In the present study,nano-sized TiO2 /Al2O3 modified PVDF membranes (MM) were fabricated and utilized for anionic polyacrylamide ( APAM) separation. The results showed that,compared with PVDF membrane (OM) ,the contac...In the present study,nano-sized TiO2 /Al2O3 modified PVDF membranes (MM) were fabricated and utilized for anionic polyacrylamide ( APAM) separation. The results showed that,compared with PVDF membrane (OM) ,the contact angle of MM decreases from 83. 64° to 67. 42°,which indicates the increase of the hydrophilicity of MM. The relative flux (RF) decline curve of this ultrafiltration of APAM in water with time shows an obvious two stage properties. The cake filtration models were used to predict the performance of different time over the complete range of filtration times. All the four cake models could simulate this UF process to a certain extent,and the suitability of the two kinds of membranes was: cake filtration > intermediate pore blocking > standard pore blocking > complete pore blocking models. However,they became more and more unsuited to this process with time extending. Surface and cross-sectional morphology of membrane was investigated by SEM to make an advanced certificate of this UF mechanism.展开更多
The Chinese longsnout catfish(Leiocassis longirostris Günther)is one of the most economically important freshwater fish in China.As wild populations have declined sharply in recent years,it is also a valuable mod...The Chinese longsnout catfish(Leiocassis longirostris Günther)is one of the most economically important freshwater fish in China.As wild populations have declined sharply in recent years,it is also a valuable model for research on sexual dimorphism,comparative biology,and conservation.However,the current lack of high-quality chromosome-level genome information for the species hinders the advancement of comparative genomic analysis and evolutionary studies.Therefore,we constructed the first high-quality chromosomelevel reference genome for L.longirostris.The total genome was 703.19 Mb,with 389 contigs and contig N50 length of 4.29 Mb.Using high-throughput chromosome conformation capture(Hi-C)data,the genome sequences(685.53 Mb)were scaffolded into 26 chromosomes ranging from 17.36 to 43.97 Mb,resulting in a chromosomal anchoring rate for the genome of 97.44%.In total,23708 protein-coding genes were identified in the genome.Phylogenetic analysis indicated that L.longirostris and its closest related species P.fulvidraco diverged approximately 26.6 million years ago.This highquality reference genome of L.longirostris should pave the way for future genomic comparisons and evolutionary research.展开更多
The bacteria in the genus Vibrio are heterothrophic, which exist in the larval rearing water of Crustacea and often show diverse pathogenicities to marine animals. In order to assess the bacterial diversity associated...The bacteria in the genus Vibrio are heterothrophic, which exist in the larval rearing water of Crustacea and often show diverse pathogenicities to marine animals. In order to assess the bacterial diversity associated with Crustacean seed production, 32 strains were isolated from black tiger shrimp (Penaeus monodon) and mangrove crab (Scylla paramamosain) larvae and their rearing-water and characterized using biochemical and molecular approaches. Two or more genotypically different species were identified. The vibriosis of black tiger shrimp was caused by V. harveyi, V. alginolyticus and Vibrio spp. predominantly, while that of crab by V. harveyi and V. alginolyticus only.展开更多
This research is based on the U8 (43) uniform table to conduct uniform experiments for improving saline soil. Different proportions of saline soil and silt, with a composted residue of marine fish and seashells that w...This research is based on the U8 (43) uniform table to conduct uniform experiments for improving saline soil. Different proportions of saline soil and silt, with a composted residue of marine fish and seashells that was mixed with sawdust and cow dung, were chosen as the assembly factors. The improvement coefficients for available nitrogen phosphorus of the mixed salt mud and for the production of tall fescue hay were adopted as the characterization values. According to the causal relations that were previously established by 64 types of permutations and combinations, the optimal assembly scheme with maximum characterization values was determined. The results indicate that the artificial soil that consisted of saline soil and silts in a ratio of 8:2;sea fish waste, shellfish trash and sawdust in a ratio of 5:4:1;and 8 kg of cow dung (10 wt%) is the best among the 64 types of composting treatments. Under the improved conditions, the predictive values of the increasing coefficients of valid nitrogen and valid phosphorus in the soil are 1.99 and 1.93, respectively;the predictive value of the tall fescue in a unit area production is 238.83 g·m-2. Its error accuracy is more than 99.82%. All of the above results indicate that utilizing the saline soil improvement media, which is composed of Haihe river silts, fish and shellfish slag, cow dung, and other wastes, provides a new option for saline soil improvement.展开更多
A 12-wk trial was conducted to compare the tolerance of tilapia to high carbohydrate and high lipid diets.Three isonitrogenous and isoenergetic diets,whose carbohydrate and lipid levels were the following:35.0%and 8%(...A 12-wk trial was conducted to compare the tolerance of tilapia to high carbohydrate and high lipid diets.Three isonitrogenous and isoenergetic diets,whose carbohydrate and lipid levels were the following:35.0%and 8%(control),44.2%and 4%(D1,high carbohydrate),and 25.8%and 12%(D2,high lipid),respectively.Three hundred tilapias(27±0.11 g)were fed the diets for 10 wk(4 replicates per group);72 fish from the D1 group were continually fed the D1(D1D1)and 72 fish from the D2 were continually fed the D2(D2D2)diet for 2 wk(3 replicates each group)to evaluate the tilapia's capacity to tolerate high carbohydrate and high lipid diets,respectively.Another 36 fish from D1 group were continually fed D2(D1D2)for comparison with D1D1 and D2D2 groups.In phase 1,hepatosomatic index,liver triglycerides(TG),glucose tolerance(GT)and crude protein in the whole body in D1 group were higher than those in D2 group(P<0.05).During phase 2,D1D1 group had lower feed intake and weight gain,as well as lower serum total protein and albumin than that of D2D2 group(P<0.05),while its liver glycogen was significantly higher than that in D1D2 and D2D2 groups(P<0.05).Moreover,serum glucose and GT were higher in D1D1 and D1D2 groups than those in D2D2 group(P<0.05).By contrast,D2D2 group had significantly higher intraperitoneal fat,subcutaneous adipose tissue(SCAT)and liver TG than those in D1D1 group(P<0.05).The mRNA expression of brain npy,hepatic nrf2,gst1 and hepatic transcriptomic data showed that immune-related genes(gama,mrc2,mhc2 and cd163),were downregulated in D1D1 group compared to D2D2 and D1D2 groups.Taken together:1)tilapia have higher tolerance to a high lipid diet than high carbohydrate diet;2)despite retention of glucose tolerance,the continuous feeding of D1 diet impaired tilapia's appetite,weight gain rate and host immune response;3)specific distri-bution of fat in intraperitoneal regions,SCAT and liver may be a risk-avoidance strategy in tilapia in response to a continuous D2 diet.展开更多
