Tachypleus Tridentatus Research Articles

Cyclic Analogues of Horseshoe Crab Peptide Tachyplesin I with Anticancer and Cell Penetrating Properties.

Tachyplesin-I (TI) is a host defense peptide from the horseshoe crab Tachypleus tridentatus that has outstanding potential as an anticancer therapeutic lead. Backbone cyclized TI (cTI) has similar anticancer properties to TI but has higher stability and lower hemolytic activity. We designed and synthesized cTI analogues to further improve anticancer potential and investigated structure-activity relationships based on peptide-membrane interactions, cellular uptake, and anticancer activity. The membrane-binding affinity and cytotoxic activity of cTI were found to be highly dependent on peptide hydrophobicity and charge. We describe two analogues with increased selectivity toward melanoma cells and one analogue with the ability to enter cells with high efficacy and low toxicity. Overall, the structure-activity relationship study shows that cTI can be developed as a membrane-active antimelanoma lead, or be employed as a cell penetrating peptide scaffold that can target and enter cells without damaging their integrity.

Nests placements and spawning in the endangered horseshoe crab Tachypleus tridentatus (Leach, 1819) (Merostomata: Xiphosurida: Limulidae) in Sabah, Malaysia

Abstract Horseshoe crab populations are declining worldwide, and Tachypleus tridentatus (Leach, 1819) has recently been classified as Endangered in the IUCN Redlist. Among the keys for species survival is successful reproduction. Although there are reports on the reproduction, particularly details on the spawning behaviour, of the American species, Limulus polyphemus (Linnaeus, 1758), information on Southeast Asia species is very scant. This field study reports the nesting activities of T. tridentatus at Jambongan Island, Sabah, Malaysia. Observation were carried out on 16 spawning pairs that were spotted during full and new moon from April-July 2016 in Sabah. Nest placements, number of nests, number of eggs, time spent at each nest, and nest widths, depth, and distance from the highest tide line were recorded for each pair. Tachypleus tridentatus generally laid an average of 967 ± 54.1 eggs/nest (171–2,282) in as many as nine nests on the intertidal zone between 125 and 940 cm from the highest tide. The first nest was dug once the tide began rising, followed by the consecutive nests towards the highest tide line with nest depths ranging between 13 and 22 cm. The complete spawning session (first nest to the last) ended in less than two hours. Time spent in spawning correlates positively with the number of nests and the total number of eggs laid by each spawning female. The spawning area, which is made up mainly by fine and medium-size sediment grains, also experience stable temperature, salinity, and dissolved oxygen conducive for egg-laying and larval development for successful reproduction. The details of spawning are important for planning successful future conservation initiatives for the species, especially in tropical regions.

Effects of copper supplement on the immune function and blood-chemistry in adult Chinese horseshoe crab Tachypleus tridentatus

Oxygen in hemocyanin binds to copper ions and turns the hemolymph of horseshoe crabs blue. Copper ions not only transport oxygen but also enhance the immune function of horseshoe crabs. A 28-day indoor culture experiment was conducted to study the effects of adding different levels of copper amino acid chelate (0, 50, or 100 mg kg−1) into semi-finished feed on the nonspecific immune enzyme activity and hemolymph biochemical parameters of Tachypleus tridentatus. Results revealed that the activities of serum antioxidant enzyme indicators, namely, copper–zinc superoxide dismutase (Cu/Zn-SOD), catalase (CAT), glutathione peroxidase (GPX), total antioxidant capacity (T-AOC), lysozyme (LZM), alkaline phosphatase (AKP), and acid phosphatase (ACP), of copper-fed adult horseshoe crabs increased; on the other hand, malondialdehyde (MDA) activity decreased. Hemolymph biochemical indicators, triglyceride (TG) and cholesterol (CHO) decreased in the copper-fed group, but hemocyanin concentration (HC) levels increased during the experiment. At the end of experiment, all antioxidant enzymes and blood biochemical indicators in the copper-fed group were significantly different from those without copper supplement. Hemolymph T-AOC, MDA, AKP, ACP values in the low-level copper group (50 mg kg−1) were significantly different from those in the high-level copper group (100 mg kg−1).

