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At least 19 recordsLinked to original sources
PubMed1995

Systematic relationships within the Anthozoa (Cnidaria: Anthozoa) using the 5'-end of the 28S rDNA.

Systematic relationships among the subclasses of Anthozoa, and especially among the orders Scleractinia, Actiniaria, and Corallimorpharia of subclass Zoantharia, were investigated by applying parsimony and distance methods of analysis to nucleotide sequence data obtained for the 5' end of the 28S rDNA. Exhaustive parsimony analysis indicates that the Ceriantipatharia are most representative of the ancestral Anthozoa. When applied to a wide range of scleractinians (nine taxa), actiniarians (seven taxa), and corallimorpharians (six taxa), both parsimony and distance analyses resolve three groups, one being the Scleractinia and the others containing both actiniarians and corallimorpharians. This indicates an unclear relationship between Actiniaria and Corallimorpharia and gives no support for Hand's hypothesis of scleractinian ancestry of actiniarians and corallimorphians; the monophyly of the Scleractinia, which is strongly supported by our analyses, is evidence to the contrary.

Animals↗
PubMed2004

The molecular properties and applications of Anthozoa fluorescent proteins and chromoproteins.

The green fluorescent protein (GFP) from the jellyfish Aequorea victoria and its fluorescent homologs from Anthozoa corals have become invaluable tools for in vivo imaging of cells and tissues. Despite spectral and chromophore diversity, about 100 cloned members of the GFP-like protein family possess common structural, biochemical and photophysical features. Anthozoa GFP-like proteins are available in colors and properties unlike those of A. victoria GFP variants and thus provide powerful new fluorophores for molecular labeling and intracellular detection. Although Anthozoa GFP-like proteins provide some advantages over GFP, they also have certain drawbacks, such as obligate oligomerization and slow or incomplete fluorescence maturation. In the past few years, effective approaches for eliminating some of these limitations have been described. In addition, several Anthozoa GFP-like proteins have been developed into novel imaging agents, such as monomeric red and dimeric far-red fluorescent proteins, fluorescent timers and photoconvertible fluorescent labels. Future studies on the structure of this diverse set of proteins will further enhance their use in animal tissues and as intracellular biosensors.

Animals↗
PubMed2003

Hetero-oligomeric tagging diminishes non-specific aggregation of target proteins fused with Anthozoa fluorescent proteins.

The tendency for tetramerization is the main disadvantage in the green fluorescent protein homologues from Anthozoa species. We report a universal method called hetero-oligomeric tagging, which diminishes troublesome consequences of tetramerization of Anthozoa-derived fluorescent proteins (FP) in intracellular protein labelling. This approach is based on the co-expression of the FP-tagged protein of interest together with an excess of free non-fluorescent FP mutant. The resulting FP heterotetramers contain only a single target polypeptide and, therefore, can be considered pseudo-monomeric. Feasibility of the method has been demonstrated with a red FP fused with cytoplasmic beta-actin or tubulin-binding protein Tau34. In addition, heterotetramers appeared to be a unique model for biophysical characterization of Anthozoa FPs in pseudo-monomeric state.

Actins↗
PubMed1999

Phylogenetic relationships within the class Anthozoa (phylum Cnidaria) based on nuclear 18S rDNA sequences.

Taxonomic relationships within the corals and anemones (Phylum Cnidaria: Class Anthozoa) are based upon few morphological characters. The significance of any given character is debatable, and there is little fossil record available for deriving evolutionary relationships. We analyzed complete 18S ribosomal sequences to examine subclass-level and ordinal-level organization within the Anthozoa. We suggest that the Subclass Ceriantipatharia is not an evolutionarily relevant grouping. The Order Corallimorpharia appears paraphyletic and closely related to the Order Scleractinia. The 18S rRNA gene may be insufficient for establishing robust phylogenetic hypotheses concerning the specific relationships of the Corallimorpharia and the Ceriantharia and the branching sequence for the orders within the Hexacorallia. The 18S rRNA gene has sufficient phylogenetic signal, however, to distinguish among the major groupings within the Class Anthozoa, and we use this information to suggest relationships for the enigmatic taxa Dactylanthus and Dendrobrachia.

