Citizen science in action: Time-resolved immunofluorescence-based field detection of antibiotics with portable analytical kit.

Citizen scientist-based environmental monitoring and public education are becoming increasingly popular. However, current technologies for antibiotic-based novel contaminant identification are still restricted to laboratory sample collection and analysis due to detection methodologies and apparatus limitations. This study developed a time-resolved immunofluorescence-based simultaneous field-based assay for ciprofloxacin (CIP) and enrofloxacin (ENR) that matches test results to geographic locations. The assay helps the public understand the potential levels of antibiotic exposures in their environments and helps them take appropriate action to reduce risk. The assay was developed using smartphones and social software in addition to rapid testing. The method uses a portable, low-cost analytical kit with a smartphone app to build a field-based detection platform for the detection and analysis of ENR and CIP in water and aquatic products. The methodological evaluation was good, with detection limits of 0.4 ng/mL and 0.5 ng/g for ENR in water and fish, and quantification limits of 1.2 ng/mL and 1.4 ng/g, with recoveries of 89.0 %-101.0 % and 78.0 %-97.0 %. For CIP in water and fish, the limits of detection were 0.3 ng/mL and 0.4 ng/g, the limits of quantification were 0.9 ng/mL and 1.2 ng/g, and the recoveries were 75.0 %-91.0 % and 72.0 %-89.0 %, both with coefficients of variation <15 %. These limits were sufficient to prevent the two antibiotics from crossing over during simultaneous detection. The assay was validated using real samples to assess the effectiveness of the assay platform in field deployments, and the results were consistent with those obtained through liquid chromatography-tandem mass spectrometry (LC-MS) and enzyme-linked immunoassay (ELISA) techniques. In addition, the TRFIA assay process requires less time, uses more portable instruments, and is less complex than traditional methods. This study provides a new scientific, accurate, and rapid detection method for antibiotic detection by citizen scientists, helping scientists to obtain a wider range of data and providing more opportunities to solve scientific problems.

Aquaculture activities influencing the generation of geosmin and 2-methylisoborneol: a case study in the aquaculture regions of Hongze Lake, China.

Contamination by odor substances such as geosmin (GSM) and 2-methylisoborneol (2-MIB) was examined in the cultured water from aquaculture farming in the region of the Hongze Lake in 2022, and some factors influencing residual levels of them in the water were analyzed. Geographically, high concentrations of GSM were located mainly in the north and northeast culture areas of the lake, while those of 2-MIB were found in the northeast and southwest. Analysis of the water in the enclosure culture revealed significant differences in the concentrations of GSM and 2-MIB among the cultured species. The mean concentrations of GSM in culture water were ranked in the order: crab > the four major Chinese carps > silver and bighead carp, and silver and bighead carp > crab > the four major Chinese carps for 2-MIB. The concentration of GSM was significantly higher at 38.99 ± 18.93 ng/L in crab culture water compared to other fish culture water. Significant differences were observed in GSM concentrations between crab enclosure culture and pond culture, while 2-MIB levels were comparable. These findings suggest that cultural management practices significantly affect the generation of odor substances. The taste and odor (T&O) assessment revealed that the residual levels of GSM and 2-MIB in most samples were below the odor threshold concentrations (OTCs), although high levels of GSM and 2-MIB in all water bodies were at 30.9% and 27.5%, respectively. Compared with the corresponding data from other places and the regulation guidelines of Japan, USA, and China, the region in the Hongze Lake is generally classified as a slightly T&O area, capable of supporting the aquaculture production scale.

Significant decline of water pollution associated with inland fishery across China.

Water pollution seriously threatens the sustainable development of fisheries in China. To inform effective pollution control policies, a comprehensive understanding of the fishery environment status is needed. However, nationwide data on the temporal changes of major pollutants in the fishery waters of China are scarce. This study collected data on the major water pollutants, including total nitrogen, total phosphorus, heavy metals, and total petroleum hydrocarbons (TPHs), from 2003 to 2017 to evaluate dynamic changes in the inland fishery water environment across China. We discovered that the levels of four heavy metals (Cu, Zn, Pb, and Cd) and TPH decreased during the 15-year period, corresponding to the reduced national discharge of pollution sources from 2003 to 2015. However, nitrogen and phosphorus levels in the inland fishery waters showed no significant changes during this period. A comparative analysis of water quality in different periods indicated that these improvements were highly associated with effective measures for water pollution control in China. In addition, the decline in pollution was consistent among the three regions of China (north, west, and southeast) from 2003 to 2017, while southeast China exhibited the weakest pollution mitigation among the three regions. These findings suggest that the inland fishery water quality improved during 2003-2017, but still faced eutrophication risk.

