Dynamic changes and importance of plasma concentrations of ether phospholipids, of which the majority are plasmalogens, in postpartum Holstein dairy cows.

CONTEXT: Ethanolamine plasmalogens (EPls) and choline plasmalogens (CPls) are classes of ethanolamine ether phospholipids (ePE) and choline ether phospholipids (ePC), respectively. EPls play crucial roles in maternal and breastfed infant bodies and stimulate gonadotropin secretion by gonadotrophs. AIMS: To estimate changes in and importance of plasma concentrations of EPls and CPls, utilising newly developed enzymatic fluorometric assays for ePE and ePC in postpartum Holstein cows. METHODS: Plasma samples were collected from 3weeks before expected parturition until approximately 8weeks after parturition (16 primiparous and 38 multiparous cows) for analysis. KEY RESULTS: Plasma concentrations of ePE and ePC, most of which are plasmalogens, declined before and increased after parturition and stabilised near the day of the first postpartum ovulation (1stOV). From weeks 2 to 3 after parturition, third-parity cows exhibited ePE concentrations that were higher than those of other parity cows. The days from parturition to 1stOV correlated with days from parturition to conception. On the day of 1stOV, milk yield correlated with plasma concentration of both ePE and ePC, while ePC concentration correlated negatively with milk fat percentage. At the early luteal phase after 1stOV, plasma ePE concentration correlated with plasma anti-Müllerian hormone concentration (r =0.39, P <0.01), and plasma ePC concentration correlated with plasma follicle-stimulating hormone concentration (r =0.43, P <0.01). CONCLUSION: The concentrations of ePE and ePC changed dramatically around parturition and 1stOV, and the concentrations correlated with important parameters for milk production and reproduction. IMPLICATIONS: The blood plasmalogen may play important roles in postpartum dairy cows.

Metagenomic profile of caudal fin morphology of farmed red sea bream Pagrus major.

The morphology of farm-reared fish often differs from that of their wild counterparts, impacting their market value. Two caudal fin tip shapes, acutely angled and blunted, are recognized in farmed populations of red sea bream Pagrus major. The angled form is preferred by consumers over the blunt since it resembles that of wild fish. Discovering the cause of the blunted tip is crucial to maximizing the commercial value of farmed red sea bream. We hypothesized that the blunt fin tip is the result of opportunistic bacteria and conducted partial 16S rRNA metagenomic barcoding and generated a clone library of the 16S rRNA gene to compare bacterial communities of the 2 fin forms. Metagenomic barcoding revealed an abundance of 5 bacterial genera, Sulfitobacter, Vibrio, Tenacibaculum, Psychrobacter, and an unknown genus of Rhodobacteraceae, on the caudal fin surface. Sulfitobacter was significantly more common on the angled caudal fin than the blunted. Vibrio is the dominant genus on the blunted caudal fin. The clone library identified these genera to species level, and Sulfitobacter sp., Vibrio harveyi, Tenacibaculum maritimum, and Psychrobacter marincola were frequently observed in blunt caudal fins. Our results suggest that opportunistic pathogenic bacteria such as V. harveyi and T. maritimum are not the primary cause of caudal fin malformation, and multiple factors such as combinations of injury, stress, and pathogenic infection may be involved. The reason for the significantly greater occurrence of Sulfitobacter sp. in the angled caudal fin is unknown, and further investigation is needed.

Heavy oil exposure suppresses antiviral activities in Japanese flounder Paralichthys olivaceus infected with viral hemorrhagic septicemia virus (VHSV).

