title: Congruence between nuclear and mitochondrial genes in Demospongiae: a new hypothesis for relationships within the G4 clade (Porifera: Demospongiae).
abstract: The current morphological classification of the Demospongiae G4 clade was tested using large subunit ribosomal RNA (LSU rRNA) sequences from 119 taxa. Fifty-three mitochondrial cytochrome oxidase 1 (CO1) barcoding sequences were also analysed to test whether the 28S phylogeny could be recovered using an independent gene. This is the largest and most comprehensive study of the Demospongiae G4 clade. The 28S and CO1 genetrees result in congruent clades but conflict with the current morphological classification. The results confirm the polyphyly of Halichondrida, Hadromerida, Dictyonellidae, Axinellidae and Poecilosclerida and show that several of the characters used in morphological classifications are homoplasious. Robust clades are clearly shown and a new hypothesis for relationships of taxa allocated to G4 is proposed.
authors: School of Biological Sciences, MBC, 97 Lisburn Road, Queen's University, Belfast BT9 7BL, UK. christinemorrow@gmail.com
authors: C C
authors: CC
authors: Morrow
authors: B E
authors: BE
authors: Picton
authors: D
authors: D
authors: Erpenbeck
authors: N
authors: N
authors: Boury-Esnault
authors: C A
authors: CA
authors: Maggs
authors: A L
authors: AL
authors: Allcock
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D058893:DNA Barcoding, Taxonomic; D003576:Electron Transport Complex IV / Q000235:genetics; D019143:Evolution, Molecular; D050259:Genes, Mitochondrial; D016013:Likelihood Functions; D008957:Models, Genetic; D010802:Phylogeny; D011161:Porifera / Q000033:anatomy & histology / Q000145:classification / Q000235:genetics*; D012339:RNA, Ribosomal, 28S / Q000235:genetics
chemical_list: D012339:RNA, Ribosomal, 28S; D003576:Electron Transport Complex IV