‘Delayed’ interference effects of air exposure on adult Chinese horseshoe crabTachypleus tridentatus

As the haemolymph supplier of the tachypleus amebocyte lysate industry in China, Chinese horseshoe crab (Tachypleus tridentatus) inevitably undergoes air-exposure stress during transportation and haemolymph collection. In this study, the effects of air-exposure stress and subsequent recovery process on the activities of phosphatases, antioxidant enzymes and haemocyanin concentration in Chinese horseshoe crab were investigated to understand its ability to resist air-exposure stress. Results showed no significant effects on the total antioxidant capacity (T-AOC), superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA) and alkaline phosphatase (AKP) between the control and experimental groups during the air-exposure stress period (0–4 hr), except acid phosphatase (ACP). During the subsequent recovery period in water, significant differences in plasma T-AOC levels and SOD, CAT, AKP and ACP activities were observed between both groups. No significant effects of CAT activity, SOD activity, MDA content and T-AOC level were noted between the two groups after 12 hr of recovery. However, the AKP and ACP activities of the experimental group were significantly lower than those of the control group. Results revealed that air exposure may affect the activities of most non-specific immune enzymes in the plasma of Chinese horseshoe crab, showing a ‘delayed” interference effect. Nevertheless, tested antioxidant enzymes have a strong recovery ability and can generally recover to the control group level after 12 hr. Haemocyanin concentration was not affected by air-exposure stress during the whole experiment. Hereby, Chinese horseshoe crab can strongly resist air-exposure stress.

How survival and food intake of tri-spine horseshoe crabs, Tachypleus tridentatus respond to thermal variation: implications for understanding its distribution limit

ABSTRACTTemperature appears to have pervasive effects on larval development, feeding and movement patterns of tri-spine horseshoe crabs, Tachypleus tridentatus. To investigate how temperature determines their geographic distribution range, we examined the survival rate (SR), survival time (ST) and food intake of subadult T. tridentatus under different temperature levels in a seven-day experiment, followed by a three-day recovery to room temperature at 25°C. Significantly lower SR and ST of subadults were found at 40°C after the end of the seven-day experiment. Meanwhile, SR and ST of individuals at 0°C were negatively affected when the temperature was brought back to 25°C. Mean food intake of the subadults was statistically lower at 0–20°C and 35–40°C compared to that at 25°C and 30°C. After the subsequent three-day recovery to 25°C, only the individuals previously exposed to 15°C and 20°C had recovered to their normal level of feeding activities, but not the other treatment groups. These findings may provide preliminary data on how thermal tolerance determines the present distribution of T. tridentatus, which are found in large numbers around Beibu Gulf (annual temperature variation: 22–30°C), while considerably lower population densities are observed in the colder southern Sea of Japan and warmer seas of Southeast Asia.

Socio‐demographic drivers and public perceptions of consumption and conservation of Asian horseshoe crabs in northern Beibu Gulf, China

