Two IFNa3s mediate the regulation of IRF9 in the process of infection with Streptococcus iniae in yellowfin seabream, Acanthopagrus latus (Hottuyn, 1782).

IRF9 can play an antibacterial role by regulating the type I interferon (IFN) pathway. Streptococcus iniae can cause many deaths of yellowfin seabream, Acanthopagrus latus in pond farming. Nevertheless, the regulatory mechanism of type I IFN signalling by A. latus IRF9 (AlIRF9) against S. iniae remains elucidated. In our study, AlIRF9 has a total cDNA length of 3200 bp and contains a 1311 bp ORF encoding a presumed 436 amino acids (aa). The genomic DNA sequence of AlIRF9 has nine exons and eight introns, and AlIRF9 was expressed in various tissues, containing the stomach, spleen, brain, skin, and liver, among which the highest expression was in the spleen. Moreover, AlIRF9 transcriptions in the spleen, liver, kidney, and brain were increased by S. iniae infection. By overexpression of AlIRF9, AlIRF9 is shown as a whole-cell distribution, mainly concentrated in the nucleus. Moreover, the promoter fragments of -415 to +192 bp and -311 to +196 bp were regarded as core sequences from two AlIFNa3s. The point mutation analyses verified that AlIFNa3 and AlIFNa3-like transcriptions are dependent on both M3 sites with AlIRF9. In addition, AlIRF9 could greatly reduce two AlIFNa3s and interferon signalling factors expressions. These results showed that in A. latus, both AlIFNa3 and AlIFNa3-like can mediate the regulation of AlIRF9 in the process of infection with S. iniae.

De Novo Genome Assembly of the Whitespot Parrotfish (Scarus forsteni): A Valuable Scaridae Genomic Resource.

Scarus forsteni, a whitespot parrotfish from the Scaridae family, is a herbivorous fish inhabiting coral reef ecosystems. The deterioration of coral reefs has highly affected the habitats of the parrotfish. The decline in genetic diversity of parrotfish emphasizes the critical importance of conserving their genetic variability to ensure the resilience and sustainability of marine ecosystems for future generations. In this study, a genome of S. forsteni was assembled de novo through using Illumina and Nanopore sequencing. The 1.71-Gb genome of S. forsteni, was assembled into 544 contigs (assembly level: contig). It exhibited an N50 length of 17.97 Mb and a GC content percentage of 39.32%. Our BUSCO analysis revealed that the complete protein of the S. forsteni genome had 98.10% integrity. Combined with structure annotation data, 34,140 (74.81%) genes were functionally annotated out of 45,638 predicted protein-coding genes. Upon comparing the genome size and TE content of teleost fishes, a roughly linear relationship was observed between these two parameters. However, TE content is not a decisive factor in determining the genome size of S. forsteni. Population history analysis results indicate that S. forsteni experienced two major population expansions, both of which occurred before the last interglacial period. In addition, through a comparative genomic analysis of the evolutionary relationship of other species, it was found that S. forsteni had the closest relationship with Cheilinus undulatus, another member of the Labridae family. Our expansion and contraction analysis of the gene family showed that the expansion genes were mainly associated with immune diseases, organismal systems, and cellular processes. At the same time, cell transcription and translation, sex hormone regulation, and other related pathways were also more prominent in the positive selection genes. The genomic sequence of S. forsteni offers valuable resources for future investigations on the conservation, evolution, and behavior of fish species.

Identification of two MEF2s and their role in inhibiting the transcription of the mstn2a gene in the yellowfin seabream, Acanthopagrus latus (Hottuyn, 1782).

