The role of Pm-miR-184-3p in regulating the immune response in the pearl oyster Pinctada fucata martensii.

microRNAs are a class of non-coding RNAs with post-transcriptional regulatory functions in eukaryotes. In our previous study, miR-184-3p was identified in the hemocyte transcriptome of Pinctada fucata martensii (Pm-miR-184-3p), and its expression was shown to be up-regulated following transplantation surgery; however, its role in regulating transplantation immunity has not yet been clarified. Here, the role of Pm-miR-184-3p in regulating the immune response of P. f. martensii was studied. The expression of Pm-miR-184-3p increased following the stimulation of pathogen-associated molecular patterns, and Pm-miR-184-3p overexpression increased the activity of antioxidant-related enzymes, such as superoxide dismutase and catalase. Transcriptome analysis obtained 1096 differentially expressed genes (DEGs) after overexpression of Pm-miR-184-3p, and these DEGs were significantly enriched in conserved pathways such as the Cell cycle pathway and NF-kappa B signaling pathway, as well as GO terms including base excision repair, cell cycle, and DNA replication, suggesting that Pm-miR-184-3p could enhance the inflammation process. Target prediction and dual luciferase analysis revealed that pro-inflammatory related genes Pm-TLR3 and Pm-FN were the potential target of Pm-miR-184-3p. We speculate that Pm-miR-184-3p may utilize negative regulation of target genes to delay the activation of corresponding immune pathways, potentially preventing excessive inflammatory responses and achieving a delicate balance within the organism. Overall, Pm-miR-184-3p play a key role in regulating cellular responses to transplantation. Our findings provide new insights into the immune response of P. f. martensii to transplantation.

Immunomodulatory effects of one novel microRNA miR-63 in pearl oyster Pinctada fucata martensii.

Novel microRNA miR-63 (novel-miR-63) from pearl oyster Pinctada fucata martensii (Pm-novel-miR-63) is a species-specific miRNA. Our previous research has shown that the expression of Pm-novel-miR-63 was significantly downregulated at 24 h after nucleus transplantation. In this study, we analyzed the function and regulatory role of Pm-novel-miR-63 in the immune response of pearl oysters. The results showed that Pm-novel-miR-63 expression increased after the stimulation of pathogen associated molecular patterns at 6-12 h, and the activity of immune and antioxidant enzymes in the serum decreased after Pm-novel-miR-63 overexpression. Transcriptome analysis revealed that Pm-novel-miR-63 participated in regulating transplantation immunity through the Notch and mRNA surveillance signaling pathways. Target prediction and dual luciferase analysis revealed that Pm-GDP-FucTP, Pm-CysLTR2, and Pm-RLR were the target genes of Pm-novel-miR-63. These results suggested that Pm-novel-miR-63 participated in regulating the immune response in pearl oysters and can serve as a new interference target to reasonably control excessive immune rejection in pearl culture.

Identification and comparative analysis of miRNA transcriptomes after allograft and xenograft transplantation in Pinctada fucata martensii.

Effective immune regulation after transplantation during pearl production is crucial for the cultivation of high-quality pearls. MicroRNAs (miRNAs) play an important role in a variety of physiological processes. To understand the regulatory rules of miRNAs after transplantation in Pinctada funcata martensii, we constructed 13 miRNA transcriptomes, including the control group (Con), allograft (Al), and xenograft (Xe) transplantation at six time points (6, 12, and 24 h and 3, 6, and 12 days), in which the xenografted mantle tissue was from Pinctada maxima. We identified 159 differentially expressed miRNAs (DEMs) and found that these DEMs showed high expression at 12 h, 24 h, and 3 days after transplantation. A total of 130 DEMs, such as Let-7, were present in the Al and Xe groups; miR-34 and 16 other DEMs were specifically present in the Al group; miR-216b and 13 other DEMs were specifically present in the Xe group. Compared with the Con group, the target genes of DEMs in the Al group were significantly enriched in protein complex, cytoskeleton, and macromolecular complex, and the Xe group was significantly enriched in ribonucleoside metabolic process, nucleoside binding, and cell division. Compared with the Al group, the target genes in the Xe group were significantly enriched in response to DNA damage stimulation. Overall, multiple pathways associated with cellular activity were enriched in higher numbers of genes in the Xe group than in the Al group. These findings enriched the information on immune regulatory mechanisms at the expression level of miRNAs in P. f. martensii after transplantation.