Abstract Overharvesting Asian horseshoe crabs for food is a primary threat to their populations. In the present study, 451 residents were interviewed from the northern Beibu Gulf, the coastal area that is believed to accommodate the highest density of the Chinese horseshoe crab Tachypleus tridentatus worldwide, to obtain baseline information on their consumption behaviour and underlying drivers. Based on the survey data, it is estimated that a mean individual consumption rate of ten meals per year. Nearly half of the respondents (49.7%) claimed that they had previously eaten at least two horseshoe crab meals. Among the six occupation categories (managers, professionals, workers, environmental‐related workers, fishers and farmers, and students), fishers and farmers were identified as the group that had eaten a significantly higher number of horseshoe crab meals, had consumed them more frequently, and had a greater intention of eating them than that of students. The age, education level, and salary of participants were the important socio‐demographic variables related to their consumption behaviour. More than one‐third of respondents decided to consume horseshoe crabs because they perceived them as tasty ‘seafood’ and valuable ingredients of traditional Chinese medicine. Eighty‐three per cent of participants reported an overall decrease in the number of horseshoe crabs in the region. Although the community was supportive towards horseshoe crab conservation, their ecological knowledge of horseshoe crabs was limited. The findings may be useful for providing insights to merge the gap between scientific data and management planning for the horseshoe crab population in the region. Conservation management initiatives, such as the involvement of fishers in monitoring and enforcement, developing a reporting system for landings and by‐catch, and implementing long‐term conservation education through the school curriculum could promote the protection and management of the population.

Rhamnose Binding Protein as an Anti-Bacterial Agent-Targeting Biofilm of Pseudomonas aeruginosa.

More than 80% of infectious bacteria form biofilm, which is a bacterial cell community surrounded by secreted polysaccharides, proteins and glycolipids. Such bacterial superstructure increases resistance to antimicrobials and host defenses. Thus, to control these biofilm-forming pathogenic bacteria requires antimicrobial agents with novel mechanisms or properties. Pseudomonas aeruginosa, a Gram-negative opportunistic nosocomial pathogen, is a model strain to study biofilm development and correlation between biofilm formation and infection. In this study, a recombinant hemolymph plasma lectin (rHPLOE) cloned from Taiwanese Tachypleus tridentatus was expressed in an Escherichia coli system. This rHPLOE was shown to have the following properties: (1) Binding to P. aeruginosa PA14 biofilm through a unique molecular interaction with rhamnose-containing moieties on bacteria, leading to reduction of extracellular di-rhamnolipid (a biofilm regulator); (2) decreasing downstream quorum sensing factors, and inhibiting biofilm formation; (3) dispersing the mature biofilm of P. aeruginosa PA14 to improve the efficacies of antibiotics; (4) reducing P. aeruginosa PA14 cytotoxicity to human lung epithelial cells in vitro and (5) inhibiting P. aeruginosa PA14 infection of zebrafish embryos in vivo. Taken together, rHPLOE serves as an anti-biofilm agent with a novel mechanism of recognizing rhamnose moieties in lipopolysaccharides, di-rhamnolipid and structural polysaccharides (Psl) in biofilms. Thus rHPLOE links glycan-recognition to novel anti-biofilm strategies against pathogenic bacteria.

Classification and characterization of hemocytes from two Asian horseshoe crab species Tachypleus tridentatus and Carcinoscorpius rotundicauda

In present study, transmission electron microscopy and flow cytometry were utilized to investigate the classification, characterization and immune functions of hemocytes from horseshoe crab, Tachypleus tridentatus and Carcinoscorpius rotundicauda. Three types of hemocytes were distinguished respectively: the granular cell, the semi-granular cell and the hyaline cell by transmission electron microscopy, while three hemocyte subpopulations (Gate 1 cell, Gate 2 cell, Gate 3 cell) were classified by flow cytometry. Hyaline cell was the major cell type with the highest nuclear-cytoplasmic ratio and granular cell and semi-granular cell showed lower ratios. Immune parameters of hemocytes in horseshoe crabs were investigated by flow cytometry. Different hemocyte subpopulations respond for diverse functions. Lysosomal contents and hemocyte mortality in Gate 3 cell subpopulation were higher than that in other subpopulations, while reactive oxygen species, phagocytosis and non-specific esterase, in Gate 1 cell subpopulation, were higher than those in other subpopulations. The hemocyte types between the two species had no significant differences in staining or morphology.

The Ameliorating Effect of Plasma Protein from Tachypleus tridentatus on Cyclophosphamide-Induced Acute Kidney Injury in Mice.

