We investigated intra and inter-colony sequence variation in a population of the dominant Hawaiia... more We investigated intra and inter-colony sequence variation in a population of the dominant Hawaiian coral Montipora capitata by analyzing marker gene and genomic data. Ribosomal ITS1 regions showed evidence of a reticulate history among the colonies, suggesting incomplete rDNA repeat homogenization. Analysis of the mitochondrial genome identified a major (M. capitata) and a minor (M. flabellata) haplotype in single polyp-derived sperm bundle DNA with some colonies containing 2-3 different mtDNA haplotypes. In contrast, Pax-C and newly identified single-copy nuclear genes showed either no sequence differences or minor variations in SNP frequencies segregating among the colonies. Our data suggest past mitochondrial introgression in M. capitata, whereas nuclear single-copy loci show limited variation, highlighting the divergent evolutionary histories of these coral DNA markers. PeerJ Preprints | https://doi.org/10.7287/peerj.preprints.2896v1 | CC BY 4.0
Transcriptome and genome data from twenty stony coral species and a selection of reference bilate... more Transcriptome and genome data from twenty stony coral species and a selection of reference bilaterians were studied to elucidate coral evolutionary history. We identified genes that encode the proteins responsible for the precipitation and aggregation of the aragonite skeleton on which the organisms live, and revealed a network of environmental sensors that coordinate responses of the host animals to temperature, light, and pH. Furthermore, we describe a variety of stress-related pathways, including apoptotic pathways that allow the host animals to detoxify reactive oxygen and nitrogen species that are generated by their intracellular photosynthetic symbionts, and determine the fate of corals under environmental stress. Some of these genes arose through horizontal gene transfer and comprise at least 0.2% of the animal gene inventory. Our analysis elucidates the evolutionary strategies that have allowed symbiotic corals to adapt and thrive for hundreds of millions of years.
Reef-building corals begin as non-calcifying larvae that, upon settling, rapidly begin to accrete... more Reef-building corals begin as non-calcifying larvae that, upon settling, rapidly begin to accrete skeleton and a protein-rich skeletal organic matrix that attach them to the reef. Here, we characterized the temporal and spatial expression pattern of a suite of biomineralization genes during three stages of larval development in the reef-building coral Pocillopora damicornis: stage I, newly released; stage II, oral-aborally compressed and stage III, settled and calcifying spat. Transcriptome analysis revealed 3882 differentially expressed genes that clustered into four distinctly different patterns of expression change across the three developmental stages. Immunolocalization analysis further reveals the spatial arrangement of coral acid-rich proteins (CARPs) in the overall architecture of the emerging skeleton. These results provide the first analysis of the timing of the biomineralization ‘toolkit’ in the early life history of a stony coral.
Results of persistent spectral hole burning (PSHB) experiments in fluorescence spectra of Fe-limi... more Results of persistent spectral hole burning (PSHB) experiments in fluorescence spectra of Fe-limited and Fe-replete cells of D. tertiolecta are reported. Low temperature fluorescence spectra exhibit an increase of PS II fluorescence of Fe-limited cells due to a decrease of an efficiency of excitation energy transfer (EET) in PS II. A 1.5 nm blue shift of PS II fluorescence maximum observed for Fe-limited cells is the result of excessive light harvesting complexes LHCII in thylakoid membrane. The PSHB experiments revealed an influence of Fe stress on EET from and between core antenna proteins CP43 and CP47. EET within core antenna proteins CP43 and CP47 is not affected by iron limitation.
... Oxford University Press. CRAIG, H. 1974. ... Lake Tanganyika. Finnish International Developme... more ... Oxford University Press. CRAIG, H. 1974. ... Lake Tanganyika. Finnish International Development Agency/ Food and Agriculture Organization of the United Nations, GCP/RAF/217/FIN-TD/78 (En). JOHANNES, E., J. NOWAK, MG NZEYIMANA, AND L. WIMBA. 1999. ...