Quantitative benefit and risk assessment of arsenic and nutrient levels in tilapia products sold on Chinese e-commerce platforms.

E-commerce platforms have become a significant sales channel for processed tilapia products such as frozen tilapia fillets, pickled tilapia, and canned tilapia in China. As food safety issues are worldwide concerned, the imbalance between the nutritional benefits of fish and the risk of contamination has become a major constraint on fish consumption. Therefore, it is necessary to assess the safety of tilapia products sold on e-commerce platforms. We conducted a quantitative benefit-risk assessment of arsenic and nutrient levels for tilapia products sold on Chinese e-commerce platforms using the hazard quotient (HQ). A total of 147 tilapia products were collected from the central Chinese e-commerce platforms Tmall, Taobao, and Jingdong for arsenic determination. Arsenic concentrations in tilapia products ranged from 0.004 to 0.820 mg·kg-1. The inorganic arsenic content of tilapia products was lower than the national limit (0.1 mg·kg-1). One-way analysis of variance revealed that there was no significant difference in arsenic levels in tilapia products among different regions (p > 0.05), while there was a significant difference in product form, with canned tilapia containing significantly higher arsenic levels than frozen tilapia fillets and pickled tilapia fillets (p < 0.05). We conducted an aquaculture experiment to analyze the nutrient levels of tilapia. The mean value of EPA + DHA content of tilapia was 20.634 mg·100 g-1. The HQ values of tilapia products ranged from 0.004 to 0.736. In a word, the nutritional benefits of consuming tilapia products exceed the risk of arsenic exposure. These data can help demonstrate that tilapia products are low-risk, high-yield nutritious food and provide relevant safety recommendations for consumers purchasing processed tilapia products online.

The Gill-Associated Bacterial Community Is More Affected by Exogenous Chlorella pyrenoidosa Addition than the Bacterial Communities of Water and Fish Gut in GIFT Tilapia (Oreochromis niloticus) Aquaculture System.

Microalgae has been widely used in aquaculture to improve both the water environment and fish growth; however, the current understanding of the effects of microalgae addition on the key players involved in regulating the water environment and fish health, such as microorganisms, remains limited. Here, a 50-day mesocosm experiment was set up to simulate the culture of Genetic Improvement of Farmed Tilapia (GIFT, Oreochromis niloticus) with an average weight of 14.18 ± 0.93 g and an average length of 82.77 ± 2.80 mm. Different amounts of Chlorella pyrenoidosa were added into these artificial systems to investigate dynamics of bacterial communities in aquaculture water, fish gill, and gut using amplicon-based high-throughput sequencing technology. Our results showed that Chlorella pyrenoidosa addition increased diversity and network complexity of gill-associated bacterial communities rather than those of the water and gut. Furthermore, more biomarkers in the gill-associated bacterial communities were detected in response to Chlorella pyrenoidosa addition than the water and fish gut samples. These findings highlighted the high sensitivity of gill-associated bacterial communities in response to the Chlorella pyrenoidosa addition, implying Chlorella pyrenoidosa addition could play important roles in regulating the fish mucosal immunity by altering the gill-associated microbiota.

The neurobehavioral impacts of typical antibiotics toward zebrafish larvae.