Hydrogen-Donor-Controlled Polybrominated Dibenzofuran (PBDF) Formation from Polybrominated Diphenyl Ether (PBDE) Photolysis in Solutions: Competition Mechanisms of Radical-Based Cyclization and Hydrogen Abstraction Reactions.

Polybrominated dibenzofurans (PBDFs) are characteristic dioxin-like products of polybrominated diphenyl ether (PBDE) photolysis. In this study, competition mechanisms of radical-based cyclization and hydrogen abstraction reactions are proposed in PBDF formation. Commonly, the ortho C-Br bond dissociation during photolysis generates aryl radicals, which undergo intramolecular cyclization to form PBDFs or hydrogen abstraction with hydrogen donors (such as organic solvents and water) to form lower brominated PBDEs. By using 2,4,4'-tribromodiphenyl ether (BDE-28) as the model reactant, the experimental PBDF formation ratios in various solutions are explained quantitatively by the calculated rate constants of cyclization and hydrogen abstraction reactions using the density functional theory (DFT) method. The solvent effect of pure and mixed solvents on PBDF formation is illustrated successfully. The structure-related hydrogen donation ability for hydrogen abstraction controls the bias of competition reactions and influences PBDF formation. Water resulted to be the most significant generation of PBDFs. Fulvic and humic acid display higher hydrogen donation ability than small-molecule organics due to the partitioning effect in aqueous solution. Quantitative structure-activity relationship (QSAR) models of the calculated rate constants for 512 cyclization and 319 hydrogen abstraction reactions using 189 PBDEs as the initial reactants in water are established, revealing the high risk of PBDF formation in aqueous solution.

Adsorption behavior of hierarchical porous biochar from shrimp shell for tris(2-chloroethyl) phosphate (TCEP): Sorption experiments and DFT calculations.

Tris(2-chloroethyl) phosphate (TCEP) as a new type of flame retardant exists in various water environments, causing great risks to humans and the environment. In this study, shrimp shell was used to prepare an economical and environmental-friendly adsorbent for the efficient removal of TCEP. The systematic studies including characterization, removal performance, and adsorption mechanism of shrimp shell biochar toward TCEP were carried out. Adsorption kinetics and thermodynamics showed that fast equilibrium reached within 30 min, the maximum adsorption capacity qm was 108 µmol g-1 at 298 K, and the adsorption process is spontaneous and exothermic. The environmental factor, such as temperature, pH, inorganic anions and organic matter hardly affected the adsorption performance. Structural characterization indicated that the hierarchical porous structure of shrimp shell biochar is the key to excellent adsorption performance. The adsorption mechanisms were further revealed using density functional theory (DFT) calculations, and the hydrogen bond, van der Waals interactions, Cl-H interactions, and pi-H interactions were identified as potential interaction mechanisms between TCEP and specific biochar structures. The calculated binding energy between TCEP and simplified biochar structure suggested that oxygen-containing groups especially carboxyl, hydroxyl and aldehyde facilitate the adsorption. Our work not only provides a novel strategy for the quick remediation of organophosphate-contaminated water environments but also offers new opportunities for crustacean waste biomass valorization.

Oxidation of 1,3-diphenylguanidine (DPG) by goethite activated persulfate: Mechanisms, products identification and reaction sites prediction.

