The Influence of Aerial Exposure on Sea Anemones Aulactinia veratra Mucin Genes Expression Using the RNA Sequencing

Mucin genes are the main component of mucus. The sea anemone species, Aulactinia veratra (Phylum Cnidaria) contains different types of mucin genes. In the intertidal zone, A. veratra is found to be exposed to air during the low tide and produces large quantities of mucus as an external covering. The relation between low tide and mucus secretion is still unclear, and what is the role of mucin during arial exposure is not yet investigated. This study hypothesised that the mucin genes in A. veratra would have significantly high expression in response to aerial exposure. Therefore, the aim of current study was to examine and analyses the response of A. veratra mucins in response to an experiment involving three hours of aerial exposure. To achieve this, aim the RNA-sequencing and bioinformatics analyses were used to examine the expression profile of A. veratra mucin genes in response to aerial exposure. The generated results have shown that, Mucin4-like and mucin5B-like were up-regulated in response to the three hours of aerial exposure in A. veratra. This finding shows a significant role of mucin5B-like and mucin4-like genes in response to air stress at low tide. The data generated from this study could be used in conjunction with future mucin gene studies of sea anemones and other cnidarians to compare A. veratra mucin gene expression results across time, and to extend our understanding of mucin stress response in this phylum.

Isolation and identifi cation of antimicrobial metabolites from sea anemone-derived fungus Emericella sp.SMA01

Marine symbiotic fungi represent an intriguing source of discovery of novel secondary metabolites with various biological activities.Sea anemones are benthic marine invertebrates,however,the cultivable symbiotic fungi residing in the sea anemones are paid few attentions compared to those derived from their cnidarian counterparts.Here we show the identification of antimicrobial secondary metabolites from the sea anemone-derived symbiotic fungi.Out offive isolated fungal strains,only the strain SMA01 showed strong antimicrobial activities,which was assigned into the genus Emericella based on the morphological characteristics and the ITS sequencing.Media swift from liquid fermentation to solid rice medium presented little influence on its antibacterial activity.A chemical investigation of the ethyl acetate extract of the Emericella sp.SMA01 led to discovery of the primary antibiotic metabolite phenazine-1-carboxylic acid.The IC_(50) values of the phenazine-1-carboxylic acid against Phytophthora capsici,Gibberella zeae,and Verticillium dahliae were determined to be 23.26-53.89μg/mL.To the best of our knowledge,this was the first report of Emericella sp.in sea anemones.The current study may benefit understanding of the defensive chemical interactions between the symbiotic fungi and their host sea anemones.

Preparation and Insecticidal Activity of Sea Anemone Peptide AP-GI from Aiptasia pallida

[Objectives] This study was conducted to synthesize sea anemone peptide Ap-GI and investigate its insecticidal activity. [Methods] The linear peptide Ap-GI was synthesized by solid phase peptide synthesis(SPPS), and the linear peptide was subjected to the two-step oxidative folding, mass spectrometry identification and high performance liquid chromatography(HPLC) purification. Then, the MTT method and insect injection method were used to study its insecticidal activity. [Results] The synthesized sea anemone peptide had a purity of 95%. The test results of the MTT method showed that the peptide Ap-GI had the activity of inhibiting the growth of insect cells sf9 with the median effective dose of 0.7 nM;and the test results of the injection method on yellow mealworms showed that the peptide Ap-GI had high insecticidal activity, and the median lethal dose was 16.9 nM. [Conclusions] The sea anemone peptide Ap-GI from Aiptasia pallida has a good inhibitory effect on the growth of insect cells and high-efficiency insecticidal activity, which can lay a foundation for the development of new, safe and efficient peptide biological insecticides.

