Anadara Granosa Research Articles

Distribution and Abundance of Blood Shells (Anadara granosa) on the Coast of Concong Luar Village Indragiri Hilir Regency

This study was conducted in September 2021, around the coastal of Concong luar village Indragiri Hilir Regency with the aim to find out the abundance, distribution, and morphometrics of blood shell (Anadara granosa). The method used survey methods, in which blood shell sampling and aquatic substrates, as well as measurements of environmental parameters, were conducted in the field and in the laboratory. Determination of sampling location by purposive sampling is based on the character of the environment in the location of the research. Based on the results of research that has been obtained an abundance value at the station 1 = 4,8 Ind/m2, station 2 = 8,7 Ind/m2, and station 3 = 3 Ind/m2. The pattern of blood shell levy in the waters of Concong Luar Village stations 1 and 2 is clustered, while station 3 is evenly distributed. Furthermore, the results of measurement of the width of the highest blood shells are 16 - 30 mm in 70 individuals, followed by size >31 mm of 43 individuals, the lowest measurement result is <15 mm in 27 individuals, and the highest measurement of the length of the blood shells 16 – 30 mm of 77 ind, followed by a size >31 mm of 42 ind, and the lowest measurement result is <15 mm of 29 ind.

Prediction and characterization of a novel hemoglobin-derived mutant peptide (mTgHbP7) from Tegillarca granosa

The hemoglobin (Hb) is identified in Tegillarca granosa and its derived peptides have been proved to possess antibacterial activity against gram-positive and gram-negative bacteria. In this study, we identified a series of novel antimicrobial peptides (AMPs) and artificially mutated AMPs derived from subunits of T. granosa Hbs, among which, a mutant T. granosa hemoglobin peptide (mTgHbP) mTgHbP7, was proved to possess predominant antibacterial activity against three bacteria strains (Vibrio alginolyticus, V. parahaemolyticus and Escherichia coli). Besides, mTgHbP7 was predicted to form α-helical structure, which was known to be an important feature of bactericidal AMPs. Furthermore, upon contact with HEK293 cell line, we confirmed that mTgHbP7 had no cytotoxicity to mammalian cell even at a high concentration of 160 μM. Therefore, the findings reported here provide a rationalization for antimicrobial peptide prediction and optimization from mollusk hemoglobin, which will be useful for future development of antimicrobial agents.

Investigation of the Concentration of some Metals in Blood Cockle (Senilia senilis) and Oyster (Crassostrea gasar) from Bonny Estuary and Assessment of the Human Health Risk Associated with their Consumption

There is a growing concerns over the health risk of consuming seafood contaminated with poisonous metals from human activities. This study examined the concentration and human health risk of Pb, Cd, Cr, Ni, Co, Zn, V and Hg associated with the consumption of blood cockle (Senilia senilis) and oyster (Crassostrea gasar) from Bonny Estuary, Rivers state Nigeria by analyzing the levels of the selected metals using Atomic Absorption Spectrometer Model A 200 AA. Data were used to calculate the non-carcinogenic health risk using Daily Intake Rate (DIR) Target Hazard Quotient (THQ) and Hazard Index (HI). The results showed variations in the concentration of the different heavy metals in the two shellfish. The trend of the metal concentrations in decreasing order was: Crassostrea gasar > Senilia senilis. Levels of metals in Senilia senilis, were all below the WHO and FAO permissible limit for fish. Also, all metals except Pb were below the WHO maximum permissible limit in Crassostrea gasar. The DIR (9.4684E-06 - 0.00281); THQ (8.286E-07 – 1.842E-04) and HI (2.519E-05 -2.595E-04) for all metals were below one indicating no risk for non-carcinogenic effects individually and collectively. The shell fish analyzed from the Bonny Estuary are free from potential human health hazards from heavy metals. However, continuous monitoring of levels of metals in fish from the estuary is recommended.