The diadinoxanthin cycle (DD-cycle) in chromophyte algae involves the interconversion of two caro... more The diadinoxanthin cycle (DD-cycle) in chromophyte algae involves the interconversion of two carotenoids, diadinoxanthin (DD) and diatoxanthin (DT). We investigated the kinetics of light-induced DD-cycling in the marine diatom Phaeodactylum tricornutum and its role in dissipating excess excitation energy in PS II. Within 15 min following an increase in irradiance, DT increased and was accompanied by a stoichiometric decrease in
We investigated intra and inter-colony sequence variation in a population of the dominant Hawaiia... more We investigated intra and inter-colony sequence variation in a population of the dominant Hawaiian coral Montipora capitata by analyzing marker gene and genomic data. Ribosomal ITS1 regions showed evidence of a reticulate history among the colonies, suggesting incomplete rDNA repeat homogenization. Analysis of the mitochondrial genome identified a major (M. capitata) and a minor (M. flabellata) haplotype in single polyp-derived sperm bundle DNA with some colonies containing 2-3 different mtDNA haplotypes. In contrast, Pax-C and newly identified single-copy nuclear genes showed either no sequence differences or minor variations in SNP frequencies segregating among the colonies. Our data suggest past mitochondrial introgression in M. capitata, whereas nuclear single-copy loci show limited variation, highlighting the divergent evolutionary histories of these coral DNA markers. PeerJ Preprints | https://doi.org/10.7287/peerj.preprints.2896v1 | CC BY 4.0
Transcriptome and genome data from twenty stony coral species and a selection of reference bilate... more Transcriptome and genome data from twenty stony coral species and a selection of reference bilaterians were studied to elucidate coral evolutionary history. We identified genes that encode the proteins responsible for the precipitation and aggregation of the aragonite skeleton on which the organisms live, and revealed a network of environmental sensors that coordinate responses of the host animals to temperature, light, and pH. Furthermore, we describe a variety of stress-related pathways, including apoptotic pathways that allow the host animals to detoxify reactive oxygen and nitrogen species that are generated by their intracellular photosynthetic symbionts, and determine the fate of corals under environmental stress. Some of these genes arose through horizontal gene transfer and comprise at least 0.2% of the animal gene inventory. Our analysis elucidates the evolutionary strategies that have allowed symbiotic corals to adapt and thrive for hundreds of millions of years.
Reef-building corals begin as non-calcifying larvae that, upon settling, rapidly begin to accrete... more Reef-building corals begin as non-calcifying larvae that, upon settling, rapidly begin to accrete skeleton and a protein-rich skeletal organic matrix that attach them to the reef. Here, we characterized the temporal and spatial expression pattern of a suite of biomineralization genes during three stages of larval development in the reef-building coral Pocillopora damicornis: stage I, newly released; stage II, oral-aborally compressed and stage III, settled and calcifying spat. Transcriptome analysis revealed 3882 differentially expressed genes that clustered into four distinctly different patterns of expression change across the three developmental stages. Immunolocalization analysis further reveals the spatial arrangement of coral acid-rich proteins (CARPs) in the overall architecture of the emerging skeleton. These results provide the first analysis of the timing of the biomineralization ‘toolkit’ in the early life history of a stony coral.
Results of persistent spectral hole burning (PSHB) experiments in fluorescence spectra of Fe-limi... more Results of persistent spectral hole burning (PSHB) experiments in fluorescence spectra of Fe-limited and Fe-replete cells of D. tertiolecta are reported. Low temperature fluorescence spectra exhibit an increase of PS II fluorescence of Fe-limited cells due to a decrease of an efficiency of excitation energy transfer (EET) in PS II. A 1.5 nm blue shift of PS II fluorescence maximum observed for Fe-limited cells is the result of excessive light harvesting complexes LHCII in thylakoid membrane. The PSHB experiments revealed an influence of Fe stress on EET from and between core antenna proteins CP43 and CP47. EET within core antenna proteins CP43 and CP47 is not affected by iron limitation.
... Oxford University Press. CRAIG, H. 1974. ... Lake Tanganyika. Finnish International Developme... more ... Oxford University Press. CRAIG, H. 1974. ... Lake Tanganyika. Finnish International Development Agency/ Food and Agriculture Organization of the United Nations, GCP/RAF/217/FIN-TD/78 (En). JOHANNES, E., J. NOWAK, MG NZEYIMANA, AND L. WIMBA. 1999. ...
The diadinoxanthin cycle (DD-cycle) in chromophyte algae involves the interconversion of two caro... more The diadinoxanthin cycle (DD-cycle) in chromophyte algae involves the interconversion of two carotenoids, diadinoxanthin (DD) and diatoxanthin (DT). We investigated the kinetics of light-induced DD-cycling in the marine diatom Phaeodactylum tricornutum and its role in dissipating excess excitation energy in PS II. Within 15 min following an increase in irradiance, DT increased and was accompanied by a stoichiometric decrease in
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