As emerging pollutants continue to be discovered, studies on the degradation behavior of emerging pollutants have proliferated, but few studies have focused on the reactivity of the new pollutants themselves. The work investigated the oxidation of a representative roadway runoff-derived organic contaminant, 1,3-diphenylguanidine (DPG) by goethite activated persulfate (PS). DPG exhibited the highest degradation rate (kd = 0.42 h-1) with present of PS and goethite at pH 5.0, then started to decrease with increasing pH. Chloride ion inhibited DPG degradation by scavenging HO·. Both HO· and SO4-· were generated in goethite activated PS system. Competitive kinetic experiments and flash photolysis experiments were conducted to investigate free radical reaction rate. The second-order reaction rate constants for DPG reacting with HO· and SO4-· were quantified (kDPG + HO·,kDPG + SO4-·), which both reached above 109 M-1 s-1. Chemical structures of five products were identified, four of them were previously detected in DPG photodegradation, bromination and chlorination processes. By density functional theory (DFT) calculations, ortho- and para- C were more easily attacked by both HO· and SO4-·. Abstraction of H on N by HO· and SO4-· were the favorable pathways, and the product TP-210 might be generated by cyclization of DPG radical from abstraction of H on N (3). The results of this study help us to better understand the reactivity of DPG with SO4-· and HO·.

Balloon Dilation Eustachian Tuboplasty Combined with Tympanotomy Tube Insertion for Treatment of Refractory Otitis Media with Effusion: A Randomized, Prospective, Controlled Trial Comparing Local Anesthesia Combined Sedation Versus General Anesthesia.

BACKGROUND Balloon dilation eustachian tuboplasty (BET) is used to treat eustachian dysfunction but its therapeutic effect and cost-effectiveness when combined with tympanotomy tube insertion (TBI) on refractory otitis media with effusion under local anesthesia with sedation compared to traditional general anesthesia are not well understood. MATERIAL AND METHODS Forty patients with refractory secretory otitis media who received BET+TBI were enrolled in this study and randomized into the local anesthesia with sedation group (n=20) and general anesthesia group (n=20). Tympanometry (TMM), 7-item eustachian tube dysfunction questionnaire (ETDQ-7) results, intraoperative anesthesia accidents, and operation costs were compared between the groups. RESULTS Patients in the local anesthesia with sedation group exhibited intraoperative awareness and pain. Differences in TMM, ETDQ-7 results, and postoperative VAS scores between the groups were comparable (P>0.05). Notably, operative time and treatment costs in the local anesthesia group were lower compared with general anesthesia group. CONCLUSIONS The treatment effects and safety of local anesthesia and general anesthesia under BET combined with TBI for treatment of refractory otitis media with effusion are comparable. However, further studies should aim at reducing pain and discomfort.

Efficient removal of polybrominated diphenyl ethers from soil washing effluent by dummy molecular imprinted adsorbents: Selectivity and mechanisms.

Surfactant enhanced elution is an effective method for removing hydrophobic organic pollutants from soils. The key to the development of leaching technology is selective removal of targeted pollutants in soil washing effluent and recycling of surfactant solutions. In this study, a molecular imprinting technique was applied to selectively sorb polybrominated diphenyl ethers (PBDEs) in soil washing effluent. The novel molecular imprinted polymers (MIPs) using different template molecules were synthesized by precipitation polymerization. Adsorption behaviors and mechanisms of MIPs were studied through experiments and theoretical calculations. The results show that 4-bromo-4'-hydroxybiphenyl and toluene can be effective imprinting molecule for MIPs synthesis. The maximal adsorption capacity of selected dummy molecular imprinted polymer (D1-MIP) was 1032.36 µmol/g, and that of part molecular imprinted polymer (P-MIP) was 981.13 µmol/g. Their imprinting factors in 5 PBDEs adsorption ranged from 2.13 to 5.88, the recovery percentage of Triton X-100 can reach 99.09%, confirming the feasibility of reusing surfactant. Various PBDEs could be removed by MIPs, and Quantitative Structure Property Relationship analysis revealed that PBDEs' molecular volume, planarity, polarity, and hydrophobicity have major influences on their adsorption performance. DFT calculation revealed that Van der Waals force and hydrogen bonding played important roles during selective adsorption. These results can provide effective theoretical guidance for surfactant enhanced soil elution in practical engineering applications.

