Storage of Carotenoids in Crustaceans as an Adaptation to Modulate Immunopathology and Optimize Immunological and Life-History Strategies.

Why do some invertebrates store so much carotenoids in their tissues? Storage of carotenoids may not simply be passive and dependent on their environmental availability, as storage variation exists at various taxonomic scales, including among individuals within species. While the strong antioxidant and sometimes immune-stimulating properties of carotenoids may be beneficial enough to cause the evolution of features improving their assimilation and storage, they may also have fitness downsides explaining why massive carotenoid storage is not universal. Here, the functional and ecological implications of carotenoid storage for the evolution of invertebrate innate immune defenses are examined, especially in crustaceans, which massively store carotenoids for unclear reasons. Three testable hypotheses about the role of carotenoid storage in immunological (resistance and tolerance) and life-history strategies (with a focus on aging) are proposed, which may ultimately explain the storage of large amounts of these pigments in a context of host-pathogen interactions.

Identifying Potential Co-Sensitization and Cross-Reactivity Patterns Based on Component-Resolved Diagnosis.

BACKGROUND: Component-Resolved diagnosis (CRD) can help to establish immunoglobulin E (IgE) sensitization profiles and potential risks and determines whether specific IgE is the result of primary sensitization or cross-reactivity, especially for those who are polysensitized. METHODS: We recruited 432 patients with mite-sensitized respiratory allergic diseases to study the co-sensitization and cross-reactivity of the 17 allergen components in Guangdong Province, China, using the CRD method and to describe the potential association between allergen components. RESULTS: Among the 432 patients, serum specific immunoglobulin E of the 17 components were tested by EUROIMMUN system. Der p 1 (81.48%), Der f 2 (77.78%), Der f 1 (74.07%), Der p 2 (66.20%) and Der p 23 (54.63%) were the main sensitized components in patients with mite-sensitized respiratory allergy, while the components of cockroach, crab, and shrimp had a lower positive rate. In the crude extract allergen-positive samples, Der f 2 (91.06%) and Der f 1 (86.72%) were the major sensitized components of Der f, while Der p 1 (94.52%), Der p 2 (78.36%), Der p 23 (63.29%) were the major sensitized components of Der p, And other components of Der p such as Der p 7 (34.25%), Der p 5 (17.81%), Der p 10 (12.05%), Der p 3 (1.92%) were all below 50.00%. Blo t 5 (54.55%) was one of the major components of Blo t. The positive rates of all Bla g components were as follows, rBla g 2 (15.56%) >rBla g 5 (8.89%) >rBla g 4 (4.44%) >rBla g 1 (1.11%). The positive rate of the only available pen a 1 component was 9.43%. Using hierarchical cluster and optimal scale analysis, 17 components can be roughly divided into 5 different sensitization clusters. Also, from the results of the Venn diagram, the allergen component in each cluster has a high proportion of co-sensitization and cross-reactivity. Regardless of age, total IgE levels, and disease type factors, similar sensitization profiles were observed for each component in the same category based on hierarchical clustering analysis. CONCLUSIONS: Epidemiological data on allergen components causing allergic symptoms can be further understood using CRD. Der p 1, Der p 2, Der p 23, Der f 1, Der f 2 as the primary sensitizing component of the study cohort. The positive rate for Blo t 5 was 28.01% for all populations and 54.45% for Blo t-positive samples. In addition, CRD allows us to identify more potential allergen associations such as common sensitivities and cross-reactions between component proteins. Based on these results, we suggest that when patients are identified as sensitized to a particular allergen, clinicians can pay more attention to other allergy components that are closely related to it.

A barrier-to-autointegration factor promotes white spot syndrome virus infection in a crustacean Cherax quadricarinatus.