Characterization of a novel activating protein-1 (AP-1) gene and the association of its single nucleotide polymorphisms with vibrio resistance in Tegillarca granosa

The blood clam Tegillarca granosa is a commercial marine bivalve of economic value, accounting for approximately 50% of clam production in China. In recent years, the yield of blood clams has been threatened by bacterial infections caused by marine Vibrio species that thrive under a rising sea temperature. The transcription factor activating protein-1 (AP-1) is emerging as an important player in the innate immunity of marine bivalves against viral or bacterial infections. In this study, the full-length cDNA of a novel T. granosa AP-1 (TgAP-1) was cloned for the first time. The 1591-bp cDNA encoded a protein of 292 amino acid residues with a calculated molecular weight of 32.8 kDa. The TgAP-1 protein contained an N-terminal Jun domain and a C-terminal basic region leucine zipper domain typically found in Jun proteins (a subfamily of AP-1 proteins). TgAP-1 was ubiquitously expressed in T. granosa, with the highest expression detected in the gill and foot, followed by the mantle, hemolymph, and hepatopancreas. Exposure to Vibrio harveyi induced TgAP-1 expression in gill tissues and the expression levels of TgAP-1 of resistant blood clams were always lower than that of control population whether Vibro infection or not. A total of 18 single nucleotide polymorphisms (SNPs) of TgAP-1 were detected in T. granosa. SNP-typing and haplotyping of resistant and susceptible populations revealed that six SNPs (AG type of TgSNP-1, GA type of TgSNP-2, TG type of TgSNP-4, CT type of TgSNP-7, AG type of TgSNP-11, and GA type of TgSNP-12) and four haplotypes (fHap2, fHap3, fHap6, and fHap7) were significantly associated with V. harveyi resistance. Risk assessment showed that fHap2 (CG) and fHap7 (GA) were associated with an increased resistance, while fHap3 (CT) and fHap6 (AG) were associated with an increased susceptibility. The results from this study supported a potential role of TgAp-1 in the anti-Vibro immunity of T. granosa. The discovery of the genetic molecular markers and haplotypes related to Vibrio resistance can provide guidance for selective breeding of T. granosa in the future.

Optimization of Slow Sand Filtration for the Raw Municipal Wastewater Treatment by Using the Blood Cockle (<i>Anadara granosa</i>) Shell as an Alternative Filter Media through the Response Surface Methodology

Optimization of Slow Sand Filtration for the Raw Municipal Wastewater Treatment by Using the Blood Cockle (<i>Anadara granosa</i>) Shell as an Alternative Filter Media through the Response Surface Methodology

Calcium Carbonate of Blood Cockle (Anadara granosa) Shells induced VEGF-A Expression in Dentin Pulp Complex An In Vivo Study

Introduction: Mild or moderate-intensity injury will respond with a brief inflammatory response followed by reactionary dentinogenesis. Calcium hydroxide has been considered the gold standard for pulp capping materials for decades to stimulate the formation of tertiary dentin. Blood clamshells (Anadara granosa) contained a high content of calcium carbonate (CaCO3) in the blood clamshells. It is a source of calcium and it has good biocompatibility to be used as a bone repair material. This study is aimed to reveal the expression VEGF-A in odontoblast pulp cells on days 1, 3, and 7 after administration of blood clam shells derived calcium carbonate in dentin pulp complex. Methods: Thirty Wistar rats (Rattus norvegicus) were divided into 6 groups consist of 5 random samples each. The experimental group’s cavity was prepared on the occlusal side of the right upper molar, and they were treated with blood clamshell calcium carbonate suspension and sealed with RMGIC. For decalcification, the solution was replaced with ethylene-diamine tetra acetic acid (EDTA) after 24 hours and was refreshed every day. Anti-VEGF-A monoclonal antibodies were used for HE and immunohistochemical staining. Result: In this study, the results were obtained consecutively on the 1st, 3rd, and 7th day with p> 0.05 for VEGF-A in all groups. Conclusion: The application of calcium carbonate is expected to be an innovative treatment in opening up new pathways for the regenerative dentin process through upregulation of VEGF-A