Globular C1q domain-containing protein from Pinctada fucata martensii participates in the immune defense process.

The globular C1q domain-containing (C1qDC) protein can recognize a variety of ligands, such as pathogen-associated molecular patterns, and plays an important role in the innate immune response. Our previous studies showed that a novel globular C1q domain-containing protein (PmC1qDC-1) is involved in the damage repair process of pearl oyster shells. However, the function of PmC1qDC-1 in pearl oyster innate immunity remains unknown. In the present study, the high-level structural analysis showed that PmC1qDC-1 was a spherical structure composed of 10 strands and was similar to the AiC1qDC-2 of bay scallop (Argopecten irradians). In situ hybridization indicated that PmC1qDC-1 had strong fluorescence signal in gills. Furthermore, the mRNA expression of PmC1qDC-1 was highly induced at 6-48 h in gill after lipopolysaccharide, peptidoglycan and polyinosinic-polycytidylic acid stimulation. Additionally, we obtained the recombinant protein of PmC1qDC-1 (rPmC1qDC-1) and found that rPmC1qDC-1 had antibacterial activity against Gram-negative (i.e., Pseudomonas aeruginosa, Vibrio parahaemolyticus, Escherichia coli, and Aeromonas hydrophila) and Gram-positive (i.e., Staphylococcus aureus and Bacillus subtilis) bacteria. These results indicated that PmC1qDC-1 might play an important role in the immune response against bacteria and viruses. This study provides clues for further studying the immune defense of Pinctada fucata martensii against pathogens and exploring the evolution of the classic pathway of complement system.

Surgical outcomes and observation in exotropia cerebral palsy children with cortical visual impairment.

PURPOSE: Cortical visual impairment (CVI) is the common cause of pediatric visual impairment in cerebral palsy (CP) while exotropia is the most common strabismus associated with CP. We aim to observe the strabismic surgery outcomes in pediatric patients with CP and CVI. METHOD: Our medical records were collected from pediatric patients treated in our hospital from May 1, 2017 to Jan 1, 2022. With normal intelligence assessment and diagnosis of exotropia in children with CP and CVI, microsurgeries were performed under intravenous combined inhalation anesthesia. The strabismus was examined by the prism test under best vision correction and the contrast sensitivity testing (CST) was measured at five levels of spatial frequencies. RESULT: A total of 38 exotropia patients with CP and CVI were identified and included for analysis during the study period with age ranged from 5 to 12 years (mean 8.45 years) and mean follow up duration was 8.7 months (6-42 months). After bilateral lateral rectus recession (with/without medial rectus resection or inferior oblique transposition), the exotropia amount of participants were obviously revealed from - 30 ~ - 140 (median, IQR: - 50, 40) prism diopters (PD) preoperatively to 0 ~ - 15 (0, 5) PD postoperatively. Statistically significantly improvements were observed at all levels of spatial frequency on CST postoperatively, especially at high spatial frequency areas (p < 0.05). CONCLUSION: Our results demonstrated that the effect of strabismus surgery on exotropia in children with CP and CVI were stable and monocular contrast sensitivity post- operation increased significantly at all spatial frequencies levels.

Use of a Remote Oncology Pharmacy Service Platform for Patients With Cancer During the COVID-19 Pandemic: Implementation and User Acceptance Evaluation.