In the study, the protective effect of plasma protein from Tachypleus tridentatus (PPTT) on acute kidney injury (AKI) and the related molecular mechanisms were first investigated by Western blotting analyses, TdT-mediated dUTP Nick-End Labeling (TUNEL) assay, and immunohistochemistry. It was found that PPTT had an obviously inhibitory effect on Reactive oxygen species (ROS) in cyclophosphamide (CTX)-exposed mice. Furthermore, results demonstrated that the renal cell death mode is due to inducing apoptosis and autophagy inhibited by dose-dependent PPTT in mice treated with CTX by decreasing the protein expression of bax, beclin-1, and LC3 and increasing the expression of bcl-2. Moreover, the p38 MAPK and PI3K/Akt signaling pathways were observed to take part in the PPTT-induced renal cell growth effect by enhancing the upregulation of the expression of Akt and p-Akt as well as the downregulation of the expression of p38 and p-p38, which indicated a PPTT ameliorating effect on AKI CTX-induced in mice through p38 MAPK and PI3K/Akt signaling pathways. Briefly, this article preliminarily studies the mechanism of the PPTT ameliorating effect on AKI CTX-induced in mice, which helps to provide a reference for PPTT clinical application in AKI therapy.

Draft genomic and transcriptome resources for marine chelicerate Tachypleus tridentatus

Chinese horseshoe crabs (Tachypleus tridentatus), ancient marine arthropods dating back to the mid-Palaeozoic Era, have provided valuable resources for the detection of bacterial or fungal contamination. However, excessive exploitation for the amoebocyte lysate of Tachypleus has dramatically decreased the population of the Chinese horseshoe crabs. Thus, we present sequencing, assembly and annotation of T. tridentatus, with the hope of understanding the genomic feature of the living fossil and assisting scientists with the protection of this endangered species. The final genome contained a total size of 1.943 Gb, covering 90.23% of the estimated genome size. The transcriptome of three larval stages was constructed to investigate the candidate gene involved in the larval development and validate annotation. The completeness of the genome and gene models was estimated by BUSCO, reaching 96.2% and 95.4%, respectively. The synonymous substitution distribution of paralogues revealed that T. tridentatus had undergone two rounds of whole-genome duplication. All genomic and transcriptome data have been deposited in public databases, ready to be used by researchers working on horseshoe crabs.

Rapid decline in the number of breeding pairs of Tachypleus tridentatus and the degradation of sandbanks for spawning due to cumulative bay mouth modifications at Tsuyazaki Cove, Fukuoka, Japan

Rapid decline in the number of breeding pairs of <i>Tachypleus tridentatus</i> and the degradation of sandbanks for spawning due to cumulative bay mouth modifications at Tsuyazaki Cove, Fukuoka, Japan