Myocyte-specific enhancer binding factor 2 (MEF2), which belongs to the MADS superfamily, is a pivotal and conserved transcription factor that combines with the E-box motif to control the expression of muscle genes. Myostatin (mstn), a muscle growth inhibitor, is a vital member of the TGF-ß superfamily. Currently, an understanding of the mechanisms of A. latus mstn (Almstn) transcriptional regulation mediated by MEF2 in fish muscle development is lacking. In the present study, two AlMEF2s (AlMEF2A and AlMEF2B) and Almstn2a were characterized from Acanthopagrus latus. AlMEF2A and AlMEF2B had 456 and 315 amino acid (aa) residues, respectively. Two typical regions, a MADS-box, MEF2, and transcriptionally activated (TAD) domains, are present in both AlMEF2s. The expression profiles of the two AlMEF2 genes were similar. The AlMEF2 genes were mainly expressed in the brain, white muscle, and liver, while Almstn2a expression was higher in the brain than in other tissues. Moreover, the expression trends of AlMEF2s and Almstn2a were significantly changed after starvation and refeeding in the five groups. Additionally, truncation experiments showed that -987 to +168 and -105 to +168 were core promoters of Almstn2a that responded to AlMEF2A and AlMEF2B, respectively. The point mutation experiment confirmed that Almstn2a transcription relies on the mutation binding sites 1 or 5 (M1/5) and mutation binding sites 4 or 5 (M4/5) for AlMEF2A and AlMEF2B regulation, respectively. The electrophoretic mobile shift assay (EMSA) further verified that M1 (-527 to -512) was a pivotal site where AlMEF2A acted on the Almstn2a gene. Furthermore, a siRNA interference gene expression experiment showed that reduced levels of AlMEF2A or AlMEF2B could prominently increase Almstn2a transcription. These results provide new information about the regulation of Almstn2a transcriptional activity by AlMEF2s and a theoretical basis for the regulatory mechanisms involved in muscle development in fish.

Arsenite adsorption and oxidation affected by soil humin: The significant role of persistent free radicals and reactive oxygen species.

Humin (HM), as the main component of soil organic matter, carries various reactive groups and plays a crucial regulatory role in the transformation of arsenic (As). However, current research on the redox pathway of As and its interactions with HM is relatively limited. This study aimed to explore the impact of different HM samples on the redox characteristics of As. The results showed that HM can not only adsorb arsenite [As(III)] but also oxidize As(III) into arsenate [As(V)]. However, once As(III) is adsorbed on the HM, it cannot undergo further oxidation. HMNM (extracted from peat soil) exhibited the highest adsorption capacity of As(III), with a maximum amount of 1.95 mg/kg. The functional groups of HM involved in As complexation were primarily phenolic hydroxyl and carboxyl groups. The adsorption capacity of HM samples for As(III) was consistent with their carboxyl group contents. The oxygen-containing functional groups and environmentally persistent free radicals (EPFRs) on HM can directly oxidize As(Ⅲ) through electron transfer, or indirectly induce the production of reactive oxygen species (ROS), such as hydroxyl radicals, to further oxidize As(Ⅲ). This study provides new insight into the transport and transformation process of As mediated by soil HM, and establishes a theoretical basis for As remediation.

Genome-wide identification of heat shock protein gene family and their responses to pathogen challenge in Trachinotus ovatus.

Heat Shock Proteins (HSPs) are a widely distributed family of proteins produced in response to heat and other stresses. To develop a deeper understanding of the mechanisms governing expression of HSPs in the bony fish Trachinotus ovatus, we carried out a whole genome analysis and identified 43 HSP genes. Based on their phylogenetic relationships with Danio rerio, Seriola dumerili, and Seriola lalandi, they were divided into four subfamilies: HSP20, HSP60, HSP70, and HSP90. We performed an analysis of the predicted physicochemical properties and subcellular localization of proteins encoded by these genes. The chromosomal localization results showed that the HSP genes are distributed across 20 chromosomes of T. ovatus.These genes were found to be expressed in different tissues, and they showed differential expression in the immune response against Streptococcus agalactiae. However, there was no significant differential expression in the different skin tissue locations of T. ovatus after infection by Cryptocaryon irritans Brown. This study provides basic information for further research on the evolution and structure and function of HSPs in teleosts.

Identification of the NOD-like receptor family of golden pompano and expression in response to bacterial and parasitic exposure reveal its key role in innate immunity.

