Oysters

The Notch signaling pathway plays a pivotal role in governing cell fate determinations within the gonadal niche. This study provides an extensive elucidation of the male and female gonadal niches within Crassostrea gigas. Examination via transmission electron microscopy revealed the presence of desmosome-like connection not only between germ cells and niche cells but also among adjacent niche cells within the oyster gonad. Transcriptomic analysis identified several putative Notch pathway components, including CgJAG1, CgNOTCH1, CgSuh, and CgHey1...

Oyster culture is a sustainable solution to food production. However, this activity can be severely impacted by the presence and proliferation of harmful microalgae such as the benthic dinoflagellates Prorocentrum hoffmannianum and Ostreopsis cf. ovata. This study aimed to evaluate the in vitro effects of P. hoffmannianum and O. cf. ovata on immune system cells (hemocytes) of the native cultured oyster Crassostrea gasar. The direct toxicity of both dinoflagellates was first evaluated assessing hemocyte viability exposed to eight concentrations of each HAB species...

Comprehending the potential effects of environmental variability on bivalves aquaculture becomes crucial for its sustainability under climate change scenarios, specially in the Humboldt Current System (HCS) where upwelling intensification leading to frequent hypoxia and acidification is expected. In a year-long study, Pacific oysters (Magallana gigas) were monitored at two depths (1.5m, 6.5m) in a bay affected by coastal upwelling. Surface waters exhibited warmer, well-oxygenated conditions and higher chlorophyll-a concentrations, while at depth greater hypoxia and acidification events occur, especially during upwelling...

Boring sponge infection affects growth, development and reduces the soft tissue weight of oysters. In this study, we investigated the effects of boring sponge on the activity of three antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GP)) in the mantle, and the production of reactive oxygen species (ROS) and potential genotoxicity in hemocytes of the Pacific oyster Magallana gigas. Our results showed a significant increase in ROS production and DNA damage in hemocytes...

Tetrodotoxin (TTX) is a potent neurotoxin causing human intoxications from contaminated seafood worldwide and is of emerging concern in Europe. Shellfish have been shown to contain varying TTX concentrations globally, with concentrations typically higher in Pacific oysters Crassostrea gigas in Europe. Despite many decades of research, the source of TTX remains unknown, with bacterial or algal origins having been suggested. The aim of this study was to identify potential source organisms causing TTX contamination in Pacific oysters in French coastal waters, using three different techniques...

There is growing evidence that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) contaminates the marine environment and is bioaccumulated in filter-feeding shellfish. Previous study shows the Pacific oyster tissues can bioaccumulate the SARS-CoV-2, and the oyster heat shock protein 70 (oHSP70) may play as the primary attachment receptor to bind SARS-CoV-2's recombinant spike protein S1 subunit (rS1). However, detailed information about the interaction between rS1 and oHSP70 is still unknown. In this study, we confirmed that the affinity of recombinant oHSP70 (roHSP70) for rS1 (KD  = 20...

BACKGROUND: Oyster polypeptide (OP) is a mixture of oligopeptides extracted from oysters through enzyme lysis, separation and purification. OP is associated with immunomodulatory effects, but the underlying mechanisms are not known. Therefore, this study combined 1 H-NMR urinary metabolomics and 16S rRNA gene sequencing of the gut microbiome to determine the immunoprotective mechanisms of OP in rats subjected to cyclophosphamide-induced immunosuppression. RESULTS: OP can restored the body weight and the structure of spleen and thymus in cyclophosphamide-induced immunosuppression rats...

This study aims to optimize the prediction model of personalized water pills that has been established by our research group. Dioscoreae Rhizoma, Leonuri Herba, Codonopsis Radix, Armeniacae Semen Amarum, and calcined Oyster were selected as model medicines of powdery, fibrous, sugary, oily, and brittle materials, respectively. The model prescriptions were obtained by uniform mixing design. With hydroxypropyl methylcellulose E5(HPMC-E5) aqueous solution as the adhesive, personalized water pills were prepared by extrusion and spheronizaition...

Marine heatwaves (MHWs) have a significant impact on intertidal bivalves and the ecosystems they sustain, causing the destruction of organisms' original habitats. Saccostrea mordax mainly inhabits the intertidal zone around the equator, exhibiting potential tolerance to high temperatures and maybe a species suitable for habitat restoration. However, an understanding about the tolerance mechanism of S. mordax to high temperatures is unclear. It is also unknown the extent to which S. mordax can tolerate repeated heatwaves of increasing intensity and frequency...

The JAK (Janus kinase)-STAT (Signal transducer and activator of transcription) is a well-known functional signaling pathway that plays a key role in several important biological activities such as apoptosis, cell proliferation, differentiation, and immunity. However, limited studies have explored the functions of STAT genes in invertebrates. In the present study, the gene sequences of two STAT genes from the Pacific oyster (Crassostrea gigas), termed CgSTAT-Like-1 (CgSTAT-L1) and CgSTAT-Like-2 (CgSTAT-L2), were obtained using polymerase chain reaction (PCR) amplification and cloning...