BACKGROUND: The COVID-19 outbreak has increased challenges associated with health management, especially cancer management. In an effort to provide continuous pharmaceutical care to cancer patients, Sun Yat-sen University Cancer Center (SYSUCC) implemented a remote pharmacy service platform based on its already existing web-based hospital app known as Cloud SYSUCC. OBJECTIVE: The aim of this study was to investigate the characteristics, acceptance, and initial impact of the Cloud SYSUCC app during a COVID-19 outbreak in a tertiary cancer hospital in China. METHODS: The total number of online prescriptions and detailed information on the service were obtained during the first 6 months after the remote service platform was successfully set up. The patients' gender, age, residence, primary diagnosis, drug classification, weekly number of prescriptions, and prescribed drugs were analyzed. In addition, a follow-up telephonic survey was conducted to evaluate patients' satisfaction in using the remote prescription service. RESULTS: A total of 1718 prescriptions, including 2022 drugs for 1212 patients, were delivered to 24 provinces and municipalities directly under the Central Government of China between February 12, 2020, and August 11, 2020. The majority of patients were female (841/1212, 69.39%), and 90.18% (1093/1212) of them were aged 31-70 years old. The top 3 primary diagnoses for which remote medical prescriptions were made included breast cancer (599/1212, 49.42%), liver cancer (249/1212, 20.54%), and thyroid cancer (125/1212, 10.31%). Of the 1718 prescriptions delivered, 1435 (83.5%) were sent to Guangdong Province and 283 (16.5%) were sent to other provinces in China. Of the 2022 drugs delivered, 1012 (50.05%) were hormonal drugs. The general trend in the use of the remote prescription service declined since the 10th week. A follow-up telephonic survey found that 88% (88/100) of the patients were very satisfied, and 12% (12/100) of the patients were somewhat satisfied with the remote pharmacy service platform. CONCLUSIONS: The remote pharmacy platform Cloud SYSUCC is efficient and convenient for providing continuous pharmaceutical care to patients with cancer during the COVID-19 crisis. The widespread use of this platform can help to reduce person-to-person transmission as well as infection risk for these patients. Further efforts are needed to improve the quality and acceptance of the Cloud SYSUCC platform, as well as to regulate and standardize the management of this novel service.

Molecular and functional analysis of PmC1qDC in nacre formation of Pinctada fucata martensii.

The C1q-domain-containing (C1qDC) proteins are a family of proteins characterized by a globular C1q (gC1q) domain in their C-terminus which hold the potential function in the shell formation as shell matrix proteins. In this study, a C1qDC protein was identified and characterized in pearl oyster (Pinctada fucata martensii) (PmC1qDC) to explore its function in nacre formation. The PmC1qDC-deduced protein sequence carried a typical globular C1q (gC1q) domain that possessed the typical 10-stranded ß-sandwich fold with a jelly-roll topology common to all C1qDC family members and shared high homology with other gC1q domains. Homologous analysis of PmC1qDC presented it contained conserved secondary structure and Phe135, Phe155, Tyr166, Phe173, Tyr181, Phe183, and Phe256 amino acid residues. Expression pattern analysis showed that PmC1qDC expressed in all the detected tissues and exhibited a significantly higher expression level in nacre formation-associated tissues. After the shell notching, the expression level of PmC1qDC showed significantly up-regulation after 12 h in the central zone of mantle (MC). PmC1qDC expression significantly decreased in the MC after RNA interference (RNAi). Furthermore, disordered crystals with evident rough surface and irregular crystal tablets were observed in the nacre after RNAi. Results suggested that PmC1qDC affects the shell nacre formation, which is significant to improve the pearl production of pearl oyster.

Identification of a long non-coding RNA (LncMSEN2) from pearl oyster and its potential roles in exoskeleton formation and LPS stimulation.