Hypoxia-mediated immunotoxicity in the blood clam Tegillarca granosa

In marine ecosystems, dissolved oxygen (DO) is essential for maintaining intracellular energy balance during aerobic metabolism. Bivalve mollusks are frequently exposed to hypoxia environments due to tides, temperature changes, and anthropogenic activities. The blood clam, Tegillarca granosa, mainly inhabits intertidal mudflats and is more susceptible to low oxygen events. In this study, we investigated the effect of hypoxia on immune responses in clams, and showed that hypoxia exposure reduced total hemocyte counts (THC), hemoglobin concentrations, and intracellular reactive oxygen species (ROS) levels. Also, phagocytic and cell activities of hemocyte were significantly inhibited. Furthermore, immune-related gene expression was also down-regulated. In conclusion, hypoxia greatly affected immune functions in blood clams, and our research provided the foundation for further mechanistic studies on hypoxia tolerance in clams.

Identification, characterization, and antimicrobial activity of a novel big defensin discovered in a commercial bivalve mollusc, Tegillarca granosa

Molluscs, the second largest animal phylum on earth, primarily rely on cellular and humoral immune responses to fight against pathogen infection. Although antimicrobial peptides (AMPs) such as big defensin play crucial roles in the humoral immune response, it remains largely unknown in the ecological and economic important blood clam (Tegillarca granosa). In this study, a novel big defensin gene (TgBD) was identified in T. granosa through transcripts and whole genome searching. Bioinformatic analyses were conducted to explore the molecular characteristics of TgBD, and comparisons of TgBD with those reported in other molluscs were performed by multiple alignments and phylogenetic analysis. In addition, the expression patterns of TgBD in various tissues and upon bacterial challenge were investigated while the antimicrobial activity of synthetic N-terminal domain of TgBD was confirmed in vitro by radial diffusion experiment. Results obtained showed TgBD had an open reading frame (ORF) of 369 bp, encoding a prepropeptide containing a signal peptide and a propeptide. Similar to big defensins reported in other species, TgBD consists of a hydrophobic N-terminal domain containing β1-α1-α2-β2 folds and a cysteine-rich cationic C-terminal domain with three disulfide bonds between C1–C5, C2–C4, and C3–C6. Phylogenetic analysis showed that TgBD shared 76.80% similarity to its close relative ark shell (Scapharca broughtoni). In addition, TgBD expression was observed in all tissues investigated under normal conditions and was significantly induced by injection of Vibrio parahaemolyticus. Furthermore, synthetic N-terminal peptide of TgBD exhibited strong antimicrobial activity against Gram-positive bacteria tested. Our results indicated that TgBD is a constitutive and inducible acute phase AMP, which provides a universal and prompt protection for T. granosa.

Diversity of Bivalvia in Estuarine of Suramadu Bridge of Surabaya

The coast of the Suramadu Bridge is one of the important areas that has function as a route for transportation, recreation, as well as a protected area. However, the data of aquatic biota is rarely studied. One of them is bivalves. This research was conducted in February 2021 with the aim to analyze the diversity of bivalves in the Suramadu Coast. Observations and sampling were carried out in 3 transects 5 x 5 m based on different habitats. Five species of bivalves (Mimachlamys sanguinea, Anadara rhomboidalis, Tegillarca granosa, Barbatia trapezina, and Atrina pectinata) from three families (Pectinidae, Arcidae, and Pinnidae) were identified. The results of the community index show the individual distribution pattern and community stability in the medium category, there is a dominant species (Anadara rhomboidalis) but without significant differences in the number of individuals. This shows that the bivalves community is in a state of stress. A. rhomboidalis has the greatest role in the stability of the community, which can be seen from the value of the Important Value Index and the total volume of the shell. Recently, there are only two species that can be used sustainably, namely T. granosa and A. rhomboidalis.