基于MAXENT模型评估北部湾潮间带中国鲎和圆尾鲎稚鲎的潜在地理分布及种群保育对策

PDF HTML阅读 XML下载 导出引用 引用提醒 基于MAXENT模型评估北部湾潮间带中国鲎和圆尾鲎稚鲎的潜在地理分布及种群保育对策 DOI: 10.5846/stxb201805161079 作者: 作者单位: 1水产科学国家级实验教学示范中心(上海海洋大学) 201306 2海洋生物科学国际联合研究中心(上海海洋大学)，中国科学技术部 201306 3上海水产养殖工程技术研究中心(上海海洋大学) 201306,广西壮族自治区水产科学研究院,天津市一瑞生物工程有限公司,上海海洋大学信息学院,1水产科学国家级实验教学示范中心(上海海洋大学) 201306 2海洋生物科学国际联合研究中心(上海海洋大学)，中国科学技术部 201306 3上海水产养殖工程技术研究中心(上海海洋大学) 201306,1水产科学国家级实验教学示范中心(上海海洋大学) 201306 2海洋生物科学国际联合研究中心(上海海洋大学)，中国科学技术部 201306 3上海水产养殖工程技术研究中心(上海海洋大学) 201306 作者简介: 通讯作者: 中图分类号: 基金项目: 香港海洋公园保育基金（OT03.1617）；2017北海市"十三五"海洋经济创新发展示范项目（Bhsfs006） Prediction of potential distribution areas of Chinese horseshoe crab and mangrove horseshoe crab in the Beibu Gulf of Guangxi based on MAXENT model and their population conservation strategies Author: Affiliation: National Demonstration Center for Experimental Fisheries Science Education,Shanghai Ocean University,Shanghai,,,,National Demonstration Center for Experimental Fisheries Science Education,Shanghai Ocean University,Shanghai,National Demonstration Center for Experimental Fisheries Science Education,Shanghai Ocean University,Shanghai Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:鲎具有极高的经济价值和科研意义。近年来由于过度捕捞和栖息地受损等原因，亚洲鲎种群数量正急剧下降。鲎漫长的生命周期使得鲎资源的保护和增殖迫在眉睫。生态位模型已经广泛应用于物种的潜在地理分布预测。基于实地调研数据和公开发表的北部湾中国海域中国鲎和圆尾鲎地理分布数据，运用MAXENT模型得到中国鲎和圆尾鲎在广西北部湾（中国部分）的栖息地适宜度指数（Habitat suitability index，HSI），确定了这两种稚鲎在北部湾中国海域潜在适生区。模型分析结果表明，潮间带坡度和地形指数是影响中国鲎分布的主要环境因子，而潮间带底质的有机物含量和植被指数是影响圆尾鲎分布的主要环境因子，根据研究结果建议在两种稚鲎适生区建立保护区，进行人工放流稚鲎，加强对海草和红树林的生态建设，进而促进鲎资源种群恢复和发展。 Abstract:Horseshoe crab has high economic and scientific values. In recent years, because of overfishing and habitat degradation, the population of horseshoe crabs in China is decreasing rapidly. However, their long life cycle makes it extremely urgent to protect horseshoe crabs. Ecological niche models have been widely applied to predict the potential geographic distribution of species. The habitat suitability index of the Chinese horseshoe crab Tachypleus tridentatus and mangrove horseshoe crab Carcinoscorpius rotundicauda in the Beibu Gulf (Chinese part) was determined by using the maximum entropy model and the distribution of habitat suitability of the two types of juvenile horseshoe crab in the Beibu Gulf was determined based on field survey data and published data on the geographical distribution of two horseshoe crab species in the Beibu Gulf. The model analysis results showed that the slope of the intertidal zone and topographic index were the main environmental factors affecting the distribution of the Chinese horseshoe crab, while the organic content and vegetation index of intertidal sediment were the main environmental factors affecting the distribution of the mangrove horseshoe crab. According to the results, to promote the recovery and development of horseshoe crab resources, protected areas should be established, artificial release of juvenile horseshoe crabs in habitat suitability areas of horseshoe crab should be conducted, and the ecological construction of seagrasses and mangroves in these areas should be strengthened. 参考文献 相似文献 引证文献

Postembryonic development of the Tri-spine Horseshoe Crab Tachypleus tridentatus (Merostomata: Xiphosura) in a nursery habitat in the Philippines

Populations of the Tri-spine Horseshoe Crab Tachypleus tridentatus have dramatically decreased over their distribution range and conservation efforts are now crucial. The implementation of appropriate management strategies and stock assessment rely on accurate growth-rate estimates. The postembryonic development of the species in the tropics, however, is not elucidated. To provide the information needed to assess the demographics of juvenile populations and to judge the status of T. tridentatus in the Philippines, we conducted a mark-recapture experiment in a nursery habitat on Palawan Island. The results obtained during the 10-month period provide the first consecutive data on the stepwise growth of the species in the Philippines and the first near comprehensive dataset collected within a single population of juveniles in the tropics. By analyzing size-frequency (prosomal width) distributions of 853 individuals and by using 94 juveniles that molted during the study, 13 molt stages were differentiated. Based on the intermolt periods of six instars, we estimated the growth curve of T. tridentatus following two models (non-linear and power function). The data support the assumption that growth continues year-round in the tropics and also indicate that the average age of mature male and female T. tridentatus in the Philippines ranges from three to four years. The agreement with a field study in Japan suggests that 14 postembryonic stages may be characteristic for the development of natural populations throughout the range of the species. Though more data are needed to validate these results, the study provides a sound baseline for future studies in the tropics.