Long non-coding RNAs (lncRNAs) play regulatory roles in various biological processes, including exoskeleton formation and immune response. The exoskeleton-based mantle-shell defense system is an important defense mechanism in shellfish. In this study, we found a novel lncRNA, herein formally named, LncMSEN2, from the pearl oyster Pinctada fucuta martensii, and its sequence was validated via polymerase chain reaction (PCR). LncMSEN2 was highly expressed in mantle tissues, especially in the central region (P < 0.05), and was also expressed in the pearl sac as detected by quantitative real-time PCR. In situ hybridization experiments revealed that LncMSEN2 had a strong positive signal in the inner and outer epidermal cells of the mantle pallial and central regions. RNA interference experiments showed that interference of LncMSEN2 expression with dsRNA in mantle tissues led to an abnormal crystal structure of the nacre. In addition, LncMSEN2 expression significantly increased 6 h after lipopolysaccharide stimulation in mantle tissues (P < 0.05). These results indicated that LncMSEN2 may be a novel regulator of the mantle-shell defense system of pearl oyster.

Response of pearl oyster Pinctada fucata martensii to allograft-induced stress from lipid metabolism.

The pearl oyster, Pinctada fucata martensii, produces high-quality pearls. During pearl production, excess immune and inflammatory response after transplantation will lead to nucleus rejection, pearl sac formation failure, and death of the host pearl oyster. The hemocyte transcriptome and fatty acid (FA) contents in the adductor muscle before and after transplantation were analyzed to investigate the response of pearl oyster P. f. martensii to allograft-induced stress from lipid metabolism. The hemocyte transcriptome analysis detected 193 lipid metabolism-related genes, such as the elongation of very long-chain FA protein 5, acyl-CoA 6-desaturase, cytochrome P450, phospholipase A2, glycerol-3-phosphate O-acyltransferase, and prostaglandin-H2 d-isomerase. Pathway enrichment analyses revealed that these genes were mainly involved in the "biosynthesis of unsaturated FAs," "FA biosynthesis," "ARA metabolism," and "glycerolipid metabolism." An analysis of FA contents in the adductor muscle indicated no significant difference in the contents of lauric acid, myristic acid, pentadecanoic acid, palmitic acid, palmitoleic acid, heptadecanoic acid, stearic acid, oleic acid, vaccenic acid, linoleic acid, arachidic acid, α-linolenic acid, eicosadienoic acid, docosadienoic acid, and 11,14,17-eicosatrienoic acid. However, ARA, DHA, and EPA in the adductor muscle after transplantation were significantly greater than those processed without grafting surgery. These results suggest that pearl oysters require more polyunsaturated FAs (PUFAs) to regulate their inflammatory and immune response after transplantation. However, their ability to biosynthesize unsaturated FAs is limited. Given these results, the addition of PUFA-containing diets or selection of a line with strong ability to biosynthesize unsaturated FAs may be valuable for pearl oyster recovery after transplantation.

Comparison of radical and non-radical activated persulfate systems for the degradation of imidacloprid in water.

The study focuses on degradation efficiency of non-radical activation and radical activation systems of persulfate (PS) to degrade imidacloprid (IMI) by using sodium persulfate (SPS) as PS source. Copper oxide (CuO)-SPS and CuO/biochar (BC)-SPS were selected as PS non-radical activation systems, and pyrite (PyR)-SPS was selected as PS radical activation system. The degradation by CuO-SPS, CuO/BC-SPS and PyR-SPS systems was investigated from acidic to basic conditions (pH 3.0-11.0). Highest degradation by CuO-SPS and CuO/BC-SPS systems was achieved over pH 11.0. In contrast, highest degradation by PyR-SPS system was achieved over pH 3.0, however, PyR-SPS system was also found effective up to pH 9.0. It was found that degradation was more efficient in PS radical activation system, indicating that IMI could be oxidized by radicals rather than by activated PS. Electron paramagnetic resonance (EPR) analysis was carried out to investigate the generation of sulfate (SO4-) and hydroxyl (OH) radicals, which indicated the presence of SO4- and OH in CuO-SPS, CuO/BC and PyR-SPS systems. However, free radical quenching analysis indicated that radicals were main reactive oxygen species for degradation. The lower degradation in PS non-radical activation systems was probably resulted from radicals existed as minor reactive oxygen species. The findings indicated that non-radical oxidation systems showed low reality for degradation and good degradation could be achieved by radical oxidation system. The degradation was also carried out in real waters to investigate the potential applicability of applied systems, which supported PyR-SPS system for effective degradation.