Barrier-to-autointegration factor (BAF) is a highly conserved DNA binding protein that participates in a variety of biological processes such as transcription, epigenetic regulation and antiviral immunity in vertebrates. However, the function of BAF is poorly understood in crustaceans. In this study, we identified a barrier-to-autointegration factor (CqBAF) from red claw crayfish Cherax quadricarinatus, which was responsive to white spot syndrome virus (WSSV) infection. The full-length cDNA sequence of CqBAF was 544 bp, including an open reading frame of 273 bp encoding 90 amino acids, a 107 bp of 5'-Untranslated Regions (5'-UTR) and a 164 bp of 3'-UTR. Gene expression analysis showed that CqBAF was distributed in all tissues examined with the highest expression in the crayfish haematopietic tissue (Hpt), which protein expression was also significantly up-regulated by WSSV infection in Hpt cells. Furthermore, the transcripts of both an immediate early gene IE1 and a late envelope protein gene VP28 of WSSV were clearly reduced in Hpt cells after gene silencing of CqBAF. Importantly, the promoter activity of two immediate early genes of WSSV, including WSV051 and IE1, was strongly enhanced by the increased phosphorylation of CqBAF, which also facilitated the accumulation of CqBAF protein in the cytoplasm of Sf9 cells. Taken together, these data suggest that CqBAF is likely to increase the replication of WSSV by promoting the transcription of viral immediate early genes, probably regulated by phosphorylation of CqBAF, which sheds new light on the molecular mechanism of WSSV infection.

Two C-type lectins (ReCTL-1, ReCTL-2) from Rimicaris exoculata display broad nonself recognition spectrum with novel carbohydrate binding specificity.

C-type lectins are Ca2+-dependent carbohydrate-binding proteins containing one or more carbohydrate-recognition domains (CRDs). C-type lectins play crucial roles in innate immunity, including nonself-recognition and pathogen elimination. In the present study, two C-type lectins (designated ReCTL-1 and ReCTL-2) were identified from the shrimp Rimicaris exoculata which dwells in deep-sea hydrothermal vents. The open reading frames of ReCTL-1 and ReCTL-2 encoded polypeptides of 171 and 166 amino acids respectively, which were both composed of a signal peptide and a single CRD. The key motifs determining the carbohydrate binding specificity of ReCTL-1 and ReCTL-2 were respectively Glu-Pro-Ala (EPA) and Gln-Pro-Asn (QPN), which were firstly discovered in R. exoculata. ReCTL-1 and ReCTL-2 displayed similar pathogen-associated molecular pattern (PAMP) binding features and they bound three PAMPs-ß-glucan, lipopolysaccharide and peptidoglycan-with relatively high affinity. In addition, both could efficiently recognize and bind Gram-positive bacteria, Gram-negative bacteria and fungi. However, ReCTL-1 and ReCTL-2 exhibited different microbial agglutination activities: ReCTL-1 agglutinated Staphylococcus aureus and Saccharomyces cerevisiae, while ReCTL-2 agglutinated Micrococcus luteus, Vibrio parahaemolyticus and V. fluvialis. Both ReCTL-1 and ReCTL-2 inhibited the growth of V. fluvialis. All these results illustrated that ReCTL-1 and ReCTL-2 could function as important pattern-recognition receptors with broad nonself-recognition spectra and be involved in immune defense against invaders, but their specificities are not the same. In addition, the two ReCTLs possessed different carbohydrate binding specificities from each other and from the classical pattern: ReCTL-1 with an EPA motif bound d-galactose and l-mannose, while ReCTL-2 with a QPN motif bound d-fucose and N-acetylglucosamine.

House Dust Mite-Shrimp Allergen Interrelationships.

PURPOSE OF REVIEW: Focusing on the strict relationship between house dust mites and crustaceans from the allergenic point of view. RECENT FINDINGS: The well-known tropomyosin was considered for years as the cross-reacting allergen between shrimp and house dust mites. In the last few years, several allergens not only in shrimps but also in house dust mite have been identified and other molecules other than tropomyosin have been shown to cross-react between crustaceans and mites. The present review investigates the very complex allergen sources in shrimp and mites, giving a satisfactorily complete picture of the interrelationships between common allergens. Several minor HDM allergens are homologous to major and minor shrimp allergens; tropomyosin is not the only cross-reactive allergen between shrimp and mites.

Effects of environmental stress on shrimp innate immunity and white spot syndrome virus infection.

