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This study primarily aims to evaluate the phenolic content and biological activity of Salvia macrochlamys both in vitro and in silico. The antioxidant activities of Salvia macrochlamys were assessed using various methods. Additionally, cytotoxic effects and the α-amylase, α-glucosidase, and acetylcholinesterase (AChE) enzyme inhibitory abilities of ethanolic extract of the aerial parts of Salvia macrochlamys (EESM) were evaluated. Then, the molecular docking interactions and molecular dynamic calculations of EESM against α-amylase, α-glycosidase, and AChE enzymes were carried out. High antioxidant activity was determined in both ethanol and water extracts. The IC50 values of EESM against AChE (EC 3.1.1.7), α-glycosidase (E.C.3.2.1.20), and α-amylase (E.C.3.2.1.1) were determined as 1.622 μg/mL, 0.530 μg/mL, and 1.320 μg/mL, respectively. High enzyme-inhibiting properties of EESM were determined in also in silico. Rosmarinic acid was identified as one of the most abundant phenolic compounds in both EESM and water extract of the aerial parts of Salvia macrochlamys (WESM) (3919.65 mg/kg and 10520.77 mg/kg, respectively). Their high level of flavonoids and phenolics, as well as the potent antioxidant and enzyme-inhibitory properties displayed by extracts, may contribute to broadening the use of Salvia macrochlamys in both traditional and modern therapeutic applications. [ABSTRACT FROM AUTHOR]

This study examined the survival rates of Anadara broughtonii and Chlamys farreri with varying heights throughout winter and summer aquaculture periods under varying ratios of mixed-culture conditions in marine environments. The aim was to assess the viability and economic advantages of mixed-culture practices among different bivalve species. Results indicate that the winter (from December to February of the following year) mortality rate for A. broughtonii in mixed culture ranges from 12.04% to 16.85%, markedly lower than in single-species cultures. Mixed-culture A. broughtonii measuring 2.5–4.0 cm exhibit a significantly reduced summer (from July to September) mortality rate compared to those in single-species cultures (p < 0.05). No significant mortality difference was observed between the monoculture and polyculture of C. farreri. Growth rates of C. farreri and A. broughtonii showed no significant differences between monoculture and polyculture conditions. The optimal size for combining two different species of bivalves is 2.5 cm, with a 1:1 ratio being the most effective. An equal number of seedlings were cultivated across various seawater aquaculture systems for a period of one year. The survival rates of monoculture seedlings of Anadara broughtonii and Chlamys farreri were 60.34% and 86.55%, respectively. In contrast, polyculture seedlings exhibited higher survival rates after one year of mariculture, with Anadara broughtonii at 73.36% and Chlamys farreri at 89.74%. The polyculture of A. broughtonii and C. farreri in suspension cages demonstrates a favorable input–output ratio of 1:2.02. This approach effectively reduces winter and summer mortality rates of A. broughtonii, representing an efficient new method for marine bivalve aquaculture. [ABSTRACT FROM AUTHOR]

Heat stress resulting from global climate change has been demonstrated to adversely affect growth, development, and reproduction of marine organisms. The Zhikong scallop (Chlamys farreri), an important economical mollusk in China, faces increasing risks of summer mortality due to the prolonged heat waves. The heart, responsible for transporting gas and nutrients, is vital in maintaining homeostasis and physiological status in response to environmental changes. In this study, the effect of heat stress on the cardiac function of C. farreri was investigated during the continuous 30-day heat stress at 27 °C. The results showed the heart rate of scallops increased due to stress in the initial phase of high temperature exposure, peaking at 12 h, and then gradually recovered, indicating an acclimatization at the end of the experiment. In addition, the levels of catalase (CAT), superoxide dismutase (SOD), and total antioxidant capacity (T-AOC) exhibited an initial increase followed by recovery in response to heat stress. Furthermore, transcriptome analysis of the heart identified 3541 differentially expressed genes (DEGs) in response to heat stress. Subsequent GO and KEGG enrichment analysis showed that these genes were primarily related to signal transduction and oxidative stress, such as the phosphatidylinositol signaling system, regulation of actin cytoskeleton, MAPK signaling pathway, FoxO signaling pathway, etc. In addition, two modules were identified as significant responsive modules according to the weighted gene co-expression network analysis (WGCNA). The upregulation of key enzymes within the base excision repair and gap junction pathways indicated that the heart of C. farreri under heat stress enhanced DNA repair and maintained cellular integrity. In addition, the variable expression of essential signaling molecules and cytoskeletal regulators suggested that the heart of C. farreri modulated cardiomyocyte contraction, intracellular signaling, and heart rate through complex regulation of phosphorylation and calcium dynamics in response to heat stress. Collectively, this study enhances our understanding of cardiac function and provides novel evidence for unraveling the mechanism underlying the thermal response in mollusks. [ABSTRACT FROM AUTHOR]

This research encompasses a comprehensive study of Nepeta phyllochlamys, an endemic species around the Antalya province of Turkey. Morphological investigations revealed decumbent stems with dense tomentose or villous hairs, triangular-ovate or deltoid leaves covered in velutinous and tomentose hairs, and pinkish-yellow corollas. Micromorphological examinations using scanning electron microscopy unveiled intricate surface characteristics. Molecular analysis demonstrated 96% similarity with Nepeta cataria and established phylogenetic relationships. Biological activity investigations focused on antioxidant properties. The 70% ethyl alcohol extract exhibited notable antioxidant activity (IC50: 0.32 ± 0.025 mg/mL), albeit weaker than gallic acid. The total phenolic content assessment showed the highest in ethyl alcohol extract (88.8 ± 0.04 mg GAE/g extract) and the lowest in ethyl acetate extract (29.4 ± 0.02 mg GAE/g extract). These findings highlighted N. phyllochlamys' morphological, micromorphological, molecular, and biological aspects, contributing to a comprehensive understanding of this species. [ABSTRACT FROM AUTHOR]

During a survey of fungi on electricity utility poles in South Africa, a diverse range of fungi were discovered. Paecilomyces was frequently isolated, with five species identified using ITS and β-tubulin (BenA) sequences. These were P. brunneolus, P. dactylethromorphus, P. lecythidis, P. paravariotii and a potential new species. The genomes of 30 of these strains were subsequently sequenced and used in a phylogenomic analysis with 45 previously published genomes of the genus. Phylogenetic analyses were also conducted using ITS, BenA, calmodulin (CaM), RNA polymerase II second largest subunit (RPB2), RNA polymerase II largest subunit (RPB1), the genes coding for the theta subunit of the TCP-1 chaperonin complex (Cct8), and for a putative ribosome biogenesis protein (Tsr1). Both phylogenomic and phylogenetic analyses supported the 15 Paecilomyces species currently accepted and confirmed the novelty of the new species, which we describe as P. lignorum. The latter is the sister species of P. brunneolus and belongs to a clade also containing P. variotii and P. paravariotii. Morphologically, the new species produces longer ellipsoidal conidia and grows more restricted on malt extract agar at 30 °C compared to its closest relatives. [ABSTRACT FROM AUTHOR]