A combined treatment of heavy oil (HO) exposure and virus infection induces increased mortality in Japanese flounder (Paralichthys olivaceus). In this study, we addressed how HO exposure affects the immune system, especially antiviral activities, in Japanese flounder. The fish were infected with viral hemorrhagic septicemia virus (VHSV), followed by exposure to HO. We analyzed virus titers in the heart and mRNA expression in the kidney of surviving fish. The virus titers in fish exposed to heavy oil were higher than the threshold for onset. The results suggest that HO exposure may allow the replication of VHSV, leading to higher mortality in the co-treated group. Gene-expression profiling demonstrated that the expression of antiviral-activity-related genes, such as those for interferon and apoptosis induction, were lower in the co-treated group than in the group with VHSV infection only. These results helped explain the high virus titers in fish treated with both stressors. Thus, interferon production in the virus-infected cells and apoptosis induction by natural killer cells worked normally in the VHSV-infected fish without HO exposure, but these antiviral activities were slightly suppressed by HO exposure, possibly leading to extensive viral replication in the host cells and the occurrence of VHS.

Innate immunity in the edible ascidian Halocynthia roretzi developing soft tunic syndrome: Hemolymph can eliminate the causative flagellates and discriminate allogeneic hemocytes.

The infection of the kinetoplastid flagellate Azumiobodo hoyamushi causes soft tunic syndrome that often results in mass mortality in the aquaculture of the edible ascidian Halocynthia roretzi. In the diseased ascidian individuals, the flagellates are exclusively found in the tunic matrix that entirely cover the epidermis, and never invade into internal tissues, such as a mantle. The present study for the first time demonstrated that the ascidian blood plasma and hemolymph have an activity to agglutinate and disintegrate the flagellates, suggesting the innate immunity protects the internal tissue from the invasion of A. hoyamushi. This activity is indifferent between the healthy and the diseased individuals. Allo-specific recognition and cytotoxic reaction among ascidian hemocytes, so-called contact reaction, occur among the individuals of healthy-healthy, healthy-diseased, and diseased-diseased combination, and therefore, the hemocytes from diseased individuals still retain the allo-reactivity. Moreover, the allo-reactive combinations are not changed under the presence of the flagellates, indicating the flagellates neither suppress nor induce the effector system of the contact reaction. These results suggest that the infection of A. hoyamushi does not impair the innate immunity in the ascidian hemolymph.

Sulfur(VI) Fluoride Exchange (SuFEx)-Enabled High-Throughput Medicinal Chemistry.

Optimization of small-molecule probes or drugs is a synthetically lengthy, challenging, and resource-intensive process. Lack of automation and reliance on skilled medicinal chemists is cumbersome in both academic and industrial settings. Here, we demonstrate a high-throughput hit-to-lead process based on the biocompatible sulfur(VI) fluoride exchange (SuFEx) click chemistry. A high-throughput screening hit benzyl (cyanomethyl)carbamate (Ki = 8 µM) against a bacterial cysteine protease SpeB was modified with a SuFExable iminosulfur oxydifluoride [RN═S(O)F2] motif, rapidly diversified into 460 analogs in overnight reactions, and the products were directly screened to yield drug-like inhibitors with 480-fold higher potency (Ki = 18 nM). We showed that the improved molecule is active in a bacteria-host coculture. Since this SuFEx linkage reaction succeeds on picomole scale for direct screening, we anticipate our methodology can accelerate the development of robust biological probes and drug candidates.

Aryl Hydrocarbon Receptor Signaling Is Functional in Immune Cells of Rainbow Trout (Oncorhynchus mykiss).

The arylhydrocarbon receptor (AhR) is an important signaling pathway in the immune system of mammals. In addition to its physiological functions, the receptor mediates the immunotoxic actions of a diverse range of environmental contaminants that bind to and activate the AhR, including planar halogenated aromatic hydrocarbons (PHAHs or dioxin-like compounds) and polynuclear aromatic hydrocarbons (PAHs). AhR-binding xenobiotics are immunotoxic not only to mammals but to teleost fish as well. To date, however, it is unknown if the AhR pathway is active in the immune system of fish and thus may act as molecular initiating event in the immunotoxicity of AhR-binding xenobiotics to fish. The present study aims to examine the presence of functional AhR signaling in immune cells of rainbow trout (Oncorhynchus mykiss). Focus is given to the toxicologically relevant AhR2 clade. By means of RT-qPCR and in situ hybdridization, we show that immune cells of rainbow trout express ahr 2α and ahr 2ß mRNA; this applies for immune cells isolated from the head kidney and from the peripheral blood. Furthermore, we show that in vivo as well as in vitro exposure to the AhR ligand, benzo(a)pyrene (BaP), causes upregulation of the AhR-regulated gene, cytochrome p4501a, in rainbow trout immune cells, and that this induction is inhibited by co-treatment with an AhR antagonist. Taken together, these findings provide evidence that functional AhR signaling exists in the immune cells of the teleost species, rainbow trout.

