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Marine Biotechnology (New York, N.Y.) Jun 2021Planula larvae of the scleractinian coral, Acropora tenuis, consist of elongated ectodermal cells and developing inner endodermal cells. To establish in vitro cell lines...
Planula larvae of the scleractinian coral, Acropora tenuis, consist of elongated ectodermal cells and developing inner endodermal cells. To establish in vitro cell lines for future studies of cellular and developmental potential of coral cells, larvae were successfully dissociated into single cells by treating them with a tissue dissociation solution consisting of trypsin, EDTA, and collagenase. Brown-colored cells, translucent cells, and pale blue cells were the major components of dissociated larvae. Brown-colored cells began to proliferate transiently in the culture medium that was devised for the coral, while translucent cells and pale blue cells decreased in number about 1 week after cell dissociation. In addition, when a modular protease, plasmin, was added to the cell culture medium, brown-colored cells extended pseudopodia and assumed amorphous shapes. They then continued to proliferate in clumps for more than 6 months with a doubling time of approximately 4-5 days. From 3 weeks of cell culture onward, brown-colored cells often aggregated and exhibited morphogenesis-like behavior to form flat sheets, and blastula-like clusters or gastrula-like spheres. Single cells or cell-clusters of the cell lines were analyzed by RNA-seq. This analysis showed that genes expressed in these cells in vitro were A. tenuis genes. Furthermore, each cell line expressed a specific set of genes, suggesting that their properties include gastroderm, secretory cells, undifferentiated cells, neuronal cells, and epidermis. All cell properties were maintained stably throughout successive cell cultures. These results confirm the successful establishment of a coral in vitro cell line.
Topics: Animals; Anthozoa; Cell Culture Techniques; Cell Line; Larva; Sequence Analysis, RNA; Transcriptome
PubMed: 33899125
DOI: 10.1007/s10126-021-10031-w -
PeerJ 2024, a prized resource in Japan, plays a vital role in traditional arts and fishing industries. Because of diminished stock due to overexploitation, ongoing efforts are...
BACKGROUND
, a prized resource in Japan, plays a vital role in traditional arts and fishing industries. Because of diminished stock due to overexploitation, ongoing efforts are focused on restoration through transplantation. This study aimed to enhance our understanding of the reproductive biology of these valuable corals and find more efficient methods for sex determination, which may significantly contribute to conservation initiatives.
METHODS
We used 12 three-month aquarium reared colony fragments, conducted histological analysis for maturity and sex verification, and performed transcriptome analysis via assembly and mapping using the transcriptome to explore gene expression differences between female and male .
RESULTS
Our histological observations enabled sex identification in 33% of incompletely mature samples. However, the sex of the remaining 67% of samples, classified as immature, could not be identified. RNA-seq yielded approximately 21-31 million short reads from 12 samples. assembly yielded 404,439 highly expressed transcripts. Among them, 855 showed significant differential expression, with 786 differentially expressed transcripts between females and males. Heatmap analysis highlighted 283 female-specific and 525 male-specific upregulated transcripts. Transcriptome assembly mapped to yielded 28,092 contigs, leading to the identification of 190 highly differentially expressed genes, with 113 upregulated exclusively in females and 70 upregulated exclusively in males. Blastp analysis provided putative protein annotations for 83 female and 72 male transcripts. Annotation analysis revealed that female biological processes were related to oocyte proliferation and reproduction, whereas those in males were associated with cell adhesion.
DISCUSSION
Transcriptome analysis revealed sex-specific gene upregulation in incompletely mature and shared transcripts with , providing insight into its gene expression patterns. This study highlights the importance of using both and reference-based assembly methods. Functional enrichment analysis showed that females exhibited enrichment in cell proliferation and reproduction pathways, while males exhibited enrichment in cell adhesion pathways. To the best of our knowledge, this is the first report on the gene expressions of each sex during the spawning season. Our findings offer valuable insights into the physiological ecology of incompletely mature red Japanese precious corals and suggest a method for identifying sex using various genes expressed in female and male individuals. In the future, techniques such as transplantation, artificial fertilization, and larval rearing may involve sex determination methods based on differences in gene expression to help conserve precious coral resources and ecosystems.
