title: The 'other' coral symbiont: Ostreobium diversity and distribution.
abstract: Ostreobium is an endolithic algal genus thought to be an early-diverging lineage of the Bryopsidales (Ulvophyceae, Chlorophyta). Ostreobium can live in low-light conditions on calcium carbonate substrata in tropical conditions. It is best known as a symbiont of corals, where it lives deep within the animal skeleton and exchanges nitrogen and carbon, as well as providing nutrients and photoassimilates. In contrast to the relatively well-studied role of the photosynthetic zooxanthellae symbionts in coral (Symbiodinium), Ostreobium phylogeny, diversity and distribution are all poorly understood. Here, we describe the phylogenetic position and diversity of Ostreobium based on plastid 16S ribosomal DNA (rDNA), 18S rDNA and rbcL genes from a nuclear genome survey and complete plastid genome, and determined its environmental diversity and distribution by screening the publicly available environmental data for those genes. The results shed light on the phylogeny and the ecology of the 'other' coral symbiont.
authors.affiliation: Department of Botany, Canadian Institute for Advanced Research, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Javier
authors.initials: J
authors.lastname: Del Campo
authors.affiliation: College of Science, Illinois Institute of Technology, Chicago, IL, USA.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Pombert
authors.affiliation: The School of Life and Environmental Sciences, Faculty of Veterinary Science, The University of Sydney, Sydney, NSW, Australia.
authors.forename: Jan
authors.initials: J
authors.lastname: Šlapeta
authors.affiliation: University of Technology Sydney, Ultimo NSW, Australia.
authors.forename: Anthony
authors.initials: A
authors.lastname: Larkum
authors.affiliation: Department of Botany, Canadian Institute for Advanced Research, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Keeling
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000469:parasitology* / Q000502:physiology; D044822:Biodiversity; D000460:Chlorophyta / Q000235:genetics / Q000469:parasitology / Q000502:physiology*; D004275:DNA, Ribosomal / Q000235:genetics; D004141:Dinoflagellida / Q000469:parasitology / Q000502:physiology; D004777:Environment; D010788:Photosynthesis; D010802:Phylogeny; D013559:Symbiosis
chemical_list: D004275:DNA, Ribosomal