title: ALG11--a new variable DNA marker for sponge phylogeny: comparison of phylogenetic performances with the 18S rDNA and the COI gene.
abstract: Phylogenetic relationships within sponge classes are highly debated. The low phylogenetic signal observed with some current molecular data can be attributed to the use of few markers, usually slowly-evolving, such as the nuclear rDNA genes and the mitochondrial COI gene. In this study, we conducted a bioinformatics search for a new molecular marker. We sought a marker that (1) is likely to have no paralogs; (2) evolves under a fast evolutionary rate; (3) is part of a continuous exonic region; and (4) is flanked by conserved regions. Our search suggested the nuclear ALG11 as a potential suitable marker. We next demonstrated that this marker can indeed be used for solving phylogenetic relationships within sponges. Specifically, we successfully amplified the ALG11 gene from DNA samples of representatives from all four sponge classes as well as from several cnidarian classes. We also amplified the 18S rDNA and the COI gene for these species. Finally, we analyzed the phylogenetic performance of ALG11 to solve sponge relationships compared to and in combination with the nuclear 18S rDNA and the COI mtDNA genes. Interestingly, the ALG11 marker seems to be superior to the widely-used COI marker. Our work thus indicates that the ALG11 marker is a relevant marker which can complement and corroborate the phylogenetic inferences observed with nuclear ribosomal genes. This marker is also expected to contribute to resolving evolutionary relationships of other apparently slow-evolving animal phyla, such as cnidarians.
authors.affiliation: Department of Zoology, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv 69978, Israel.
authors.forename: Frida
authors.initials: F
authors.lastname: Belinky
authors.forename: Amir
authors.initials: A
authors.lastname: Szitenberg
authors.forename: Itay
authors.initials: I
authors.lastname: Goldfarb
authors.forename: Tamar
authors.initials: T
authors.lastname: Feldstein
authors.forename: Gert
authors.initials: G
authors.lastname: Wörheide
authors.forename: Micha
authors.initials: M
authors.lastname: Ilan
authors.forename: Dorothée
authors.initials: D
authors.lastname: Huchon
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D003576:Electron Transport Complex IV / Q000235:genetics*; D005819:Genetic Markers; D016013:Likelihood Functions; D008364:Mannosyltransferases / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D011161:Porifera / Q000235:genetics*; D012337:RNA, Ribosomal, 18S / Q000235:genetics*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
chemical_list: D005819:Genetic Markers; D012337:RNA, Ribosomal, 18S; D003576:Electron Transport Complex IV; D008364:Mannosyltransferases