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A preliminary investigation of the order Bangiales (Bangiophycidae, Rhodophyta) based on sequences of nuclear small-subunit ribosomal RNA genes |
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| Authors: | Mariana C Oliveira Joelius Kurniawan Carolyn J Bird Ellen L Rice Colleen A Murphy Rama K Singh Robin R Gutell Mark A Ragan |
| Institution: | Institute for Marine Biosciences, National Research Council of Canada, 1411 Oxford St, Halifax, Nova Scotia B3H 3ZI, Canada;Institute de Biociências, Universidade de Sao Paulo, CP 11461, 05422-970 São Paulo SP, Brazil;Department of Biology, Dalhousie University, Halifax, Nova Scotia B3H 4J1. Canada;Biological Sciences Branch, Scotia-Fundy Region, Fisheries and Oceans Canada, PO Box 550, Halifax, Nova Scotia B3J 2S7, Canada;Department or Molecular, Celt and Developmental Biology, Campus Box 347, University of Colorado, Boulder CO 80309, USA;Canadian Institute for Advanced Research, Program in Evolutionary Biology |
| Abstract: | We investigated phylogenetic relationships among red algae of the order Bangiales by analysis of sequences of the nuclear gene encoding cytosolic small-subunit ribosomal RNA in Bangia atropurpurea (Roth) C. Ag. and eight samples representing seven species of Porphyra. The ssu-rDNA range from 1818 to 1845 nucleotides in length, with guanosine plus cytosine ratios between 47.0% and 48.6%. A group IC1 intron occurs in the B atropurpurea ssu-rDNAs at the same position as in P. spiralis var. amplifolia Oliveira Filho et Coll and several other eukaryote ssu-rDNAs. The nine sequences form a stable monophyletic group upon phylogenetic analysis. The ssu-rDNA from B. atropurpurea nests stably within the Porphyra group and is closely related to P. amplissima (Kjellm.) Setchell et Hus in Hus, making the genus Porphyra paraphyletic. No correlation is seen between phylogenetic position and number of cell layers in the Porphyra thallus. We discuss possible taxonomic and evolutionary implications of these observations. |
| Keywords: | Bangia Bangiales group I intron nuclear small-subunit ribosomal RNA gene sequences Porphyra red algal phylogeny Rhodophyta |