Sea Anemone Stichodactyla Haddoni Research Articles

Physiological responses of the symbiotic shrimp Ancylocaris brevicarpalis and its host sea anemone Stichodactyla haddoni to ocean acidification

In this study, the physiology of symbiotic ‘peacock-tail’ shrimp Ancylocaris brevicarpalis and its host ‘Haddon's carpet’ sea anemone Stichodactyla haddoni were tested under lowered pH (7.7) and control (8.1) conditions. The biochemical responses such as digestive enzyme (AP), organic acids (lactate and succinate), oxidative damages (MDA), antioxidants metabolites/enzymes (ASC, GSH, SOD, CAT, APX, GPX, GR, POX, and PHOX), and detoxification enzyme (GST) were measured. The AP showed insignificantly reduced values in both the organisms in lowered pH conditions compared to control indicating the effect of abiotic stress. The hierarchical clustering analysis indicated low MDA in sea anemone can be explained by higher POX, APX, GR, ASC, and GSH levels compared to shrimps. However, the detoxification enzyme GST showed less activity in sea anemones compared to shrimps. The results suggest that A. brevicarpalis and sea anemone S. haddoni may have deleterious effects when exposed to short-term acidification stress.

Genomic Structure of Two Kv1.3 Channel Blockers from Scorpion Mesobuthus eupeus and Sea Anemone Stichodactyla haddoni and Construction of their Chimeric Peptide as a Novel Blocker.

Different toxins acting on Kv1.3 channel have been isolated from animal venom. MeuKTX toxin from Mesobuthus eupeus phillipsi scorpion and shtx-k toxin from Stichodactyla haddoni sea anemone have been identified as two effective Kv1.3 channel blockers. In this work, we characterized the genomic organization of both toxins. MeuKTX gene contains one intron and two exons, similar to the most scorpion toxins. There are a few reports of genomic structure of sea anemone toxins acting on Kv channels. The sequence encoding mature peptide of shtx-k was located in an exon separated by an intron from the coding exon of the propeptide and signal region. In order to make a peptide with more affinity for Kv1.3 channel and greater stability, the shtx-k/ MeuKTX chimeric peptide was designed and constructed using splicing by overlap extension-PCR (SOE-PCR) method. MeuKTX, shtx-k, and shtx-k/MeuKTX were cloned and the expression of the soluble proteins in E. coli was determined. Molecular docking studies indicated more inhibitory effect of shtx-k/MeuKTX on Kv1.3 channel compared to shtx-k and MeuKTX toxins. Key amino acids binding channel from both toxins, also involved in interaction of chimeric peptide with channel. Our results showed that the fusion peptide, shtx-k/MeuKTX could be an effective agent to target Kv1.3 channel.

The Mitochondrial Genome of the Sea Anemone Stichodactyla haddoni Reveals Catalytic Introns, Insertion-Like Element, and Unexpected Phylogeny

A hallmark of sea anemone mitochondrial genomes (mitogenomes) is the presence of complex catalytic group I introns. Here, we report the complete mitogenome and corresponding transcriptome of the carpet sea anemone Stichodactyla haddoni (family Stichodactylidae). The mitogenome is vertebrate-like in size, organization, and gene content. Two mitochondrial genes encoding NADH dehydrogenase subunit 5 (ND5) and cytochrome c oxidase subunit I (COI) are interrupted with complex group I introns, and one of the introns (ND5-717) harbors two conventional mitochondrial genes (ND1 and ND3) within its sequence. All the mitochondrial genes, including the group I introns, are expressed at the RNA level. Nonconventional and optional mitochondrial genes are present in the mitogenome of S. haddoni. One of these gene codes for a COI-884 intron homing endonuclease and is organized in-frame with the upstream COI exon. The insertion-like orfA is expressed as RNA and translocated in the mitogenome as compared with other sea anemones. Phylogenetic analyses based on complete nucleotide and derived protein sequences indicate that S. haddoni is embedded within the family Actiniidae, a finding that challenges current taxonomy.

