelihood Functions; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009792:Oceans and Seas; D010802:Phylogeny; D011161:Porifera / Q000145:classification / Q000235:genetics*; D012337:RNA, Ribosomal, 18S / Q000235:genetics*; D017422:Sequence Analysis, DNA; D013045:Species Specificity
chemical_list: D017931:DNA Primers; D021903:DNA, Ribosomal Spacer; D012337:RNA, Ribosomal, 18S