For aromatic monomer compounds (AMCs), ozonation outcomes were usually predicted by the substituents of the benzene ring based on the electron inductive effect. However, the predicted results were occasionally unrelia...For aromatic monomer compounds (AMCs), ozonation outcomes were usually predicted by the substituents of the benzene ring based on the electron inductive effect. However, the predicted results were occasionally unreliable for complex substituents, and other factors caused concern. In this study, p-chloronitrobenzene (p-CNB) and ibuprofen (IBP) were selected for ozonation. According to the electron inductive theory, p-CNB should be less oxidizable, but the opposite was true. The higher rates of p-CNB were due to various sources of assistance. First, the hydroxyl radical (•OH) contributed 90 % to p-CNB removal at pH 7.0, while its contribution to IBP removal was 50 %. Other contributions came from molecular O3 oxidation. Second, p-CNB achieved 40 % of the total organic carbon (TOC) removal and fewer by-product types and quantities, when compared to the results for IBP. Third, the oxidation of p-CNB started with hydroxyl substitution reactions on the benzene ring;then, the ring opened. However, IBP was initially oxidized mainly on the butane branched chain, with a chain-shortening process occurring before the ring opened. Finally, the degradation pathway of p-CNB was single and consumed fewer oxidants. However, both branches of IBP were attacked simultaneously, and three degradation pathways that relied on more oxidants were proposed. All of these factors were determinants of the rapid removal of p-CNB.展开更多
A biochar-assisted anaerobic membrane bioreactor(BC-AnMBR)was conducted to evaluate the performance in treating swine wastewater with different organic loading rates(OLR)ranging from 0.38 to 1.13 kg-COD/(m3.d).Results...A biochar-assisted anaerobic membrane bioreactor(BC-AnMBR)was conducted to evaluate the performance in treating swine wastewater with different organic loading rates(OLR)ranging from 0.38 to 1.13 kg-COD/(m3.d).Results indicated that adding spent coffee grounds biochar(SCG-BC)improved the organic removal efficiency compared to the conventional AnMBR,with an overall COD removal rate of>95.01%.Meanwhile,methane production of up to 0.22 LCH4/gCOD with an improvement of 45.45%was achieved under a high OLR of 1.13 kg-COD/(m3.d).Furthermore,the transmembrane pressure(TMP)in the BC-AnMBR system was stable at 4.5 kPa,and no irreversible membrane fouling occurred within 125 days.Microbial community analysis revealed that the addition of SCG-BC increased the relative abundance of autotrophic methanogenic archaea,particularly Methanosarcina(from 0.11%to 11.16%)and Methanothrix(from 16.34%to 24.05%).More importantly,Desulfobacterota and Firmicutes phylum with direct interspecific electron transfer(DIET)capabilities were also enriched with autotrophic methanogens.Analysis of the electron transfer pathway showed that the concentration of c-type cytochromes increased by 38.60%in the presence of SCGBC,and thus facilitated the establishment of DIET and maintained high activity of the elec-tron transfer system even at high OLR.In short,the BC-AnMBR system performs well under various OLR conditions and is stable in the recovery energy system for swine wastewater.展开更多
Swine wastewater is an important pollution source of antibiotics entering the aquatic environment. In this work,the adsorption behavior of sulfamethazine(SMN),a commonlyused sulfonamide antibiotic,on activated sludg...Swine wastewater is an important pollution source of antibiotics entering the aquatic environment. In this work,the adsorption behavior of sulfamethazine(SMN),a commonlyused sulfonamide antibiotic,on activated sludge from a sequencing batch reactor treating swine wastewater was investigated. The results show that the adsorption of SMN on activated sludge was an initially rapid process and reached equilibrium after 6 hr. The removal efficiency of SMN from the water phase increased with an increasing concentration of mixed liquor suspended solids,while the adsorbed concentration of SMN decreased. Solution pH influenced both the speciation of SMN and the surface properties of activated sludge,thus significantly impacting the adsorption process. A linear partition model could give a good fit for the equilibrium concentrations of SMN at the test temperatures(i.e.,10,20 and 30°C). The partition coefficient(Kd) was determined to be 100.5 L/kg at 20°C,indicating a quite high adsorption capacity for SMN. Thermodynamic analysis revealed that SMN adsorption on activated sludge was an exothermic process. This study could help to clarify the fate and behavior of sulfonamide antibiotics in the activated sludge process and assess consequent environmental risks arising from sludge disposal as well.展开更多
Pretreatment of thickened waste activated sludge (TWAS) by combined microwave and alkaline pretreatment (MAP) was studied to improve thermophilic anaerobic digestion efficiency. Uniform design was applied to deter...Pretreatment of thickened waste activated sludge (TWAS) by combined microwave and alkaline pretreatment (MAP) was studied to improve thermophilic anaerobic digestion efficiency. Uniform design was applied to determine the combination of target temperature (110-210°C), microwave holding time (1-51 min), and NaOH dose (0-2.5 g NaOH/g suspended solids (SS)) in terms of their effect on volatile suspended solids (VSS) solubilization. Maximum solubilization ratio (85.1%) of VSS was observed at 210°C with 0.2 g-NaOH/g-SS and 35 min holding time. The effects of 12 different pretreatment methods were investigated in 28 thermophilic batch reactors by monitoring cumulative methane production (CMP). Improvements in methane production in the TWAS were directly related to the microwave and alkaline pretreatment of the sludge. The highest CMP was a 27% improvement over the control. In spite of the increase in soluble chemical oxygen demand concentration and the decrease in dewaterability of digested sludge, a semi-continuous thermophilic reactor fed with pretreated TWAS without neutralization (at 170~C with 1 min holding time and 0.05 g NaOH/g SS) was stable and functioned well, with volatile solid (VS) and total chemical oxygen demand (TCOD) reductions of 28% and 18%, respectively, which were higher than those of the control system. Additionally, methane yields (L@STP/g-CODaded, at standard temperature and pressure (STP) conditions of 0°C and 101.325 kPa) and (L@STP/g VSadad) increased by 17% and 13%, respectively, comoared to the control reactor.展开更多
The Cypriniformes comprise approximately 4,200 species accounting for 25% of the diversity of all freshwater fish, which is widely distributed across the world's continents except Antarctica, South America, and Au...The Cypriniformes comprise approximately 4,200 species accounting for 25% of the diversity of all freshwater fish, which is widely distributed across the world's continents except Antarctica, South America, and Australia. The highest species diversity is found in Southeastern Asia. Despite its remarkable species diversity and broad-scale geographic patterns of distribution, the evolutionary history of this major freshwater fish group remains largely unresolved. To gain insight of the evolutionary history of Cypriniformes, we present a phylogeny of this group using 1 mitochondrial gene and 15 nuclear genes comprising a total of14,061 bp. Bayesian inference using all gene fragments yielded a well resolved phylogeny, which is mostly consistent with topologies obtained from Maximum Likelihood analyses. Our results further confirmed the monophyly of Cypriniformes and seven constituent subclades including Cyprinidae, Catostomidae, Gyrinocheilidae, Balitoridae, Cobitidae, Nemacheilidae, and Botiidae. Bayesian divergence time analysis indicated that the origin of the Cypriniformes was about 193 Mya during the early Jurassic, coinciding with the onset of the Pangaea breakup. The basal divergence of Cypriniformes is 154 Mya during the late Jurassic. Our findings from molecular divergence and biogeographical analysis indicate the most likely initial geographical range of the ancient Cypriniformes was both East and South Asia(Southeastern area of Mesozoic Laurasia). Moreover, the burst in species diversity in Cyprinidae afforded by the nearly worldwide colonization is possibly in response to the plasticity of pharyngeal dentition. The present study demonstrates that the Cypriniformes was about 193 Mya during the early Jurassic,coinciding with the onset of the Pangaea breakup. The plasticity of pharyngeal dentition of cyprinids might contribute to the burst and radiation of this lineage. The phylogenetic and biogeographic analyses in this study help to improve our understanding of the evolutionary history of this diverse and important freshwater fish group.展开更多