Due to the widely usage in livestock, aquaculture and clinics, antibiotic residues are existed in aqueous environments and their potential toxicity to aquatic organisms is concerning. Here, we used zebrafish as the model to investigate the neurotoxicity and involved mechanism of seven antibiotics that were frequently detected in surface waters. The results revealed that the short-term exposure to clarithromycin (CLA), chlortetracycline (CTC) and roxithromycin (ROX) induced behavioral effects, with effective concentration of 1 µg/L (CTC and ROX) and 100 µg/L (CLA, CTC and ROX) respectively. A significant decrease in the travel distance and velocity as well as an increase in turn angle was measured. TUNEL assay identified increased cell apoptosis in brain sections of larvae exposed to three neurotoxic antibiotics, which raised the possibility that the behavioral symptoms were associated with neural damage. Transcriptome sequencing showed that the three antibiotics could affect the nervous system of zebrafish including the alteration of synaptogenesis and neurotransmission. Additionally, ROX and CTC affected pathways involved in mitochondrial stress response and endocrine system in zebrafish larvae. Besides, BDNF, ASCL1, and CREBBP are potential upstream regulatory factors that mediated these impacts. These findings indicated that exposure of CTC, ROX and CLA may cause abnormal behavior toward zebrafish larvae under environmental relevant concentration and revealed the potential role of neural cell apoptosis and synaptogenesis signaling in mediating this effect.

Responses of bacterial and three sub-microeukaryote communities in the water of white shrimp Penaeus vannamei aquaculture ponds in two polyculture models.

Polyculture operations in freshwater aquaculture ponds can disrupt microbial communities. High-throughput sequencing was used to assess the impact of polyculture operations on bacterial and three sub-microeukaryote communities (fungi, zooplankton, and eukaryotic phytoplankton) in Penaeus vannamei aquaculture ponds containing oriental river prawns and giant freshwater prawns, respectively. The results showed that the bacterial community was less sensitive than the microeukaryote communities to both the polyculture activity and environmental variations. The polyculture of giant freshwater prawns rather than oriental river prawns was the primary factor affecting the beta diversity of the three sub-microeukaryote communities. This may be due to the larger biomass of the polyculture varieties of giant freshwater prawns compared with oriental river prawns. The polyculture activity of giant freshwater prawns with a higher density and that of oriental river prawns with a lower density increased the stochasticity of the community assembly of the three sub-microeukaryote communities. It also affected the topological properties of the microbial communities, including greater correlations between ecosystem elements, and reducing the correlations among zooplanktons. The eukaryotic phytoplankton was the only microbial community that could also be explained by nutrient variation (mainly the total nitrogen). This highlights the potential role of the eukaryotic phytoplankton as a suitable indicator of the effects of nutrient input into ecosystems.

Assessment of the benefits of essential fatty acids and risks associated with antimicrobial residues in aquatic products: A case study of Chinese mitten crab (Eriocheir sinensis).

Much attention has been given to the safety and quality of aquatic products, including consuming Chinese mitten crab (Eriocheir sinensis), which offers both nutritional benefits and toxicological risks. Eighteen sulfonamides, 9 quinolones and 37 fatty acids were analyzed in 92 crab samples from primary aquaculture provinces in China. Enrofloxacin and ciprofloxacin have been mentioned as typical antimicrobials occurring at the greatest concentrations (>100 µg/kg, wm). By use of an in vitro method, the proportions of enrofloxacin, ciprofloxacin and essential fatty acids (EFAs, DHA and EPA) in ingested nutrients were determined to be 12 %, none and 95 %, respectively. The risk-benefit quotient (HQ) between the adverse effects of antimicrobials and nutritional benefits of EFAs in crabs found that HQs based on data after digestion were significantly less (HQ = 0.0086) than that of the control group where no digestion occurred (HQ = 0.055). This result suggested that (1) there was less risk posed by antimicrobials due to the consumption of crab, and (2) ignoring the bioaccessible fraction of antimicrobials in crabs might overestimate risks to the health of humans due to dietary exposure. Meaning bioaccessibility can improve the accuracy of the risk assessment process. Realistic risk evaluation should be recommended to achieve a quantified assessment of the dietary risks and benefits of aquatic products.

Quantitative detection of malachite green in sediment by a time-resolved immunofluorescence method combined with a portable 3D printing equipment platform.