This study presents a genome-wide identification of NOD-like receptors (NLRs) in the golden pompano, key to its innate immunity. We identified 30 ToNLRs, analyzing their chromosomal positions, characteristics, evolutionary relationships, evidence of positive selection, and synteny with the yellowtail kingfish. Our findings categorize these NLRs into three main subgroups: NLRA, NLRC, and the distinct ToNLRX1. Post-exposure to Streptococcus agalactiae, most ToNLRs increased expression in the spleen, whereas NLRC3like13, NLRC3like16, and NLRC3like19 so in the kidneys. Upon Cryptocaryon irritans exposure, we categorized our groups based on the site of infection into the control group (BFS), the trophont-attached skin (TAS), and the nearby region skin (NRS). ToAPAF1 and ToNOD1 expressions rose in the NRS, in contrast to decreased expressions of ToNLRC5, ToNWD1 and ToCIITA. Other ToNLRs showed variable expressions in the TAS. Overall, this research lays the groundwork for further exploration of innate immunity in the golden pompano.

Functional Characterization of the Almstn2 Gene and Its Association with Growth Traits in the Yellowfin Seabream Acanthopagrus latus (Hottuyn, 1782).

Myostatin (mstn), also known as GDF8, is a growth and differentiation factor of the transforming growth factor-ß (TGF-ß) superfamily and plays a key inhibitory effect in the regulation of skeletal muscle development and growth in vertebrates. In the present study, to comprehend the role of the mstn2 gene of the yellowfin seabream Acanthopagrus latus (Almstn2b), the genomic sequence of Almstn2b is 2359 bp, which encodes 360 amino acids and is composed of three exons and two introns, was obtained. Two typical regions, a TGF-ß propeptide and TGF-ß domain, constitute Almstn2b. The topology indicated that Almstn2 was grouped together with other Perciformes, such as the gilthead seabream Sparus aurata. Moreover, Almstn2b was mainly expressed in the brain, fins, and spleen. Furthermore, five SNPs, one in the exons and four in the introns, were identified in the Almstn2b gene. The allele and genotype frequencies of SNP-Almstn2b +1885 A/G were significantly related to the total weight, interorbital distance, stem length, tail length, caudal length, caudal height, body length, and total length (p < 0.05). The allele and genotype frequencies of SNP-Almstn2b +1888 A/G were significantly related to the weight, interorbital distance, long head behind the eyes, body height, tail length, caudal length, and body length. Additionally, the relationship between the SNP-Almstn2b +1915 A/G locus and weight and long head behind the eyes was significant (p < 0.05). Furthermore, the other two SNPs were not significantly associated with any traits. Thus, the SNPs identified in this study could be utilized as candidate SNPs for breeding and marker-assisted selection in A. latus.

Transcriptomic Analysis Reveals Functional Interaction of mRNA-lncRNA-miRNA in Trachinotus ovatus Infected by Cryptocaryon irritans.

The skin of Trachinotus ovatus is a crucial component of the mucosal immune system and serves as the primary site of infection by Cryptocaryon irritans. In order to investigate the significant role of skin in C. irritans infection, a comprehensive transcriptome analysis was conducted on skin tissues from the infection group, infection-adjacent group, and infection group compared with the infection-adjacent group (ATT_vs_PER, ADJ_vs_PER, ATT_vs_ADJ). This study identified differentially expressed long non-coding RNAs (DE lncRNAs), microRNAs (DE miRNAs), and differentially expressed genes (DEGs). The prediction of lncRNA target genes was accomplished by utilizing positional relationship (co-location) and expression correlation (co-expression) with protein-coding genes. Subsequently, functional enrichment analysis was conducted on the target genes of differentially expressed lncRNAs, revealing their involvement in signaling pathways such as tight junction, MAPK, and cell adhesion molecules. This study describes the regulatory network of lncRNA-miRNA-mRNA in T. ovatus skin tissue infected with C. irritans. Functional prediction analysis showed that differentially expressed lncRNA and miRNA may regulate the expression of immune genes such as interleukin-8 (il8) to resist the infection of C. irritans. Conducting additional research on these non-coding RNAs will facilitate a deeper understanding of their immune regulatory function in T. ovatus during C. irritans infection. The study of non-coding RNA in this study laid a foundation for revealing the molecular mechanism of the immune system of T. ovatus to respond to the infection of C. irritans. It provided a choice for the molecular breeding of Trachinotus ovatus against C. irritans.