Sea anemone (Stichodactyla haddoni) induces apoptosis in lung cancer A549 cells: an in vitro evaluation of biological activity of mucus derivatives

Bioactive compounds obtained from sea anemones have multiple biological effects, including cytotoxic, cytolytic and anti-carcinogenic activities. This study investigated the cellular and molecular effects of crude mucus (CM) and four derived fractions (F1, F2, F3, and F4) of sea anemone Stichodactyla haddoni on human lung cancer cell line (A549). The samples were collected from the intertidal zone of Hormuz Island in the Persian Gulf. The cytotoxicity of CM and their fractions extracted from the sea anemone was assayed using the MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) assay for 24 and 48 h. The F1 (30–50 kDa) fraction had the most effect on the lung cancer cell line compared with CM and F2 (10–30 kDa). The cell apoptosis was measured via expression rate of apoptotic marker genes such as BAK, BAX, and BCL2 by Real-time PCR (RT-PCR). Cell morphology was analyzed by a light microscopy though Giemsa staining. The results demonstrated that the S. haddoni mucus induced a significant reduction in the number of viable cells as well as increased cell death in a dose-dependent manner. The expression of pro-apoptotic genes such as BAK and BAX were upregulated, but BCL2 was downregulated when A549 cells treated with CM (50, 75 and 100 μg/mL) and F1, F2 fractions (5 and 25 μg/mL). The morphological characteristics of apoptotic cells were observed after treatment with CM, F1 and F2 fractions. These findings suggest that S. haddoni mucus has inhibitory effects on growth of the A549 lung cancer cells via the mitochondria-mediated apoptotic pathway. In addition, further purifying the F1 and F2 fractions, which have the greatest cytolytic effects, can hopefully help to better understand the inhibition of cancer cell growth.

Novel and Facile Synthesis of Sea Anemone Adhesive Protein-Coated ZnO Nanoparticles: Antioxidant, Antibiofilm, and Mosquito Larvicidal Activity Against Aedes aegypti

Recently, marine bio-products have provided a new insight on biomaterials for pharmaceutical applications. Herein, the use of adhesive protein in the fabrication of bio-inspired nanomaterials noted to the possible realization of vital biomedical applications. This study illustrates the biosynthesize ZnO nanoparticles (ZnO NPs) using adhesive protein from sea anemone Stichodactyla haddoni (ShAp). ShAp-ZnO NPs were characterized via SDS-PAGE, UV–Visible, XRD, FTIR, TEM and SAED. The molecular weight of the adhesive protein was determined by SDS-PAGE to be between 36 and 42 kDa. The UV–Vis peak of ShAp-ZnO NPs was revealed at 210 nm while XRD exhibited the crystalline nature of ShAp-ZnO NPs. FTIR revealed that functional group of ShAp-ZnO NPs, which exhibited peaks at 3441.31–1073.36 cm−1. HR-TEM revealed that ShAp-ZnO NPs obtained structure were hexagonal with 10 nm diameter. The antioxidant properties of ShAp, zinc acetate, and ShAp-ZnO NPs were noted at 100 µg/mL. Further, microscopic analysis demonstrated that 50 µg/mL of ShAp, zinc acetate, and ShAp-ZnO NPs efficiently repressed the biofilm formation of both Gram(+) and Gram(−) bacteria. In addition, maximal larvicidal effects were noticed at 100 µg/mL of ShAp-ZnO NPs against the 3rd instar of Aedes aegypti. Overall, the ShAp-ZnO NPs could have entomological and pharmaceutical applications.

Revisiting venom of the sea anemone Stichodactyla haddoni: Omics techniques reveal the complete toxin arsenal of a well-studied sea anemone genus