Rapid detection technology of aquaculture fishery drug residues is needed to supplement large-scale instrument methods. To do this, the time-resolved fluorescence immunoassay (TRFIA) method and portable three-dimensional (3D) printing equipment platform were used, in combination with smartphones, to detect malachite green (MG) in pond sediments. The TRFIA was coupled to MG monoclonal antibodies (mAb) through lanthanide metal microspheres europium (Eu3+). The labeled antibody produced competitive immunity in the immune reaction system, and the specific fluorescence intensity in the product was determined by a portable 3D printing equipment platform to achieve quantitative analysis. To test this method, leucomalachite green (LMG) was converted to MG by oxidation of dicyanoquinone (DDQ), and a qualitative analysis was achieved. Methodological evaluation results were satisfactory, recoveries were 83 %-104 %, the limit of detection (LOD) was 0.3 ng/g, the limit of quantitation (LOQ) was 0.7 ng/g, and the coefficient of variation was 1.3 %-7.3 %. The linear equation y = -0.1496x + 0.5585 was in the range of 0-10 ng/g. The linear regression correlation coefficient was 99.2 %. The TRFIA was confirmed and positive samples were measured. Results were consistent with the standard method, which demonstrated that the TRFIA was feasible and that the detection results were reliable. Compared with the national standard method, the TRFIA saves time, is more convenient, and has high sensitivity. It provides an efficient technical method for the rapid screening of MG in the sediments of aquaculture environments.

Risk and benefit assessment of potential neurodevelopment effect resulting from consumption of cultured largemouth bass (Micropterus salmoides) in China.

The aim of this study was to evaluate the net effects of dietary consumption on the potential neurodevelopmental effects of largemouth bass (Micropterus Salmoides, simplify as bass) cultured in China, especially when the bait of largemouth bass is changed from iced trash fish to formulated feed. A total of three bait group bass samples were collected from main producing areas during harvest period, including formulated feed group, iced trash fish group, and both group (converting from iced trash fish to formulated feed). Net neurodevelopment value (expressed as intelligence quotient or IQ) was calculated using FAO/WHO deterministic methods and probabilistic assessment model. The results showed net IQ of largemouth bass fed by the three baits groups all showed positive or beneficial neurodevelopmental effects, with the values of 1.55 ± 0.97 (formulated feed group), 3.17 ± 1.76 (iced trash fish group), and 2.65 ± 1.29 (both group) respectively. Bass samples fed with ice trash fish showed the highest neurodevelopmental effect. The present study suggested that more valuable formulated feed should be developed to improve the quality of cultured largemouth bass.

Bacterial Community Structure and Diversity in the Aqueous Environment of Shihou Lake and its Relationship with Environmental Factors.

Microorganisms are sensitive to changes in the external environment and are often used as indicators to monitor and reflect water quality. Using Illumina MiSeq sequencing, the characteristics of the microbial community in Shihou Lake water at different time points were analyzed and the key environmental factors affecting the bacterial community were identified. The microbial community diversity in Shihou Lake water was rich and showed significant differences over time. The main bacterial phyla were the Cyanobacteria, Proteobacteria, Actinobacteria, Verrucomicrobia, Bacteroidetes, Chloroflexi, Planctomycetes, Firmicutes, Chlorobi, WS6 and Saccharibacteria. The relative abundance of these major phyla in the sample accounted for 97.83%-99.07% of the total abundance; Cyanobacteria had the highest relative abundance, accounting for 13.07%-44.61% of the total, and the abundance of each dominant phylum was significantly different at different time points. The Shannon and Simpson indexes showed that the diversity of each month was as follows: August > October > July > September > November. The Chao1 and Ace indexes indicated that the order of richness was: November > October > July > August > September. Beta diversity analysis found significant differences in the samples from month to month. Environmental factors such as temperature, total nitrogen, chlorophyll-a, permanganate index, nitrite, pH and ammonia nitrogen had significant effects on microbial community structure.

Metagenomics Analysis Reveals Compositional and Functional Differences in the Gut Microbiota of Red Swamp Crayfish, Procambarus clarkii, Grown on Two Different Culture Environments.

