@article{0c4a33cb5a254810a1fa5fa5b03ee34c,
title = "Genomic variation of an endosymbiotic dinoflagellate (Symbiodinium {\textquoteleft}fitti{\textquoteright}) among closely related coral hosts",
abstract = "Mutualisms where hosts are coupled metabolically to their symbionts often exhibit high partner fidelity. Most reef-building coral species form obligate symbioses with a specific species of photosymbionts, dinoflagellates in the family Symbiodiniaceae, despite needing to acquire symbionts early in their development from environmental sources. Three Caribbean acroporids (Acropora palmata, A. cervicornis and their F1 hybrid) are sympatric across much of their range, but often occupy different depth and light habitats. Throughout this range, both species and their hybrid associate with the endosymbiotic dinoflagellate Symbiodinium {\textquoteleft}fitti{\textquoteright}. Because light (and therefore depth) influences the physiology of dinoflagellates, we investigated whether S. {\textquoteleft}fitti{\textquoteright} populations from each host taxon were differentiated genetically. Single nucleotide polymorphisms (SNPs) among S. {\textquoteleft}fitti{\textquoteright} strains were identified by aligning shallow metagenomic sequences of acroporid colonies sampled from across the Caribbean to a ~600-Mb draft assembly of the S. {\textquoteleft}fitti{\textquoteright} genome (from the CFL14120 A. cervicornis metagenome). Phylogenomic and multivariate analyses revealed that genomic variation among S. {\textquoteleft}fitti{\textquoteright} strains partitioned to each host taxon rather than by biogeographical origin. This is particularly noteworthy because the hybrid has a sparse fossil record and may be of relatively recent origin. A subset (37.6%) of the SNPs putatively under selection were nonsynonymous mutations predicted to alter protein efficiency. Differences in genomic variation of S. {\textquoteleft}fitti{\textquoteright} strains from each host taxon may reflect the unique selection pressures created by the microenvironments associated with each host. The nonrandom sorting among S. {\textquoteleft}fitti{\textquoteright} strains to different hosts could be the basis for lineage diversification via disruptive selection, leading to ecological specialization and ultimately speciation.",
author = "Reich, {Hannah G.} and Kitchen, {Sheila A.} and Stankiewicz, {Kathryn H.} and Meghann Devlin-Durante and Fogarty, {Nicole D.} and Baums, {Iliana B.}",
note = "Funding Information: We thank the PSU genomics facility for assistance with library preparation and sequencing. We thank Prof. Todd LaJeunesse for assistance with the phylogeny. Comments from three anonymous reviewers improved the quality of the paper. Funding for this project was supported by NSF‐OCE‐1537959 (to I.B.B.), NSF‐OCE‐1538469 (to N.D.F.) and NSF‐OCE‐1929979 (to N.D.F.). H.G.R. was supported through NSF‐OCE‐1636022 (to T. LaJeunesse). This is contribution 1045 of the Caribbean Coral Reef Ecosystems (CCRE) Program, Smithsonian Institution. Permits for samples include Florida: CRF permit nos. CRF‐2017‐009, CRF‐2017‐012, NOAA FKNMS permit nos. FKNMS‐2011‐159‐A4, FKNMS‐2001‐009, FKNMS‐2014‐148‐A2 and FKNMS‐2010‐130‐A, Belize: CITES Permits 0385, 7487 and 7488; Curacao: CITES Permits 16US784243/9 and 12US784243/9; and USVI Department of planning and natural resources, Division of fish and wildlife DFW14017T. psbA Funding Information: We thank the PSU genomics facility for assistance with library preparation and sequencing. We thank Prof. Todd LaJeunesse for assistance with the psbA phylogeny. Comments from three anonymous reviewers improved the quality of the paper. Funding for this project was supported by NSF-OCE-1537959 (to I.B.B.), NSF-OCE-1538469 (to N.D.F.) and NSF-OCE-1929979 (to N.D.F.). H.G.R. was supported through NSF-OCE-1636022 (to T. LaJeunesse). This is contribution 1045 of the Caribbean Coral Reef Ecosystems (CCRE) Program, Smithsonian Institution. Permits for samples include Florida: CRF permit nos. CRF-2017-009, CRF-2017-012, NOAA FKNMS permit nos. FKNMS-2011-159-A4, FKNMS-2001-009, FKNMS-2014-148-A2 and FKNMS-2010-130-A, Belize: CITES Permits 0385, 7487 and 7488; Curacao: CITES Permits 16US784243/9 and 12US784243/9; and USVI Department of planning and natural resources, Division of fish and wildlife DFW14017T. Publisher Copyright: {\textcopyright} 2021 John Wiley & Sons Ltd",
year = "2021",
month = jul,
doi = "10.1111/mec.15952",
language = "English (US)",
volume = "30",
pages = "3500--3514",
journal = "Molecular Ecology",
issn = "0962-1083",
publisher = "Wiley-Blackwell",
number = "14",
}