Assessment of Laying Hens' Thermal Comfort Using Sound Technology.

Heat stress is one of the most important environmental stressors facing poultry production and welfare worldwide. The detrimental effects of heat stress on poultry range from reduced growth and egg production to impaired health. Animal vocalisations are associated with different animal responses and can be used as useful indicators of the state of animal welfare. It is already known that specific chicken vocalisations such as alarm, squawk, and gakel calls are correlated with stressful events, and therefore, could be used as stress indicators in poultry monitoring systems. In this study, we focused on developing a hen vocalisation detection method based on machine learning to assess their thermal comfort condition. For extraction of the vocalisations, nine source-filter theory related temporal and spectral features were chosen, and a support vector machine (SVM) based classifier was developed. As a result, the classification performance of the optimal SVM model was 95.1 ± 4.3% (the sensitivity parameter) and 97.6 ± 1.9% (the precision parameter). Based on the developed algorithm, the study illustrated that a significant correlation existed between specific vocalisations (alarm and squawk call) and thermal comfort indices (temperature-humidity index, THI) (alarm-THI, R = -0.414, P = 0.01; squawk-THI, R = 0.594, P = 0.01). This work represents the first step towards the further development of technology to monitor flock vocalisations with the intent of providing producers an additional tool to help them actively manage the welfare of their flock.

Developmental characteristics of pearl oyster Pinctada fucata martensii: insight into key molecular events related to shell formation, settlement and metamorphosis.

BACKGROUND: Marine bivalves undergo complex development processes, such as shell morphology conversion and changes of anatomy and life habits. In this study, the transcriptomes of pearl oyster Pinctada fucata martensii and Pacific oyster Crassostrea gigas at different development stages were analyzed to determine the key molecular events related to shell formation, settlement and metamorphosis. RESULT: According to the shell matrix proteome, biomineralization-related genes exhibited a consensus expression model with the critical stages of shell formation. Differential expression analysis of P. f. martensii, revealed the negative regulation and feedback of extracellular matrixs as well as growth factor pathways involved in shell formation of larvae, similar to that in C. gigas. Furthermore, neuroendocrine pathways in hormone receptors, neurotransmitters and neuropeptide receptors were involved in shell formation, settlement and metamorphosis. CONCLUSION: Our research demonstrated the main clusters of regulation elements related to shell formation, settlement and metamorphosis. The regulation of shell formation and metamorphosis could be coupled forming the neuroendocrine-biomineralization crosstalk in metamorphosis. These findings could provide new insights into the regulation in bivalve development.

Effect of vitamin D3 on immunity and antioxidant capacity of pearl oyster Pinctada fucata martensii after transplantation: Insights from LC-MS-based metabolomics analysis.

