DOI: 10.5061/dryad.r84n5
title: Data from: Population genetic data of a model symbiotic cnidarian system reveal remarkable symbiotic specificity and vectored introductions across ocean basins

description: The Aiptasia-Symbiodinium symbiosis is a promising model for experimental
 studies of cnidarian-dinoflagellate associations, yet relatively little is
 known regarding the genetic diversity of either symbiotic partner. To
 address this we collected Aiptasia from 17 localities throughout the world
 and examined the genetic diversity of both anemones and their
 endosymbionts. Based on newly-developed SCAR markers, Aiptasia consisted
 of two genetically-distinct populations, one Aiptasia lineage from Florida
 and a second network of Aiptasia genotypes found at other localities.
 These populations did not conform to the distributions of described
 Aiptasia species, suggesting that taxonomic re-evaluation is needed in
 light of molecular genetics. Associations with Symbiodinium further
 demonstrated the distinctions among Aiptasia populations. According to
 18S-RFLP, ITS2-DGGE, and microsatellite flanker region sequencing, Florida
 anemones engaged in diverse symbioses predominantly with members of
 Symbiodinium Clades A and B, but also C, whereas anemones from elsewhere
 harboured only S. minutum within Clade B. Symbiodinium minutum apparently
 does not form a stable symbiosis with other hosts, which implies a
 highly-specific symbiosis. Fine-scale differences among S. minutum
 populations were quantified using six microsatellite loci. Populations of
 S. minutum had low genotypic diversity and high clonality (R=0.14).
 Furthermore, minimal population structure was observed among regions and
 ocean basins, due to allele and genotype sharing. The lack of genetic
 structure and low genotypic diversity suggest recent vectoring of Aiptasia
 and S. minutum across localities. This first ever molecular-genetic study
 of a globally-distributed cnidarian and its Symbiodinium assemblages
 reveals host-symbiont specificity and widely-distributed populations in an
 important model system.
description: MicroSatResultsSymbiodinium genotypes associated with Aiptasia. Genotypes were determined using 18S RFLP, ITS2 DGGE, and 6 microsatellite markers specific to Symbiodinium Clade B. The spreadsheets provide sample location, sample ID, RFLP and DGGE proflies, as well as the allele sizes for each microsatellite. The data are presented on two worksheets within the file. The first worksheet includes samples in which Clade B was detected according to the 18S RFLP. The second worksheet includes samples from Florida in which only Clade A was detected according to the 18S RFLP, but the samples were screened with the Clade B-specific microsatellites to determine whether low levels of Clade B (i.e., "background" or "cryptic" populations) could be detected.Aiptasia_Sym_B_MicSat_Fla2Nucleotide alignment of DNA sequences from microsatellite flanking region loci CA4.86 and Si15. The alignment includes Symbiodinium minutum associated with Aiptasia from field collected and cultured specimens as well as Symbiodinium samples collected from other hosts.Aiptasia-specific SCAR marker nucleotide sequence alignment.2,026 bp of concatenated nucleotide sequences from four Aiptasia-specific SCAR markers.Aiptasia_SCAR_alignment.nex.nex