Kontribusi mata pencaharian alternatif terhadap pendapatan rumah tangga nelayan: Studi kasus di Kelurahan Bagan Hulu, Kecamatan Bangko, Kabupaten Rokan Hilir, Indonesia

This study aimed to determine the types of alternative livelihoods carried out by fishermen and analyze the contribution of alternative livelihoods to the total income of fishermen in Bagan Hulu Village. The method used in this study was a survey method. The population in this study was 28 fishermen who have alternative livelihoods, and respondents were taken from the entire population carried out by census. The data collected is primary and secondary data through direct interviews, questionnaires then analyzed descriptively. The types of alternative livelihoods carried out by fishermen in Bagan Hulu Village, Bangko District, Rokan Hilir Regency were blood cockle aquaculture (Anadara granosa), motorcycle repair shops, shrimp paste makers, farmers, laborers/artisans, salted fish managers, and pond security. Alternative work carried out by fisherman households in the fishery and non-fishery sectors contributed enough to the total income, i.e., the primary income of fishermen was 49.33 while alternative work was 50.67%. Nevertheless, there was a need for socialization and training on salted fish processing or other skill from relevant agencies and NGOs that could be used as references for alternative jobs by fishermen during lousy weather.

THE USE OF BIO-MOLECULAR SUBSTANCE OF MARINE BIOTA AS AN ALTERNATIVE EARLY INDICATOR OF OIL POLLUTED ENVIRONMENT: A NEW APPROACH FOR MONITORING CONSIDERATION

THE USE OF BIO-MOLECULAR SUBSTANCE OF MARINE BIOTA AS AN ALTERNATIVE EARLY INDICATOR OF OIL POLLUTED ENVIRONMENT: A NEW APPROACH FOR MONITORING CONSIDERATION

Analysis of Heavy Metals in Shellfish in Tanjung Balai Waters

Abstract: Shellfish is a source of toxic heavy metals and the maximum levels of heavy metals allowed in shellfish by BPOM RI are Lead 1.5 mg/kg, Cadmium 1 mg/kg and Copper 20 mg/kg. Heavy metal content in shellfish is influenced by environmental pollution in which the shellfish live. The purpose of this study was to determine the levels of heavy metals in three types of shellfish in Tanjung Balai Asahan waters. Shellfish samples were taken from 3 different locations in Tanjung Balai in July 2021. Determination of the levels of heavy metals Pb, Cd and Cu in green mussels, mussels and blood clams was carried out using the AAS method with atomic absorption spectrophotometer. The results showed the levels of lead (Pb), cadmium (Cd) and copper (Cu) in Green mussels in Tanjung Balai, namely: Pb of 0.273 mg/kg – 0.406 mg/kg, Cd of 0.089 mg/kg – 0.106 mg/kg mg /kg, Cu is 1,864 mg/kg – 2,011 mg/kg. In oyster shells Pb was 0.051 – 0.095 mg/kg, Cd was 0.077 – 0.091 mg/kg, and Cu was 1.024 mg/kg – 1.064 mg/kg. It was concluded that green mussels had the highest heavy metal content. The levels of heavy metals in the analyzed shellfish samples were still below the maximum levels permitted by BPOM RI.
 Keywords: Lead, Cadmium, Copper,Atomic Absorption Spectrophotometry, Shells

Fatty Acid Profiles of Venus Clam (Marcia opima) and Blood Cockles (Anadara granosa) Harvested at Different Geographical Locations in the Northwest Coast of Sri Lanka