Self-Assembly of Amphiphilic Amylose Derivatives in Aqueous Media.

Six amylose derivative (C12CMA) samples with hydrophobic dodecyl ether groups and hydrophilic sodium carboxymethyl groups were synthesized from an enzymatically synthesized amylose for which the weight-average molar mass is 50 kg mol-1 to realize amylose-based amphiphilic polymer micelles. The degree of substitution of hydrophobic (DSC12) and hydrophilic (DSCM) groups ranges between 0.076 and 0.39 and between 0.35 and 1.83, respectively. Static and dynamic light scattering, small-angle X-ray scattering (SAXS), and fluorescence measurements with pyrene as a probe were carried out for the samples in 150 mM aqueous NaCl to characterize the higher-order structure in solution. The fluorescence from pyrene showed that all six samples have hydrophobic environment, while the hydrophobicity tends to increase with rising DSC12. All six samples have high scattering intensity owing to the relatively large concentrated droplets ranging in the hydrodynamic radius from 50 to 110 nm, whereas the weight fraction of such large particles is substantially small except for the highest DSC12 sample. Most polymer chains for relatively low DSC12 of 0.076 were molecularly dispersed with a very small amount of large droplets. The dispersed chain has a slightly smaller helix pitch per residue and a more rigid main chain than those for amylose in dimethyl sulfoxide, suggesting that the amylosic main chain of C12CMA has a helical structure with dodecyl groups at least locally. On the other hand, an anisotropic shaped micelle-like structure is only found for relatively high DSC12 (0.23 and 0.39) samples, which was detected by the SAXS profile at a high scattering vector range. The micelle structure for high DSC12 samples is consistent with the high chain stiffness.

A novel intracellular dextranase derived from Paenibacillus sp. 598K with an ability to degrade cycloisomaltooligosaccharides.

Paenibacillus sp. 598K produces cycloisomaltooligosaccharides (CIs) in culture from dextran and starch. CIs are cyclic oligosaccharides consisting of seven or more α-(1 → 6)-linked-D-glucose residues. The extracellular enzyme CI glucanotransferase (PsCITase), which is the member of glycoside hydrolase family 66, catalyzes the final stage of CI production and produces mainly cycloisomaltoheptaose. We have discovered a novel intracellular CI-degrading dextranase (PsDEX598) from Paenibacillus sp. 598K. The 69.7-kDa recombinant PsDEX598 does not digest isomaltotetraose or shorter isomaltooligosaccharides, but digests longer ones of at least up to isomaltoheptaose. It also digests oligoCIs of cycloisomaltoheptaose, cycloisomaltooctaose, and cycloisomaltononaose better than it does with megaloCIs of cycloisomaltodecaose, cycloisomaltoundecaose, and cycloisomaltododecaose, as well as an α-(1 → 6)-D-glucan of dextran 40. PsDEX598 is produced intracellularly when culture medium is supplemented with cycloisomaltoheptaose or dextran, but not with isomaltooligosaccharides (a mixture of isomaltose, isomaltotriose, and panose), starch, or glucose. The whole genomic DNA sequence of the strain 598K implies that it harbors two genes for enzymes belonging to glycoside hydrolase family 66 (PsCITase and PsDEX598), and PsDEX598 is the only dextranase in the strain. PsDEX598 does not have any carbohydrate-binding modules (CBMs) and has a low similarity (< 30%) with other family 66 dextranases, and the catalytic amino acids of this enzyme are predicted to be Asp191, Asp303, and Glu368. The strain Paenibacillus sp. 598K appears to take up CI-7, so these findings indicate that this bacterium can degrade CIs using a dextranase within the cells and so utilize them as a carbon source for growth.

