Zebrafish are increasingly being utilized as a laboratory animal species to study various biological processes,both normal and pathological.It is crucial to comprehend the dynamics of zebrafish locomotion and put fort...Zebrafish are increasingly being utilized as a laboratory animal species to study various biological processes,both normal and pathological.It is crucial to comprehend the dynamics of zebrafish locomotion and put forth realistic models since their locomotion characteristics are employed as feedback indicators in diverse experiments.In this study,we conducted experimental research on the locomotion of zebrafish across various spatial sizes,focusing on the analysis of motion step size and motion direction.The results indicated that the motion step exhibits long-range correlations,the motion direction shows unbiased randomness,and the data characteristics are not influenced by spatial size.The dynamic mechanisms are complicated dynamical processes rather than fractional Brownian or Lévy processes motion.Based on the experimental results,we proposed a model for describing the movement of zebrafish in a circular container.Our findings shed light on the locomotion characteristics of zebrafish,and have the potential to benefit both the biological outcomes of animal tests and the welfare of the subjects.展开更多
Phenanthrene(Phe)is one of the common polycyclic aromatic hydrocarbons in the environment,and recent studies show that it can cause cardiac developmental toxicity and immunotoxicity.However,it is still unknown whether...Phenanthrene(Phe)is one of the common polycyclic aromatic hydrocarbons in the environment,and recent studies show that it can cause cardiac developmental toxicity and immunotoxicity.However,it is still unknown whether it can affect the hematopoietic development in aquatic organisms.To address this question,zebrafish(Danio rerio)were chronically exposed to Phe at different concentrations.We found that Phe caused structural damage to the renal tubules in the kidney,induced malformed erythrocytes in peripheral blood,and decreased the proportion of myeloid cells in adult zebrafish,suggesting possible negative impacts that Phe posed to hematopoietic development.Then,using in situ hybridization technology,we found that Phe decreased the expression of primitive hematopoietic marker genes,specifically gata1 and pu.1,accompanied by an obstruction of primitive erythrocyte circulation.Furthermore,Phe impaired definitive hematopoiesis,increased aberrations of the transient hematopoietic site(PBI),and reduced the generation of hematopoietic stem cells,ultimately influencing the number of erythrocytes and myeloid cells.The findings suggested that Phe could induce hematopoietic toxicity in zebrafish embryos and pose unknown ecological risks.展开更多
Rab5 is a GTPase protein that is involved in intracellular membrane trafficking. It functions by binding to various effector proteins and regulating cellular responses, including the formation of transport vesicles an...Rab5 is a GTPase protein that is involved in intracellular membrane trafficking. It functions by binding to various effector proteins and regulating cellular responses, including the formation of transport vesicles and their fusion with the cellular membrane. Rab5 has been reported to play an important role in the development of the zebrafish embryo;however, its role in axonal regeneration in the central nervous system remains unclear. In this study, we established a zebrafish Mauthner cell model of axonal injury using single-cell electroporation and two-photon axotomy techniques. We found that overexpression of Rab5 in single Mauthner cells promoted marked axonal regeneration and increased the number of intra-axonal transport vesicles. In contrast, treatment of zebrafish larvae with the Rab kinase inhibitor CID-1067700markedly inhibited axonal regeneration in Mauthner cells. We also found that Rab5 activated phosphatidylinositol 3-kinase(PI3K) during axonal repair of Mauthner cells and promoted the recovery of zebrafish locomotor function. Additionally, rapamycin, an inhibitor of the mechanistic target of rapamycin downstream of PI3K, markedly hindered axonal regeneration. These findings suggest that Rab5 promotes the axonal regeneration of injured zebrafish Mauthner cells by activating the PI3K signaling pathway.展开更多
