title: Generalist dinoflagellate endosymbionts and host genotype diversity detected from mesophotic (67-100 m depths) coral Leptoseris.
abstract: BACKGROUND
  Mesophotic corals (light-dependent corals in the deepest half of the photic zone at depths of 30-150 m) provide a unique opportunity to study the limits of the interactions between corals and endosymbiotic dinoflagellates in the genus Symbiodinium. We sampled Leptoseris spp. in Hawaii via manned submersibles across a depth range of 67-100 m. Both the host and Symbiodinium communities were genotyped, using a non-coding region of the mitochondrial ND5 intron (NAD5) and the nuclear ribosomal internal transcribed spacer region 2 (ITS2), respectively.
  
  
  RESULTS
  Coral colonies harbored endosymbiotic communities dominated by previously identified shallow water Symbiodinium ITS2 types (C1_ AF333515, C1c_ AY239364, C27_ AY239379, and C1b_ AY239363) and exhibited genetic variability at mitochondrial NAD5.
  
  
  CONCLUSIONS
  This is one of the first studies to examine genetic diversity in corals and their endosymbiotic dinoflagellates sampled at the limits of the depth and light gradients for hermatypic corals. The results reveal that these corals associate with generalist endosymbiont types commonly found in shallow water corals and implies that the composition of the Symbiodinium community (based on ITS2) alone is not responsible for the dominance and broad depth distribution of Leptoseris spp. The level of genetic diversity detected in the coral NAD5 suggests that there is undescribed taxonomic diversity in the genus Leptoseris from Hawaii.
authors.affiliation: Hawaii Institute of Marine Biology, PO Box 1346, Kaneohe, HI, 96744, USA. ylhchan@hawaii.edu
authors.forename: Yvonne L
authors.initials: YL
authors.lastname: Chan
authors.forename: Xavier
authors.initials: X
authors.lastname: Pochon
authors.forename: Marla A
authors.initials: MA
authors.lastname: Fisher
authors.forename: Daniel
authors.initials: D
authors.lastname: Wagner
authors.forename: Gregory T
authors.initials: GT
authors.lastname: Concepcion
authors.forename: Samuel E
authors.initials: SE
authors.lastname: Kahng
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Toonen
authors.forename: Ruth D
authors.initials: RD
authors.lastname: Gates
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000145:classification / Q000235:genetics*; D016172:DNA Fingerprinting; D004141:Dinoflagellida / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D014644:Genetic Variation; D005838:Genotype; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism; D013559:Symbiosis
chemical_list: D015800:Protozoan Proteins