Reducing the undesirable odor of barley by cooking with superheated steam.

Superheated steam was used to cook barley and the volatile odor compounds and release of odorants from the steamed barley were analyzed. The main odor compounds in cooked barley were aldehydes (hexanal and (E,E)-2,4-decadienal) and acids (acetic acid and hexanoic acid). Compared to ordinary cooked barley, barley cooked by superheated steam had less odorants, and the release of odorants was reduced by almost half. Sensory evaluation revealed that this barley was preferred to ordinary cooked barley, because it had weaker smell and tasted less sour and less bitter. The steaming process steam distils and eliminates some odor compounds, while some water-soluble compounds (mainly acids) are washed away by water during steaming. Therefore, this steam cooking method, applied to barley for the first time here using a comprehensive analysis, improves the acceptability and palatability of this high-quality food rich in dietary fiber.

Molecular cloning, characterization and expression analysis of complement components in red sea bream (Pagrus major) after Edwardsiella tarda and red sea bream Iridovirus (RSIV) challenge.

The complement system plays an important role in immune regulation and acts as the first line of defense against any pathogenic attack. To comprehend the red sea bream (Pagrus major) immune response, three complement genes, namely, pmC1r, pmMASP and pmC3, belonging to the classical, lectin and alternative complement cascade, respectively, were identified and characterized. pmC1r, pmMASP, and pmC3 were comprised of 2535, 3352, and 5735 base mRNA which encodes 732, 1029 and 1677 aa putative proteins, respectively. Phylogenetically, all the three studied genes clustered with their corresponding homologous clade. Tissue distribution and cellular localization data demonstrated a very high prevalence of all the three genes in the liver. Both bacterial and viral infection resulted in significant transcriptional alterations in all three genes in the liver with respect to their vehicle control counterparts. Specifically, bacterial challenge affected the pmMASP and pmC3 expression, while the viral infection resulted in pmC1r and pmC3 mRNA activation. Altogether, our data demonstrate the ability of pmC1r, pmMASP and pmC3 in bringing about an immune response against any pathogenic encroachment, and thus activating, not only one, but all the three complement pathways, in red sea bream.

Measurement of Tunic Hardness in an Edible Ascidian, Halocynthia roretzi, with Remarks on Soft Tunic Syndrome.

The infection caused by a kinetoplastid flagellate, Azumiobodo hoyamushi, in an ascidian, Halocynthia roretzi, results in softening of the tunic, and finally death. This disease is usually recognized using palpation of the softening tunic, and A. hoyamushi infection is detectable using microscopy or PCR amplification of specific gene fragments. The present study is the first quantitative evaluation of the symptoms of soft tunic syndrome by measuring the amount of bending (bending) and the peak force required to pierce the tunic (force). There was a strong correlation between bending and force. Correlation analyses among other parameters (ascidian total weight, tunic thickness, and tunic water content) indicated that larger ascidians had harder and thicker tunics with a higher water content. As compared to the tunic of healthy individuals, softened tunic was thinner and had lower water content. Infected tunics thus possibly lose water and become softer and thinner. Mechanisms for maintaining the appropriate water level content may be crucial for preventing tunic softening.

Tunic extract of the host ascidian attracts the causal agent of soft tunic syndrome, Azumiobodo hoyamushi (Kinetoplastea: Neobodonida).