This work described the development, optimization and validation of an analytical method for rapid detection of multiple-class pharmaceuticals in both municipal wastewater and sludge samples based on ultrasonic solven...This work described the development, optimization and validation of an analytical method for rapid detection of multiple-class pharmaceuticals in both municipal wastewater and sludge samples based on ultrasonic solvent extraction, solid-phase extraction, and ultra high performance liquid chromatography-tandem mass spectrometry quantification. The results indicated that the developed method could effectively extract all the target pharmaceuticals (25) in a single process and analyze them within 24 min. The recoveries of the target pharmaceuticals were in the range of 69%-131% for wastewater and 54%-130% for sludge at different spiked concentration levels. The method quantification limits in wastewater and sludge ranged from 0.02 to 0.73 ng/L and from 0.02 to 1.00μg/kg, respectively. Subsequently, this method was validated and applied for residual pharma- ceutical analysis in a wastewater treatment plant located in Beijing, China. All the target pharmaceuticals were detected in the influent samples with concentrations varying from 0.09 ng/L (tiamulin) to 15.24 μg/L (caffeine); meanwhile, up to 23 pharmaceuticals were detected in sludge samples with concentrations varying from 60 ng/kg (sulfamethizole) to 8.55 mg/kg (ofloxacin). The developed method demonstrated its selectivity, sensitivity, and reliability for detecting multiple-class pharmaceuticals in complex matrices such as municipal wastewater and sludge.展开更多
Membrane bioreactors(MBR) are highly efficient at intercepting particles and microbes and have become an important technology for wastewater reclamation. However, many pathogens can accumulate in activated sludge du...Membrane bioreactors(MBR) are highly efficient at intercepting particles and microbes and have become an important technology for wastewater reclamation. However, many pathogens can accumulate in activated sludge due to the long residence time usually adopted in MBR, and thus may pose health risks when membrane integrity problems occur.This study presents data from a survey on the occurrence of water-borne Giardia pathogens in reclaimed water from a full-scale wastewater treatment plant with MBR experiencing membrane integrity failure, and assessed the associated risk for green space irrigation. Due to membrane integrity failure, the MBR effluent turbidity varied between 0.23 and 1.90 NTU over a period of eight months. Though this turbidity level still met reclaimed water quality standards(≤ 5 NTU), Giardia were detected at concentrations of 0.3 to 95 cysts/10 L, with a close correlation between effluent turbidity and Giardia concentration. All β-giardin gene sequences of Giardia in the WWTP influents were genotyped as Assemblages A and B, both of which are known to infect humans. An exponential dose–response model was applied to assess the risk of infection by Giardia. The risk in the MBR effluent with chlorination was9.83 × 10-3, higher than the acceptable annual risk of 1.0 × 10^-4. This study suggested that membrane integrity is very important for keeping a low pathogen level, and multiple barriers are needed to ensure the biological safety of MBR effluent.展开更多
The contaminant of herbicide clopyralid(3,6-dichloro-2-pyridine-carboxylic acid,CLP)poses a potential threat to the ecological system.However,there is a general lack of research devoted to the perturbation of CLP to t...The contaminant of herbicide clopyralid(3,6-dichloro-2-pyridine-carboxylic acid,CLP)poses a potential threat to the ecological system.However,there is a general lack of research devoted to the perturbation of CLP to the bio-denitrification process,and its biological response mechanism remains unclear.Herein,long-term exposure to CLP was systematically investigated to explore its influences on denitrification performance and dynamic microbial responses.Results showed that low-concentration of CLP(<15 mg/L)caused severe nitrite accumulation initially,while higher concentrations(35e60 mg/L)of CLP had no further effect after long-term acclimation.The mechanistic study demonstrated that CLP reduced nitrite reductase(NIR)activity and inhibited metabolic activity(carbon metabolism and nitrogen metabolism)by causing oxidative stress and membrane damage,resulting in nitrite accumulation.However,after more than 80 days of acclimation,almost no nitrite accumulation was found at 60 mg/L CLP.It was proposed that the secretion of extracellular polymeric substances(EPS)increased from 75.03 mg/g VSS at 15 mg/L CLP to 109.97 mg/g VSS at 60 mg/L CLP,which strengthened the protection of microbial cells and improved NIR activity and metabolic activities.Additionally,the biodiversity and richness of the microbial community experienced a U-shaped process.The relative abundance of denitrification-and carbon metabolism-associated microorganisms decreased initially and then recovered with the enrichment of microorganisms related to the secretion of EPS and N-acyl-homoserine lactones(AHLs).These microorganisms protected microbe from toxic substances and regulated their interactions among interand intra-species.This study revealed the biological response mechanism of denitrification after successive exposure to CLP and provided proper guidance for analyzing and treating herbicide-containing wastewater.展开更多
Reverse electrodialysis(RED)is an emerging membrane-based technology for the production of renewable energy from mixing waters with different salinities.Herein,the impact of the stack configuration on the Ohmic and no...Reverse electrodialysis(RED)is an emerging membrane-based technology for the production of renewable energy from mixing waters with different salinities.Herein,the impact of the stack configuration on the Ohmic and non-Ohmic resistances as well as the performance of RED were systematically studied by using in situ electrochemical impedance spectroscopy(EIS).Three different parameters(membrane type,number of cell pairs and spacer design)were controlled.The Ohmic and non-Ohmic resistances were evaluated for RED stacks equipped with two types of commercial membranes(Type I and Type II)supplied by Fujifilm Manufacturing Europe B.V:Type I Fuji membranes displayed higher Ohmic and non-Ohmic resistances than Type II membranes,which was mainly attributed to the difference in fixed charge density.The output power of the stack was observed to decrease with the increasing number of cell pairs mainly due to the increase in ionic shortcut currents.With the reduction in spacer thickness from 750 to 200μm,the permselectivity of membranes in the stack decreased from 0.86 to 0.79 whereas the energy efificiency losses increased from 31%to 49%.Overall,the output of the present study provides a basis for understanding the impact of stack design on internal losses during the scaling-up of RED.展开更多