Biochar-Associated Free Radicals Reduce Soil Bacterial Diversity: New Insight into Ecoenzymatic Stoichiometry.

The toxicity of environmentally persistent free radicals (EPFRs), often generated during biochar production, on soil bacteria is still not truly reflected when considering the conditions in real soil. Herein, the influence of free radicals within biochar on soil bacteria was investigated from the perspectives of enzyme activity, community structure, and ecoenzymatic stoichiometry. Biochar addition enhanced the contents of EPFRs and derived hydroxyl radicals (•OH) in the soil, while it reduced bacterial alpha diversity by 5.06-35.44%. The results of redundancy analysis and inhibition experiments collectively demonstrated the key role of EPFRs and •OH in reducing the bacterial alpha diversity. Specifically, EPFRs and •OH increased the stoichiometric imbalance by promoting the release of dissolved organic carbon and ammonium N, thus aggravating the P limitation in soil. This was further confirmed by increased alkaline phosphatase activity from 702 to 874 nmol g-1 h-1. The P limitation induced by EPFRs and •OH decreased the bacterial alpha diversity, as evidenced by the negative correlation between P limitation and bacterial alpha diversity (r2 = -0.931 to -0.979, P < 0.01) and the structural equation model. The obtained results demonstrate a ubiquitous but previously overlooked mechanism for bacterial toxicity of biochar-associated free radicals, providing scientific guidance for safe utilization of biochar.

Genome-Wide Identification of Trachinotus ovatus Antimicrobial Peptides and Their Immune Response against Two Pathogen Challenges.

Golden pompano, Trachinotus ovatus, as a highly nutritious commercially valuable marine fish, has become one of the preferred species for many fish farmers due to its rapid growth, wide adaptability, and ease of feeding and management. However, with the expansion of aquaculture scale, bacterial and parasitic diseases have also become major threats to the golden pompano industry. This study, based on comparative genomics, shows the possibility of preferential evolution of freshwater fish over marine fish by analyzing the phylogenetic relationships and divergence times of 14 marine fish and freshwater fish. Furthermore, we identified antimicrobial peptide genes from 14 species at the genomic level and found that the number of putative antimicrobial peptides may be related to species evolution. Subsequently, we classified the 341 identified AMPs from golden pompano into 38 categories based on the classification provided by the APD3. Among them, TCP represented the highest proportion, accounting for 23.2% of the total, followed by scolopendin, lectin, chemokine, BPTI, and histone-derived peptides. At the same time, the distribution of AMPs in chromosomes varied with type, and covariance analysis showed the frequency of its repeat events. Enrichment analysis and PPI indicated that AMP was mainly concentrated in pathways associated with disease immunity. In addition, our transcriptomic data measured the expression of putative AMPs of golden pompano in 12 normal tissues, as well as in the liver, spleen, and kidney infected with Streptococcus agalactiae and skin infected with Cryptocaryon irritans. As the infection with S. agalactiae and C. irritans progressed, we observed tissue specificity in the number and types of responsive AMPs. Positive selection of AMP genes may participate in the immune response through the MAPK signaling pathway. The genome-wide identification of antimicrobial peptides in the golden pompano provided a complete database of potential AMPs that can contribute to further understanding the immune mechanisms in pathogens. AMPs were expected to replace traditional antibiotics and be developed into targeted drugs against specific bacterial and parasitic pathogens for more precise and effective treatment to improve aquaculture production.

Acetyltransferases CBP/p300 Control Transcriptional Switch of ß-Catenin and Stat1 Promoting Osteoblast Differentiation.