The structure and function of intestinal microorganisms are closely related to host metabolism, development, physiology, and health. The red swamp crayfish, Procambarus clarkii, is an important farmed aquatic species in China, which is grown in aquaculture ponds and rice paddy fields. Since these are two distinct cultivation environments with important differences in nutrient input and ecological community composition, we hypothesized that they may have different effects on the gut microbiota of the crayfish. Here, we sought to examine this hypothesis. To that aim, metagenomics analyses were applied to unveil the taxonomic composition and functional diversity of the microbiota in the intestines of red swamp crayfish grown in aquaculture ponds and rice-crayfish cultivation environments. The results showed that Firmicutes and Proteobacteria were the two most abundant microbial components. In addition, the relative abundance of bacterial and archaeal communities, but not that of fungal and viral communities, significantly differed between the two environments. The abundance of genes involved in pathways related to genetic information processing and human diseases was lower in the guts of red swamp crayfish grown in rice-crayfish cultivation environments. In particular, the abundance of two gene sets, K13730 and K08303, which are related to epithelial cell invasion by Listeria monocytogenes and Helicobacter pylori, respectively, decreased in this culture environment. In addition, the samples from rice-crayfish cultivation environments tended to have lower relative abundance of glycosyltransferases (GTs), which were the most abundant carbohydrate-active enzymes in the samples from both groups, higher abundance of glycoside hydrolases, and lower abundance of GT2.

Antibiotic accumulation, growth performance, intestinal diversification, and function of Nile tilapia (Oreochromis niloticus) feed by diets supplemented with different doses of sulfamethoxazole.

To comprehensively investigate the effects of exposure to legal doses of sulfamethoxazole (SMZ) in Nile tilapia (Oreochromis niloticus), fishes were exposed to diets supplemented with different doses of SMZ (NS, normal feed; LS, 20 mg/kg·day; MS, 200 mg/kg·day; and HS, 1000 mg/kg·day) for 4 weeks and then fed with normal feed for 4 weeks. General SMZ accumulation, growth performance, intestinal short-chain fatty acids, intestinal flora diversity, composition, and function were systemically evaluated. Results indicated that the SMZ accumulation in O. niloticus muscles, intestinal contents, and aquaculture environment positively correlated to the exposure dose. The growth performance, measured by weight increase, was MS>LS>NS, while HS antibiotics retarded the growth. SMZ-exposed O. niloticus had an increased number of fat particles in the liver and a change in the content of intestinal SCFAs. Moreover, SMZ exposure changed the biological diversity of the intestinal flora and subsequently induced microbiota dysbiosis, primarily inhibiting the growth of Fusobacteria, especially in HS group. Overall, exposure to higher SMZ doses than the recommended ones impair general intestinal functions and provokes health risk in fish. This study highlights the importance of rational and regulated use of SMZ in aquaculture.

Metagenomics analysis reveals the distribution and communication of antibiotic resistance genes within two different red swamp crayfish Procambarus clarkii cultivation ecosystems.

Antibiotic resistance genes (ARGs) are emerging contaminants that pose a potential risk to human health worldwide. In this study, a metagenomic analysis was performed to investigate the distribution of ARGs in paddy field ecosystems, crayfish monoculture pond ecosystems, and rice-crayfish cultivation field ecosystems. The results showed that MacB and BcrA are two dominant ARGs, and macrolide is the dominant antibiotic not only in the water, but also in the sediment and gut of crayfish, in both the crayfish monoculture and the rice-crayfish cultivation ecosystems. Meanwhile, some lower-abundance ARGs in the water and sediment of crayfish cultivation ecosystems were significantly different in their abundance than those in rice paddy fields, and the ARGs in crayfish culture system and rice paddy fields showed even higher dissimilarities of diversity. Comprehensive analysis with redundancy analysis（RDA）and the distribution of dominant ARGs showed that the dissimilarity was related to the higher concentrations of total nitrogen (TN), total phosphorus (TP), chlorophyll a (Chla), permanganate index (CODMn), and nitrate in the water of rice paddy fields, and was related to the higher contents of N, P, K, and organic matter (OM) in the sediment of rice paddy fields. The source trackers of ARGs within the crayfish cultivation ponds and the rice-crayfish cultivation fields showed that the sediment in crayfish cultivation ponds mainly played the role of the 'sink' for ARGs, and the water and gut of crayfish mutually contributed to the high rates of ARGs. The ARG contribution rates of crayfish gut and sediment decreased and increased, respectively, in rice-crayfish cultivation fields and in crayfish monoculture ponds, which might be related to the lower crayfish biomass and the lower water depth in rice-crayfish cultivation fields.