Animals↗
PubMed2002

Stable expression of Anthozoa fluorescent proteins in mammalian cells.

BACKGROUND: Fluorescent proteins have become invaluable reporters in many areas of cellular and developmental biology. An enhanced version of the Aequorea victoria green fluorescent protein (AvEGFP) is the most widely used fluorescent protein. For a variety of reasons, it is useful to have alternative fluorescent proteins to AvEGFP. METHODS: The cDNA sequences for enhanced variants of the Anemonia cyan fluorescent protein (AmCyan1), as well as the Zoanthus green (ZsGreen1) and yellow (ZsYellow1) fluorescent proteins, were cloned downstream of a constitutive cytomegalovirus (CMV) promoter within a retroviral expression vector. NIH3T3, HEK293, SW620, and WM35 cells were transduced with recombinant retroviruses at a low multiplicity of infection (MOI) to bias for single-copy integration. Both unselected and stably selected cells transduced with the retroviral expression constructs were characterized. Expression of each fluorescent protein in cells was detected using flow cytometry and fluorescence microscopy with filter sets typically used for AvEGFP/fluorescein isothiocyanate (FITC) detection and was compared with the expression of AvEGFP. In addition, a fluorescence plate reader with several excitation and emission filter sets was used for detection. RESULTS: Expression of each protein was observable by fluorescence microscopy. Under given conditions of flow cytometry, the ZsGreen1 mean fluorescence was approximately 3-fold, 10-fold, and 50-fold greater than that of AvEGFP, ZsYellow1, and AmCyan1, respectively. AmCyan1, ZsGreen1, and AvEGFP were detected by a fluorescence plate reader. CONCLUSION: We determined that fluorescent proteins from Anthozoa species are detectable using a standard flow cytometer and fluorescence microscope. All of the mammalian cell lines tested expressed detectable levels of fluorescent proteins from stable integrated provirus. In cell lines where the AvEGFP protein is toxic or poorly expressed, these Anthozoa fluorescent proteins may serve as alternative fluorescent reporters.

3T3 Cells↗
PubMed2002

Green fluorescent protein-like proteins in reef Anthozoa animals.

Green fluorescent protein (GFP) from the bioluminescent jellyfish Aequorea victoria has become an important tool in molecular and cellular biology as a transcriptional reporter, fusion tag, and biosensor. Most significantly, it encodes a chromophore intrinsically within its protein sequence, obviating the need for external substrates or cofactors and enabling the genetic encoding of strong fluorescence. Mutagenesis studies have generated GFP variants with new colors, improved fluorescence and other biochemical properties. In parallel, GFPs and GFP-like molecules have been cloned from other organisms, including the bioluminescent sea pansy Renilla reniformis and other non-bioluminescent Anthozoa animals. In the jellyfish and sea pansy, the GFPs are coupled to their chemoluminescence. Instead of emitting the blue light generated by aequorin and luciferase, the GFPs absorb their energy of primary emission and emit green light, which travels farther in the sea. In contrast, GFP-like proteins in reef Anthozoa are thought to play a role in photoprotection of their symbiotic zooxanthellae in shallow water; they transform absorbed UV radiation contained in sunlight into longer fluorescence wavelengths (Salih, A., Larkum, A., Cox, G., Kuhl, M., and Hoegh-Guldberg, O. 2000. Nature, 408: 850-853). In this review, I will describe both the biological and practical aspects of Anthozoan GFP-like proteins, many of which will be greatly improved in utility and commercially available before long. The ubiquity of these molecular tools makes it important to appreciate the interplay between sunlight and GFP-like proteins of Anthozoan animals, and to consider the optimal use of these unique proteins in biological studies.

Animals↗
PubMed1996

DNA sequence variation of mitochondrial large-subunit rRNA provides support for a two-subclass organization of the Anthozoa (Cnidaria).