ABSTRACT The present study elucidated the effects of species and geographical location on the fatty acid profile and lipid indices of bivalves. Lipid profiles of venus clam (Marcia opima) and blood cockles (Anadara granosa) harvested from Naruvilikulam and Achchankulam situated on the northwest coast of Sri Lanka were determined, and lipid indices were calculated. The dominant fatty acid group found in bivalves was saturated fatty acids. Total n-3 and n-6 fatty acid contents were similar between the two species. Both bivalve species were identified as potential sources of docosahexaenoic acid. Bivalves from Naruvilikulam site had significantly abundant levels of linolenic and eicosapentaenoic acids (0.83% and 5.69%, respectively). Thrombogenicity index was not influenced by species and geographical location of bivalves. M. opima and bivalves from Naruvilikulam site were detected with lower atherogenicity indices and higher hypocholesterolemic/hypercholesterole-mic ratios than their counterparts and, therefore, can be recommended for consumers interested in healthy food selection.

Structural Insights Into the Effects of Interactions With Iron and Copper Ions on Ferritin From the Blood Clam Tegillarca granosa.

In addition to its role as an iron storage protein, ferritin can function as a major detoxification component in the innate immune defense, and Cu2+ ions can also play crucial antibacterial roles in the blood clam, Tegillarca granosa. However, the mechanism of interaction between iron and copper in recombinant Tegillarca granosa ferritin (TgFer) remains to be investigated. In this study, we investigated the crystal structure of TgFer and examined the effects of Fe2+ and Cu2+ ions on the TgFer structure and catalytic activity. The crystal structure revealed that TgFer presented a typically 4–3–2 symmetry in a cage-like, spherical shell composed of 24 identical subunits, featuring highly conserved organization in both the ferroxidase center and the 3-fold channel. Structural and biochemical analyses indicated that the 4-fold channel of TgFer could be serviced as potential binding sites of metal ions. Cu2+ ions appear to bind preferentially with the 3-fold channel as well as ferroxidase site over Fe2+ ions, possibly inhibiting the ferroxidase activity of TgFer. Our results present a structural and functional characterization of TgFer, providing mechanistic insight into the interactions between TgFer and both Fe2+ and Cu2+ ions.

Microplastic Contamination in Blood Cockles and Mussels in Bandon Bay, Suratthani Province, Thailand

Widespread microplastic contamination has been of growing concern worldwide and poses a growing threat to the marine environment, particularly the impact on the food chain. This study quantified the presence of microplastics in two bivalves of commercial interest at the Pak Kadae Estuary, Bandon Bay, Surat Thani province, Thailand: green mussel Perna viridis (L.) and cockles Tegillarca granosa (L.). Data collection was carried out over two seasons: dry season (April - May 2019) and wet season (June - August 2019). Microplastics were extracted using a 10 % potassium hydroxide (KOH) digestion method and then identified under a microscope. Results confirmed the presence of microplastics in both cockles and green mussels, during the dry season, with mean concentrations of 0.30±0.07 and 1.26±0.10 items/individual, respectively. During the wet season, the mean microplastic concentrations were 0.20±0.07 and 0.56±0.15 items/individual in the cockles and green mussels, respectively. There was a greater concentration of microplastics found in green mussels compared to cockles (P < 0.05) with no seasonal variation being observed. Five different shapes of microplastics, including fiber, fragment, pellet, rod, and film, were detected in the soft tissues of the bivalves. Fibers were the most common shape in green mussels (49 - 69 %) during both seasons. Cockles, in contrast, predominantly contained the pellet shape in the dry season (49 %) and fiber in the wet season (59 %). In addition, the microplastic concentrations were positively correlated to shell heights of the bivalves (P < 0.01). The number of microplastics recorded in the two commercially exploited species demonstrated the need for controlling plastic pollution in coastal ecosystems.
 HIGHLIGHTS
 
 Green mussels showed higher contamination with microplastics than blood cockles
 An average (Mean±SD) of 0.28±0.05 to 2.14±0.36 items/individual in cockles and 0.65±0.13 to 3.43±0.21 items /individual in mussels were obtained
 Microplastic fibers were the dominant shape found in shellfish
 Blue microplastics was the most frequently found in green mussels whereas the black color dominated in cockles
 