Fish skin is mainly composed of the epidermis,dermis,and its derivative scales.There is a wide diversity in scale number in fishes,but the diversity of skin structure lacks systematic histological comparison.This rese...Fish skin is mainly composed of the epidermis,dermis,and its derivative scales.There is a wide diversity in scale number in fishes,but the diversity of skin structure lacks systematic histological comparison.This research aimed to improve our understanding of the functional relationship between the scale number and the skin structure in freshwater fishes and to determine which ecological factors affect the scale number and skin structure.First,we presented a method to quantify skin structure in fish and histologically quantified the skin structure of 54 freshwater fishes.Second,we collected the scale number and habitat information of 509 Cyprinidae fishes in China and explored which ecological factors were related to their scale number.Third,common carp and scaleless carp were used as models to study the effects of scale loss on swimming.We found a strong negative correlation between scale thickness and scale number.The main factor affecting the skin structure of fishes was the species’water column position,and the skin of benthic fishes was the most well-developed(thicker skin layers(dermis,epidermis)or more/larger goblet cells and club cells).The scale number was related to two factors,namely,temperature and water column position,and cold,benthic and pelagic adaptation may have contributed to increased scale numbers.Only in benthic fishes,the more well-developed their skin,the more scales.In common carp,scale loss did not affect its swimming performance.In summary,we suggest that there is a rich diversity of skin structure in freshwater fishes,and the scales of fish with well-developed skin tend to degenerate(greater number/smaller size/thinner,or even disappear),but the skin of fish with degenerated scales is not necessarily well developed.展开更多
The role of glucocorticoids in oogenesis remains to be elucidated. cyp11c1 encodes the key enzyme involved in the synthesis of cortisol, the major glucocorticoid in teleosts. In our previous study, we mutated cyp11c1 ...The role of glucocorticoids in oogenesis remains to be elucidated. cyp11c1 encodes the key enzyme involved in the synthesis of cortisol, the major glucocorticoid in teleosts. In our previous study, we mutated cyp11c1 in tilapia and analyzed its role in spermatogenesis. In this study, we analyzed its role in oogenesis. cyp11c1^(+/-)XX tilapia showed normal ovarian morphology but poor egg quality, as indicated by the mortality of embryos before 3 d post fertilization, which could be partially rescued by the supplement of exogenous cortisol to the mother fish. Transcriptome analyses revealed reduced expression of maternal genes in the eggs of the cyp11c1^(+/-)XX fish. The cyp11c1^(-/-)females showed impaired vitellogenesis and arrested oogenesis due to significantly decreased serum cortisol. Further analyses revealed decreased serum E2 level and expression of amh, an important regulator of follicular cell development, and increased follicular cell apoptosis in the ovaries of cyp11c1^(-/-)XX fish, which could be rescued by supplement of either exogenous cortisol or E2. Luciferase assays revealed a direct regulation of cortisol and E2 on amh transcription via GRs or ESRs. Taken together, our results demonstrate that cortisol safeguards oogenesis by promoting follicular cell survival probably via Amh signaling.展开更多
Spermatogenesis is a complex process in which spermatogonial stem cells differentiate and develop into mature spermatozoa.The transcriptional regulatory network involved in fish spermatogenesis remains poorly understo...Spermatogenesis is a complex process in which spermatogonial stem cells differentiate and develop into mature spermatozoa.The transcriptional regulatory network involved in fish spermatogenesis remains poorly understood.Here,we demonstrate in Nile tilapia that the Sox transcription factor family member Sox30 is specifically expressed in the testes and mainly localizes to spermatocytes and spermatids.CRISPR/Cas9-mediated sox30 mutation results in abnormal spermiogenesis,reduction of sperm motility,and male subfertility.Comparative transcriptome analysis shows that sox30 mutation alters the expression of genes involved in spermatogenesis.Further chromatin immunoprecipitation followed by high-throughput sequencing(Ch IP-seq),Ch IP-PCR,and luciferase reporter assays revealed that Sox30 positively regulates the transcription of ift140 and ptprb,two genes involved in spermiogenesis,by directly binding to their promoters.Our data,taken together,indicate that Sox30 plays an essential role in Nile tilapia spermatogenesis by directly regulating the transcription of the spermiogenesis-related genes ift140 and ptprb.展开更多
Gene editing nucleases including zinc-finger nucleases(ZFNs), transcription activator like effector nucleases(TALENs) and clustered regularly interspaced short palindromic repeats(CRISPR)–CRISPR-associated(Cas) syste...Gene editing nucleases including zinc-finger nucleases(ZFNs), transcription activator like effector nucleases(TALENs) and clustered regularly interspaced short palindromic repeats(CRISPR)–CRISPR-associated(Cas) system(CRISPR/Cas9) provide powerful tools that improve our ability to understand the physiological processes and their underlying mechanisms. To date, these approaches have already been widely used to generate knockout and knockin models in a large number of species. Fishes comprise nearly half of extant vertebrate species and provide excellent models for studying many aspects of biology. In this review, we present an overview of recent advances in the use of gene editing nucleases for studies of fish species. We focus particularly on the use of TALENs and CRISPR/Cas9 genome editing for studying sex determination in tilapia.展开更多
Traditional bioelectrochemical systems(BESs)coupled with stripping units for ammonia recovery suffer from an insufficient supply of electron acceptors due to the low solubility of oxygen.In this study,we proposed a no...Traditional bioelectrochemical systems(BESs)coupled with stripping units for ammonia recovery suffer from an insufficient supply of electron acceptors due to the low solubility of oxygen.In this study,we proposed a novel strategy to efficiently transport the oxidizing equivalent provided at the stripping unit to the cathode by introducing a highly soluble electron mediator(EM)into the catholyte.To validate this strategy,we developed a new kind of iron complex system(tartrate-EDTA-Fe)as the EM.EDTA-Fe contributed to the redox property with a midpoint potential of0.075 V(vs.standard hydrogen electrode,SHE)at pH 10,whereas tartrate acted as a stabilizer to avoid iron precipitation under alkaline conditions.At a ratio of the catholyte recirculation rate to the anolyte flow rate(RC-A)of 12,the NH4 t-N recovery rate in the system with 50mM tartrate-EDTA-Fe complex reached 6.9±0.2 g Nm^(-2) d^(-1),approximately 3.8 times higher than that in the non-EM control.With the help of the complex,our system showed an NH4 t-N recovery performance comparable to that previously reported but with an extremely low RC-A(0.5 vs.288).The strategy proposed here may guide the future of ammonia recovery BES scale-up because the introduction of an EM allows aeration to be performed only at the stripping unit instead of at every cathode,which is beneficial for the system design due to its simplicity and reliability.展开更多
基金Sponsored by the National Natural Science Foundation of China (Grant No.50978068)International Cooperation Program (Grant No.2010DFA92460)+1 种基金National High Technology Research and Development Program of China (863 Program,Grant No.2008AA06Z304)Tianjin Key Laboratory of Aquatic Science and Technology
文摘In the present study,nano-sized TiO2 /Al2O3 modified PVDF membranes (MM) were fabricated and utilized for anionic polyacrylamide ( APAM) separation. The results showed that,compared with PVDF membrane (OM) ,the contact angle of MM decreases from 83. 64° to 67. 42°,which indicates the increase of the hydrophilicity of MM. The relative flux (RF) decline curve of this ultrafiltration of APAM in water with time shows an obvious two stage properties. The cake filtration models were used to predict the performance of different time over the complete range of filtration times. All the four cake models could simulate this UF process to a certain extent,and the suitability of the two kinds of membranes was: cake filtration > intermediate pore blocking > standard pore blocking > complete pore blocking models. However,they became more and more unsuited to this process with time extending. Surface and cross-sectional morphology of membrane was investigated by SEM to make an advanced certificate of this UF mechanism.