We have sequenced a portion of the mitochondrial 16S rRNA gene from 29 species of Anthozoa, representing six orders of the subclasses Ceriantipatharia, Hexacorallia, and Octocorallia, with the focus on deep-seamount corals (> 500-m depth). We have detected significant length variation in the gene, with homologous gene fragments ranging from 545 bp in a shallow-water scleractinian coral to 911 bp in a deep-sea antipatharian black coral. The aligned sequences were divided into five regions: three high-identity sequence blocks (HSBs) and two highly variable blocks of insertions/deletions (INDELs). Most of the length variation among species occurred as varying numbers of nucleotides in the two INDELs. Little or no intraspecific sequence variation was detected over spatial scales of up to approximately 150 km. Interspecific sequence variation was lowest among the octocorals and greatest among the ceriantipatharians. Our data indicate that the orders Ceriantharia and Antipatharia are highly divergent, and a phylogenetic reconstruction provides support for the two-subclass system of the class Anthozoa (Hexacorallia and Octocorallia).

Animals↗
PubMed2006

Anthozoa red fluorescent protein in biosensing.

The identification and cloning of a red fluorescent protein (DsRed) obtained from Anthozoa corals has provided an alternative to commonly used green fluorescent proteins (GFPs) in bioanalytical and biomedical research. DsRed in tandem with GFPs has enhanced the feasibility of multicolor labeling studies. Properties of DsRed, for example high photostability, red-shifted fluorescence emission, and stability to pH changes have proven valuable in its use as a fluorescent tag in cell-biology applications. DsRed has some limitations, however. Its slow folding and tendency to form tetramers have been a hurdle. Several different mutational studies have been performed on DsRed to overcome these problems. In this paper, applications of DsRed in biosensing, specifically in FRET/BRET assays, whole-cell assays, and in biosensors, is discussed. In the future, construction of DsRed mutants with unique characteristics will further expand its applications in bioanalysis.

Animals↗
PubMed2004

Identification of GFP-like proteins in nonbioluminescent, azooxanthellate anthozoa opens new perspectives for bioprospecting.

We screened nonbioluminescent, azooxanthellate cnidaria as potential sources for advanced marker proteins and succeeded in cloning a tetrameric green fluorescent protein (GFP) from the tentacles of Cerianthus membranaceus. The fluorescence of this protein (cmFP512) is characterized by excitation maximum at 503 nm, emission maximum at 512 nm, extinction coefficient of 58,800 M-1 cm-1, quantum yield of 0.66, and fluorescence lifetime of 2.4 ns. The chromophore is formed from the tripeptide Gln-Tyr-Gly. The amino acid sequence of this protein shares 17.8% identical residues with GFP from Aequorea victoria. Weak interactions between the subunits of the tetramer make cmFP512 a promising lead structure for the generation of monomeric variants of fluorescent proteins. Both red fluorescent proteins and nonfluorescent proteins of the GFP family were also purified from tissue homogenates of Adamsia palliata and Calliactis parasitica. The results presented here indicate that a photoprotective function of GFP-like proteins is unlikely in the examined anthozoa species.

Amino Acid Sequence↗
PubMed2006

The complete mitochondrial genome of the black coral Chrysopathes formosa (Cnidaria:Anthozoa:Antipatharia) supports classification of antipatharians within the subclass Hexacorallia.

Black corals comprise a globally distributed shallow- and deep-water taxon whose phylogenetic position within the Anthozoa has been debated. We sequenced the complete mitochondrial genome of the antipatharian Chrysopathes formosa to further evaluate its phylogenetic relationships. The circular mitochondrial genome (18,398 bp) consists of 13 energy pathway protein-coding genes and two ribosomal RNAs, but only two transfer RNA genes (trnM and trnW), as well as a group I intron within the nad5 gene that contains the only copies of nad1 and nad3. No novel genes were found in the antipatharian mitochondrial genome. Gene order and genome content are most similar to those of the sea anemone Metridium senile (subclass Hexacorallia), with differences being the relative location of three contiguous genes (cox2-nad4-nad6) and absence (from the antipatharian) of a group I intron within the cox1 gene. Phylogenetic analyses of multiple protein-coding genes support classifying the Antipatharia within the subclass Hexacorallia and not the subclass Ceriantipatharia; however, the sister-taxon relationships of black corals within Hexacorallia remain inconclusive.