The shrimp aquaculture industry is plagued by disease. Due to the lack of deep understanding of the relationship between innate immune mechanism and environmental adaptation mechanism, it is difficult to prevent and control the diseases of shrimp. The shrimp innate immune system has received much recent attention, and the functions of the humoral immune response and the cellular immune response have been preliminarily characterized. The role of environmental stress in shrimp disease has also been investigated recently, attempting to clarify the interactions among the innate immune response, the environmental stress response, and disease. Both the innate immune response and the environmental stress response have a complex relationship with shrimp diseases. Although these systems are important safeguards, allowing shrimp to adapt to adverse environments and resist infection, some pathogens, such as white spot syndrome virus, hijack these host systems. As shrimp lack an adaptive immune system, immunization therapy cannot be used to prevent and control shrimp disease. However, shrimp diseases can be controlled using ecological techniques. These techniques, which are based on the innate immune response and the environmental stress response, significantly reduce the impact of shrimp diseases. The object of this review is to summarize the recent research on shrimp environmental adaptation mechanisms, innate immune response mechanisms, and the relationship between these systems. We also suggest some directions for future research.

Effects of different dietary protein sources on the immunological and physiological responses of marron, Cherax cainii (Austin and Ryan, 2002) and its susceptibility to high temperature exposure.

A two phased feeding trial was conducted to evaluate the effects of alternative protein sources on the immunophysiological responses of marron. During the phase I, marron were fed with five alternative protein supplemented diets for 90 days, while in phase II, the same marron were exposed to elevated temperature (30 °C) and their immunophysiological responses were investigated post exposure. Five isoproteic (crude protein 30%) and isoenergetic diets were prepared by containing fishmeal, poultry by-product meal, feather meal, lupin meal, and meat and bone meal as the main protein source. A hundred and fifty juvenile marron (Cherax cainii) of the average weight 9.09 ±â€¯0.21 g were randomly distributed into 15 tanks (three replicates per feeding treatments). In the Phase I, general immune response parameters, such as, total haemocyte count (THC), proportion of hyaline cells, neutral red retention time (NRRT), phagocytic rate (PR), heamolymph bacteraemia, and condition indices of marron were investigated. The highest (P < 0.05) THC among dietary protein sources was obtained in marron fed with PbM at the end of experiment. Marron fed with FeM protein sources resulted in the highest survival rate followed by PbM fed group. Longer microvilli length (3.83 ±â€¯0.18 µm) was demonstrated in marron fed with PbM diet. Diets containing FM and PbM protein sources revealed significantly (P < 0.05) lower number of microvilli/group than diets containing FeM and LM. The results demonstrated that different dietary protein sources in the marron diets did not detect significant (P > 0.05) change of the condition indices throughout the experiment period, however highest Hiw and Hid was recorded in marron fed with PBM at day 45. The PR of marron fed dietary protein from PbM did not change significantly after temperature exposure. Increased NRRT, PR and haemolymph bacteraemia was observed with dietary feeding of FM at the end of the trial. However, results revealed that PbM could be an alternative protein source for culture of marron as reflected in terms of increased THC, longer microvillus length and improved susceptibility to high temperature exposure. Overall, result could serve as useful baseline data in developing cost effective potential diets for marron aquaculture.

Bursicon homodimers induce innate immune by activating the expression of anti-microbial peptide genes in the shrimp Neocaridina heteropoda.

Bursicon is a neurohormone belonging to the cystine knot protein family. It consists of two subunits (burs α and burs ß) and plays a pivotal role in cuticle tanning and wing expansion in insects. Recent studies show that homologous crustacean bursicon stimulates cuticle thickening and granulation of hemocytes in the crab Callinectes sapidus. Here we investigate whether bursicon homodimers function in immunoprotective defense systems of shrimp. We found that abdominal ganglion was the main neurohemal release site of bursicon in Neocaridina heteropoda. Bacterial infections induced overexpression of burs α (bursicon α) and burs ß (bursicon ß). RNAi of burs α, burs ß or both inhibited the expression of anti-microbial peptide (AMP) genes. Treating shrimp adults with r-bursicon (recombinant bursicon) homodimers led to up-regulation of three AMP genes. Besides, through the induced AMPs, r-bursicon homodimers enhanced the bacteriostasis of shrimp in vivo and in vitro. These findings demonstrate a novel function of bursicon in crustacean that it induces innate immune via up-regulating the expression of genes encoding AMPs.