Introduction: In aquatic animals, colors not only reflect their sensory qualities but also affect their nutritional components and market price. Noble scallop Chlamys nobilis is an importantly economical bivalve cultured in the south sea of China and renowned for its various shell colors. Methods: In this study, the nutrient compositions were compared among golden, yellow, and brown shell colour noble scallops originating from the same population for breeding new varieties. Results: Among three colour scallops, there is no significant difference in the content of moisture, ash, and total protein content (TPC) but significant differences in total carotenoid content (TCC), total lipid content (TLC), and amino acids (AAs) (P < 0.05), with the TCC of the brown scallop being about 2 times lower. The yellow scallop contained the same nutrients as TCC, TLC, ΣPUFAs (including EPA and DHA), and n-3/n-6 as the golden scallop, and both were significantly higher than the brown scallop (P < 0.05), but they had significantly lower ΣSFAs than the latter (P < 0.05). The correlation between the nutrient indices and the shell color of scallops was 67.5%. There is a significantly positive correlation between TCC and ΣPUFAs (P < 0.05), while a significantly negative correlation exists between TCC and ΣSFAs (P < 0.05). More importantly, the yellow scallop had significantly higher EAAs and FAAs than the golden scallop (P < 0.05). Discussion: This study showed that the yellow noble scallop not only enriched in carotenoids and PUFAs but also enriched in amino acids. Therefore, the yellow scallop is more benefit to human health, which can provide high-quality food for customers. [ABSTRACT FROM AUTHOR]

Recently, the increase in marine temperatures has become an important global marine environmental issue. The ability of energy supply in marine animals plays a crucial role in avoiding the stress of elevated temperatures. The investigation into anaerobic metabolism, an essential mechanism for regulating energy provision under heat stress, is limited in mollusks. In this study, key enzymes of four anaerobic metabolic pathways were identified in the genome of scallop Chlamys farreri, respectively including five opine dehydrogenases (CfOpDHs), two aspartate aminotransferases (CfASTs) divided into cytoplasmic (CfAST1) and mitochondrial subtype (CfAST2), and two phosphoenolpyruvate carboxykinases (CfPEPCKs) divided into a primitive type (CfPEPCK2) and a cytoplasmic subtype (CfPEPCK1). It was surprising that lactate dehydrogenase (LDH), a key enzyme in the anaerobic metabolism of the glucose–lactate pathway in vertebrates, was absent in the genome of scallops. Phylogenetic analysis verified that CfOpDHs clustered according to the phylogenetic relationships of the organisms rather than substrate specificity. Furthermore, CfOpDHs, CfASTs, and CfPEPCKs displayed distinct expression patterns throughout the developmental process and showed a prominent expression in muscle, foot, kidney, male gonad, and ganglia tissues. Notably, CfASTs displayed the highest level of expression among these genes during the developmental process and in adult tissues. Under heat stress, the expression of CfASTs exhibited a general downregulation trend in the six tissues examined. The expression of CfOpDHs also displayed a downregulation trend in most tissues, except CfOpDH1/3 in striated muscle showing significant up-regulation at some time points. Remarkably, CfPEPCK1 was significantly upregulated in all six tested tissues at almost all time points. Therefore, we speculated that the glucose–succinate pathway, catalyzed by CfPEPCK1, serves as the primary anaerobic metabolic pathway in mollusks experiencing heat stress, with CfOpDH3 catalyzing the glucose–opine pathway in striated muscle as supplementary. Additionally, the high and stable expression level of CfASTs is crucial for the maintenance of the essential functions of aspartate aminotransferase (AST). This study provides a comprehensive and systematic analysis of the key enzymes involved in anaerobic metabolism pathways, which holds significant importance in understanding the mechanism of energy supply in mollusks. [ABSTRACT FROM AUTHOR]

Benzo[a]pyrene (B[a]P), a polycyclic aromatic hydrocarbon (PAH) with the most carcinogenic effects of all the PAHs, has multiple toxic effects on marine bivalves. We investigated the interference mechanism of B[a]P on food metabolism (sugars, proteins, and sugars), and on reproductive endocrine and ovarian development in female scallops (Chlamys farreri). Scallops were exposed to different concentrations of B[a]P concentrations of 0, 0.38, 3.8, and 38 μg/L throughout gonadal development. Total cholesterol and triglyceride contents in the digestive glands were increased, and their synthesis genes were upregulated. The plasma glucose contents decreased with the inhibition of glycogen synthesis genes and the induction of glycolysis genes in the digestive gland. The results showed that B[a]P had endocrine‐disrupting effects on scallops, that it negatively affected genes related to ovarian cell proliferation, sex differentiation, and egg development, and that it caused damage to ovarian tissue. Our findings supplement the information on B[a]P disruption in gonadal development of marine bivalves. Environ Toxicol Chem 2024;43:748–761. © 2023 SETAC [ABSTRACT FROM AUTHOR]

Summary: The present study aimed to comparatively analyse the functional properties of the spray drying particles prepared from the noble scallop (Chlamys nobilis) mantle protein‐pectin hydrated mixtures. And the microstructural characteristics of the particles were assessed by Fourier transform infrared, scanning electronic microscopy, and SDS‐PAGE to detect critical changes. The results showed that the solubility of enzymatically extracted protein was significantly improved by spray drying after pectin hydration (AP‐LMP and AP‐HMP), from 76.77% (AP) to 97.87% (AP‐LMP) and 97.13% (AP‐HMP), respectively. And the spray drying water‐extracted protein (HP) after pectin hydration (HP‐LMP and HP ‐HMP) exhibited a greater emulsifying property, from 103.10 m2/g (HP) to 145.55 ± 0.92 m2/g (HP‐LMP) and 200.29 ± 1.16 m2/g (HP‐HMP). The spray drying after pectin hydration had successfully enhanced emulsifying and rheological properties when compared with AP and HP. The results of SDS‐PAGE showed more protein participated in the formation of macromolecule and FT‐IR spectra demonstrated the formation of protein‐pectin spray drying particles facilitated not only by electrostatic interactions but also by covalent binding via Maillard reaction, made a closely compatible protein structure verified by the improvement of fluorescence intensity. This work is expected to provide a theoretical basic data for the development and application of scallop mantle extracted proteins. [ABSTRACT FROM AUTHOR]

The classification of Boesenbergia (Zingiberaceae) has long been a challenge, and recent insights from molecular phylogenetic studies have both raised and resolved a number of questions. Combined morphological and molecular revisions resulted in the description of new species as well as merging of Haplochorema and Jirawongsea into Boesenbergia. This study uses the most complete set of Boesenbergia accessions and sister genera to investigate the evolutionary relationships of the genus in a phylogenetic framework. This framework confirms the previously identified clades and the placement of the included accessions within those clades. These clades share being single-flowered and having a basipetalous flowering sequence, characters uniting all taxa in Boesenbergia, but also have unique or mostly unique characters that are clade specific. In addition, the phylogeny identifies two species, B. purpureorubra and B. siamensis, that are hard to place within these clades based on both molecular and morphological data, while the morphological data points to a stronger affiliation with the clade including the type of the genus. [ABSTRACT FROM AUTHOR]

A strain of oogamous biflagellate green alga was isolated during a study on soil algal diversity in the Russian Far East (Sakhalin Region, Iturup Island) and examined using an integrative approach. Phylogenetic analyses, based on the SSU rDNA gene, resolved the new strain as a part of the RL clade (sensu Watanabe and Nakada) within Oogamochlamydinia (Volvocales, Chlorophyceae). The strain was similar to members of the genus Oogamochlamys (parietal and massive cup-shaped chloroplasts; two apical contractile vacuoles), but was, however, distinguished from them based on the size and shape of the mature vegetative cells, the flagellar length, the presence of only one pyrenoid in both the mature vegetative cells and the zoospores, the anterior nucleus position, and the spermatozoids' shape. Although a concept of the genus Oogamochlamys has been compromised in recent phylogenetic analysis based on the SSU rDNA sequence data and its likely affinity to anisogamous Chlamydomonas allensworthii, we described the strain from Iturup Island as Oogamochlamys kurilensis sp. nov. [ABSTRACT FROM AUTHOR]