Azumiobodo hoyamushi, a kinetoplastid flagellate, is the causative agent of soft tunic syndrome, an infectious disease of the edible ascidian Halocynthia roretzi. The flagellate is thought to invade the tunic matrix via a damaged area of the tunic on the siphon wall. We hypothesized that the flagellate locates the tunic entry site by a chemotactic response to soluble substances diffused from the host ascidians. To investigate this hypothesis, we examined whether the flagellate shows a chemotactic response to tissue extracts (tunic and other tissues) from the host ascidian H. roretzi. We tested extracts from 5 tissues as well as hemolymph. Only the tunic extract showed significant positive chemotactic activity, and the activity decreased with increasing dilution. Furthermore, autoclaved tunic extract, extracts from diseased individuals, and extract from the styelid ascidian Styela clava also had chemotactic activity, although the activities were lower than that of tunic extract from healthy H. roretzi. Ultrafiltration of the tunic extract through a 3 kDa cutoff membrane completely abrogated the activity; the ultrafiltration retentate still showed activity. Thus, the soluble factors that attract the flagellate are present exclusively in the tunic extract, and the chemotactic factors are larger than 3 kDa. Our experiments also suggested that the tunic extract contains both heat-stable and heat-labile factors. We conclude that the flagellate locates the tunic entry site by chemotaxis toward soluble factors that diffuse from a damaged area of the tunic on the siphon wall.

Fucosyltransferases produce N-glycans containing core l-galactose.

l-Galactose (l-Gal) containing N-glycans and cell wall polysaccharides have been detected in the l-Fuc deficient mur1 mutant of Arabidopsis thaliana. The l-Gal residue is thought to be transferred from GDP-l-Gal, which is a structurally related analog of GDP-l-Fuc, but in vitrol-galactosylation activity has never been detected. In this study, we carried out preparative scale GDP-l-Gal synthesis using recombinant A. thaliana GDP-mannose-3',5'-epimerase. We also demonstrated the l-galactosylation assay of mouse α1,6-fucosyltransferase (MmFUT8) and A. thaliana α1,3-fucosyltransferase (AtFucTA). Both fucosyltransferases showed l-galactosylation activity from GDP-l-Gal to asparagine-linked N-acetyl-ß-d-glucosamine of asialo-agalacto-bi-antennary N-glycan instead of l-fucosylation. In addition, the apparent Km values of MmFUT8 and AtFucTA suggest that l-Fuc was preferentially transferred to N-glycan compared with l-Gal by fucosyltransferases. Our results clearly demonstrate that MmFUT8 and AtFucTA transfer l-Gal residues from GDP-l-Gal and synthesize l-Gal containing N-glycan in vitro.

Molecular engineering of cycloisomaltooligosaccharide glucanotransferase from Bacillus circulans T-3040: structural determinants for the reaction product size and reactivity.

Cycloisomaltooligosaccharide glucanotransferase (CITase) is a member of glycoside hydrolase family 66 and it produces cycloisomaltooligosaccharides (CIs). Small CIs (CI-7-9) and large CIs (CI-≥10) are designated as oligosaccharide-type CIs (oligo-CIs) and megalosaccharide-type CIs (megalo-CIs) respectively. CITase from Bacillus circulans T-3040 (BcCITase) produces mainly CI-8 with little megalo-CIs. It has two family 35 carbohydrate-binding modules (BcCBM35-1 and BcCBM35-2). BcCBM35-1 is inserted in a catalytic domain of BcCITase and BcCBM35-2 is located at the C-terminal region. Our previous studies suggested that BcCBM35-1 has two substrate-binding sites (B-1 and B-2) [Suzuki et al. (2014) J. Biol. Chem. 289, 12040-12051]. We implemented site-directed mutagenesis of BcCITase to explore the preference for product size on the basis of the 3D structure of BcCITase. Mutational studies provided evidence that B-1 and B-2 contribute to recruiting substrate and maintaining product size respectively. A mutant (mutant-R) with four mutations (F268V, D469Y, A513V and Y515S) produced three times as much megalo-CIs (CI-10-12) and 1.5 times as much total CIs (CI-7-12) as compared with the wild-type (WT) BcCITase. The 3D structure of the substrate-enzyme complex of mutant-R suggested that the modified product size specificity was attributable to the construction of novel substrate-binding sites in the B-2 site of BcCBM35-1 and reactivity was improved by mutation on subsite -3 on the catalytic domain.

Structural elucidation of the cyclization mechanism of α-1,6-glucan by Bacillus circulans T-3040 cycloisomaltooligosaccharide glucanotransferase.