Identification and characterization of a symbiotic agglutination-related C-type lectin from the hydrothermal vent shrimp Rimicaris exoculata.

Rimicaris exoculata (Decapoda: Bresiliidae) is one of the dominant species of hydrothermal vent communities, which inside its gill chamber harbors ectosymbioses with taxonomic invariability while compositional flexibility. Several studies have revealed that the establishment of symbiosis can be initiated and selected by innate immunity-related pattern recognition receptors (PRRs), such as C-type lectins (CTLs). In this research, a CTL was identified in R. exoculata (termed RCTL), which showed high expression at both mRNA and protein levels in the scaphognathite, an organ where the ectosymbionts are attached outside its setae. Linear correlationships were observed between the relative quantities of two major symbionts and the expression of RCTL based on analyzing different shrimp individuals. The recombinant protein of RCTL could recognize and agglutinate the cultivable γ-proteobacterium of Escherichia coli in a Ca2+-dependent manner, obeying a dose-dependent and time-cumulative pattern. Unlike conventional crustacean CTLs, the involvement of RCTL could not affect the bacterial growth, which is a key issue for the successful establishment of symbiosis. These results implied that RCTL might play a critical role in symbiotic recognition and attachment to R. exoculata. It also provides insights to understand how R. exoculata adapted to such a chemosynthesis-based environment.

Improved diagnostic clarity in shrimp allergic non-dust-mite sensitized patients.

BACKGROUND: Allergen specific immunoglobulin E (sIgE) levels predictive of shrimp allergy have not been identified, but these may be helpful in identifying patients at risk for shrimp-induced allergic reactions. OBJECTIVE: This study sought to identify component resolved diagnostic tests useful for diagnosis of shrimp allergy in patients with or without house-dust mite (HDM) sensitization to the major allergen cysteine protease (Der p 1). METHODS: Patients with positive skin-prick test (SPT) results and/or sIgE values were recruited. Shrimp allergy was classified by oral food challenge (OFC) or by a clear history of anaphylaxis after shrimp ingestion. Patients with shrimp allergy and patients who were tolerant were further classified based on HDM sensitivity (Der p 1 > 0.35 kUA/L). Testing for sIgE to total shrimp, and shrimp and HDM components was performed. The Fisher exact test, Wilcoxon sum rank test, and receiver operating characteristics analyses were used to compare sIgE levels in patients with allergy and patients who were tolerant. RESULTS: Of 79 patients recruited, 12 patients with shrimp allergy (7 with positive OFC results and 5 with a history of anaphylaxis) and 18 patients who were shrimp tolerant were enrolled. Of the patients not HDM sensitized, sIgE levels to shrimp (10.5 kUA/L, p = 0.012) and Der p 10 (4.09 kUA/L, p = 0.035) were higher in patients with shrimp allergy. Shrimp sIgE of ≥3.55 kUA/L had 100% diagnostic sensitivity and 85.7% specificity (receiver operating characteristic 0.94 [0.81, 1.0] 95% CI) and Der p 10 sIgE levels of ≥3.98 kUA/L had a diagnostic sensitivity of 80% and specificity of 100% (receiver operating characteristic 0.86 [0.57, 1.0] 95% CI) for prediction of clinical reactivity. CONCLUSION: HDM sensitization influences shrimp and HDM component sIgE levels and, consequently, their diagnostic accuracy in shrimp allergy. In our series, in the patients who were non-HDM sensitized, a shrimp sIgE level of >3.55 kUA/L showed 100% sensitivity and, Der p 10 sIgE of >3.98 kUA/L showed 100% specificity for the diagnosis of shrimp allergy. These levels may not be applicable to every patient and, therefore, may not obviate the need for OFC.

Recent progress toward the identification of anti-viral immune mechanisms in decapod crustaceans.