Topics: Animals; Anthozoa; Female; Gametogenesis; Male; Japan; Transcriptome; Gene Expression Profiling; East Asian People
PubMed: 38646482
DOI: 10.7717/peerj.17182 -
Marine Pollution Bulletin Nov 2015Dredging, river plumes and natural resuspension events can release sediments into the water column where they exert a range of effects on underlying communities. In this... (Review)
Review
Dredging, river plumes and natural resuspension events can release sediments into the water column where they exert a range of effects on underlying communities. In this review we examine possible cause-effect pathways whereby light reduction, elevated suspended sediments and sediment deposition could affect the reproductive cycle and early life histories of corals. The majority of reported or likely effects (30+) were negative, including a suite of previously unrecognized effects on gametes. The length of each phase of the life-cycle was also examined together with analysis of water quality conditions that can occur during a dredging project over equivalent durations, providing a range of environmentally relevant exposure scenarios for future testing. The review emphasizes the need to: (a) accurately quantify exposure conditions, (b) identify the mechanism of any effects in future studies, and (c) recognize the close interlinking of proximate factors which could confound interpretation of studies.
Topics: Animals; Anthozoa; Conservation of Natural Resources; Embryonic Development; Environmental Exposure; Geologic Sediments; Metamorphosis, Biological; Reproduction; Rivers; Sunlight; Water; Water Quality
PubMed: 26384866
DOI: 10.1016/j.marpolbul.2015.08.021 -
Proceedings of the National Academy of... Jun 2020Viruses, microbes, and host macroorganisms form ecological units called holobionts. Here, a combination of metagenomic sequencing, metabolomic profiling, and...
Viruses, microbes, and host macroorganisms form ecological units called holobionts. Here, a combination of metagenomic sequencing, metabolomic profiling, and epifluorescence microscopy was used to investigate how the different components of the holobiont including bacteria, viruses, and their associated metabolites mediate ecological interactions between corals and turf algae. The data demonstrate that there was a microbial assemblage unique to the coral-turf algae interface displaying higher microbial abundances and larger microbial cells. This was consistent with previous studies showing that turf algae exudates feed interface and coral-associated microbial communities, often at the detriment of the coral. Further supporting this hypothesis, when the metabolites were assigned a nominal oxidation state of carbon (NOSC), we found that the turf algal metabolites were significantly more reduced (i.e., have higher potential energy) compared to the corals and interfaces. The algae feeding hypothesis was further supported when the ecological outcomes of interactions (e.g., whether coral was winning or losing) were considered. For example, coral holobionts losing the competition with turf algae had higher Bacteroidetes-to-Firmicutes ratios and an elevated abundance of genes involved in bacterial growth and division. These changes were similar to trends observed in the obese human gut microbiome, where overfeeding of the microbiome creates a dysbiosis detrimental to the long-term health of the metazoan host. Together these results show that there are specific biogeochemical changes at coral-turf algal interfaces that predict the competitive outcomes between holobionts and are consistent with algal exudates feeding coral-associated microbes.
Topics: Animals; Anthozoa; Bacteria; Chlorophyta; Coral Reefs; Ecosystem; Metagenomics; Microbiota
PubMed: 32482859
DOI: 10.1073/pnas.1915455117 -
Genome Biology and Evolution Sep 2020Corals are the ecosystem engineers of coral reefs, one of the most biodiverse marine ecosystems. The ability of corals to form reefs depends on the precipitation of... (Comparative Study)
Comparative Study
Corals are the ecosystem engineers of coral reefs, one of the most biodiverse marine ecosystems. The ability of corals to form reefs depends on the precipitation of calcium carbonate (CaCO3) under biological control. However, several mechanisms underlying coral biomineralization remain elusive, for example, whether corals employ different molecular machineries to deposit different CaCO3 polymorphs (i.e., aragonite or calcite). Here, we used tandem mass spectrometry (MS/MS) to compare the proteins occluded in the skeleton of three octocoral and one scleractinian species: Tubipora musica and Sinularia cf. cruciata (calcite sclerites), the blue coral Heliopora coerulea (aragonitic skeleton), and the scleractinian aragonitic Montipora digitata. Reciprocal Blast analysis revealed extremely low overlap between aragonitic and calcitic species, while a core set of proteins is shared between octocorals producing calcite sclerites. However, the carbonic anhydrase CruCA4 is present in the skeletons of both polymorphs. Phylogenetic analysis highlighted several possible instances of protein co-option in octocorals. These include acidic proteins and scleritin, which appear to have been secondarily recruited for calcification and likely derive from proteins playing different functions. Similarities between octocorals and scleractinians included presence of a galaxin-related protein, carbonic anhydrases, and one hephaestin-like protein. Although the first two appear to have been independently recruited, the third appear to share a common origin. This work represents the first attempt to identify and compare proteins associated with coral skeleton polymorph diversity, providing several new research targets and enabling both future functional and evolutionary studies aimed at elucidating the origin and evolution of coral biomineralization.