基金supported by the China Agriculture Research System(CARS-46)Fundamental Research Funds for the Central Universities(XDJK2017B008,XDJK2017C035,XDJK2019C025,5360300098)+1 种基金Natural Science Foundation of Chongqing(cstc2020jcyj-msxmX0438)National Natural Science Foundation of China(32071651)。
文摘The Chinese longsnout catfish(Leiocassis longirostris Günther)is one of the most economically important freshwater fish in China.As wild populations have declined sharply in recent years,it is also a valuable model for research on sexual dimorphism,comparative biology,and conservation.However,the current lack of high-quality chromosome-level genome information for the species hinders the advancement of comparative genomic analysis and evolutionary studies.Therefore,we constructed the first high-quality chromosomelevel reference genome for L.longirostris.The total genome was 703.19 Mb,with 389 contigs and contig N50 length of 4.29 Mb.Using high-throughput chromosome conformation capture(Hi-C)data,the genome sequences(685.53 Mb)were scaffolded into 26 chromosomes ranging from 17.36 to 43.97 Mb,resulting in a chromosomal anchoring rate for the genome of 97.44%.In total,23708 protein-coding genes were identified in the genome.Phylogenetic analysis indicated that L.longirostris and its closest related species P.fulvidraco diverged approximately 26.6 million years ago.This highquality reference genome of L.longirostris should pave the way for future genomic comparisons and evolutionary research.
文摘The bacteria in the genus Vibrio are heterothrophic, which exist in the larval rearing water of Crustacea and often show diverse pathogenicities to marine animals. In order to assess the bacterial diversity associated with Crustacean seed production, 32 strains were isolated from black tiger shrimp (Penaeus monodon) and mangrove crab (Scylla paramamosain) larvae and their rearing-water and characterized using biochemical and molecular approaches. Two or more genotypically different species were identified. The vibriosis of black tiger shrimp was caused by V. harveyi, V. alginolyticus and Vibrio spp. predominantly, while that of crab by V. harveyi and V. alginolyticus only.
文摘This research is based on the U8 (43) uniform table to conduct uniform experiments for improving saline soil. Different proportions of saline soil and silt, with a composted residue of marine fish and seashells that was mixed with sawdust and cow dung, were chosen as the assembly factors. The improvement coefficients for available nitrogen phosphorus of the mixed salt mud and for the production of tall fescue hay were adopted as the characterization values. According to the causal relations that were previously established by 64 types of permutations and combinations, the optimal assembly scheme with maximum characterization values was determined. The results indicate that the artificial soil that consisted of saline soil and silts in a ratio of 8:2;sea fish waste, shellfish trash and sawdust in a ratio of 5:4:1;and 8 kg of cow dung (10 wt%) is the best among the 64 types of composting treatments. Under the improved conditions, the predictive values of the increasing coefficients of valid nitrogen and valid phosphorus in the soil are 1.99 and 1.93, respectively;the predictive value of the tall fescue in a unit area production is 238.83 g·m-2. Its error accuracy is more than 99.82%. All of the above results indicate that utilizing the saline soil improvement media, which is composed of Haihe river silts, fish and shellfish slag, cow dung, and other wastes, provides a new option for saline soil improvement.
基金funded by National Key R&D Program of China(2018YFD0900400)Guangdong Basic and Applied Basic Research Foundation(2019A1515110115).
文摘A 12-wk trial was conducted to compare the tolerance of tilapia to high carbohydrate and high lipid diets.Three isonitrogenous and isoenergetic diets,whose carbohydrate and lipid levels were the following:35.0%and 8%(control),44.2%and 4%(D1,high carbohydrate),and 25.8%and 12%(D2,high lipid),respectively.Three hundred tilapias(27±0.11 g)were fed the diets for 10 wk(4 replicates per group);72 fish from the D1 group were continually fed the D1(D1D1)and 72 fish from the D2 were continually fed the D2(D2D2)diet for 2 wk(3 replicates each group)to evaluate the tilapia's capacity to tolerate high carbohydrate and high lipid diets,respectively.Another 36 fish from D1 group were continually fed D2(D1D2)for comparison with D1D1 and D2D2 groups.In phase 1,hepatosomatic index,liver triglycerides(TG),glucose tolerance(GT)and crude protein in the whole body in D1 group were higher than those in D2 group(P<0.05).During phase 2,D1D1 group had lower feed intake and weight gain,as well as lower serum total protein and albumin than that of D2D2 group(P<0.05),while its liver glycogen was significantly higher than that in D1D2 and D2D2 groups(P<0.05).Moreover,serum glucose and GT were higher in D1D1 and D1D2 groups than those in D2D2 group(P<0.05).By contrast,D2D2 group had significantly higher intraperitoneal fat,subcutaneous adipose tissue(SCAT)and liver TG than those in D1D1 group(P<0.05).The mRNA expression of brain npy,hepatic nrf2,gst1 and hepatic transcriptomic data showed that immune-related genes(gama,mrc2,mhc2 and cd163),were downregulated in D1D1 group compared to D2D2 and D1D2 groups.Taken together:1)tilapia have higher tolerance to a high lipid diet than high carbohydrate diet;2)despite retention of glucose tolerance,the continuous feeding of D1 diet impaired tilapia's appetite,weight gain rate and host immune response;3)specific distri-bution of fat in intraperitoneal regions,SCAT and liver may be a risk-avoidance strategy in tilapia in response to a continuous D2 diet.
基金supported by the Education Commission Scientific Research Project of Tianjin(Natural Science)(No.2018KJ139).
文摘For aromatic monomer compounds (AMCs), ozonation outcomes were usually predicted by the substituents of the benzene ring based on the electron inductive effect. However, the predicted results were occasionally unreliable for complex substituents, and other factors caused concern. In this study, p-chloronitrobenzene (p-CNB) and ibuprofen (IBP) were selected for ozonation. According to the electron inductive theory, p-CNB should be less oxidizable, but the opposite was true. The higher rates of p-CNB were due to various sources of assistance. First, the hydroxyl radical (•OH) contributed 90 % to p-CNB removal at pH 7.0, while its contribution to IBP removal was 50 %. Other contributions came from molecular O3 oxidation. Second, p-CNB achieved 40 % of the total organic carbon (TOC) removal and fewer by-product types and quantities, when compared to the results for IBP. Third, the oxidation of p-CNB started with hydroxyl substitution reactions on the benzene ring;then, the ring opened. However, IBP was initially oxidized mainly on the butane branched chain, with a chain-shortening process occurring before the ring opened. Finally, the degradation pathway of p-CNB was single and consumed fewer oxidants. However, both branches of IBP were attacked simultaneously, and three degradation pathways that relied on more oxidants were proposed. All of these factors were determinants of the rapid removal of p-CNB.