The sustainable intensification of crustacean aquaculture, which is dominated by the farming of penaeid shrimp species, continues to be beset by viral disease outbreaks. Despite this, reports exist of differential susceptibility to viral infection between different shrimp species and populations, and between shrimp and other decapod crustaceans. These reports have, in part, provided the motivation to identify key mechanisms of antiviral resistance, or refractivity, in commercially-important species. Within the last decade these studies have created significant advances in our understanding of host virus interactions in decapod models. However, at the same time, the complexity of host virus interactions has presented significant challenges for interpretation of anti-viral immune responses. In this short review, recent progress in our understanding of the complexity of host virus interactions are considered, and challenges to the unequivocal identification of anti-viral immunity are highlighted. Special consideration is given to the advances in understanding being created by the use of RNA interference approaches. Based on the 'state of the art', it is concluded that the identification of effective intervention strategies for application at farm scale currently presents an unrealistic target for the aquaculture industry. Future technical developments necessary to support continued progress are also considered.

Immune status of the spiny lobster Jasus edwardsii with tail fan necrosis.

Tail fan necrosis (TFN), a disorder commonly found in some populations of commercially fished and cultured lobsters, is thought to be initiated by injuries caused by handling and containment. The unsightly appearance of affected lobster tails significantly lowers their commercial value. Knowledge about TFN is limited. In this study we describe the morphological features of TFN and apply 6 common methods for evaluating the immune status of wild-caught Australasian red spiny lobsters Jasus edwardsii with and without TFN. The disease was more frequent in uropods than in telsons of the tail fan, and more extensive on the ventral versus the dorsal surfaces of the tail fan. Missing appendages (i.e. antenna, pereiopod or pleopod) were significantly more common and greater in number for individual lobsters affected with TFN versus those without, possibly as a result of handling in the fishery or as an indirect effect of the disease. Two immune parameters, total haemocyte count and phenoloxidase activity in the haemocyte lysate supernatant (HLS), were significantly compromised in lobsters with TFN. No differences were found in the other immune parameters, i.e. haemocyte viability, haemolymph bacterial count and the protein content of haemolymph plasma and HLS. The results are consistent with injury sustained during prior capture and handling that initiates TFN in these natural caught lobsters. These results raise some potential concerns about the fitness of lobsters in natural populations that are affected by TFN, and some potential solutions are proposed.

WSSV-induced crayfish Dscam shows durable immune behavior.

One of the major gaps in our understanding of arthropod specific immune priming concerns the mechanism[s] by which the observed long-term (>2 weeks) protective effects might be mediated. Hypervariable Dscam (Down syndrome cell adhesion molecule) might support arthropod innate immunity with specificity for more extended periods. We show here that, in the relatively long-lived arthropod Cherax quadricarinatus, CqDscam does not behave like a typical, immediately-acting, short-lived innate immune factor: CqDscam was not induced within hours after challenge with a lethal virus, but instead was only up-regulated after 2-5 days. This initial response faded within ∼ 2 weeks, but another maximum was reached ∼ 1 month later. At around 2 months after the initial challenge, the virus-induced CqDscam bound to the virus virion and acted to neutralize the virus However, although CqDscam helped crayfish to survive during persistent infection, it nevertheless failed to provide any enhanced protection against a subsequent WSSV challenge. Thus, CqDscam is capable of supporting extended anti-virus immune memory in arthropods. Also, during a persistent virus infection, the balance of "immune firepower" in crayfish appears to be altered such that the general immune factors become depleted while CqDscam becomes relatively predominant.

The application of bacterial indicator phylotypes to predict shrimp health status.

The incidence of shrimp disease is closely associated with the microbial composition in surrounding water, but it remains uncertain whether microbial indicator phylotypes are predictive for shrimp health status (healthy or diseased). To test this idea, we combined the data from our previous works, to investigate the feasibility of indicator phylotypes as independent variables to predict the health status during a shrimp culture procedure. The results showed linearly increased dissimilarities (P<0.001) of the bacterioplankton community over time, while the communities dramatically deviated from this defined trend when disease occurred. This sudden shift in the bacterial community appears to cause severe mass mortality of the shrimps. In particular, we created a model to identify indicators that discriminated ponds with diseased shrimp populations from these with healthy shrimp populations. As a result, 13 indicative families were screened, in which seven are healthy indicator and six are diseased indictor. An improved logistic regression model additionally revealed that the occurrences of these indicator families could be predictive of the shrimp health status with a high degree of accuracy (>79 %). Overall, this study provides solid evidences that indicator phylotypes could be served as independent variables for predicting the incidences of shrimp disease.