Topics: Animals; Anthozoa; Biological Evolution; Biomineralization; Calcium Carbonate; Proteome; Species Specificity
PubMed: 32761183
DOI: 10.1093/gbe/evaa162 -
Journal of the Royal Society, Interface May 2015Scleractinian corals are a major source of biogenic calcium carbonate, yet the relationship between their skeletal microstructure and mechanical properties has been... (Comparative Study)
Comparative Study
Scleractinian corals are a major source of biogenic calcium carbonate, yet the relationship between their skeletal microstructure and mechanical properties has been scarcely studied. In this work, the skeletons of two coral species:solitary Balanophyllia europaea and colonial Stylophora pistillata, were investigated by nanoindentation. The hardness HIT and Young's modulus E(IT) were determined from the analysis of several load-depth data on two perpendicular sections of the skeletons: longitudinal (parallel to the main growth axis) and transverse. Within the experimental and statistical uncertainty,the average values of the mechanical parameters are independent on the section's orientation. The hydration state of the skeletons did not affect the mechanical properties. The measured values, EIT in the 76-77 GPa range, and H(IT) in the 4.9–5.1 GPa range, are close to the ones expected for polycrystalline pure aragonite. Notably, a small difference in H(IT) is observed between the species. Different from corals, single-crystal aragonite and the nacreous layer of the seashell Atrina rigida exhibit clearly orientation-dependent mechanical properties. The homogeneous and isotropic mechanical behaviour of the coral skeletons at the microscale is correlated with the microstructure,observed by electron microscopy and atomic force microscopy, and with the X-ray diffraction patterns of the longitudinal and transverse sections.
Topics: Animal Shells; Animals; Anisotropy; Anthozoa; Elastic Modulus; Hardness; Models, Biological; Porosity; Species Specificity; Stress, Mechanical
PubMed: 25977958
DOI: 10.1098/rsif.2015.0168 -
The Journal of Biological Chemistry Oct 2020Coral reefs are experiencing precipitous declines around the globe with coral diseases and temperature-induced bleaching being primary drivers of these declines....
Coral reefs are experiencing precipitous declines around the globe with coral diseases and temperature-induced bleaching being primary drivers of these declines. Regulation of apoptotic cell death is an important component in the coral stress response. Although cnidaria are known to contain complex apoptotic signaling pathways, similar to those in vertebrates, the mechanisms leading to cell death are largely unexplored. We identified and characterized two caspases each from , a disease-sensitive reef-building coral, and , a disease-resistant reef-building coral. The caspases are predicted homologs of the human executioner caspases-3 and -7, but OfCasp3a ( caspase-3a) and PaCasp7a ( caspase-7a), which we show to be DDases, contain an N-terminal caspase activation/recruitment domain (CARD) similar to human initiator/inflammatory caspases. OfCasp3b ( caspase-3b) and PaCasp3 ( caspase-3), which we show to be VDases, have short pro-domains, like human executioner caspases. Our biochemical analyses suggest a mechanism in coral which differs from that of humans, where the CARD-containing DDase is activated on death platforms but the protease does not directly activate the VDase. The first X-ray crystal structure of a coral caspase, of PaCasp7a determined at 1.57 Å resolution, reveals a conserved fold and an N-terminal peptide bound near the active site that may serve as a regulatory exosite. The binding pocket has been observed in initiator caspases of other species. These results suggest mechanisms for the evolution of substrate selection while maintaining common activation mechanisms of CARD-mediated dimerization.
Topics: Amino Acid Sequence; Animals; Anthozoa; Apoptosis; Caspases; Coral Reefs; Crystallography, X-Ray; Enzyme Activation; Humans; Models, Molecular; Protein Conformation; Protein Domains; Sequence Alignment; Substrate Specificity
PubMed: 32788218
DOI: 10.1074/jbc.RA120.014345 -
BMC Evolutionary Biology May 2018Previous phylogenetic analyses of primnoid octocorals utilizing morphological or molecular data have each recovered evolutionary relationships among genera that are...
BACKGROUND
Previous phylogenetic analyses of primnoid octocorals utilizing morphological or molecular data have each recovered evolutionary relationships among genera that are largely incongruent with each other, with some exceptions. In an effort to reconcile molecular-based phylogenies with morphological characters, phylogenetic reconstructions were performed with 33 of 43 primnoid genera using four loci (mtMutS, COI, 28S and 18S), and ancestral state reconstructions were performed using 9 taxonomically relevant characters. In addition, an updated illustrated key to the current 48 genus-level (43 genera, 5 subgenera) primnoids is presented.