Owing to the constant wind generated by the vast ocean, energy production from offshore wind farms (OWFs) plays an important role in the expansion of renewable energy. However, areas close to large wind farms are often left unutilized, and aquaculture farmers find it difficult to efficiently utilize these unoccupied spaces due to limited information showing the feasibility of utilization of OWFs as potential scallop culture sites. To analyze whether the two scallop species Zhikong scallop (Chlamys farreri) and bay scallop (Argopecten irradians) can be grown at OWFs of Gochang and Buan, Jeollabuk-do, Republic of Korea, the growth characteristics of the two scallop species were analyzed and compared with those grown at the Tongyeong Megacosm Test Station. The results clearly showed that the growth of scallops at the OWF was significantly lower with respect to the shell lengths, height, width, and weight, compared to those grown at the megacosm station. However, scallops grown at the OWF still showed consistent growth in parallel with those grown at the megacosm test station. Yet, there was a species-specific mortality rate between the two sites. In addition, our results suggest that temperature may be a key determinant of the growth of C. farreri and A. irradians. Overall, this study contributes to establishing a foundation for the stable and continuous farming of marine bivalves (e.g., clams, oysters, mussels, and scallops) in OWF areas. [ABSTRACT FROM AUTHOR]

The long-distance migration of polycyclic aromatic hydrocarbons (PAHs) promotes their release into the marine environment, posing a serious threat to marine life. Studies have shown that PAHs have significant immunotoxicity effects on bivalves, but the exact mechanism of immunotoxicity remains unclear. This paper aims to investigate the effects of exposure to 0.4, 2, and 10 μg/L of benzo(a)pyrene (B[a]P) on the immunity of Chlamys farreri under environmental conditions, as well as the potential molecular mechanism. Multiple biomarkers, including phagocytosis rate, metabolites, neurotoxicity, oxidative stress, DNA damage, and apoptosis, were adopted to assess these effects. After exposure to 0.4, 2, and 10 μg/L B[a]P, obvious concentration-dependent immunotoxicity was observed, indicated by a decrease in the hemocyte index (total hemocyte count, phagocytosis rate, antibacterial and bacteriolytic activity). Analysis of the detoxification metabolic system in C. farreri revealed that B[a]P produced B[a]P-7,8-diol-9,10-epoxide (BPDE) through metabolism, which led to an increase in the expression of protein tyrosine kinase (PTK). In addition, the increased content of neurotransmitters (including acetylcholine, γ -aminobutyric acid, enkephalin, norepinephrine, dopamine, and serotonin) and related receptors implied that B[a]P might affect immunity through neuroendocrine system. The changes in signal pathway factors involved in immune regulation indicated that B[a]P interfered with Ca2+ and cAMP signal transduction via the BPDE-PTK pathway or neuroendocrine pathway, resulting in immunosuppression. Additionally, B[a]P induced the increase in reactive oxygen species (ROS) content and DNA damage, as well as an upregulation of key genes in the mitochondrial pathway and death receptor pathway, leading to the increase of apoptosis rate. Taken together, this study comprehensively investigated the detoxification metabolic system, neuroendocrine system, and cell apoptosis to explore the toxic mechanism of bivalves under B[a]P stress. [ABSTRACT FROM AUTHOR]

Fungi produce secondary metabolites that are not directly involved in their growth, but often contribute to their adaptation to extreme environmental stimuli and enable their survival. Conidial pigment or melanin is one of the secondary metabolites produced naturally by a polyketide synthesis (PKS) gene cluster in several filamentous fungi and is known to protect these fungi from extreme radiation conditions. Several pigmented or melanized fungi have been shown to grow under extreme radiation conditions at the Chernobyl nuclear accident site. Some of these fungi, including Paecilomyces variotii, were observed to grow towards the source of radiation. Therefore, in this study, we wanted to identify if the pigment produced by P. variotii, contributes to providing protection against radiation condition. We first identified the PKS gene responsible for synthesis of pigment in P. variotii and confirmed its role in providing protection against UV irradiation through CRISPR-Cas9 mediated gene deletion. This is the first report that describes the use of CRISPR methodology to create gene deletions in P. variotii. Further, we showed that the pigment produced by this fungus, was not inhibited by DHN-melanin pathway inhibitors, indicating that the fungus does not produce melanin. We then identified the pigment synthesized by the PKS gene of P. variotii, as a naptho-pyrone Ywa1, by heterologously expressing the gene in Aspergillus nidulans. The results obtained will further aid in understanding the mechanistic basis of radiation resistance.

In order to tap the potential of high-value utilization of Chlamys nobilis, using compound protease to hydrolyze Chlamys nobilis adductor muscle, the effect of EHCA(enzymatic hydrolysate of Chlamys nobilis adductor muscle) on the activity of α-glucosidase and the scavenging ability of DPPH free radicals was explored. The fasting blood glucose concentration, serum insulin content, liver malondialdehyde and superoxide dismutase content were used as indicators to evaluate the auxiliary hypoglycemic function and antioxidant activity of EHCA in normal mice. The results showed that EHCA had good a-glucosidase inhibitory activity, and its DPPH free radical scavenging ability increased with the concentration of the enzymatic hydrolysate. The results of animal experiments showed that a certain concentration of EHCA could enhance the glucose tolerance of mice, significantly reduced the liver malondialdehyde and increase the activity of superoxide dismutase. In conclusion, the compound protease can effectively enzymolyze the adductor muscle of Chlamys nobilis, and its enzymatic hydrolysate has good α-glucosidase inhibitory activity and antioxidant activity with a certain auxiliary hypoglycemic effect. The results may provide a theoretical basis for the development of auxiliary hypoglycemic marine functional foods. [ABSTRACT FROM AUTHOR]

Gonadotropin-releasing hormone (GnRH) controls synthesis of sex steroid hormones through hypothalamic-pituitary-gonadal (HPG) axis in vertebrates. But in mollusks, research on neuroendocrine control of gonadal function, such as the function of GnRH during gonadal development is limited. In this study, we investigated the morphology and structure of the nerve ganglia of Zhikong scallop Chlamys farreri by physiological and histological observations. We also cloned the ORF and studied the expression patterns of GnRH in the scallop. Tissue expression analysis showed that GnRH was highly expressed in parietovisceral ganglion (PVG). The in situ hybridization result further confirmed that GnRH mRNA only distributed in some good-sized neurons in the posterior lobe (PL) and some pint-sized neurons in the lateral lobe (LL). In addition, by examining the expression of GnRH during gonadal development in ganglia, we found GnRH displayed higher expression in the female scallops, and showed significant high expression at the growing stage of female scallops in PVG. This study would contribute to gaining insight into the mechanism underlying reproduction regulation by GnRH in the scallop and help to provide a better understanding of reproductive neuroendocrine in mollusks. [ABSTRACT FROM AUTHOR]

The element ratio of Mg/Ca is a primary proxy in studying the composition of seashells, and laser-induced breakdown spectroscopy (LIBS) is a practical technique for elemental analysis. In this work, we tried to apply LIBS to investigate the Mg/Ca ratio in cultured seashells of two scallop species (Chlamys farreri and Patinopecten yessoensis). It was found that LIBS was capable of tracking Mg/Ca variation on the cross section of the scallop shell (Chlamys farreri), and the variation trend was well verified by the measurement of SEM-EDS. Based on this, LIBS detection was carried out for Mg/Ca investigation on another species of the scallop shell (Patinopecten yessoensis), and the intensity ratio of Mg/Ca presented a similar variation to δ18O measurement under mass spectroscopy. The result also indicated that the LIBS technique is appropriate in the Mg/Ca investigation for scallop shells, and in cultured scallops, the Mg/Ca ratio would be equally useful for tracking temperature variations. In the future, LIBS is expected to be developed as a diagnostic tool in seashell cultivation, and more elemental compositions would be involved in this kind of investigation. [ABSTRACT FROM AUTHOR]