Postoperative care is a critical step of pearl culture that ultimately determines culture success. To determine the effect of dietary vitamin D3 (VD3) levels on immunity and antioxidant capacity of pearl oyster Pinctada fucata martensii during postoperative care and explore the mechanisms behind this phenomenon, five isonitrogenous and isolipidic experimental diets were formulated by adding different levels of dietary VD3 (0, 500, 1000, 3000, and 10000 IU/kg), and the diets were fed to five experimental groups (EG1, EG2, EG3, EG4, and EG5) in turn and cultured indoors. The control group (CG) was cultured in the natural sea. Pearl oysters that were 1.5 years old were subjected to nucleus insertion. After culturing for 30 days, EG3 exhibited significantly higher survival rates than those in CG and EG5 (P < 0.05). Moreover, EG3 exhibited the highest activities of alkaline phosphatase, acid phosphatase, catalase, superoxide dismutase, and lysozyme. However, EG5 achieved the highest activities of glutathione peroxidase. Metabolomics-based profiling of pearl oysters fed with high levels of dietary VD3 (EG5) and optimum levels of dietary VD3 (EG3) revealed 76 significantly differential metabolites (SDMs) (VIP > 1 and P < 0.05). Pathway analysis indicated that SDMs were involved in 21 pathways. Furthermore, integrated key metabolic pathway analysis suggested that pearl oysters in EG5 regulated the pentose phosphate pathway, glutathione metabolism, sphingolipid metabolism, and arachidonic acid metabolism in response to stress generated from excessive VD3. These findings had significant implications on strengthening the future development and application of VD3 in aquaculture of pearl oyster P. f. martensii.

HSP40 gene family in pearl oyster Pinctada fucata martensii: Genome-Wide identification and function analysis.

HSP40, also called DnaJ, functions as a molecular chaperone by binding to Hsp70 and plays critical roles in the growth, development, and response to heat stress. However, this gene family is rarely reported in pearl oyster. In this study, 31 putative HSP40 genes from Pinctada fucata martensii (PmHSP40) were identified through bioinformatics methods and classified into three groups according to the presence of the complete three domains (J, G/F zinc finger domain, and cysteine rich domain). Further analysis showed that the PmHSP40 genes are highly diverse in sequence, domain structure, and tissue and development expression profile, implying diversified functions. In addition, one highly induced PmHSP40 in low-temperature (PmHSP40LT) was cloned, and its function in temperature response was explored. PmHSP40LT has a full length of 1741 bp, containing 1059 bp ORF, 152 bp 5'UTR, and a 507 bp 3'UTR, and encodes 352 amino acids. PmHSP40LT expression was significantly induced at low (17 °C) and high temperature (32 °C) at 6 h, 1 d, and 3 d relative to the control group. Thus, PmHSP40LT possibly participates in response to high and low temperatures in pearl oyster. In conclusion, all these results provide a comprehensive basis for the further analysis of PmHSP40 function in pearl oysters.

Comprehensive transcriptome analysis reveal key molecular events in the pearl oyster after pre-grafting conditioning.

Pre-grafting conditioning is a crucial procedure before transplant surgery during pearl production. To investigate the molecular response of the pearl oyster Pinctada fucata martensii to conditioning, we constructed two hemocyte transcriptomes from pearl oysters with and without conditioning. A total of 134,222,686 raw reads were generated and assembled using the reference genome of the pearl oyster. Transcriptome analysis revealed 3,074 differentially expressed genes (DEGs). Gene ontology and pathway enrichment analyses revealed that these DEGs were mainly associated with "microtubule-based process", "regulation of actin cytoskeleton", and "cell cycle". All related genes were over-expressed in pearl oysters after conditioning. Some nucleotide-binding oligomerization domain-like receptors (NLR), toll-like receptor, myd88, proinflammatory cytokine interleukin-17 (IL-17), and apoptosis-related genes were highly expressed in pearl oysters after conditioning, indicating that conditioning induced the immune response of pearl oysters. "Fatty acid biosynthesis" (FA biosynthesis) was included in the enriched terms, and all eight FA synthase genes in this pathway were highly induced after conditioning. Four tandemly duplicated arginine kinase genes (PmAK) were found in the genome of P. f. martensii, gene structure and sequence analysis indicated PmAK genes were more diverse compared with that from human and zebra fish. The four tandemly duplicated PmAKs were highly up-regulated after conditioning. These findings will help to elucidate the responding molecular events after conditioning and explain the high pearl oyster survival rate with conditioning after transplantation, thereby providing useful information in perfecting the conditioning method to improve pearl oyster survival rate after transplantation.