RESULTS
Ancestral state reconstruction recovered the ancestral colony shape of primnoids as dichotomous planar. Convergence was detected among all 9 characters, and reversals to the character state of the common ancestor occurred in 4 characters. However, some characters were found to be informative. For example, the weak ascus scale of Metafannyella is not likely homologous to the ascus scales of Onogorgia and Fannyella, and the monophyly of two subgenera within Thouarella, which contain polyps in either whorls or an isolated arrangement, was supported. Phylogenetic analyses were generally consistent with previous studies, and resulted in the synonymy of one genus and a subgenus, the elevation of two subgenera, and the transfer of two species back to an original genus. For example, body wall ornamentation of Fanellia was re-evaluated, indicating a synonymy with Callogorgia; the utility of polyp arrangement for the subgenus Plumarella (Dicholaphis) was not supported, and is synonymized with the nominate subgenus Plumarella (Plumarella); the subgenera Plumarella (Faxiella) and Plumarella (Verticillata) are raised to generic status; and the two Plumarella species (P. diadema and P. undulata) are transferred back to Thouarella based on the homology of their marginal scales.
CONCLUSIONS
Altogether, and similar to other octocorallian groups, these results indicate that many of the morphological characters examined among primnoids, particularly colony morphology, are labile and exhibit complex evolutionary histories. However, some morphological characters such as coordination of polyps, presence of the ascus body wall scale, number of rows of body wall scales, and number of marginal scales help identify many clades, and are suitable for robust systematic assessments among primnoids.
Topics: Animals; Anthozoa; Bayes Theorem; Phylogeny; Sequence Analysis, DNA; Species Specificity
PubMed: 29716521
DOI: 10.1186/s12862-018-1182-5 -
Scientific Reports Oct 2018As the world's oceans are currently threatened by anthropogenic pollution and climate change, coral breeding has become an important conservation method, since it can...
As the world's oceans are currently threatened by anthropogenic pollution and climate change, coral breeding has become an important conservation method, since it can limit marine organisms' exposure to sub-optimal environment conditions. However, the aquarium environment is inherently different from the ocean, and this could manifest in physiological changes in the reared organisms, particularly with respect to their reproduction. Therefore, the aim of this study was to observe and compare the ultrastructure of the oocytes from wild Oxypora lacera and Echinopora gemmacea with the oocytes from cultured corals using transmission electron microscope. The oocytes from Wild O. lacera and E. gemmacea were larger than cultured ones, though their microvillus layers were significantly thiner. Internally, lipid granule areas and yolk material density in the oocytes of wild O. lacera and E. gemmacea were ~25% lower than in their cultured counterparts. Food availability and the presence and availability of symbiotic dinoflagellates (genus Symbiodinium) may have played a role in driving these lipid-based differences, in particular, as cultured corals had limited potential for heterotrophic feeding. These data will aid in future coral husbandry efforts.
Topics: Animals; Anthozoa; Endangered Species; Oocytes
PubMed: 30310130
DOI: 10.1038/s41598-018-33341-x -
The ISME Journal Nov 2019Coral reefs are threatened by global warming, which disrupts the symbiosis between corals and their photosynthetic symbionts (Symbiodiniaceae), leading to mass coral...
Coral reefs are threatened by global warming, which disrupts the symbiosis between corals and their photosynthetic symbionts (Symbiodiniaceae), leading to mass coral bleaching. Planktonic diazotrophs or dinitrogen (N)-fixing prokaryotes are abundant in coral lagoon waters and could be an alternative nutrient source for corals. Here we incubated untreated and bleached coral colonies of Stylophora pistillata with a N-pre-labelled natural plankton assemblage containing diazotrophs. N assimilation rates in Symbiodiniaceae cells and tissues of bleached corals were 5- and 30-fold higher, respectively, than those measured in untreated corals, demonstrating that corals incorporate more nitrogen derived from planktonic diazotrophs under bleaching conditions. Bleached corals also preferentially fed on Synechococcus, nitrogen-rich picophytoplanktonic cells, instead of Prochlorococcus and picoeukaryotes, which have a lower cellular nitrogen content. By providing an alternative source of bioavailable nitrogen, both the incorporation of nitrogen derived from planktonic diazotrophs and the ingestion of Synechococcus may have profound consequences for coral bleaching recovery, especially for the many coral reef ecosystems characterized by high abundance and activity of planktonic diazotrophs.
Topics: Animals; Anthozoa; Coral Reefs; Dinoflagellida; Ecosystem; Global Warming; Heterotrophic Processes; Photosynthesis; Symbiosis; Synechococcus
PubMed: 31249389
DOI: 10.1038/s41396-019-0456-2