CREB-binding protein (CBP) (CREBBP) and p300 (EP300) are multifunctional histone acetyltransferases (HATs) with extensive homology. Germline mutations of CBP or p300 cause skeletal abnormalities in humans and mice. However, the precise roles of CBP/p300 in bone homeostasis remain elusive. Here, we report that conditional knockout of CBP or p300 in osteoblasts results in reduced bone mass and strength due to suppressed bone formation. The HAT activity is further confirmed to be responsible for CBP/p300-mediated osteogenesis using A-485, a selective inhibitor of CBP/p300 HAT. Mechanistically, CBP/p300 HAT governs osteogenic gene expression in part through transcriptional activation of ß-catenin and inhibition of Stat1. Furthermore, acetylation of histone H3K27 and the transcription factor Foxo1 are demonstrated to be involved in CBP/p300 HAT-regulated ß-catenin and Stat1 transcription, respectively. Taken together, these data identify acetyltransferases CBP/p300 as critical regulators that promote osteoblast differentiation and reveal an epigenetic mechanism responsible for maintaining bone homeostasis. © 2023 American Society for Bone and Mineral Research (ASBMR).

Transcriptomics Reveal the Effects of Breeding Temperature on Growth and Metabolism in the Early Developmental Stage of Platax teira.

The growth, development, and survival of fish, especially in the early stages of development, is influenced by a complex of environmental factors, among which temperature is one of the most important. Although the physiological effects of environmental stress in fish have been extensively studied, the molecular mechanisms are poorly understood. However, recent advances in transcriptomic techniques have facilitated the study of the molecular mechanisms of environmental stress responses in aquatic species. Here, we aimed to elucidate the effects of breeding temperatures (21, 24, 27, and 30 °C) on the growth and nutrient metabolism in the early developmental stage of Platax teira, using transcriptomic techniques. Transcriptomic analysis identified 5492, 6937, and 4246 differentially expressed genes (DEGs) in the 21 vs. 24 °C, 27 vs. 24 °C, and 30 vs. 24 °C comparisons, respectively, most of which were involved in cell processes, single organism, metabolism, catalytic activity, and cell part, based on gene ontology (GO) functional annotations. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that the DEGs were mainly enriched in pathways related to metabolism of matter and energy, protein digestion and absorption, and glucose and lipid metabolism. Additionally, the expression of genes related to energy, lipid, and glucose metabolism in the fish liver was upregulated under a low-temperature condition (21 °C), although increasing the temperature within the acceptable threshold improved nutrient metabolism and growth in the fish. Meanwhile, nutrient metabolism and growth were suppressed by an extremely high temperature (30 °C) owing to oxidative stress. Overall, it was shown that nutrient metabolism pathways were involved in thermal stress responses in P. teira, and the optimal breeding temperature range was 24-27 °C. Through transcriptomics, the regulatory mechanism of larval development in P. teira under different growth temperatures was elucidated, with the goal of establishing a theoretical basis for industrial breeding.

Genetic Diversity, Population Structure, and Environmental Adaptation Signatures of Chinese Coastal Hard-Shell Mussel Mytilus coruscus Revealed by Whole-Genome Sequencing.

The hard-shell mussel (Mytilus coruscus) is widespread in the temperate coastal areas of the northwest Pacific and holds a significant position in the shellfish aquaculture market in China. However, the natural resources of this species have been declining, and population genetic studies of M. coruscus are also lacking. In this study, we conducted whole-genome resequencing (WGR) of M. coruscus from eight different latitudes along the Chinese coast and identified a total of 25,859,986 single nucleotide polymorphism (SNP) markers. Our findings indicated that the genetic diversity of M. coruscus from the Zhoushan region was lower compared with populations from other regions. Furthermore, we observed that the evolutionary tree clustered into two primary branches, and the Zhangzhou (ZZ) population was in a separate branch. The ZZ population was partly isolated from populations in other regions, but the distribution of branches was not geographically homogeneous, and a nested pattern emerged, consistent with the population differentiation index (FST) results. To investigate the selection characteristics, we utilized the northern M. coruscus populations (Dalian and Qingdao) and the central populations (Zhoushan and Xiangshan) as reference populations and the southern ZZ population as the target population. Our selection scan analysis identified several genes associated with thermal responses, including Hsp70 and CYP450. These genes may play important roles in the adaptation of M. coruscus to different living environments. Overall, our study provides a comprehensive understanding of the genomic diversity of coastal M. coruscus in China and is a valuable resource for future studies on genetic breeding and the evolutionary adaptation of this species.