 GRAPHICAL ABSTRACT

Health risks from multiroute exposure of potentially toxic elements in a coastal community: a probabilistic risk approach in Pangkep Regency, Indonesia

Populations in coastal areas are vulnerable to chronic exposure to potentially toxic elements (PTEs) from aquatic ecosystems. In this study, we estimated the health risks from Cd, Cr, Fe, and Pb exposure in river water, sediments, and edible aquatic biota (Anadara granosa and Chanos chanos). Human daily intake was determined by an interview process with 287 respondents that were selected by proportional cluster random sampling. The cumulative probability value for total risk exceeded the acceptable limit value, indicating that adverse health impacts from PTE exposure may occur in the Pangkep coastal population. The sensitivity analysis showed that exposure duration and Cr concentrations are the factors with the greatest influence in a recreational exposure scenario, whereas the frequency of exposure to shellfish and milkfish is the most influential factor for health risks in a residential scenario. Thus, reducing Cr concentrations in river water, restricting swimming duration, and limiting the frequency of shellfish and milkfish consumption are required to mitigate health risks in the future.

Cockle (Anadara granosa) shells-based hydroxyapatite and its potential for defluoridation of drinking water

The present study describes the synthesis and characterization of a hydroxyapatite (HAp)-based adsorbent derived from biogenic cockle (Anadara granosa) shells for the defluoridation of drinking water. The raw cockle shells and synthesized HAp were characterized by X-ray fluorescence spectroscopy (XRF), attenuated total reflection-Fourier transform infrared (ATR-FTIR), X-ray diffraction (XRD), Field emission scanning electron microscopes-energy dispersive X-ray (FESEM-EDX) and Brunauer-Emmett-Teller (BET) surface area analysis. As demonstrated by FTIR, cockle shells were found to be composed of calcium carbonate (97.4%), an aragonite polymorphous type of carbonate mineral. XRD and SEM analysis supported the formation of a nanocrystalline HAp with an average crystal size of 19.08 nm and 57.1 nm, respectively, with a surface area of 105.8 m2/g and a pore size of 5.6 nm, as depicted by BET. Batch adsorption experiments were conducted using the Box-Behnken design (BBD) with five input parameters: adsorbent dose (2–10 g/L), initial fluoride concentration (10–80 mg/L), contact time (0.5–24 h), reaction temperature (303–333 K), and pH. (3–11). BBD revealed the following optimum conditions: adsorbent dose (6 g/L), initial fluoride concentration (45 mg/L), contact period 12.25 h, reaction temperature (303 K), and pH 3. Experimentally, the adsorption of fluoride on HAp fitted well with the non-linear Langmuir isotherm and linear pseudo-second order kinetics, signifying the chemisorption process. A maximum adsorption capacity (qm) of 15.374 mg/g, which is closer to the experimental value of 14.053 mg/g, was presented by the Langmuir isotherm. Thermodynamically, the adsorption process was spontaneous, endothermic, and stable in nature. The defluoridation mechanism was through electrostatic attraction, ion exchange, hydrogen bonding, and precipitation. Furthermore, the synthesized HAp and bone char were used to examine their efficacy in defluoridating field water: HAp performed better at natural pH, where the treated water met WHO and TBS standards, whereas bone char had insufficient fluoride removal, especially at high fluoride levels. As a result, this study suggests that HAp derived from Anadara granosa shells could be a viable adsorbent for the defluoridation of drinking water.

Comparative Study of Potentially Toxic Nickel and Their Potential Human Health Risks in Seafood (Fish and Mollusks) from Peninsular Malaysia.