基金supported by Tianjin Municipal Science and Technology Bureau of China(Nos.20JCZDJC00380 and 18PTZWHZ00140).
文摘A biochar-assisted anaerobic membrane bioreactor(BC-AnMBR)was conducted to evaluate the performance in treating swine wastewater with different organic loading rates(OLR)ranging from 0.38 to 1.13 kg-COD/(m3.d).Results indicated that adding spent coffee grounds biochar(SCG-BC)improved the organic removal efficiency compared to the conventional AnMBR,with an overall COD removal rate of>95.01%.Meanwhile,methane production of up to 0.22 LCH4/gCOD with an improvement of 45.45%was achieved under a high OLR of 1.13 kg-COD/(m3.d).Furthermore,the transmembrane pressure(TMP)in the BC-AnMBR system was stable at 4.5 kPa,and no irreversible membrane fouling occurred within 125 days.Microbial community analysis revealed that the addition of SCG-BC increased the relative abundance of autotrophic methanogenic archaea,particularly Methanosarcina(from 0.11%to 11.16%)and Methanothrix(from 16.34%to 24.05%).More importantly,Desulfobacterota and Firmicutes phylum with direct interspecific electron transfer(DIET)capabilities were also enriched with autotrophic methanogens.Analysis of the electron transfer pathway showed that the concentration of c-type cytochromes increased by 38.60%in the presence of SCGBC,and thus facilitated the establishment of DIET and maintained high activity of the elec-tron transfer system even at high OLR.In short,the BC-AnMBR system performs well under various OLR conditions and is stable in the recovery energy system for swine wastewater.
基金financially supported by the National Natural Science Foundation of China (Nos.21107127 and 51221892)the Ministry of Housing and Urban–rural Development of China (No.2012ZX07313-001-07)the State Key Laboratory of Environmental Aquatic Chemistry (No.10Y06ESPCR)
文摘Swine wastewater is an important pollution source of antibiotics entering the aquatic environment. In this work,the adsorption behavior of sulfamethazine(SMN),a commonlyused sulfonamide antibiotic,on activated sludge from a sequencing batch reactor treating swine wastewater was investigated. The results show that the adsorption of SMN on activated sludge was an initially rapid process and reached equilibrium after 6 hr. The removal efficiency of SMN from the water phase increased with an increasing concentration of mixed liquor suspended solids,while the adsorbed concentration of SMN decreased. Solution pH influenced both the speciation of SMN and the surface properties of activated sludge,thus significantly impacting the adsorption process. A linear partition model could give a good fit for the equilibrium concentrations of SMN at the test temperatures(i.e.,10,20 and 30°C). The partition coefficient(Kd) was determined to be 100.5 L/kg at 20°C,indicating a quite high adsorption capacity for SMN. Thermodynamic analysis revealed that SMN adsorption on activated sludge was an exothermic process. This study could help to clarify the fate and behavior of sulfonamide antibiotics in the activated sludge process and assess consequent environmental risks arising from sludge disposal as well.
基金supported by the Natural Science Foundation of Tianjin, China (No. 08JCYBJC13200)the National Natural Science Foundation of China (No. 50808128)
文摘Pretreatment of thickened waste activated sludge (TWAS) by combined microwave and alkaline pretreatment (MAP) was studied to improve thermophilic anaerobic digestion efficiency. Uniform design was applied to determine the combination of target temperature (110-210°C), microwave holding time (1-51 min), and NaOH dose (0-2.5 g NaOH/g suspended solids (SS)) in terms of their effect on volatile suspended solids (VSS) solubilization. Maximum solubilization ratio (85.1%) of VSS was observed at 210°C with 0.2 g-NaOH/g-SS and 35 min holding time. The effects of 12 different pretreatment methods were investigated in 28 thermophilic batch reactors by monitoring cumulative methane production (CMP). Improvements in methane production in the TWAS were directly related to the microwave and alkaline pretreatment of the sludge. The highest CMP was a 27% improvement over the control. In spite of the increase in soluble chemical oxygen demand concentration and the decrease in dewaterability of digested sludge, a semi-continuous thermophilic reactor fed with pretreated TWAS without neutralization (at 170~C with 1 min holding time and 0.05 g NaOH/g SS) was stable and functioned well, with volatile solid (VS) and total chemical oxygen demand (TCOD) reductions of 28% and 18%, respectively, which were higher than those of the control system. Additionally, methane yields (L@STP/g-CODaded, at standard temperature and pressure (STP) conditions of 0°C and 101.325 kPa) and (L@STP/g VSadad) increased by 17% and 13%, respectively, comoared to the control reactor.
基金supported by the Pilot projects(XDB13020100)the National Natural Science Foundation of China(31372190,91131014,31502147)the Fundamental Research Funds for the Central Universities(Ministry of Education of China)(XDJK2018B025)
文摘The Cypriniformes comprise approximately 4,200 species accounting for 25% of the diversity of all freshwater fish, which is widely distributed across the world's continents except Antarctica, South America, and Australia. The highest species diversity is found in Southeastern Asia. Despite its remarkable species diversity and broad-scale geographic patterns of distribution, the evolutionary history of this major freshwater fish group remains largely unresolved. To gain insight of the evolutionary history of Cypriniformes, we present a phylogeny of this group using 1 mitochondrial gene and 15 nuclear genes comprising a total of14,061 bp. Bayesian inference using all gene fragments yielded a well resolved phylogeny, which is mostly consistent with topologies obtained from Maximum Likelihood analyses. Our results further confirmed the monophyly of Cypriniformes and seven constituent subclades including Cyprinidae, Catostomidae, Gyrinocheilidae, Balitoridae, Cobitidae, Nemacheilidae, and Botiidae. Bayesian divergence time analysis indicated that the origin of the Cypriniformes was about 193 Mya during the early Jurassic, coinciding with the onset of the Pangaea breakup. The basal divergence of Cypriniformes is 154 Mya during the late Jurassic. Our findings from molecular divergence and biogeographical analysis indicate the most likely initial geographical range of the ancient Cypriniformes was both East and South Asia(Southeastern area of Mesozoic Laurasia). Moreover, the burst in species diversity in Cyprinidae afforded by the nearly worldwide colonization is possibly in response to the plasticity of pharyngeal dentition. The present study demonstrates that the Cypriniformes was about 193 Mya during the early Jurassic,coinciding with the onset of the Pangaea breakup. The plasticity of pharyngeal dentition of cyprinids might contribute to the burst and radiation of this lineage. The phylogenetic and biogeographic analyses in this study help to improve our understanding of the evolutionary history of this diverse and important freshwater fish group.