There is increasing incidence of food spoilage and health hazards caused by heat-resistant fungi belonging to the genera Byssochlamys, Thermoascus, and Neosartorya, among others. Their ascospores cannot be sterilized by heating the food. The microbiological risk assessment studies of these fungi during the production of food and beverages indicated that these fungal species or genera in food are associated with different health risks. Therefore, it is necessary to distinguish Byssochlamys, Thermoascus, and Neosartorya from other fungi in the food industry. These genera can be identified by sequence analysis of housekeeping genes such as ß-tubulin, but the process is costly and time-consuming. Therefore, rapid and simple PCR-based methods have been developed using specific primer sets for genus-or species-level identification. PCR amplification products are observed to be specific for each of these genera or species and do not cross-react with other fungi associated with food spoilage and environmental contamination. These identification methods are simple, rapid, and highly specific, making them feasible for use in the quality management of food production plants. [ABSTRACT FROM AUTHOR]

Planktonic foraminifera were studied at Lydden Spout, near Folkestone (southeast England, UK), the reference section of the middle Cenomanian Event 1 (MCE 1) characterized by a prominent double-peak δ13C excursion of 1 ‰ identified in different ocean basins and considered a global event. Biostratigraphic and quantitative analysis of planktonic foraminifera are correlated to the δ13C perturbation, to the positive δ18O shifts identified within MCE 1 and to the occurrence of Boreal macrofossils (the bivalves Chlamys arlesiensis and Oxytoma seminudum , and the belemnite Praectinocamax primus). Variations in abundance and species richness of planktonic foraminifera and the inferred palaeoecological preferences of taxa permit the identification of distinct palaeoenvironmental settings across MCE 1. The stratigraphic interval corresponding to MCE 1 is characterized by the absence of oligotrophic rotaliporids, and by the evolutionary appearance of meso-eutrophic dicarinellids and of Muricohedbergella portsdownensis , a cold-water species that occurs at the same level as the Boreal macrofossils. These observations indicate a palaeoceanographic scenario characterized by reduced stratification of surface waters and absence/disruption of the thermocline in a dominantly eutrophic regime during MCE 1. Evidence provided by planktonic foraminifera, Boreal macrofossils and δ18O records documented for the late Cenomanian Plenus Cold Event (PCE) at Eastbourne (UK) reveal similarities that confirm the periodic inflow of cold Boreal seawater originating in the Norwegian Sea as previously postulated to explain the occurrence of Boreal fauna in the Anglo-Paris Basin. The southerly extension of this water mass may be related to the reorganization of circulation driven by the long eccentricity cycle. [ABSTRACT FROM AUTHOR]

Inhibitor of κB kinase (IKK) family proteins are key signaling molecules in the animal innate immune system and are considered master regulators of inflammation and innate immunity that act by controlling the activation of transcription factors such as NF-κB. However, few functional studies on IKK in invertebrates have been conducted, especially in marine mollusks. In this study, we cloned the IKK gene in the Zhikong scallop Chlamys farreri and named it CfIKK3. CfIKK3 encodes a 773-amino acid-long protein, and phylogenetic analysis showed that CfIKK3 belongs to the invertebrate TBK1/IKKϵ protein family. Quantitative real-time PCR analysis showed that CfIKK3 mRNA is ubiquitously expressed in all tested scallop tissues. The expression of CfIKK3 transcripts was significantly induced after challenge with lipopolysaccharide, peptidoglycan, or poly(I:C). Co-immunoprecipitation (co-IP) assays confirmed the direct interaction of CfIKK3 with MyD88 (the key adaptor in the TLR pathway) and MAVS (the key adaptor in the RLR pathway), suggesting that this IKK protein plays a crucial role in scallop innate immune signal transduction. In addition, the CfIKK3 protein formed homodimers and bound to CfIKK2, which may be a key step in the activation of its own and downstream transcription factors. Finally, in HEK293T cells, dual-luciferase reporter gene experiments showed that overexpression of CfIKK3 protein activated the NFκB reporter gene in a dose-dependent manner. In conclusion, our experimental results confirmed that CfIKK3 could respond to PAMPs challenge and participate in scallop TLR and RLR pathway signaling, ultimately activating NF-κB. Therefore, as a key signaling molecule and modulator of immune activity, CfIKK3 plays an important role in the innate immune system of scallops. [ABSTRACT FROM AUTHOR]

This study explored the effects of sous vide (SV) cooking treatments on the physicochemical quality and volatile flavor of half-shell scallop (Chlamys farreri) during 30 d of chilled storage. The vacuum-packed scallop samples were cooked at 70 °C (SV-70) and 75 °C (SV-75) and maintained for 30 min. The samples were compared with the positive control (cooked at 100 °C for 10 min, CK). The results indicate that the total volatile basic nitrogen (TVBN), pH, texture, and malondialdehyde (MDA) content gradually increased, while the myofibrillar protein (MP) extraction rate of the CK, SV-70, and SV-75 samples significantly decreased with increasing chilled storage time. Significantly, the SV cooking treatments maintained a much higher water-holding capacity of scallop muscle, compared with the conventional cooking process at 100 °C. Additionally, the SV-75 cooking treatment maintained relatively stable TVBN, pH, and MDA content, springiness, and shearing force properties of scallop samples, especially during 0–20 d of storage. Volatile flavor analysis showed that a total of 42 volatile organic compounds (VOCs) were detected in the scallop samples, and there were no considerable differences in these VOCs between the CK and SV-75 cooked samples (0 d). Overall, the SV cooking treatments effectively maintained acceptable and stable physicochemical and volatile flavor properties of half-shell scallop samples during chilled storage. [ABSTRACT FROM AUTHOR]

A strain of oogamous biflagellate green alga was isolated during a study on soil algal diversity in the Russian Far East (Sakhalin Region, Iturup Island) and examined using an integrative approach. Phylogenetic analyses, based on the SSU rDNA gene, resolved the new strain as a part of the RL clade (sensu Watanabe and Nakada) within Oogamochlamydinia (Volvocales, Chlorophyceae). The strain was similar to members of the genus Oogamochlamys (parietal and massive cup-shaped chloroplasts; two apical contractile vacuoles), but was, however, distinguished from them based on the size and shape of the mature vegetative cells, the flagellar length, the presence of only one pyrenoid in both the mature vegetative cells and the zoospores, the anterior nucleus position, and the spermatozoids’ shape. Although a concept of the genus Oogamochlamys has been compromised in recent phylogenetic analysis based on the SSU rDNA sequence data and its likely affinity to anisogamous Chlamydomonas allensworthii, we described the strain from Iturup Island as Oogamochlamys kurilensis sp. nov.