More than a century of research on sea anemone venoms has shown that they contain a diversity of biologically active proteins and peptides. However, recent omics studies have revealed that much of the venom proteome remains unexplored. We used, for the first time, a combination of proteomic and transcriptomic techniques to obtain a holistic overview of the venom arsenal of the well-studied sea anemone Stichodactyla haddoni. A purely search-based approach to identify putative toxins in a transcriptome from tentacles regenerating after venom extraction identified 508 unique toxin-like transcripts grouped into 63 families. However, proteomic analysis of venom revealed that 52 of these toxin families are likely false positives. In contrast, the combination of transcriptomic and proteomic data enabled positive identification of 23 families of putative toxins, 12 of which have no homology known proteins or peptides. Our data highlight the importance of using proteomics of milked venom to correctly identify venom proteins/peptides, both known and novel, while minimizing false positive identifications from non-toxin homologues identified in transcriptomes of venom-producing tissues. This work lays the foundation for uncovering the role of individual toxins in sea anemone venom and how they contribute to the envenomation of prey, predators, and competitors. Biological significanceProteomic analysis of milked venom combined with analysis of a tentacle transcriptome revealed the full extent of the venom arsenal of the sea anemone Stichodactyla haddoni. This combined approach led to the discovery of 12 entirely new families of disulfide-rich peptides and proteins in a genus of anemones that have been studied for over a century.

Expansion behavior, growth and survival of the sea anemone Stichodactyla haddoni (Saville-Kent, 1893) with anemonefishes in captivity

Expansion behavior, growth and survival of the sea anemone Stichodactyla haddoni (Saville-Kent, 1893) with anemonefishes in captivity

Novel peptide toxins from the sea anemone Stichodactyla haddoni

Four peptide toxins, SHTX I–III with crab-paralyzing activity and SHTX IV with crab lethality, were isolated from the sea anemone Stichodactyla haddoni and their primary structures elucidated by protein sequencing and cDNA cloning. SHTX I (new toxin, 28 residues), II (analogue of SHTX I, 28 residues) and III (Kunitz-type protease inhibitor, 62 residues) are potassium channel toxins and SHTX IV (48 residues) is a member of the type 2 sea anemone sodium channel toxins. The precursor protein of SHTX IV is composed of a signal peptide, propart and mature peptide, while the propart is missing in that of SHTX III. In addition to these four toxins, an epidermal growth factor-like peptide was detected in S. haddoni by RT-PCR.

Spatial distribution of symbiotic shrimps (Periclimenes holthuisi, P. brevicarpalis, Thor amboinensis) on the sea anemone Stichodactyla haddoni

This study investigated the spatial distribution patterns of three shrimp species, Periclimenes holthuisi, P. brevicarpalis, and Thor amboinensis on the sea anemone Stichodactyla haddoni in the laboratory. Anemones were partitioned into five zones (mouth, inner tentacle, outer tentacle, upper column, and lower column), and shrimp distribution on these zones was determined. Regardless of species, significantly higher numbers of shrimps chose outer tentacles (>40%) over other zones during daytime. Such distribution might be attributed to their feeding practices as these crustaceans clipped and ate parts of the outer tentacles. Periclimenes holthuisi also showed varying temporal distribution patterns on their hosts. At night when anemones contracted their tentacles, shrimp moved in significant numbers from the outer tentacle region either to the column or off the anemones. Shrimps returned to the tentacles during daytime when anemones expanded their tentacles. Thus, spatial and temporal distribution of shrimps depend upon their feeding activities and degree of anemone expansion.

Sea anemone host selection by the symbiotic saddled cleaner shrimp Periclimenes holthuisi

A preliminary field survey was conducted to determine the distribution of ectosymbiotic shrimp Periclimenes holthuisi on the sea anemone Stichodactyla haddoni in Moreton Bay (Queensland, Australia). Laboratory experiments were also carried out to verify whether the shrimp show a preference for one anemone host. In the field, 45 individuals of P. holthuisi were found to be associated with 70% of the specimens of S. haddoni (n�=�20). We inferred this shrimp population was not space-limited because not all anemones were colonized. After having been isolated from their natural host for 2 weeks, when placed between individuals of S. haddoni and Macrodactyla doreensis (an anemone that is sympatric with S. haddoni), shrimp overwhelmingly selected S.�haddoni (92%). To establish whether M. doreensis may serve as an alternative host for P. holthuisi, unacclimated shrimp were forced to associate with this anemone. Macrodactyla doreensis showed little tentacle reaction during this association; shrimp were found on the anemone's tentacles and the column. The finding that M. doreensis can serve as an alternative host for P. holthuisi demonstrates that this anemoneshrimp is adaptable to another anemone host and thus may not be highly host specific.