基金supported by the National Natural Science Foundation of China (No.51138009, 21107127)the Ministry ofScience and Technology of China (No.2012ZX07313-001-07)the People Programme (Marie Curie Actions) of the European Union's Seventh Programme FP7/2007–2013 under a REA grant (Agreement No.318926)
文摘This work described the development, optimization and validation of an analytical method for rapid detection of multiple-class pharmaceuticals in both municipal wastewater and sludge samples based on ultrasonic solvent extraction, solid-phase extraction, and ultra high performance liquid chromatography-tandem mass spectrometry quantification. The results indicated that the developed method could effectively extract all the target pharmaceuticals (25) in a single process and analyze them within 24 min. The recoveries of the target pharmaceuticals were in the range of 69%-131% for wastewater and 54%-130% for sludge at different spiked concentration levels. The method quantification limits in wastewater and sludge ranged from 0.02 to 0.73 ng/L and from 0.02 to 1.00μg/kg, respectively. Subsequently, this method was validated and applied for residual pharma- ceutical analysis in a wastewater treatment plant located in Beijing, China. All the target pharmaceuticals were detected in the influent samples with concentrations varying from 0.09 ng/L (tiamulin) to 15.24 μg/L (caffeine); meanwhile, up to 23 pharmaceuticals were detected in sludge samples with concentrations varying from 60 ng/kg (sulfamethizole) to 8.55 mg/kg (ofloxacin). The developed method demonstrated its selectivity, sensitivity, and reliability for detecting multiple-class pharmaceuticals in complex matrices such as municipal wastewater and sludge.
基金supported by the Creative Research Groups of China (No. 51221892, 21277169)
文摘Membrane bioreactors(MBR) are highly efficient at intercepting particles and microbes and have become an important technology for wastewater reclamation. However, many pathogens can accumulate in activated sludge due to the long residence time usually adopted in MBR, and thus may pose health risks when membrane integrity problems occur.This study presents data from a survey on the occurrence of water-borne Giardia pathogens in reclaimed water from a full-scale wastewater treatment plant with MBR experiencing membrane integrity failure, and assessed the associated risk for green space irrigation. Due to membrane integrity failure, the MBR effluent turbidity varied between 0.23 and 1.90 NTU over a period of eight months. Though this turbidity level still met reclaimed water quality standards(≤ 5 NTU), Giardia were detected at concentrations of 0.3 to 95 cysts/10 L, with a close correlation between effluent turbidity and Giardia concentration. All β-giardin gene sequences of Giardia in the WWTP influents were genotyped as Assemblages A and B, both of which are known to infect humans. An exponential dose–response model was applied to assess the risk of infection by Giardia. The risk in the MBR effluent with chlorination was9.83 × 10-3, higher than the acceptable annual risk of 1.0 × 10^-4. This study suggested that membrane integrity is very important for keeping a low pathogen level, and multiple barriers are needed to ensure the biological safety of MBR effluent.
基金the National Natural Science Foundation of China(Grant No.52000134)China Postdoctoral Science Foundation(No.2020M680894)+2 种基金Tianjin Science and Technology Program(No.21YDTPJC00700)Natural Science Foundation of Tianjin Science and Technology Correspondent Project(No.19JCQNJC07800)Tianjin Synthetic Biotechnology Innovation Capacity Improvement Project(No.TSBICIP-CXRC-007).
文摘The contaminant of herbicide clopyralid(3,6-dichloro-2-pyridine-carboxylic acid,CLP)poses a potential threat to the ecological system.However,there is a general lack of research devoted to the perturbation of CLP to the bio-denitrification process,and its biological response mechanism remains unclear.Herein,long-term exposure to CLP was systematically investigated to explore its influences on denitrification performance and dynamic microbial responses.Results showed that low-concentration of CLP(<15 mg/L)caused severe nitrite accumulation initially,while higher concentrations(35e60 mg/L)of CLP had no further effect after long-term acclimation.The mechanistic study demonstrated that CLP reduced nitrite reductase(NIR)activity and inhibited metabolic activity(carbon metabolism and nitrogen metabolism)by causing oxidative stress and membrane damage,resulting in nitrite accumulation.However,after more than 80 days of acclimation,almost no nitrite accumulation was found at 60 mg/L CLP.It was proposed that the secretion of extracellular polymeric substances(EPS)increased from 75.03 mg/g VSS at 15 mg/L CLP to 109.97 mg/g VSS at 60 mg/L CLP,which strengthened the protection of microbial cells and improved NIR activity and metabolic activities.Additionally,the biodiversity and richness of the microbial community experienced a U-shaped process.The relative abundance of denitrification-and carbon metabolism-associated microorganisms decreased initially and then recovered with the enrichment of microorganisms related to the secretion of EPS and N-acyl-homoserine lactones(AHLs).These microorganisms protected microbe from toxic substances and regulated their interactions among interand intra-species.This study revealed the biological response mechanism of denitrification after successive exposure to CLP and provided proper guidance for analyzing and treating herbicide-containing wastewater.
基金The authors gratefully acknowledge the financial support from Tianjin Enterprise Science and Technology Commissioner Project(No.19JCTPJC46900)Tianjin Municipal Education Commission Research Plan Projects(Nos.2018KJ161 and TJPU2k20170112)+5 种基金Tianjin Chengjian University research fund(No.180501412)the National Key Research and Development Program of China(No.2018YFC1903203)the Fundamental Research Funds for the Central Universities,China(2020CDJQY-A017)Chongqing Technological Innovation and Application Development Project(No.cstc2019jscx-tjsbX0002)The work described in this paper was also partially supported by a grant from the Research Grants Council of the Hong Kong Special Administration Region,China(No.C7051-17G)Tao Lei from Metrohm China is also gratefully acknowledged for providing useful information about Metrohm Autolab potensiostat.The financial support of the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie Actions IF Grant agreement(No.748683)is gratefully acknowledged.
文摘Reverse electrodialysis(RED)is an emerging membrane-based technology for the production of renewable energy from mixing waters with different salinities.Herein,the impact of the stack configuration on the Ohmic and non-Ohmic resistances as well as the performance of RED were systematically studied by using in situ electrochemical impedance spectroscopy(EIS).Three different parameters(membrane type,number of cell pairs and spacer design)were controlled.The Ohmic and non-Ohmic resistances were evaluated for RED stacks equipped with two types of commercial membranes(Type I and Type II)supplied by Fujifilm Manufacturing Europe B.V:Type I Fuji membranes displayed higher Ohmic and non-Ohmic resistances than Type II membranes,which was mainly attributed to the difference in fixed charge density.The output power of the stack was observed to decrease with the increasing number of cell pairs mainly due to the increase in ionic shortcut currents.With the reduction in spacer thickness from 750 to 200μm,the permselectivity of membranes in the stack decreased from 0.86 to 0.79 whereas the energy efificiency losses increased from 31%to 49%.Overall,the output of the present study provides a basis for understanding the impact of stack design on internal losses during the scaling-up of RED.