The regulatory mechanisms of IRF7 mediated by the type I IFN signalling pathway against Streptococcus iniae in yellowfin seabream, Acanthopagrus latus (Hottuyn, 1782).

Interferon regulatory factor 7 (IRF7) regulates type I interferon (IFN) genes via combining to the ISRE region in the immune response against bacteria. Streptococcus iniae is one of the dominant pathogenic bacteria of yellowfin seabream, Acanthopagrus latus. However, the regulatory mechanisms of A. latus IRF7 (AlIRF7) mediated by the type I IFN signalling pathway against S. iniae was ambiguously. In the present study, IRF7, and two IFNa3s (IFNa3 and IFNa3-like) were authenticated from A. latus. The total length of AlIRF7 cDNA is 2142 bp, containing a 1314 bp open reading frame (ORF) encoding an inferred 437 amino acids (aa). Three typical regions, a serine-rich domain (SRD), a DNA-binding domain (DBD), and an IRF association domain (IAD), are conserved in AlIRF7. Furthermore, AlIRF7 is fundamentally expressed in various kinds of organs, with high levels in the spleen and liver. Additionally, S. iniae challenge promoted AlIRF7 expression in the spleen, liver, kidney, and brain. AlIRF7 is confirmed to be located at the nucleus and cytoplasm by overexpression of AlIRF7. Moreover, truncation mutation analyses shows that the regions, -821 bp to +192 bp and -928 bp to +196 bp, were known as core promoters from AlIFNa3 and AlIFNa3-like, respectively. The point mutation analyses and electrophoretic mobile shift assay (EMSA) verified that AlIFNa3 and AlIFNa3-like transcriptions are depended on the M2/5 and M2/3/4 binding sites with AlIRF7 regulation, respectively. Additionally, an overexpression experiment showed that AlIRF7 can dramatically decrease the mRNA levels of two AlIFNa3s and interferon signalling molecules. These results suggest that two IFNa3s may mediate the regulation of AlIRF7 in the immune responses of A. latus against S. iniae infection.

Cryopreservation of black seabream (Acanthopagrus schlegelii) sperm.

In recent years, biotechnology has had a significant impact on the aquaculture industry, particularly in the field of breeding. Molecular selection breeding has emerged as a novel approach to breeding. Reducing the cost of genetic information for individuals with desirable traits after breeding has become an important research direction. Cryopreservation technology allows bypassing time and space constraints in genetic breeding, simplifying broodstock management. This study presents a detailed cryopreservation method for black seabream sperm, evaluating extender type, glucose concentration, cryoprotectant type and concentration, sperm-dilution ratio, and cooling protocols. Sperm motility parameters were analyzed using computer-assisted sperm analysis (CASA) before and after two days of freezing. This involved using an RS solution with a glucose concentration of 15 g/L and adding a 5% final concentration of EG as the sperm cryoprotectant. After mixing the sperm and solution at a ratio of 1:2, we subjected it to 5 min fumigation at 5 cm above the liquid nitrogen surface before plunging it into the nitrogen. Sperm motility reached 85.46 ± 7.32% after two days. Various enzymatic activities showed changes over 20 days post-cryopreservation. This improved cryopreservation protocol for black seabream sperm is beneficial for genetic breeding and reproduction and provides reference for studying the cryodamage mechanisms of black seabream sperm.