A review on fisheries and conservation status of Asian horseshoe crabs

Horseshoe crabs are the only extant xiphosurans and are believed to be morphologically unchanged for more than 200 million years. Of the four extant species namely, Limulus polyphemus, Tachypleus tridentatus, Tapinauchenius gigas and Carcinoscorpius rotundicauda, the latter three are found in Asian waters. Recent evidences showed that Asian horseshoe crabs are facing serious threats such as degradation of their spawning grounds and habitat, environmental pollution, overexploitation as a culinary delicacy and biomedical bleeding practices. Baseline data on the distribution and existing population of the wild horseshoe crabs remain poorly known in several Asian regions. Several studies have clearly revealed that pressure due to over-fishing of wild stock has increased tremendously in the last decade. Due to an increase in demand for Tachypleus Amebocyte Lysate (TAL) analogous to Limulus Amebocyte Lysate (LAL) in the United States, there is an urgent need to comprehensively address their fishing and conservation measures in the Asian region. This review addresses the overall studies on three species of Asian horseshoe crabs in relation to their fishing practices, local exploitation of their wild stock either for human consumption (or) by biomedical industries. The authors have structured the discussion on an international scale to address the existing problems in fishing and conservation of horseshoe crabs. Since no specific regulatory force or legislative protection act or a policy to preserve their natural stock are available to this date, this paper strongly recommends representative countries to include horseshoe crabs under their wildlife protection act to avoid further unsustainable exploitation of their wild populations.

Tachypleus tridentatus Lectin Enhances Oncolytic Vaccinia Virus Replication to Suppress In Vivo Hepatocellular Carcinoma Growth.

Lectins play diverse roles in physiological processes as biological recognition molecules. In this report, a gene encoding Tachypleus tridentatus Lectin (TTL) was inserted into an oncolytic vaccinia virus (oncoVV) vector to form oncoVV-TTL, which showed significant antitumor activity in a hepatocellular carcinoma mouse model. Furthermore, TTL enhanced oncoVV replication through suppressing antiviral factors expression such as interferon-inducible protein 16 (IFI16), mitochondrial antiviral signaling protein (MAVS) and interferon-beta (IFN-β). Further investigations revealed that oncoVV-TTL replication was highly dependent on ERK activity. This study might provide insights into a novel way of the utilization of TTL in oncolytic viral therapies.

Fatty acids from controlled feeding as dietary markers of juvenile Chinese horseshoe crab, Tachypleus tridentatus

The potential use of fatty acid (FA) profile as a dietary tracer in juvenile Chinese horseshoe crab Tachypleus tridentatus was assessed in a feeding experiment. Selected feed was provided to the juveniles at various growth stages according to their food sources in the wild: larval and adult brine shrimp Artemia salina for the first six months, followed by a mixture of short-neck clam Ruditapes philippinarum and greasyback shrimp Metapenaeus ensis for a further six months. Juvenile horseshoe crab haemolymph and tissues of book gill, opisthosomal spine, chelicera and swimming leg were sampled after the feeding experiment. The FA profiles revealed that the juvenile haemolymph and various tissues had a total of 23–24 FA components. The major FA components consisted of saturated (palmitic and stearic) at 22–34%, monosaturated (oleic) at 7–34% and polyunsaturated (eicosapentaenoic and arachidonic) FAs at 9–27%. According to principal component analysis, the FA signatures of juvenile haemolymph were greatly influenced by the shift of food sources from brine shrimp to clam and shrimp meat, whereas the FA profiles of different tissues were more resistant to the nutrient alteration. The present findings confirmed that the FA profile of both juvenile haemolymph and different tissues reflected the FA composition of recent and previous diets, respectively; and thus may be useful in indicating the foraging information of juvenile horseshoe crabs in the field.