Animals↗
PubMed2004

Regulatory volume increase in nematocytes isolated from acontia of Aiptasia diaphana (Cnidaria, Anthozoa).

Nematocytes, Cnidarians stinging cells used primarily in capturing prey or in turning away predators, can regulate their volume under 35% hyposmotic shock showing regulatory volume decrease (RVD). In this study, for the first time, we investigate the capability of nematocytes to regulate their volume under hypertonic conditions, through regulatory volume increase (RVI). The experiments were carried out in acontial nematocytes of Aiptasia diaphana (Cnidaria: Anthozoa) isolated by the chemical method of applying 605 mM SCN-. Channel inhibitors, as amiloride, Gd3+, NPPB, DIDS, bumetanide and ion substitution have been employed to assess the role of ions in such volume regulation mechanisms. Our results suggest that nematocytes are able to perform RVI. The regulatory volume recovery process after hypertonic stimulation involves Na+ conductance and Na+/K+/2Cl- cotransport but not Cl- conductive pathways. Further studies will be necessary to better define such mechanisms and RVI control signalling, taking into account that the nematocyte is known to be a very primitive eukaryotic cell.

Animals↗
PubMed1975

Spermatogenesis in Anthozoa: differentiation of the spermatid.

The fine structure of spermatids has been examined in Calliactis, Protanthea, Gonactinia and Parazoanthus (Cnidaria, Anthozoa). The sperm cells are relatively simple and lack distinct acrosomes. Their nuclei, spherical in the zoanthid, in the actinians are slendertipped cones. Condensation of the chromatin is interpreted in terms of progressive coiling of densely-stained filaments and the elimination of nucleoplasm. Nuclear elongation occurs in the absence of microtubules. A well-developed centriolar complex is attached to the nuclear envelope by fibres and in this area (that of a shallow fossa in actinian spern) the nuclear membranes seem to be thickened. The centrioles are surrounded by a mitochondrial collar, especially pronounced in Calliactis. In contact with the mitochondria and nucleus is a ring of lipid-containing vesicles 300-700 nm in diameter. A system of densely-staining vesicles 150-300 nm in size corresponds to the "pro-acrosomal vesicles" described for other coelenterates. They are scattered in the peripheral cytoplasm and are regarded as derivatives of the endoplasmic reticulum. Problems of organelle function and of differentiation during spermiogenesis are discussed.

Animals↗
PubMed1977

[Ultrastructural localization of acid and alkaline phosphatases in sterile septae of the anthozoa Pachycerianthus fimbriatus (author's transl)].

Acid and alkaline phosphatase activity has been localized in the cells of the sterile septae of starved and fed anthozoa. Acid phosphatase is present in lysosomes, in Golgi cisternae and old phagosomes of starved animals. In fed animals, the reaction is more intense and the number of lysosomes is increased. New phagosomes are loaded with lead phosphate. In starved animals, the alkaline phosphatase activity has been observed on the plasma membranes and in the old phagosomes.

Acid Phosphatase↗
PubMed2002

Induction of gametogenesis in the basal cnidarian Nematostella vectensis(Anthozoa).

A protocol was established to reproducibly induce spawning in the basal cnidarian Nematostella vectensis (Anthozoa). We found that a combination of feeding regime, dark-light cycle and temperature shift synergistically induced gametogenesis in adult polyps. Females lay between 100-600 eggs. This procedure led reproducibly to the production of thousands of eggs over the course of more than 1 year in weekly cycles. Gametes are released in a time window of about 2 h resulting in predictable and fairly synchronized development. We also present a method for in vitro fertilization allowing manipulation of early embryos. These methods as well as the simple culture conditions could provide important prerequisites for the use of Nematostella as a model system for the development of a basal Metazoa.

Animals↗
PubMed2002

The ancestral role of Brachyury: expression of NemBra1 in the basal cnidarian Nematostella vectensis (Anthozoa).