Stress biology and immunology in Nephrops norvegicus.

The Norway lobster Nephrops norvegicus lives at low-light depths, in muddy substrata of high organic content where water salinities are high and fluctuations in temperature are moderate. In this environment, the lobsters are naturally exposed to a number of potential stressors, many of them as a result of the surficial breakdown of organic material in the sediment. This process (early diagenesis) creates a heterogeneous environment with temporal and spatial fluctuations in a number of compounds such as oxygen, ammonia, metals, and hydrogen sulphide. In addition to this, there are anthropogenically generated stressors, such as human-induced climate change (resulting in elevated temperature and ocean acidification), pollution and fishing. The lobsters are thus exposed to several stressors, which are strongly linked to the habitat in which the animals live. Here, the capacity of Nephrops to deal with these stressors is summarised. Eutrophication-induced hypoxia and subsequent metal remobilisation from the sediment is a well-documented effect found in some wild Nephrops populations. Compared to many other crustacean species, Nephrops is well adapted to tolerate periods of hypoxia, but prolonged or severe hypoxia, beyond their tolerance level, is common in some areas. When the oxygen concentration in the environment decreases, the bioavailability of redox-sensitive metals such as manganese increases. Manganese is an essential metal, which, taken up in excess, has a toxic effect on several internal systems such as chemosensitivity, nerve transmission and immune defence. Since sediment contains high concentrations of metals in comparison to sea water, lobsters may accumulate both essential and non-essential metals. Different metals have different target tissues, though the hepatopancreas, in general, accumulates high concentrations of most metals. The future scenario of increasing anthropogenic influences on Nephrops habitats may have adverse effects on the fitness of the animals.

Occupational allergy to aquarium fish food: red midge larva, freshwater shrimp, and earthworm. A clinical and immunological study.

BACKGROUND: Chironomids seem to be the main cause of occupational allergy to aquarium fish food. OBJECTIVE: The aim of this study was to investigate the pattern of occupational sensitization to 3 different arthropod species used as components of aquarium fish food. METHODS: The study sample comprised 8 workers from a fish food packing department. The control group comprised 40 atopic patients (20 of whom were allergic to mites). We performed prick tests with extracts of red midge larva (Chironomus thummi), freshwater shrimp (Gammarus species), earthworm (Tubifex species), and other arthropod species and a battery of common inhalant allergens. We measured peak expiratory flow rate (PEFR) and specific immunoglobulin (Ig) E and performed a methacholine challenge test, nasal challenge test, and immunoblotting. Cross-reactivity analyses were completed using immunoblotting and CAP inhibition. RESULTS: Prick test results were positive to red midge larvae in 7 patients (87.5%), Gammarus in 5 (62.5%), Tubifex in 3 (37.5%), and mites in 6 (75%). In the mite-allergic controls, 30% had positive prick test results to red midge larvae. PEFR decreased > or = 20% during the packing process in all patients, and in 1 patient it indicated a dual asthmatic response. Methacholine challenge test results were positive in all participants. Nasal challenge tests were performed in 4 patients, and the results were positive. Specific IgE to red midge larvae was detected in 62.5%, Gammarus in 50%, and Tubifex in 16%. Bands of approximately 14-15 kDa and 31 kDa were observed in Gammarus and red midge larvae extracts. Cross-reactivity assays demonstrated that Gammarus totally inhibited red midge larvae, while Tubifex did so partially. Dermatophagoides pteronyssinus showed very low inhibitory capacity. CONCLUSIONS: Aquarium fish food arthropods are potent allergens with an elevated prevalence of sensitization and variable degree of crossreactivity. This is the first report of occupational allergy to Tubifex. More data are necessary to identify and characterize the responsible allergens.

The scope of the crustacean immune system for disease control.