Colorful shells in bivalves are mostly caused by the presence of biological pigments, among which melanin is a key component in the formation of shell colours. Cyclic adenosine monophosphate (cAMP) is an important messenger in the regulation of pigmentation in some species. However, the role of cAMP in bivalve melanogenesis has not yet been reported. In this study, we performed in vitro and in vivo experiments to determine the role of cAMP in regulating melanogenesis in Pacific oysters. Besides, the function of cAMP-responsive element modulator (CREM) and the interactions between CREM and melanogenic genes were investigated...

There is a growing interest in employing whole food-based strategies to prevent chronic diseases, owing to the potential synergistic interactions among various bioactive components found within whole foods. The current research aimed to determine inhibitory effects of the whole edible mushroom Pleurotus eryngii (WPE) on high-fat diet (HFD)-induced obesity in mice. Our results showed that dietary intake of WPE significantly inhibited the abnormal gain of body weight and adipose tissue weight, improved glucose tolerance, and ameliorated the serum biochemical parameters in HFD-fed mice...

Assessing the co-occurrence of multiple health risk factors in coastal ecosystems is challenging due to the complexity of multi-factor interactions and limited availability of simultaneously collected data. Understanding co-occurrence is particularly important for risk factors that may be associated with, or occur in similar environmental conditions. In marine ecosystems, the co-occurrence of harmful algal bloom toxins and bacterial pathogens within the genus Vibrio may impact both ecosystem and human health...

Titanium and its alloys are extensively applied in artificial tooth roots because of their excellent corrosion resistance, high specific strength, and low elastic modulus. However, because of their biological inertness, their surface needs to be modified to improve the osteointegration of titanium implants. The preparation of biologically active calcium-phosphorus coatings on the surface of an implant is one effective method for enhancing the likelihood of bone integration. In this study, osteoinductive peptides were extracted from oyster shells by using acetic acid...

Amorphous calcium carbonate (ACC) is an important precursor phase for the formation of aragonite crystals in the shells of Pinctada fucata . To identify the ACC-binding protein in the inner aragonite layer of the shell, extracts from the shell were used in the ACC-binding experiments. Semiquantitative analyses using liquid chromatography-mass spectrometry revealed that paramyosin was strongly associated with ACC in the shell. We discovered that paramyosin, a major component of the adductor muscle, was included in the myostracum, which is the microstructure of the shell attached to the adductor muscle...

Colorful shells in mollusks are commonly attributable to the presence of biological pigments. In Pacific oysters, the inheritance patterns of several shell colors have been investigated, but little is known about the molecular mechanisms of melanogenesis and pigmentation. cAMP-response element binding proteins (CREB) are important transcription factors in the cAMP-mediated melanogenesis pathway. In this study, we characterized two CREB genes (CREB3L2 and CREB3L3) from Pacific oysters. Both of them contained a conserved DNA-binding and dimerization domain (a basic-leucine zipper domain)...

The growth of the human population causes significant harm to ecosystems, directly affecting the biological diversity of coastal areas by replacing natural habitats with artificial structures such as breakwaters, ports, and marinas. The hard substrate from those marine facilities lacks the topographic complexity of natural habitats. Because of that, artificial habitats usually do not support a diverse community to the same extent as rocky shores in the surroundings. To address this issue and bring a strategic solution to the improper disposal of shell waste from aquaculture farms, we evaluated how increasing the environmental heterogeneity of walls by incorporating mussel and oyster shells on artificial concrete affected the diversity of sessile organisms from the subtidal zone...

In an era of unprecedented industrial and agricultural growth, metal contamination in marine environments is a pressing concern. Sentinel organisms such as the mangrove oyster Crassostrea gasar provide valuable insights into these environments' health. However, a comprehensive understanding of the molecular mechanisms underlying their response to metal exposure remains elusive. To address this gap, we reanalyzed the 454-sequencing data of C. gasar, utilizing an array of bioinformatics workflow of CDTA (Combined De Novo Transcriptome Assembly) to generate a more representative assembly...

The current study aimed to describe the annual gametogenic phenology of the oyster Magallana bilineata (Röding, 1798) (= Crassostrea madrasensis ), which is found on the west coast of Moheshkhali Island, Cox's Bazar, Bangladesh. Samples were drawn monthly from the intertidal region during low tide, from which 20 adult individuals were selected at random for biometry and histology. The mean condition index (CI), a ratio of tissue wet weight (g) to shell length (cm), varied from 0.58 ± 0.08 to 1...

The present study aimed to evaluate the effect of king oyster mushroom (Pleurotus eryngii) root waste and soybean meal co-fermented protein (CFP) on growth performance, feed utilization, immune status, hepatic and intestinal health of largemouth bass (Micropterus salmoides). Largemouth bass (12.33±0.18 g) were divided into five groups, fed with diets containing 0%, 5%, 10%, 15% and 20% CFP respectively for 7 weeks. The growth performance and dietary utilization were slightly improved by the supplementation of CFP...