Bacillus circulans T-3040 cycloisomaltooligosaccharide glucanotransferase belongs to the glycoside hydrolase family 66 and catalyzes an intramolecular transglucosylation reaction that produces cycloisomaltooligosaccharides from dextran. The crystal structure of the core fragment from Ser-39 to Met-738 of B. circulans T-3040 cycloisomaltooligosaccharide glucanotransferase, devoid of its N-terminal signal peptide and C-terminal nonconserved regions, was determined. The structural model contained one catalytic (ß/α)8-barrel domain and three ß-domains. Domain N with an immunoglobulin-like ß-sandwich fold was attached to the N terminus; domain C with a Greek key ß-sandwich fold was located at the C terminus, and a carbohydrate-binding module family 35 (CBM35) ß-jellyroll domain B was inserted between the 7th ß-strand and the 7th α-helix of the catalytic domain A. The structures of the inactive catalytic nucleophile mutant enzyme complexed with isomaltohexaose, isomaltoheptaose, isomaltooctaose, and cycloisomaltooctaose revealed that the ligands bound in the catalytic cleft and the sugar-binding site of CBM35. Of these, isomaltooctaose bound in the catalytic site extended to the second sugar-binding site of CBM35, which acted as subsite -8, representing the enzyme·substrate complex when the enzyme produces cycloisomaltooctaose. The isomaltoheptaose and cycloisomaltooctaose bound in the catalytic cleft with a circular structure around Met-310, representing the enzyme·product complex. These structures collectively indicated that CBM35 functions in determining the size of the product, causing the predominant production of cycloisomaltooctaose by the enzyme. The canonical sugar-binding site of CBM35 bound the mid-part of isomaltooligosaccharides, indicating that the original function involved substrate binding required for efficient catalysis.

Encystment and excystment of kinetoplastid Azumiobodo hoyamushi, causal agent of soft tunic syndrome in ascidian aquaculture.

Soft tunic syndrome in the edible ascidian Halocynthia roretzi is caused by the kinetoplastid flagellate Azumiobodo hoyamushi, which was found to assume a fusiform cell form with 2 flagella in axenic, pure culture. When the flagellate form was incubated in sterilized artificial seawater (pH 8.4), some of the cells became cyst-like and adhered to the bottom of the culture plate. The cyst-like forms were spherical or cuboidal, and each had 2 flagella encapsulated in its cytoplasm. Encystment was also induced in culture medium alkalified to the pH of seawater (8.4) but not in unmodified (pH 7.2) or acidified media (pH 6.4). More than 95% of the cyst-like cells converted to the flagellate form within 1 d following transfer to seawater containing ascidian tunic extracts from host ascidians. The cyst-like cells were able to survive in seawater with no added nutrients for up to 2 wk at 20°C and for a few months at 5 to 15°C. The survival period in seawater depended on temperature: some cyst-like cells survived 3 mo at 10°C, and ca. 95% of these converted to flagellate forms in seawater containing tunic extracts. Thus, A. hoyamushi is able to persist under adverse conditions in a cyst-like form able to adhere to organic and inorganic substrata for protracted periods of time.

Cellulose is not degraded in the tunic of the edible ascidian Halocynthia roretzi contracting soft tunic syndrome.

Soft tunic syndrome is a fatal disease in the edible ascidian Halocynthia roretzi, causing serious damage to ascidian aquaculture in Korea and Japan. In diseased individuals, the tunic, an integumentary extracellular matrix of ascidians, softens and eventually tears. This is an infectious disease caused by the kinetoplastid flagellate Azumiobodo hoyamushi. However, the mechanism of tunic softening remains unknown. Because cellulose fibrils are the main component of the tunic, we compared the contents and structures of cellulose in healthy and diseased tunics by means of biochemical quantification and X-ray diffractometry. Unexpectedly, the cellulose contents and structures of cellulose microfibrils were almost the same regardless of the presence or absence of the disease. Therefore, it is unlikely that thinning of the microfibrils occurred in the softened tunic, because digestion should have resulted in decreases in crystallinity index and crystallite size. Moreover, cellulase was not detected in pure cultures of A. hoyamushi in biochemical and expressed sequence tag analyses. These results indicate that cellulose degradation does not occur in the softened tunic.