Simple SummaryExposure to highly nickel (Ni)-polluted environments through oral ingestion of seafood may induce a variety of pathological and toxicological impacts, which is our main public concern. The present biomonitoring study concluded that the Ni levels of the three seafood types were found to have posed no Ni’s non-carcinogenic risk of seafood ingestion. In addition, both the average and high-level consumptions of seafood would not pose adverse effects of Ni to the consumers. This study provided a scientific basis for the food safety assessment of Ni and suggestions for risk management of potentially toxic Ni of seafood consumption in Malaysia.Human exposure to highly nickel (Ni)-polluted environments through oral ingestion pathways may cause various pathological effects. This biomonitoring study aimed to assess the human health risk of potentially toxic Ni in 19 species of marine fishes from Setiu (Terengganu) and two popular seafood molluscs (mangrove snail Cerithidea obtusa and cockle Anadara granosa) from the coastal area of Peninsular Malaysia. The Ni levels of the three seafood types were found below the maximum permissible limit for Ni. The Ni target hazard quotient values of all seafood were lower than 1.00 for average and high-level (AHL) Malaysian consumers, indicating no Ni’s non-carcinogenic risk of seafood consumption. It was also found that the calculated values of estimated weekly intake were below than established provisional tolerable weekly intake of Ni for both AHL consumers. It can be concluded that both the AHL consumption of seafood would not pose adverse effects of Ni to the consumers. This study provided a scientific basis for the food safety assessment of Ni and suggestions for risk management of potentially toxic Ni of seafood consumption in Malaysia.

Impacts of four commonly used nanoparticles on the metabolism of a marine bivalve species, Tegillarca granosa

The rapid development of nanotechnology boosts the massive production and utilization of various nanoparticles (NPs). However, the NPs escaped into environments form emergent pollutants, which pose a potential threat to marine organisms and ecosystems. Due to their sessile filter-feeding lifestyle, marine bivalves live in pollution-prone coastal areas are more susceptible to land-sourced pollutants such as NPs. However, the impacts of many NPs on the metabolism, one of the most critical physiological processes of an organism, still remain largely unknown in bivalve species. To fill up this knowledge gap, in this study the impacts of four commonly used NPs (nZnO, nFe2O3, nCuO, and multi-walled carbon tube (MWCNT)) on the filtration rate, oxygen consumption rate, ammonia excretion rate, and O:N ratio were investigated in the blood clam, Tegillarca granosa. In addition, the expressions of ten key metabolism-related genes upon exposure to these NPs were also analyzed. The results demonstrated that exposure of blood clams to the NPs resulted in a reduction in the food intake (indicated by declined filtration rate), a shift in the metabolism substance, and disruptions in key metabolism-related molecular pathways (i.e., glycolysis and tricarboxylic acid cycle), which may render blood clam in energy shortage and thus pose significant threat to the health of this important bivalve species.

Paired miRNA and RNA sequencing provides a first insight into molecular defense mechanisms of Scapharca broughtonii during ostreid herpesvirus-1 infection

Ostreid herpesvirus 1 (OsHV-1) infection caused mortalities with relevant economic losses in bivalve aquaculture industry worldwide. Initially described as an oyster pathogen, OsHV-1 can infect other bivalve species, like the blood clam Scapharca broughtonii. However, at present, little is known about the molecular interactions during OsHV-1 infection in the blood clam. We produced paired miRNA and total RNA-seq data to investigate the blood clam transcriptional changes from 0 to 72 h after experimental infection with OsHV-1. High-throughput miRNA sequencing of 24 libraries revealed 580 conserved and 270 new blood clam miRNAs, whereas no genuine miRNA was identified for OsHV-1. Total 88–203 differently expressed miRNAs were identified per time point, mostly up-regulated and mainly targeting metabolic pathways. Most of the blood clam mRNAs, in contrast, were down-regulated up to 60 h post-injection, with the trend analysis revealing the activation of immune genes only when comparing the early and latest stage of infection. Taken together, paired short and long RNA data suggested a miRNA-mediated down-regulation of host metabolic and energetic processes as a possible antiviral strategy during early infection stages, whereas antiviral pathways appeared upregulated only at late infection.