Hepatic oxidative stress, DNA damage and apoptosis in adult zebrafish following sub-chronic exposure to BDE-47 and BDE-153.

Polybrominated diphenyl ethers (PBDEs) are ubiquitous and prolific contaminant in both the abiotic and biotic environment because of the wide industrial applications of these chemicals. In the present study, the effects of 2,2',4,4'-tetrabrominateddiphenyl ether (BDE-47) and 2,2',4,4',5,5'-hexabromodiphenyl ether (BDE-153) exposure on the induction of hepatic oxidative stress, DNA damage, and the expression of apoptosis-related genes in adult zebrafish were investigated. The activities of antioxidant enzymes, such as catalase and superoxide dimutase, significantly increased when adult zebrafish was exposed to various concentrations of BDE-47 and BDE-153 for 7 and 15 days. BDE-47 and BDE-153 elicited significant alterations in zebrafish 7-Ethoxyresorufin-O-deethylase activity at 3, 7, or 15 days of exposure. In addition, the significant increase in comet assay parameters of zebrafish hepatocytes in a concentration-dependent manner indicated BDE-47 and BDE-153 induced DNA damage, probably due to observed oxidative stress. Furthermore, a monotonically upregulation of p53 and Caspase3, which are apoptotic-regulated genes, and decreased expression ratio of the anti-apoptotic B-cell lymphoma/leukaemia-2 and Bcl2-associated X protein genes for all BDE-47 and BDE-153 treatments at 7 and 15 days indicated apoptosis induction in zebrafish liver. Our findings help elucidate the mechanisms of BDE-47- and BDE-153-induced toxicity in zebrafish hepatocytes.

Variations in bacterioplankton communities in aquaculture ponds and the influencing factors during the peak period of culture.

An increase in nutrient input may disturb the bacterioplankton communities in freshwater aquaculture ponds during the peak period of culture. Water samples were collected from ponds of three cultivated species. After the samples were filtered and total DNA was extracted, Illumina high-throughput sequencing was used to profile the spatiotemporal distributions in bacterioplankton communities, the belt diversity, and the influencing factors during this period of time. The results showed that Proteobacteria, Cyanobacteria, Bacteroidetes, and Actinobacteria were the dominant phyla. Biological differences in cultivated species were the main influencing factors that shaped bacterioplankton communities. Monthly variations and thermal stratification provided little and no contribution to bacterioplankton communities, respectively. CODmn, Chla, and TN were the most appropriate parameters to describe the environmental interpretation of bacterial ordinations, and CODmn was the predominant factor. In addition, the higher similarity between CODmn and Chla, shown by clustering analysis, indicated that the algae-bacteria symbiotic system may have an important role in material circulation in freshwater aquaculture pond water during the peak period of culture. The present study has helped to elucidate the biological characteristics of aquaculture tail water, and enriched the basic data provided by bacterioplankton studies.

Risk assessment of chlorantraniliprole pesticide use in rice-crab coculture systems in the basin of the lower reaches of the Yangtze River in China.

Rice-crab (Chinese mitten crab, Eriocheir sinensis) coculture system has become one of the most important agricultural activities practiced in China. However, the effect of pesticide usage on the survival and edible safety of crab species living in the coculture system has not been investigated. In the present study, we created a field simulation experiment and discovered that the amount of pesticide chlorantraniliprole (CAP) entering the rice-crab coculture system accounted for 82.22% of the total CAP content present in the spray barrel. When CAP residues found in the soil leached into nearby areas, we observed an increase in the CAP concentration in the water and sediment. Specifically, peak CAP concentration (1.35 µg/L) was detected in water within 1 day, and a steady CAP concentration in the sediment (2.55 µg/kg) was detected within 3 days. Additionally, an extensive field sampling experiment conducted in the basin of the lower reaches of the Yangtze River revealed that CAP was routinely used in rice-crab coculture systems. Although detected CAP concentrations were below 1 µg/L in ditch water and below 1 µg/kg in ditch sediment, there was still a potential risk associated with the crab growth. Importantly, there was no risk associated with crab consumption, given the low detection frequency of CAP in the collected samples. Our analysis suggests that an increase in usage ratio and a decrease in the total CAP content will likely promote safe application of CAP in the rice-crab coculture systems.