Host responses of Japanese flounder Paralichthys olivaceus with lymphocystis cell formation.

Lymphocystis disease virus (LCDV) is the causative agent of lymphocystis disease (LCD). In this study, we investigated the mechanisms of lymphocystis cell (LCC) formation from the viewpoint of gene expression changes in the infected fish. LCC occurrence and virus titers in the experimentally infected Japanese flounder, Paralichthys olivaceus were monitored by visual confirmation and real-time PCR, respectively. The gene expression changes in the fish fin were investigated by microarray experiments. LCCs firstly appeared in the fish at 21 days post infection (dpi). LCD incidence increased with time and reached 92.9% at 62 dpi. LCDV genome was firstly detected from dorsal fins at 14 dpi, and the relative amount of the genome gradually-increased until 56 dpi. Since the occurrence of LCC was approximately synchronized with increasing of the virus genome, virus replication might play important roles for LCC formation. The microarray detected a few gene expression changes until 28 dpi. However, the number of expression changed genes dramatically increased between 28 and 42 dpi in which LCCs formation was active. From the microarray data analyses, apoptosis and cell division related genes were down-regulated, whereas cell fusion and collagen related genes were up-regulated at 42 dpi. Together with the observation of morphological changes of LCCs in previous reports, it is suggested that the following steps are involved in LCC formation: the virus infected cells were (1) inhibited apoptotic death and (2) cell division before enlargement, (3) hypertrophied by cell fusion, and (4) surrounded by a hyaline capsule associated with the alteration of collagen fibers.

Azumiobodo hoyamushi, the kinetoplastid causing soft tunic syndrome in ascidians, may invade through the siphon wall.

The infectious kinetoplastid Azumiobodo hoyamushi causes 'soft tunic syndrome', a serious problem in aquaculture of the edible ascidian Halocynthia roretzi. Infection tests using diseased tunics demonstrated that juvenile (0.8 yr old) individuals never developed soft tunic syndrome, but all individuals in the other age groups (1.8, 2.8, and 3.8 yr old) showed the disease symptoms. In the infection tests, tunic softening was first observed at the tunic around siphons. Based on ultrastructural observation of the inner wall of the branchial siphon, the tunic lining the inner wall in juveniles (0.5 yr old) was completely covered with cuticle, which had a dense structure to prevent bacterial and protist invasion. In contrast, the tunic was often partly damaged and not covered with cuticle in healthy adults (≥2.5 yr old). The damaged tunic in the siphon wall could be an entrance for A. hoyamushi into the tunic of adult hosts.

Fucoidan from brown seaweed Tubinaria decurrens: Structure and structure - anticancer activity relationship.

The aims of this study are to determine the structure of a fucoidan from brown seaweed Turbinaria decurrens, to investigate its anticancer activity and structure-activity relationship. SEC-MALLS, IR, ESI-MS and NMR spectra analysis indicated that dominant structure of the fucoidan, with a Mw 122.6 KDa, has a backbone of (1 â†’ 3)- and (1 â†’ 4)-α-L-Fucp residues, branched at C-4, sulfate groups are attached at C-2, C-3 and C-4; branches are (1 â†’ 4)-ß-D-Galp residues and sulfated at C-2. The fucoidan was hydrolyzed by HCl aqueous solution to obtain hydrolyzed fucoidans. It is assumed that native and hydrolyzed fucoidans have a rod-like conformation in solution with cross-sectional radius of gyration (Rgc) ranged from 0.53 to 1.52 nm as estimated from SAXS measurements. The fucoidans show great anticancer activity against HT29 human colon cancer cell line with IC50 ranging from 5.41 ± 0.36 to 73.52 ± 2.54 µg/mL. Anticancer activity of the fucoidan could be significantly improved by lowering molecular weight, furthermore, fucoidan required small molecular weight, small molecular weight distribution and rod-like structure with a short branch length for high anticancer activity.