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Because of the persistence and high toxicity of benzo[a]pyrene (B[a]P), the bioaccumulation and detoxification mechanisms of B[a]P have been studied extensively at the tissue level; but the data at the subcellular level in bivalves have not been reported. The present study was conducted to investigate the effects of B[a]P exposure on bioaccumulation, detoxification, and biomacromolecular damage in gills, digestive glands, and their subcellular fractions of the scallop Chlamys farreri. The subcellular fraction contains cytoplasm, mitochondria, microsome, nucleus, cell membrane, and overall organelle. The results demonstrated that B[a]P accumulation showed a clear time–dose effect. Based on the time‐dependent accumulation of B[a]P in subcellular fractions, we speculated that the intracellular migration order of B[a]P was cell membrane, organelle, and nucleus in turn. Considering the difference of B[a]P accumulation may be related to B[a]P metabolism, we have further confirmed that the activities of B[a]P metabolizing enzymes in scallop tissues and subcellular fractions were significantly tempted by B[a]P (p < 0.05), including 7‐ethoxyresorufin O‐deethylase (increased), glutathione‐S‐transferase (GST; decreased), and superoxide dismutase (increased). First, GST was detected in bivalve cytoplasm and microsome. Second, B[a]P exposure also caused biomacromolecules damage. The results demonstrated that mitochondria and microsome were more vulnerable to lipid peroxidation than cell membrane and nucleus. Taken together, the present study fills some of the gaps in our knowledge of the bioaccumulation and detoxification mechanisms of C. farreri exposed to B[a]P in subcellular fractions and deeply explores the transportation and the main metabolic and damage sites of polycyclic aromatic hydrocarbons (PAHs) in cells, which helped us to comprehensively understand the toxic mechanism of PAHs on bivalves. Environ Toxicol Chem 2022;41:2353–2364. © 2022 SETAC [ABSTRACT FROM AUTHOR]

Bivalve molluscs are filter-feeding organisms that can accumulate paralytic shellfish toxins (PST) through ingesting toxic marine dinoflagellates. While the effects of PST accumulation upon the physiology of bivalves have been documented, the underlying molecular mechanism remains poorly understood. In this study, transcriptomic analysis was performed in the gills of Zhikong scallop (Chlamys farreri) after 1, 3, 5, 10, and 15 day(s) exposure of PST-producing dinoflagellate Alexandrium minutum. Higher numbers of differentially expressed genes (DEGs) were detected at day 1 (1538) and day 15 (989) than that at day 3 (77), day 5 (82), and day 10 (80) after exposure, and most of the DEGs were only regulated at day 1 or day 15, highlighting different response mechanisms of scallop to PST-producing dinoflagellate at different stages of exposure. Functional enrichment results suggested that PST exposure induced the alterations of nervous system development processes and the activation of xenobiotic metabolism and substance transport processes at the acute and chronic stages of exposure, respectively, while the immune functions were inhibited by PST and might ultimately cause the activation of apoptosis. Furthermore, a weighted gene co-expression network was constructed, and ten responsive modules for toxic algae exposure were identified, among which the yellow module was found to be significantly correlated with PST content. Most of the hub genes in the yellow module were annotated as solute carriers (SLCs) with eight being OCTN1s, implying their dominant roles in regulating PST accumulation in scallop gills. Overall, our results reveal the gene set responding to and involved in PST accumulation in scallop gills, which will deepen our understanding of the molecular mechanism of bivalve resistance to PST. [ABSTRACT FROM AUTHOR]

Reproductive toxicity induced by benzo[a]pyrene (B[a]P) exposure has received great ecotoxicological concerns. However, huge gaps on the molecular mechanism still exist in bivalves. In this study, reproduction-related indicators were investigated in female scallops Chlamys farreri during life cycle of proliferative, growth, mature, and spawn stages, under gradient concentrations of B[a]P at 0, 0.04, 0.4, and 4 μg/L. Meanwhile, a multi-stage ovarian transcriptome analysis under 4 μg/L B[a]P exposure was also conducted to elucidate the potential molecular mechanisms. The results indicated that life-cycle exposure to 0.4 and 4 μg/L B[a]P significantly decreased GSI and sex steroid levels. Even 0.04 μg/L B[a]P could play the adverse role in DNA integrity at the mature and spawn stages. Ovarian histological sections showed that B[a]P inhibited the maturation and release of oocytes. Through the functional enrichment analysis of differentially expressed genes (DEGs) from transcriptome data, 18 genes involved in endocrine disruption effects, DNA damage and repair, and oogenesis were selected and further determined by qRT-PCR. The downregulation of genes involved in steroidogenic and estrogen signaling pathways indicated that B[a]P could cause endocrine disruption through both receptor-dependent and receptor-independent pathways. The variations of gene expressions involved in DNA single-strand break and repair implied the presence of toxic mechanisms similar with vertebrates. Additionally, the changes of gene expressions of cell cycle, apoptosis, and cell adhesion suggested that exposure to B[a]P possibly caused the reproductive toxicity effects by affecting oogenesis. Taken together, this study was a pioneer in combining genome-wide transcriptomic analysis with its corresponding reproductive indicators (GSI, sex steroid levels, DNA single-strand break, and histological sections) to explore the bivalves' toxic mechanisms under B[a]P exposure. Meanwhile, some genes involved in estrogen signaling pathway and DNA damage were firstly analyzed in bivalves, and the expression data might be useful in establishing new hypotheses and discovering new biomarkers for marine biomonitoring. [ABSTRACT FROM AUTHOR]

Temperature is an important factor affecting the growth, development and survival of marine organisms. A short episode of high temperature has been proven to be a severe threat to sustainable shellfish culture. Zhikong scallop (Chlamys farreri), a shellfish with broad economic and biological value in North China, has frequently experienced heat stress in summer in recent years. To understand the effects of heat stress on shellfish, the metabolism of C. farreri was analyzed after exposure to 27 °C for either 6 h or 30 d. After 6 h of heat stress exposure, a total of 326 and 264 significantly different metabolites (SDMs) were identified in gill and mantle tissues, respectively. After 30 d of heat stress exposure, a total of 381 and 341 SDMs were found in the gill and mantle tissues, respectively. These SDMs were mainly related to the metabolism of amino acids, carbohydrates, lipids and nucleotides. A decline in pyruvic acid, and an increase in citric acid and fumaric acid in the gills and mantle of C. farreri indicated an alteration in energy metabolism, which may be attributed to increased ATP production in order to overcome the heat stress. Among the SDMs, 33 metabolites, including pyruvic acid, glycine and citric acid, were selected as potential biomarkers for heat stress response in C. farreri. In addition, a decline in glutamine and β-Alanine levels indicated oxidative stress in C. farreri exposed to heat, as well as an increase in the total antioxidant capacity (T-AOC). Our findings suggested C. farreri have the potential to adapt to heat stress by regulating energy metabolism and antioxidant capacity. [ABSTRACT FROM AUTHOR]

As ectothermic invertebrates, mollusks are regarded as good environmental indicator species for determining the adverse effects of climate change on marine organisms. In the present study, the effects of cold stress on the tissue structure, antioxidant activity, and expression levels of genes were evaluated in the warm-water noble scallop Chlamys nobilis by simulating natural seawater cooled down during winter from 17 °C to 14 °C, 12 °C, 10 °C, and 9 °C. Firstly, the gill was severely damaged at 10 °C and 9 °C, indicating that it could be used as a visually indicative organ for monitoring cold stress. The methylenedioxyamphetamine (MDA) content significantly increased with the temperatures decreasing, meanwhile, the antioxidant enzyme activities superoxide dismutase (SOD) and catalase (CAT) showed a similar pattern, suggesting that the scallop made a positive response. More importantly, 6179 genes related to low temperatures were constructed in a module-gene clustering heat map including 10 modules. Furthermore, three gene modules about membrane lipid metabolism, amino acid metabolism, and molecular defense were identified. Finally, six key genes were verified, and HEATR1 , HSP70B2 , PI3K , and ATP6V1B were significantly upregulated, while WNT6 and SHMT were significantly downregulated under cold stress. This study provides a dynamic demonstration of the major gene pathways' response to various low-temperature stresses from a transcriptomic perspective. The findings shed light on how warm-water bivalves can tolerate cold stress and can help in breeding new strains of aquatic organisms with low-temperature resistance. [Display omitted] • The influence of Chlamys nobilis in cold winters was simulated by chronic cold stress. • The gill can be used as a visually indicative organ for monitoring cold stress. • The gill can make a positive response by increasing SOD and CAT levels under cold stress. • Some pathways and genes related to cold stress were found. [ABSTRACT FROM AUTHOR]