Molecular characterization of TNF-ß and IFN-γ in yellowfin seabream (Acanthopagrus latus, Hottuyn, 1782) and their immune responses to density stress during transport.

The inflammatory cytokines TNF-ß and IFN-γ are important mediators of the vertebrate inflammatory response and coordinators of the immune system in regard to NF-κB signalling pathways. In this study, the TNF-ß and IFN-γ genes of yellowfin seabream, Acanthopagrus latus were identified, and the multiple sequence alignments, evolutionary relationships and gene expressions of the two genes were also determined. AlTNF-ß contained a 762 bp open reading frame (ORF) encoding 253 amino acids, while AlIFN-γ contained a 582 bp ORF encoding 193 amino acids. An amino-acid sequence alignment analysis showed that these proteins have highly conserved transmembrane structural domains among teleosts. Moreover, AlTNF-ß has a close affinity with TNF-ß of yellowfin seabream while AlIFN-γ has a high evolutionary correlation with A. regius and Sparus aurata. In addition, the mRNAs of AlTNF-ß and AlIFN-γ are widely expressed in various tissues. AlTNF-ß is highly expressed in gill and intestinal tissues, and the mRNA levels of AlIFN-γ are higher in spleen, skin, and gill tissues than in other tissues. Under transportation density stress, the mRNA level of AlTNF-ß was significantly elevated in the intestine of the high-density group, while AlTNF-ß transcription in the gills did not vary significantly among the density groups. Furthermore, AlIFN-γ expression was increased in liver, intestinal, and gill tissues under high transportation density. The results of this study show that TNF-ß and IFN-γ expression in yellowfin seabream is greatly affected by density stress. The density of 125 per bag for 4-5 cm fry or 1200 per bag for 1-2 cm fry is most suitable for the transportation of live fish. These results might provide a reference for further studies on the immunomodulatory response process and auxiliary function of immune stress of TNF and IFN genes in fish under density stress.

Sulfur-Containing Persistent Free Radicals and Reactive Species on Photoaged Microplastics: Identification and the Formation Mechanism.

The elemental composition may affect the persistent free radical (PFR) and reactive species (RS) formation associated with photoaging microplastics; however, a relevant study is still lacking. This study systematically investigated the formation, evolution, and types of PFRs and RS on sulfur-containing microplastics (S-MPs) under simulated sunlight. Electron paramagnetic resonance detection and power saturation curve analysis isolated three different PFRs on each photoaging poly(phenylene sulfide) (PPS) and polysulfone (PSF). Combining the results of characterization and density functional theory calculation, these observed PFRs on the irradiated S-MPs were classified as oxygen-centered radicals with an adjacent S atom (namely, thio-oxygen radicals), oxygen-centered and sulfur-centered radicals, where the thio-oxygen radicals on PPS were benzenethiol-like radicals, and oxygen-centered radicals and sulfur-centered radicals on PSF that were identified as benzenesulfonic-like radicals and phenyl sulfonyl-like radicals, respectively. Moreover, potential precursor molecule fragments of PFRs on the photoaging S-MPs, including p-toluenesulfinic acid and benzenesulfonic acid, were detected by pyrolysis-gas chromatography/mass spectrometry and liquid chromatography-mass spectrometry. Interestingly, reactive sulfur species (SO3•-) was also observed on irradiated S-MPs in addition to reactive oxygen species, which was mainly derived from the reaction of •OH and sulfonyl radicals. These results have implications for assessing the potential risks of atmospheric S-MPs.

Effects of Natural and Synthetic Astaxanthin on Growth, Body Color, and Transcriptome and Metabolome Profiles in the Leopard Coralgrouper (Plectropomus leopardus).