文摘Fish skin is mainly composed of the epidermis,dermis,and its derivative scales.There is a wide diversity in scale number in fishes,but the diversity of skin structure lacks systematic histological comparison.This research aimed to improve our understanding of the functional relationship between the scale number and the skin structure in freshwater fishes and to determine which ecological factors affect the scale number and skin structure.First,we presented a method to quantify skin structure in fish and histologically quantified the skin structure of 54 freshwater fishes.Second,we collected the scale number and habitat information of 509 Cyprinidae fishes in China and explored which ecological factors were related to their scale number.Third,common carp and scaleless carp were used as models to study the effects of scale loss on swimming.We found a strong negative correlation between scale thickness and scale number.The main factor affecting the skin structure of fishes was the species’water column position,and the skin of benthic fishes was the most well-developed(thicker skin layers(dermis,epidermis)or more/larger goblet cells and club cells).The scale number was related to two factors,namely,temperature and water column position,and cold,benthic and pelagic adaptation may have contributed to increased scale numbers.Only in benthic fishes,the more well-developed their skin,the more scales.In common carp,scale loss did not affect its swimming performance.In summary,we suggest that there is a rich diversity of skin structure in freshwater fishes,and the scales of fish with well-developed skin tend to degenerate(greater number/smaller size/thinner,or even disappear),but the skin of fish with degenerated scales is not necessarily well developed.
基金supported by the National Key Research and Development Program of China (2018YFD0900202)the National Natural Science Foundation of China (31972778, 31861123001, 31630082, 31872556)+1 种基金the Chongqing Science and Technology Commission (cstc2018jscx-mszd0380, cstc2018jcyj AX0283)Yunnan Science and Technology project (2018IB019)。
文摘The role of glucocorticoids in oogenesis remains to be elucidated. cyp11c1 encodes the key enzyme involved in the synthesis of cortisol, the major glucocorticoid in teleosts. In our previous study, we mutated cyp11c1 in tilapia and analyzed its role in spermatogenesis. In this study, we analyzed its role in oogenesis. cyp11c1^(+/-)XX tilapia showed normal ovarian morphology but poor egg quality, as indicated by the mortality of embryos before 3 d post fertilization, which could be partially rescued by the supplement of exogenous cortisol to the mother fish. Transcriptome analyses revealed reduced expression of maternal genes in the eggs of the cyp11c1^(+/-)XX fish. The cyp11c1^(-/-)females showed impaired vitellogenesis and arrested oogenesis due to significantly decreased serum cortisol. Further analyses revealed decreased serum E2 level and expression of amh, an important regulator of follicular cell development, and increased follicular cell apoptosis in the ovaries of cyp11c1^(-/-)XX fish, which could be rescued by supplement of either exogenous cortisol or E2. Luciferase assays revealed a direct regulation of cortisol and E2 on amh transcription via GRs or ESRs. Taken together, our results demonstrate that cortisol safeguards oogenesis by promoting follicular cell survival probably via Amh signaling.
基金supported by grants from the National Natural Science Foundation of China (31772831 and 31302170, 31861123001)the National Key Research and Development Program of China (2018YFD0900202)
文摘Spermatogenesis is a complex process in which spermatogonial stem cells differentiate and develop into mature spermatozoa.The transcriptional regulatory network involved in fish spermatogenesis remains poorly understood.Here,we demonstrate in Nile tilapia that the Sox transcription factor family member Sox30 is specifically expressed in the testes and mainly localizes to spermatocytes and spermatids.CRISPR/Cas9-mediated sox30 mutation results in abnormal spermiogenesis,reduction of sperm motility,and male subfertility.Comparative transcriptome analysis shows that sox30 mutation alters the expression of genes involved in spermatogenesis.Further chromatin immunoprecipitation followed by high-throughput sequencing(Ch IP-seq),Ch IP-PCR,and luciferase reporter assays revealed that Sox30 positively regulates the transcription of ift140 and ptprb,two genes involved in spermiogenesis,by directly binding to their promoters.Our data,taken together,indicate that Sox30 plays an essential role in Nile tilapia spermatogenesis by directly regulating the transcription of the spermiogenesis-related genes ift140 and ptprb.
基金supported by the National Natural Science Foundation of China (31630082 and 31602314)the Natural Science Foundation Project of Chongqing,Chongqing Science and Technology Commission (cstc2015jcyj B0248 and cstc2013kjrc-tdjs80003)+2 种基金the Fundamental Research Funds for the Central Universities (XDJK2016C157)the China Postdoctoral Science Foundation (2015M570765,2016T90830)Chongqing Postdoctoral Science Foundation (Xm2015028)
文摘Gene editing nucleases including zinc-finger nucleases(ZFNs), transcription activator like effector nucleases(TALENs) and clustered regularly interspaced short palindromic repeats(CRISPR)–CRISPR-associated(Cas) system(CRISPR/Cas9) provide powerful tools that improve our ability to understand the physiological processes and their underlying mechanisms. To date, these approaches have already been widely used to generate knockout and knockin models in a large number of species. Fishes comprise nearly half of extant vertebrate species and provide excellent models for studying many aspects of biology. In this review, we present an overview of recent advances in the use of gene editing nucleases for studies of fish species. We focus particularly on the use of TALENs and CRISPR/Cas9 genome editing for studying sex determination in tilapia.
基金This work was supported by the NSFC-EU Environmental Biotechnology joint program(No.31861133001)Key Research and Development Project of Shandong Province(No.2020CXGC011202)+1 种基金Shenzhen Science and Technology Program(No.KQTD20190929172630447)China Postdoctoral Science Foundation(No.2020M680708).
文摘Traditional bioelectrochemical systems(BESs)coupled with stripping units for ammonia recovery suffer from an insufficient supply of electron acceptors due to the low solubility of oxygen.In this study,we proposed a novel strategy to efficiently transport the oxidizing equivalent provided at the stripping unit to the cathode by introducing a highly soluble electron mediator(EM)into the catholyte.To validate this strategy,we developed a new kind of iron complex system(tartrate-EDTA-Fe)as the EM.EDTA-Fe contributed to the redox property with a midpoint potential of0.075 V(vs.standard hydrogen electrode,SHE)at pH 10,whereas tartrate acted as a stabilizer to avoid iron precipitation under alkaline conditions.At a ratio of the catholyte recirculation rate to the anolyte flow rate(RC-A)of 12,the NH4 t-N recovery rate in the system with 50mM tartrate-EDTA-Fe complex reached 6.9±0.2 g Nm^(-2) d^(-1),approximately 3.8 times higher than that in the non-EM control.With the help of the complex,our system showed an NH4 t-N recovery performance comparable to that previously reported but with an extremely low RC-A(0.5 vs.288).The strategy proposed here may guide the future of ammonia recovery BES scale-up because the introduction of an EM allows aeration to be performed only at the stripping unit instead of at every cathode,which is beneficial for the system design due to its simplicity and reliability.