Preparation of Sea Anemone Peptide Toxin Ap-TxI and Its Insecticidal Activity

[Objectives]This study was conducted to synthesize sea anemone peptide toxin Ap-TxI and investigate its insecticidal activity. [Methods] The sea anemone linear peptide toxin Ap-TxI was synthesized by the solid-phase peptide synthesis(SPPS), and six cysteines were oxidized to form three disulfide bonds by a three-step directional oxidation method. Then, purification by high performance liquid chromatography(HPLC) and mass spectrometry identification were performed. Finally, the insect cytotoxicity and insecticidal activity of Ap-TxI were studied by the MTT method and insect injection method. [Results] The oxidized peptide Ap-TxI with three disulfide bonds in natural configuration was successfully synthesized by the SPPS method, and its purity was >90% by HPLC analysis. The results of the MTT method showed that Ap-TxI was active on the growth of insect cells sf9, with a half effective dose of 0.2 nM;and the results of the mealworm injection test showed that the polypeptide Ap-TxI had high insecticidal activity with a median lethal dose of 11.7 nM. [Conclusions] The sea anemone peptide toxin Ap-TxI with high insecticidal effect was obtained, laying a foundation for the development of new, efficient and safe biological insecticides.

Coral Reef Bleaching at Agatti Island of Lakshadweep Atolls,India

A survey on coral bleaching was carried out at Agatti Island of Lakshadweep from May to June 2010.Elevated sea surface temperatures(SSTs)of the region exceeded the seasonal average and delayed the onset of monsoon,which triggered widespread bleaching of corals.The Agatti reefs showed an average of 73%bleached corals with apparent bleaching-related mortality of sea anemones(87%)and giant clams(83%).The SST increased up to 34℃with an average maximum SST of 32.5℃ during the study period between May and June 2010.Coral reefs on the southern side of the island are fully or partially exposed to sun light during low tide in contrast to the other side.This suggests that the mortality is more likely due to the low tide exposure than exclusively due to the elevated SST.Observations indicated a clear increase in coral bleaching during April 2010,at levels higher than that in normal summer.

Study the antimicrobial activity of six marine sponges and three parts of sea anemone on Candida albicans

Objective:To evaluate the antifungal and inhibitory activity of six different species of marine sponges and one species of sea anemone that were collected from the Persian Gulf on the growth of Candida albicans(C.albicans).Methods:Sea anemone and six different sponges were gathered from the Persian Gulf and extracted by methanol macerated with dichloromethane solvents.The activity of each extracts against C.albicans was determined by paper disc diffusion and agar well diffusion methods.Also,minimum inhibitory concentration and minimal bactericidal concentration of each extract were determined.Results:The finding of current research confirmed that all sponge extracts had sufficient inhibitory effect against C.albicans but the extracts of sponge type 2 and 5 had the best inhibitory effect on C.albicans and their zones of inhibition were 45 mm and 38 mm,respectively.The tentacle of sea anemone had the best inhibitory effect against C.albicans compared to other part of the body and its zone of inhibition was 41 mm.Besides,the sponge type 5 extracts had the best minimum inhibitory concentration and minimal bactericidal concentration values with 6.25 and 12.5 mg/mL,respectively.Conclusions:It could be concluded that the crude extracts of six different sponges and sea anemone have high potential to produce broad spectral antifungal activity with minimal concentration against different pathogenic fungi.

Morphogenesis: a focus on marine invertebrates

Morphogenesis is a process describing how the shapes of living tissues and bodies are created during development. Livingand fossil organisms exhibit enormously diverse tissue architecture and body forms, although the functions of organs areevolutionally conserved. Current knowledge reveals that relatively conserved mechanisms are applied to control developmentamong different species. However, the regulations of morphogenesis are quite diverse in detail. Animals in the oceandisplay a wide range of diversity of morphology suitable for their seawater environment. Nevertheless, compared with theintensive studies on terrestrial animals, research on marine animal morphogenesis is still insufficient. The increasing genomicdata and the recently available gene editing methods, together with the fast development of imaging techniques, quantitativeanalyses and biophysical models, provide us the opportunities to have a deeper understanding of the principles that drivethe diverse morphogenetic processes in marine animals. In this review, we summarize the recent studies of morphogenesisand evolution at molecular, cellular and tissue levels, with a focus on three model marine animals, namely ascidians, seaurchins and sea anemones.