Transcriptome analysis of juvenile genetically improved farmed tilapia (Oreochromis niloticus) livers by dietary resveratrol supplementation.

Here we used RNA-Seq to explore the transcriptomic response and specific involvement of hepatic mRNA of juvenile Oreochromis niloticus (GIFT) as a result of dietary resveratrol supplementation (0.05 g/kg RES). More than 24,513,018 clean reads were reference genome guided assembly into 23,417 unigenes. 12,596 unigenes (29.64%) were annotated to GO database. There were 5, 179 and 1526 genes significantly differentially expressed genes at 15, 30 and 45 d respectively, and 8 KEGG pathways were enriched associated with this immune response. Hyperemia and compressed hepatic sinusoid, fibrosis of liver cell and abnormal hepatic epidermal cell revealed by H&E and SEM analysis respectively. Genes related with cytokine production (il12rb2, scfr), immune system (ig8l, hlfl, cd226, prf1l), autophagy regulation (atg4b), foxo signaling (ccnb2), steroid hormone biosynthesis (cyp3a40), fatty acid metabolism (scd1), metabolism (cacna1b) have been significantly decreased, while genes associated with such pathways above (leap-2, prdx4, mb, homer1, mif, sat1, cytbc1_8) and the pathway of protein processing in endoplasmic reticulum (cne1, tram1) have been significantly increased. These findings suggested RES activated some immune and biological process-related genes to enhance GIFT's innate immunity. It also suggested high concentration addition or long-time administration may bring negative effect in tilapia liver.

Testicular transcriptome alterations in zebrafish (Danio rerio) exposure to 17ß-estradiol.

The hormone 17ß-estradiol (E2) can be found in rivers, effluents, and even drinking water. Researches have demonstrated that E2 affects various metabolic pathways through gene activation and may cause reproductive toxicity in fish. Therefore, the aim of this study was to evaluate E2-induced toxicity via testicular transcriptome of zebrafish (Danio rerio) exposed to different concentrations (10 ng L-1, and 100 ng L-1) of E2. A total of >600 significant differentially expressed genes (DEGs) were enriched among the three treatments. Short time-series expression miner analysis revealed five KEGG pathways including drug metabolism, other enzymes, calcium signaling pathway, ECM-receptor interaction, gap junction, and cell adhesion molecules. Twenty genes were selected to verify the accuracy of RNA-Seq. Other reported genes related to sex differentiation, development, energy metabolism, and other processes were found. One set of genes significantly increased/decreased/fluctuated over time, especially 12 h after E2 exposure. Genes associated with ovaries (zp3c), and development (bmp15, gdf9, and sycp2l) were significantly upregulated with increasing E2 concentration. E2 and testosterone was significantly decreased by 10 (except for T) and 100 ng L-1 E2 exposure at 12 h. The current study demonstrated that sex differentiation, development, energy metabolism, immunity, and ribosome biogenesis in male zebrafish were all significantly affected by 17ß-estradiol exposure through transcriptional alterations.

Effects of multiple environmental factors on elimination of fenvalerate and its cis-trans isomers in aquaculture water.

Fenvalerate (FV) is widely used in aquaculture because of their broad spectrums and high efficiency. However, little is known regarding the elimination of FV influenced by environment factors in aquaculture water, especially its cis-trans isomers (cis-FV and trans-FV). In the present study, factors influencing the aquaculture environment (open type, temperature, pH and light) were selected, and the elimination dynamics of FV and its cis-trans isomers in aquaculture water using orthogonal experiments were investigated. The results showed that the half-life and elimination rate range of FV were 4.75-11.95 days and 65-93%, respectively, while those of trans-FV were 4.60-11.82 days and 67-93% and those of cis-FV were 4.94-12.04 days and 64-92%, respectively. The elimination rate of trans-FV was better than that of cis-FV. Additionally, analysis of variance (ANOVA) of the orthogonal experimental data indicated that the environmental factors of open type, temperature, and pH significantly influenced the elimination rate of cis- and trans-FV (P < 0.05), that is, in the aquaculture season, high temperature and pH facilitate to eliminate FV. This study would improve our understanding of natural degradation associated with FV and guide safe to use associated with pesticide in aquaculture.