The culture or wild capture of marine and freshwater shellfish, including crustaceans, is without doubt a key source of protein for a burgeoning world population. Historically the expansion of aquaculture has, however, been accompanied by the increased incidence of economically significant diseases, most notably of viral and bacterial origin. Since the late 1970s great progress has been made in our understanding of the generalized protostome innate immune system. Distinct pathways, pathogen receptor proteins and effector molecules have since been identified that are not ancestral or homologous to those of the deuterostomes, including vertebrates. Within the past decade progress has accelerated with the rapid characterisation of new classes of recognition proteins, immune effectors and regulatory pathways. This paper provides a broad overview of our current understanding of invertebrate immunology, taking the crustacean decapod immune system as its focus. Recent developments in the field are described briefly and their implications and potential considered. These advances offer fundamental new insights in our efforts to understand disease in cultured populations and also to develop knowledge of environmental effects on host/pathogen interactions within a fishery context. Of course, challenges do remain, including the lack of an immortal cell line and the limited publically-available genomic resources. These are considered in this review as priorities for future research effort. With the continued application of more insightful technologies, coupled with associated investment, it is expected that the speed at which some of these issues are resolved will accelerate.

Transgenic expression of tilapia hepcidin 1-5 and shrimp chelonianin in zebrafish and their resistance to bacterial pathogens.

Recently, tilapia hepcidin (TH)1-5 was characterized, and its antimicrobial functions against several pathogens were reported. The antimicrobial functions of another shrimp antimicrobial peptide (AMP), chelonianin, were also characterized using a recombinant chelonianin protein (rcf) that was expressed by a stably transfected Chinese hamster ovary (CHO) cell line against pathogen infections in fish. The function of the overexpression of both AMPs in zebrafish muscles was not examined in previous studies. Herein, we investigated the antimicrobial functions of TH1-5 and chelonianin against Vibrio vulnificus (204) and Streptococcus agalactiae (SA48) in transgenic TH1-5 zebrafish and transgenic chelonianin zebrafish. The presence of TH1-5 and chelonianin enhanced the inhibitory ability in transgenic AMP zebrafish against the two different bacterial infections. The bacterial number of either V. vulnificus (204) or S. agalactiae (SA48) had decreased at 96 h after injection into transgenic AMP zebrafish muscle compared to non-transgenic zebrafish muscle. Additionally, immune-related gene expressions analyzed by real-time PCR studies showed the modulation of several genes including interleukin (IL)-10, IL-22, IL-26, MyD88, Toll-like receptor (TLR)-1, TLR-3, TLR-4, nuclear factor (NF)-κB, tumor necrosis factor (TNF)-α, and lysozyme, and significant differences were found between transgenic AMP zebrafish and wild-type zebrafish injected with PBS at 1-24 h. These results suggest that several immune-related gene expressions were induced in transgenic TH1-5 and chelonianin zebrafish which effectively inhibited bacterial growth. The survival rate dropped to 86.6% in transgenic chelonianin zebrafish after 28 days of infection compared of the 50% survival rate in transgenic TH1-5 zebrafish after 28 days of infection. Overall, these results indicate that TH1-5 and chelonianin possess the potential to be novel candidate genes for aquaculture applications to treat fish diseases.

Differential immune responses of the green neon shrimp (Neocaridina denticulate) to dipropyl phthalate.

This study set out to understand the sublethal effect of xenobiotic phthalate esters (PAEs) on the relationship between the susceptibility of shrimp to bacterial infection and the immune response of the shrimp. Neocaridina denticulate were exposed to different concentrations of the PAE dipropyl phthalate (DPrP), and mortality and six immune parameters were measured on days 1, 3, 5, and 10 after exposure. On days 1 and 3 after exposure, shrimp exposed to 0, 1, 5, 10, and 50 mg/L of DPrP and challenged with Aeromonas veronii experienced 14% and 16%, 16% and 16%, 18% and 18%, 34% and 24%, and 38% and 26% mortality, respectively. On day 1, five immune parameters (acid phosphatase, AcP; ß-glucuronidase, ß-Glu; phenoloxidase, PO; superoxide dismutase, SOD; and haemocyanin mRNA) were significantly altered in the all of the groups treated with DPrP compared to the untreated shrimp and were elevated in the 10 mg/L- and 50 mg/L-treated groups. Beta-Glu activity and haemocyanin mRNA levels were significantly increased in a dose-dependent manner. These results suggest that the increased susceptibility of N. denticulate exposed to DPrP is short-term and may be related to the increased expression of DPrP-induced immune mediators.