Manganese‐superoxide dismutases (MnSODs) play vital roles in immune response and maintaining cellular physiology. In this study, a novel MnSOD (CnMnSOD) gene from noble scallop Chlamys nobilis was first cloned. The full‐length cDNA sequence of CnMnSOD contains a 681 bp ORF with 226 amino acids and includes two highly conserved domains, a SOD Fe‐N domain and a SOD Fe‐C domain. Multiple sequence alignment and phylogenetic analysis showed CnMnSOD was highly conserved to other mollusks. Tissue expression analysis showed CnMnSOD had a significant difference between golden and brown scallops. The transcript level of CnMnSOD in blood, mantle and gill of golden and brown scallops was all significant up‐regulated (p < 0.05) under lower temperature stress, and a more interesting finding was that golden scallops had a significantly higher expression levels in mantle and gill (p < 0.05) than those of brown scallops under lower temperature stress. Furthermore, analysis of variance showed the genetic and temperature stress all had significant effects on the expression level of CnMnSOD, and the interaction between them was also significant (p < 0.05). Collectively, these results indicated that CnMnSOD and carotenoids play important roles in the antioxidant system defence against the lower temperature stress, and the carotenoids in scallop may enhance the resistance by up‐regulating genes related to innate immunity. These results will deepen our understanding to innate immune response of scallop under low‐temperature stress. [ABSTRACT FROM AUTHOR]

Simple Summary: Sex formation of gonads encompasses two ancient and highly conserved biological processes, sex determination and sex differentiation. The processes are strictly regulated by a complex of gene networks. There is increasing evidence that miRNAs play key roles in many biological processes. however, information is limited in their contribution to sex differentiation in animals. In the present study, we identified the novel miRNAs involved in sex-related genes regulation and explored the miRNA–mRNA networks underlying the posttranscriptional regulation during the initial sex differentiation in Zhikong scallop, Chlamys farreri. Our findings provide an important basis for studying the sex differentiation mechanisms, as well as developing sex control techniques in bivalves. Research on expressional regulation of genes at the initial sex differentiation of gonads will help to elucidate the mechanisms of sex determination and differentiation in animals. However, information on initial sex differentiation of gonads is limited in bivalves. MicroRNAs (miRNAs) are a class of endogenous small noncoding RNAs that can regulate the target gene expression at the posttranscription level by degrading the mRNA or repressing the mRNA translation. In the present study, we investigated the small RNAs transcriptome using the testes and ovaries of Zhikong scallop Chlamys farreri juveniles with a shell height of 5.0 mm, a critical stage of initial sex differentiation of gonads. A total of 75 known mature miRNAs and 103 novel miRNAs were identified. By comparing the expression of miRNAs between the ovary and testis, 11 miRNAs were determined to be differentially expressed. GO annotations and KEGG analyses indicated that many putative target genes that matched to these differentially expressed miRNAs participated in the regulation of sex differentiation. Furthermore, two selected miRNAs, cfa-novel_miR65 and cfa-miR-87a-3p_1, were confirmed to downregulate expressions of Foxl2 (a female-critical gene) and Klf4 (a male-critical gene), respectively, using a dual-luciferase reporter analysis. Our findings provided new insights into the initial sex differentiation of gonads regulated by miRNAs in bivalves. [ABSTRACT FROM AUTHOR]

The nomenclatural status of two Carex species described by Ohwi are reviewed. We found typification errors in C. chosenica Ohwi and C. ochrochlamys Ohwi. Accordingly, proper lectotypifications for the two taxa are provided here. We desginated specimens from the Kyoto University Herbarium (KYO) as lectotype for the two Carex taxa.

Paralytic shellfish toxins (PSTs) produced by certain marine dinoflagellates accumulate in filter-feeding marine bivalves. We used LC-MS/MS to detect and quantify 13 PSTs in 188 shellfish samples of 14 species collected from Shenzhen city's Buji seafood wholesale market from March 2019 to February 2020. Twenty-six of 188 shellfish samples (13.8%) were PSTs detectable. Within 14 species, 10 out of 34 noble clam Chlamys nobilis samples contain detectable PSTs with the highest detection rate 29.4%. Seven out of 17 samples from Nan'ao island contained detectable PSTs with the highest detection rate 41.2% among 11 origins. Samples containing PSTs were concentrated in spring and winter, with the highest levels in March>December>January. Among PSTs detected, C1 was dominant. Acute dietary exposure assessment for Shenzhen residents were based on mean adult body weight, 99th percentile daily shellfish consumption of Shenzhen food consumption survey 2008 and maximum PSTs concentration for each shellfish species. The outcome for Chlamys nobilis was 2.4~3.7-fold higher than recommended ARfDs. Mean PSTs concentration, P99, and mean shellfish consumption were used to assess chronic dietary exposure. The results were lower than recommended ARfDs. In conclusion, residents in Shenzhen are at risk for acute PSTs poisoning, while relatively safe from chronic PSTs exposure. [ABSTRACT FROM AUTHOR]

Copyright of South China Fisheries Science is the property of South China Fisheries Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Arkhaia Anatolika: The Journal of Anatolian Archaeological Studies is the property of Arkhaia Anatolika and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The directed fishery for Iceland scallop (Chlamys islandica) in the Strait of Belle Isle (Northwest Atlantic Fisheries Organization [NAFO] Div. 4R) has been prosecuted annually since 1969 with the exception of four years (1975-79). Populations in the Strait of Belle Isle are found on three beds at depths from 30-120 m. They are usually on hard bottom with variable substrate composition consisting largely of sand, gravel, shell fragments, and stones. Landings have averaged approximately 250 t since 2009, with lower than average landings of 115 t and 127 t in 2017 and 2018 respectively. The total allowable catch of 1000 t has not been taken since 2000. Catch per unit effort over the last decade has remained stable. The number of active licenses has declined in recent years to its lowest level. Since 2006 more than 90% of the landings has been taken from Bed 3 (southern bed). Fisheries and Oceans Canada (DFO) resource assessment surveys in September 2011 and 2018 resulted in minimum dredgeable biomass (MDB) estimates of 4,123 (t, round) and 3,432 (t, round) respectively. For the duration of the survey time series (since 1995) the MDB estimates have varied without trend. The natural mortality estimate was 0.26 in 2018 which was the highest in the survey time series. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Applied & Regional Geology / Zeitschrift der Deutschen Gesellschaft für Geowissenschaften (ZDGG) is the property of E. Schweizerbart'sche Verlagsbuchhandlung and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Nan'ao Golden Scallop, Chlamys nobilis, is an important scallop species in aquaculture and is rich in lipids and carotenoid. Previous studies have shown that microalgae diet has a significant effect on the accumulation of total lipid content (TLC) and total carotenoid content (TCC) in bivalves. However, the effects of single‐species microalgae diet on accumulation of TLC and TCC at molecular level are unclear. In this study, we used C. nobilis as a bivalve animal model to assess the effects of single‐species microalgae diet (Tetraselmis subcordiformis, Dicrateria zhanjiangensis and Chaetoceros mulleri) on the accumulation of lipids and carotenoids, and the expression of stearoyl‐CoA desaturase (SCD) and scavenger receptor class B‐like‐3 (SRB‐like‐3) genes in C. nobilis. The results of this study indicated that high lipid microalgae diet promoted the accumulation of TCC in C. nobilis tissues. The expression of SCD and SRB‐like‐3 genes was highly affected by the lipid composition of diet, in which high expression of SCD and SRB‐like‐3 genes was correlated with low C16:1n‐9 and/or C18:1n‐9t and/or C16:1/C16:0 and/or C18:1/C18:0. In intestine and adductor muscle, the expression of SCD gene was positively correlated with accumulation of TCC, TLC and fatty acid content, suggesting that SCD gene may indirectly promote the accumulation of TCC (lipid soluble) by promoting lipid accumulation. For SRB‐like‐3 gene, the high expression of SRB‐like‐3 was only correlated to the high TCC in intestine, suggesting that SRB‐like‐3 may be a candidate gene for carotenoid absorption in C. nobilis and has nothing to do with the transport or accumulation of carotenoid. The findings of this study are of great significance for further understanding how microalgae diet affects the accumulation of TCC and TLC, and the expression of lipid‐related genes in bivalves. [ABSTRACT FROM AUTHOR]