Horseshoe crabs as potential sentinel species for coastal health: juvenile haemolymph quality and relationship to habitat conditions

As an interface between terrestrial and marine environments, coastal and estuarine areas are particularly prone to various pollution stresses. Identification of sentinel species is, therefore, essential to provide precautionary information on coastal health conditions. Given their significant ecological roles in estuarine ecosystems, horseshoe crabs are a potential species to indicate the general health status of coastal habitats. The present study demonstrated that the changes in haemolymph composition pattern of two Asian juvenile horseshoe crab species (Tachypleus tridentatus and Carcinoscorpius rotundicauda) are sensitive to reflect heavy metal (lead, nickel and iron) and nutrient (nitrate and ammonia) concentrations of intertidal sediments. In particular, a significant negative correlation was found for the amebocyte viability and ratio of granular–spherical to granular–flattened and degranulated dendritic-like morphological states of amebocytes in juvenile haemolymph with nitrate and lead concentrations respectively. There were also significantly higher concentrations of haemolymph haemocyanin and plasma protein in juvenile C. rotundicauda than in T. tridentatus on the same shore, possibly being related to the difference in foraging habitats of these two horseshoe crab species. Such non-lethal sampling of haemolymph from juvenile horseshoe crabs can be useful for a further development of the monitoring program in assessing potential environmental impacts by anthropogenic activities.

The Establishment of the 3rd National Reference Standard for Tachypleus Tridentatus Lysate

&lt;p&gt;&lt;strong&gt;Objective&lt;/strong&gt; To establish the 3rd national reference standard for Tachypleus Tridentatus Lysate Reagent. &lt;strong&gt;Method&lt;/strong&gt; &lt;strong&gt;and Results&lt;/strong&gt; The candidates of reference standard were studied for the physical and chemical properties, and the stability. To determined its sensitivity by collaboration calibration. &lt;strong&gt;Conclusions&lt;/strong&gt; The sensitivity of the 3rd national reference standard for TAL is 0.06EU / ml, lot number is 150603-201003.&lt;/p&gt;

Comparative in vitro study on cytotoxicity of recombinant β-hairpin peptides.

Natural antimicrobial peptides (AMPs) are important components of the innate immune system with a wide spectrum of biological activity. In this study, we investigated the cytotoxic effect of three recombinant β-hairpin cationic AMPs: arenicin-1 from the polychaeta Arenicola marina, tachyplesin I from the horseshoe crab Tachypleus tridentatus, and gomesin from the spider Acanthoscurria gomesiana. All the three β-hairpin AMPs were overexpressed in Escherichia coli. Different cell lines were incubated with various concentrations of the investigated AMPs in order to evaluate their cytotoxic activity. Double staining with subsequent flow cytometric analysis was used to determine the predominant way of cell death mediated by each AMP. Hemolytic activity of the peptides was tested against fresh human red blood cells. Our results indicated that all the three AMPs exhibited significant cytotoxic effect against cancer cells that varied depending on the cell line type and, in most cases, on the presence of serum components. Flow cytometric analysis implicitly indicated that tachyplesin I mostly promoted late apoptosis/necrosis, while arenicin-1 and gomesin induced early apoptosis under the same conditions. Tachyplesin I proved to be the most promising therapeutic candidate as it displayed the highest specific cytotoxicity against cancer cell lines, independent of the serum presence.

Ancestral whole-genome duplication in the marine chelicerate horseshoe crabs.

This corrects the article DOI: 10.1038/hdy.2015.89.