Natural and synthetic astaxanthin can promote pigmentation in fish. In this study, the effects of dietary astaxanthin on growth and pigmentation were evaluated in leopard coralgrouper (Plectropomus leopardus). Fish were assigned to three groups: 0% astaxanthin (C), 0.02% natural astaxanthin (HP), and 0.02% synthetic astaxanthin (AS). Brightness (L*) was not influenced by astaxanthin. However, redness (a*) and yellowness (b*) were significantly higher for fish fed astaxanthin-containing diets than fish fed control diets and were significantly higher in the HP group than in the AS group. In a transcriptome analysis, 466, 33, and 32 differentially expressed genes (DEGs) were identified between C and HP, C and AS, and AS and HP, including various pigmentation-related genes. DEGs were enriched for carotenoid deposition and other pathways related to skin color. A metabolome analysis revealed 377, 249, and 179 differential metabolites (DMs) between C and HP, C and AS, and AS and HP, respectively. In conclusion, natural astaxanthin has a better coloration effect on P. leopardus, which is more suitable as a red colorant in aquaculture. These results improve our understanding of the effects of natural and synthetic astaxanthin on red color formation in fish.

Nerve conduction velocity is independently associated with bone mineral density in type 2 diabetes mellitus.

Aim: This study investigated the association between nerve conduction velocity (NCV) and bone mineral density (BMD) in patients with type 2 diabetes mellitus (T2DM). Methods: This study retrospectively collected medical data of T2DM patients who underwent dual-energy X-ray absorptiometry and nerve conduction study at the Shanghai Ruijin Hospital, Shanghai, China. The primary outcome was the total hip BMD T-score. The main independent variables were motor nerve conduction velocities (MCVs), sensory nerve conduction velocities (SCVs), and composite Z-scores of MCV and SCV. T2DM patients were divided into total hip BMD T-scores < -1 and total hip BMD T-scores ≥ -1 groups. The association between the primary outcome and main independent variables was evaluated by Pearson bivariate correlation and multivariate linear regression. Results: 195 female and 415 male patients with T2DM were identified. In male patients with T2DM, bilateral ulnar, median, and tibial MCVs and bilateral sural SCVs were lower in the total hip BMD T-score < -1 group than T-score ≥ -1 group (P < 0.05). Bilateral ulnar, median, and tibial MCVs, and bilateral sural SCVs showed positive correlations with total hip BMD T-score in male patients with T2DM (P < 0.05). Bilateral ulnar and tibial MCVs, bilateral sural SCVs, and composite MCV SCV and MSCV Z-scores were independently and positively associated with total hip BMD T-score in male patients with T2DM, respectively (P < 0.05). NCV did not show significant correlation with the total hip BMD T-score in female patients with T2DM. Conclusion: NCV showed positive association with total hip BMD in male patients with T2DM. A decline in NCV indicates an elevated risk of low BMD (osteopenia/osteoporosis) in male patients with T2DM.

Characterization of the MMP9 Gene and Its Association with Cryptocaryon irritans Resistance Traits in Trachinotus ovatus (Linnaeus, 1758).

The MMPs are endogenous proteolytic enzymes that require zinc and calcium as cofactors. MMP9 is one of the most complex matrix metalloproteinases in the gelatinase family and has many biological functions. In mammals, mmp9 is thought to be closely associated with cancer. However, studies in fish have rarely been reported. In this study, to understand the expression pattern of the ToMMP9 gene and its association with the resistance of Trachinotus ovatus to Cryptocaryon irritans, the sequence of the MMP9 gene was obtained from the genome database. The expression profiles were measured by qRT-PCR, the SNPs were screened by direct sequencing, and genotyping was performed. The ToMMP9 gene contained a 2058 bp ORF encoding a putative amino acid sequence of 685 residues. The homology of the ToMMP9 in teleosts was more than 85%, and the genome structure of ToMMP9 was conserved in chordates. The ToMMP9 gene was expressed in different tissues of healthy individuals and was highly expressed in the fin, the gill, the liver and the skin tissues. The ToMMP9 expression in the skin of the infected site and its adjacent sites increased significantly after C. irritans infection. Two SNPs were identified in the ToMMP9 gene, and the SNP (+400A/G) located in the first intron was found to be significantly associated with the susceptibility/resistance to C. irritans. These findings suggest that ToMMP9 may play an important role in the immune response of T. ovatus against C. irritans.