Cathepsin D is a soluble lysosomal aspartic proteinase of the pepsin superfamily that plays a crucial role in immune response. In this study, a novel cathepsin D of noble scallop Chlamys nobilis (named as CnCD) was cloned and its immune response to three different immunostimulants, including polyinosinic polycytidylic acid, lipopolysaccharide and Vibrio parahaemolyticus, was investigated in golden scallops and brown scallops of C. nobilis with different carotenoids content. The full-length cDNA of CnCD is 1844 bp, containing a 63-bp 5' terminal untranslated region (5'-UTR), a 1212-bp ORF encoding 403 amino acids and a 569-bp 3'-UTR. The predicted protein sequence of CnCD is composed of a signal peptide, a propeptide domain and a mature domain, and has a conserved bilobal structure. Phylogenetic analysis showed the CnCD was clustered into invertebrate group, and especially close to mollusc. Tissue distribution analysis of CnCD showed it was widely distributed in all tested tissues with higher levels in intestine, haemocytes and hepatopancreas. After immunostimulants challenged, CnCD transcripts were significantly up-regulated compared with the control group, indicating the CnCD plays important roles in immune response. Furthermore, the expression levels of CnCD in golden scallops were significantly higher than that of brown ones at most time points, suggesting carotenoids in golden scallops are important in promoting the immune response against pathogens. These results suggested that CnCD plays important roles in the immune defence against pathogens and the carotenoids can enhance the immune ability by up-regulating immune-related genes in noble scallop. [ABSTRACT FROM AUTHOR]

Antioxidant system plays important roles in organisms under environmental stress by eliminating hydrogen peroxide. Catalase is an indispensable antioxidant protein that is essential for maintaining the redox balance of innate immune system. In this study, a novel catalase gene was first cloned from noble scallop Chlamys nobilis (named as CnCAT), and then its potential roles in respond to low temperature stress were investigated using golden (rich in carotenoids) and brown (less in carotenoids) C. nobilis. The CnCAT contains an ORF of 1569 bp encoding 522 amino acids. Phylogenetic tree analysis of CnCAT showed it had a higher identity with other molluscs. The distribution analysis indicated that the highest and the lowest expression level of CnCAT were found in gill and adductor respectively. Under low temperature stress, CnCAT expression level and CAT activity were significantly up-regulated, suggesting they play important roles in defence against the low temperature stress. In addition, the expression levels of CnCAT and CAT in golden scallops were significantly higher than those of brown scallops under low temperature stress, suggesting that the high carotenoid levels in the golden scallops may strengthen their toleration to low temperature stress. Collectively, these results indicated that CnCAT plays vital roles in the antioxidant system, and carotenoids in golden scallops may enhance their resistance to low temperature stress. These results will provide us a better understand to the immune response of scallops under low temperature stress. [ABSTRACT FROM AUTHOR]

The tribe Chlamydini was highly diversified in the marine Neogene of southern South America, reaching its maximum taxonomic diversity during the Miocene. However, the evolutionary relationships of South American taxa remain uncertain. This is the first phylogenetic analysis based on a large morphological matrix on Pectinidae, which focuses on South American taxa and species related to Chlamys s.s. The phylogenetic analysis is based on a matrix composed of 145 shell‐characters scored for 48 species, and multiple searches were conducted using equal and implied weighting. Two new monophyletic clades are defined, Multiplicata and Pauciplicata. The first includes Dietotenhosen, Ckaraosippur, Zygochlamys, Moirechlamys (South America), the North‐West Pacific Azumapecten, and the North‐East Pacific Chlamys hastata. Pauciplicata is represented by Chokekenia (Patagonia, Argentina), Laevichlamys (tropical Atlantic and Indo‐Pacific), Semipallium (Indo‐Pacific), Swiftopecten (South America and North Pacific), and Jorgechlamys + Reticulochlamys (Patagonia, Argentina). All of these genera are monophyletic except for the paraphyletic Jorgechlamys. The oldest documented occurrence of the tribe is Semipallium foulcheri from the lower Oligocene, a derived taxon that pushes the divergence time of basal genera to the Eocene–Oligocene boundary, generating ghost lineages in all clades, except Jorgechlamys + Reticulochlamys. Pauciplicata and Multiplicata diverge in the early history of the tribe, at the Eocene–Oligocene boundary. Future analyses are necessary to gain a better understanding of the taxonomic arrangement of this poorly understood tribe. Further insights into the relationships of its deepest nodes may well resolve many ghost lineages. [ABSTRACT FROM AUTHOR]

The noble scallop Chlamys nobilis that rich in carotenoids is one of the most popular scallop species for aquaculture. Very little is known whether bivalve SRB‐like‐3 gene expression is regulated by retinoic acid receptor (RAR) and/or retinoic X receptor (RXR). In this study, the full‐length cDNA of RAR and RXR genes of C. nobilis was cloned and characterized for the first time, and then, the tissue differential expression of RAR and RXR mRNA in polymorphic C. nobilis was assessed. The roles of RAR and RXR in carotenoid accumulation in C. nobilis were assessed by manipulating the carotenoid content in tissues of C. nobilis via inhibiting the expression of SRB‐like‐3 gene. The results revealed that two isoforms of RAR (cnRARa (1958 bp/434 aa) and cnRARb (1901 bp/415 aa)) and four RXR isoforms (cnRXRa (1353‐bp/450 aa), cnRXRb (1341‐bp/446 aa), cnRXRc (1298‐bp/436 aa) and cnRXRd (1286‐bp/432 aa)) were cloned and characterized from C. nobilis. The reduction of carotenoid content caused by inhibition of SRB‐like‐3 gene induced the up‐regulation of RAR and RXR genes, suggesting that RAR and RXR genes may play a role in the regulation of carotenoid accumulation in haemolymph of C. nobilis. The findings of this study provide important clues for the regulation mechanism of total carotenoid accumulation in C. nobilis. [ABSTRACT FROM AUTHOR]

Copyright of Croatian Journal of Fisheries is the property of Sciendo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Here, a novel decapeptide IVTNWDDMEK with Maillard reactivity derived from scallop Chlamys farreri mantle was identified. The structural characteristics and in vitro hepatoprotective effects of IVTNWDDMEK conjugated with ribose were further investigated. The changes in decapeptide structures were determined by ultraviolet–visible (UV–vis), Fourier transform infrared (FTIR), and atomic force microscopy (AFM), and the modification sites induced by Maillard reaction of IVTNWDDMEK and ribose were monitored by high performance liquid chromatography/tandem mass spectrometry (HPLC‐MS/MS). Maillard reaction products (MRPs) of IVTNWDDMEK‐ribose demonstrate hepatoprotective benefits through the suppression of DNA damage and apoptosis induced by oxidative stress in human HepG2 cells in addition to enhancing the antioxidant activities. Moreover, after treatment with decapeptide‐ribose MRPs, the activities of cellular antioxidative enzymes, such as catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH‐Px), and glutathione reductase (GSH‐Rx) were remarkably increased, while the content of malondialdehyde (MDA) was decreased compared with H2O2‐treated group, thereby enhancing the intracellular antioxidant defenses. These findings demonstrate the potential utilization of decapeptide IVTNWDDMEK‐ribose MRPs as food antioxidants to suppress oxidative damage. Practical Application: In recent years, several food‐derived bioactive peptides and their derivatives are regarded as good dietary antioxidants for reducing oxidative stress and improving liver function. Here, a novel Maillard reactive decapeptide IVTNWDDMEK, identified from scallop mantle hydrolysates by peptidomics in the previous study was synthesized. Then, the correlation between intercellular antioxidant activities and chemical structure changes of IVTNWDDMEK‐ribose Maillard reaction conjugates was further studied. The preferable hepatoprotective activities of decapeptide IVTNWDDMEK‐ribose MRPs indicated that these MRPs could be potentially utilized as food antioxidants or additives in the production of nutritional foods. [ABSTRACT FROM AUTHOR]