The T-Box transcription factor Brachyury plays important roles in the development of all bilateral animals examined so far. In order to understand the ancestral function of Brachyury we cloned NemBra1, a Brachyury homolog from the anthozoan sea anemone Nematostella vectensis. Anthozoa are considered the basal group among the Cnidaria. First NemBra1 expression could be detected at the blastula/gastrula transition and gene activity persists until adulthood of the animals. In situ hybridization shows that NemBra1 expression in gastrulae and early planula larvae is restricted to a circle around the blastopore. When the larvae begin to metamorphose into primary polyps, the expression zone extends into the developing mesenteries. In adult polyps Brachyury expression persists in the mesenteries, but is excluded from the septal filament and the differentiated retractor muscles, which also develop from the mesenteries. We conclude that the ancestral function of Brachyury was in specifying the blastopore and its endodermal derivatives.

Amino Acid Sequence↗
PubMed1994

Isolation of nucleic acids from the sea anemone Condylactis gigantea (Cnidaria: Anthozoa).

Standard procedures for isolating nucleic acids from specialized tissues such as the mucus-containing tissues found in many marine organisms are, in many cases, not effective, resulting in isolates contaminated with polysaccharides that encumber subsequent analysis. A method is described for isolating nucleic acids from the sea anemone Condylactis gigantea (Cnidaria: Anthozoa) using the compound hexadecyltrimethyl ammonium bromide (CTAB). This substance has historically been effective in producing digestible chromosomal DNA from a variety of polysaccharide-enriched sources. In the presence of CTAB, DNA can be isolated and extracted from Condylactis gigantea and is suitable for digestion with restriction endonucleases. With a minor modification, RNA can also be extracted and used to obtain mRNA. The technique is useful for Cnidarian tissues and may be appropriate for a variety of other marine invertebrates and algae.

Animals↗
PubMed2000

Pax gene diversity in the basal cnidarian Acropora millepora (Cnidaria, Anthozoa): implications for the evolution of the Pax gene family.

Pax genes encode a family of transcription factors, many of which play key roles in animal embryonic development but whose evolutionary relationships and ancestral functions are unclear. To address these issues, we are characterizing the Pax gene complement of the coral Acropora millepora, an anthozoan cnidarian. As the simplest animals at the tissue level of organization, cnidarians occupy a key position in animal evolution, and the Anthozoa are the basal class within this diverse phylum. We have identified four Pax genes in Acropora: two (Pax-Aam and Pax-Bam) are orthologs of genes identified in other cnidarians; the others (Pax-Cam and Pax-Dam) are unique to Acropora. Pax-Aam may be orthologous with Drosophila Pox neuro, and Pax-Bam clearly belongs to the Pax-2/5/8 class. The Pax-Bam Paired domain binds specifically and preferentially to Pax-2/5/8 binding sites. The recently identified Acropora gene Pax-Dam belongs to the Pax-3/7 class. Clearly, substantial diversification of the Pax family occurred before the Cnidaria/higher Metazoa split. The fourth Acropora Pax gene, Pax-Cam, may correspond to the ancestral vertebrate Pax gene and most closely resembles Pax-6. The expression pattern of Pax-Cam, in putative neurons, is consistent with an ancestral role of the Pax family in neural differentiation and patterning. We have determined the genomic structure of each Acropora Pax gene and show that some splice sites are shared both between the coral genes and between these and Pax genes in triploblastic metazoans. Together, these data support the monophyly of the Pax family and indicate ancient origins of several introns.

Amino Acid Sequence↗
PubMed1975

Colonial conduction systems in the Anthozoa: Octocorallia.

1. The octocorals Alcyonium digitatum, Pennatula phosphorea and Virgularia mirabilis each have a through-conducting nerve net. The nerve net demonstrated electrophysiologically may well be the same as that previously shown by the use of histological techniques. 2. It exhibits both facilitation and defacilitation in the rate of conduction of pulses. 3. The distance of spread of nerve net activity is not limited by the number of stimuli applied. 4. The nerve net controls fast muscle contractions; the frequency of pulses is important in determining which muscles contract and in which sequence. 5. The nerve net is 'spontaneously' active. 6. A previously undescirbed slow system has been identified in Pennatula. It has many of the properties of slow systems in sea anemones and may well be ectodermal. It is suggested that multiple conduction systems are of common occurrence in the Anthozoa.

Animals↗