Mitogen-activated protein kinase (MAPK) cascades are fundamental signal transduction modules in all eukaryotic organisms, participating growth and development, as well as stress response. In the present study, three MAPK genes were successfully identified from the genome of Chlamys farreri , respectively, named CfERK1/2 , CfJNK , and Cfp38 , and only one copy of ERK , JNK , and p38 were detected. Domain analysis indicated that CfMAPK s possessed the typical domains, including S_TKc, Pkinase, and PKc_like domain. Phylogenetic analysis showed that three CfMAPK s of MAPK subfamilies exists in the common ancestor of vertebrates and invertebrates. All CfMAPK s specifically expressed during larval development and in adult tissues, and the expression level of CfERK1/2 and Cfp38 was apparently higher than that of CfJNK. Under heat stress, the expression of CfERK1/2 and Cfp38 were significantly downregulated and then upregulated in four tissues, while the expression of CfJNK increased in all tissues; these different expression patterns suggested a different molecular mechanism of CfMAPKs for bivalves to adapt to temperature changes. The diversity of CfMAPKs and their specific expression patterns provide valuable information for better understanding of the functions of MAPK cascades in bivalves. [ABSTRACT FROM AUTHOR]

Copyright of South China Fisheries Science is the property of South China Fisheries Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Microplastics (MPs) pollution's impact on the marine ecosystem is widely recognized. This study compared the effects of polyethylene (PE) and polyethylene terephthalate (PET) on two bivalve species, Ruditapes philippinarum (clam) and Chlamys farreri (scallop), at two particle concentrations (10 and 1000 μg/L). MPs were found in the digestive glands and gills of both species. Although clearance rates showed no significant changes, exposure to different MPs caused oxidative stress, energy disruption, and lipid metabolism disorders in both clam and scallop. Histopathological damage was observed in gills and digestive glands. IBR values indicated increasing toxicity with concentration, with PET being more toxic than PE. WOE model suggested increasing hazard with concentration, highlighting higher PET toxicity on clam digestive glands. In contrast, PE hazard increased in gills, showing different species responses. R. philippinarum exhibited higher sensitivity to MPs than C. farreri , providing insights for assessing ecological risk under realistic conditions and stress conditions. [Display omitted] • MPs exposure caused oxidative stress and energy metabolism disorder in bivalves. • MPs exposure induces histopathological damage in bivalves. • PET MPs are more toxic to these bivalves than PE MPs. • The physiological responses of clam to MPs were not wholly consistent with scallop. [ABSTRACT FROM AUTHOR]

The multixenobiotic resistance mechanism (MXR) provides aquatic organisms with the capacity to adapt to polluted environments, which can be inhibited by chemosensitizers. In the present study, the effect of two typical marine persistent organic pollutants, benzo(a)pyrene (BaP) and tetrabromobisphenol A (TBBPA), on the most relevant ABC transporters, ABCB1, ABCC1, and ABCG2 of scallop Chlamys farreri was tested. MXR transporter efflux activity of cultured gill cells of the scallops was evaluated by measuring the intracellular fluorescent intensity of Calcein-AM and rhodamine 123 with flow cytometry. The results showed that ABCB1 and ABCC1 transporters demonstrated increased activity compared with ABCG2 in mediating MXR efflux activity. BaP and TBBPA were able to suppress the efflux transporter activity of ABC transporters significantly, of which BaP revealed block effects by acting on the ABCB1 transporter. Additionally, exposure of BaP and TBBPA only significantly upregulated the expression level of ABCC1 gene. This study demonstrated the promising utility of efflux transporter activity in conjunction with biomarkers such as mRNA levels in identification of chemosensitizer. [ABSTRACT FROM AUTHOR]

This paper describes a rich bivalve fauna from the Tubiphytes‐Limestone Member (Bithynian, early middle Anisian) of the Caerace Formation in North Dobrogea (Romania). We report 51 bivalve species, including 7 new species and 2 new genera: Atrina multicostata sp. nov., Pinna simionescui sp. nov., Chlamys (Praechlamys) prima sp. nov., Entolium reticulatum sp. nov., Scythentolium anisicum sp. nov., Romaniamya mahmudiaensis gen. et sp. nov. and Praedicerocardium vetulus gen. et sp. nov. The latter taxon represents the oldest Triassic megalodontoid. We provide detailed descriptions of the bivalve fauna, discuss the ecology and compare species richness in the Early and Middle Triassic, showing that the bivalve assemblage of North Dobrogea is much more diverse than all previously described Early Triassic bivalve faunas, but not as rich as several faunas from the late Anisian and Ladinian. The relative richness of the Dobrogea fauna with respect to geologically older and younger faunas suggests that it represents an early stage of the main rediversification of bivalves after the end‐Permian mass extinction. [ABSTRACT FROM AUTHOR]

Paecilomyces variotii (a filamentous fungus), is a promising novel protein source in fish feeds due to its high nutritional value. Also, P. variotii has Microbial-Associated Molecular Patterns (MAMPs) such as glucans and nucleic acids that could modulate the host's immune response. To understand the potential bioactive properties of this fungus in Atlantic salmon (Salmo salar), our study was conducted to evaluate the gene expression of immune-related biomarkers (e.g., cytokines, effector molecules and receptors) on primary cultures from salmon head kidney (HKLs) and spleen leukocytes (SLs) exposed to either UV inactivated or fractions from P. variotii with or without inactivated Moritella viscosa (a skin pathogen in salmonids). Moreover, the effect of the fermentation conditions and down-stream processing on the physical ultrastructure and cell wall glucan content of P. variotii was characterized. The results showed that drying had a significant effect on the cell wall ultrastructure of the fungi and the choice of fermentation has a significant effect on the quantity of β-glucans in P. variotii. Furthermore, stimulating Atlantic salmon HKLs and SLs with P. variotii and its fractions induced gene expression related to pro-inflammatory (tnfα, il1β) and antimicrobial response (cath2) in HKLs, while response in SLs was related to both pro-inflammatory and regulatory response (tnfα, il6 and il10). Similarly, the stimulation with inactivated M. viscosa alone led to an up-regulation of genes related to pro-inflammatory (tnfα, il1β, il6) antimicrobial response (cath2), intra-cellular signalling and recognition of M. viscosa (sclra, sclrb) and a suppression of regulatory response (il10) in both HKLs and SLs. Interestingly, the co-stimulation of cells with P. variotii and M. viscosa induced immune homeostasis (il6, tgfβ) and antimicrobial response (cath2) in SLs at 48h. Thus, P. variotii induces immune activation and cellular communication in Atlantic salmon HKLs and SLs and modulates M. viscosa induced pro-inflammatory responses in SLs. Taken together, the results from physical and chemical characterization of the fungi, along with the differential gene expression of key immune biomarkers, provides a theoretical basis for designing feeding trials and optimize diets with P. variotii as a functional novel feed ingredient for Atlantic salmon., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)