After brain damage,regenerative angiogenesis and neurogenesis have been shown to occur simultaneously in mammals,suggesting a close link between these processes.However,the mechanisms by which these processes interact...After brain damage,regenerative angiogenesis and neurogenesis have been shown to occur simultaneously in mammals,suggesting a close link between these processes.However,the mechanisms by which these processes interact are not well understood.In this work,we aimed to study the correlation between angiogenesis and neurogenesis after a telencephalic stab wound injury.To this end,we used zebrafish as a relevant model of neuroplasticity and brain repair mechanisms.First,using the Tg(fli1:EGFP×mpeg1.1:mCherry)zebrafish line,which enables visualization of blood vessels and microglia respectively,we analyzed regenerative angiogenesis from 1 to 21 days post-lesion.In parallel,we monitored brain cell proliferation in neurogenic niches localized in the ventricular zone by using immunohistochemistry.We found that after brain damage,the blood vessel area and width as well as expression of the fli1 transgene and vascular endothelial growth factor(vegfaa and vegfbb)were increased.At the same time,neural stem cell proliferation was also increased,peaking between 3 and 5 days post-lesion in a manner similar to angiogenesis,along with the recruitment of microglia.Then,through pharmacological manipulation by injecting an anti-angiogenic drug(Tivozanib)or Vegf at the lesion site,we demonstrated that blocking or activating Vegf signaling modulated both angiogenic and neurogenic processes,as well as microglial recruitment.Finally,we showed that inhibition of microglia by clodronate-containing liposome injection or dexamethasone treatment impairs regenerative neurogenesis,as previously described,as well as injury-induced angiogenesis.In conclusion,we have described regenerative angiogenesis in zebrafish for the first time and have highlighted the role of inflammation in this process.In addition,we have shown that both angiogenesis and neurogenesis are involved in brain repair and that microglia and inflammation-dependent mechanisms activated by Vegf signaling are important contributors to these processes.This study paves the way for a better understanding of the effect of Vegf on microglia and for studies aimed at promoting angiogenesis to improve brain plasticity after brain injury.展开更多
Increased accumulation of oxytetracycline(OTC)in environmental water bodies could potentially lead to its accumulation in human body,thereby damaging human intestinal tract.Dietary interventions could be helpful for r...Increased accumulation of oxytetracycline(OTC)in environmental water bodies could potentially lead to its accumulation in human body,thereby damaging human intestinal tract.Dietary interventions could be helpful for recovery of intestinal morphology and function.Therefore,this study set zebrafish as model to explore the potential of kefir supplementation in the recovery of intestinal damage caused by exposure to OTC.In experiments by zebrafish,the rearing units used were glass tanks,each with volume of 5 L.The tanks were stocked with 12 zebrafish each.For each treatment,there were 8 replicate tanks.The zebrafish were treated with OTC followed by the addition of kefir to the food.The results showed positive improvements with kefir supplementation.Kefir treatment mitigated intestinal inflammation by reducing the levels of TNF-α,IL-6,and IL-1β;enhancing the activity of the antioxidant enzymes catalase,superoxide dismutase,glutathione peroxidase and increasing the gene expression of intestinal tight junction proteins(ZO-1a and ZO-1b).These effects were beneficial for reversing reduced integrity of intestinal barrier caused by OTC.Moreover,kefir helped to reverse the disruption of gut microbiota caused by OTC and further impacted host metabolism.Specifically,Lactobacillus kefiranofaciens and Lactobacillus kefiri,which were derived from the kefir microbiota,were found to be enriched in the zebrafish intestine.This helped to inhibit the increased abundance of some Proteobacteria species induced by OTC treatment.Liver metabolomics analysis revealed that kefir improved OTC-induced disruptions in the tricarboxylic acid cycle,glycerophospholipid and amino acid metabolism.The differentially abundant metabolites identified included a total of 80 types after OTC exposure,with the abundance of 74 kinds significantly reversed following kefir treatment.Correlation analysis revealed that certain Proteobacteria species and above Lactobacillus species were closely linked with metabolic inhibition in zebrafish caused by OTC and metabolic restoration caused by kefir treatment,respectively.展开更多
Objective:To investigate the effect of cerebrolysin(CBL)on motor impairment,neuroinflammation,oxidative stress,and neurotransmitter profile in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-induced Parkinson’s di...Objective:To investigate the effect of cerebrolysin(CBL)on motor impairment,neuroinflammation,oxidative stress,and neurotransmitter profile in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-induced Parkinson’s disease(PD)in zebrafish.Methods:In the current study,zebrafish were treated with CBL at doses of 1.25,2.5,and 5 mL/kg body weight for 7 consecutive days.MPTP(20 mg/kg body weight)was administered on alternative days-1st,3rd,5th,and 7th.On day 7,zebrafish were sacrificed,and their brains were isolated for biochemical,neurochemical,histopathological,IHC,and neurotransmitter analysis.Results:The treatment with CBL significantly increased total distance traveled and the number of entries in the top zone,which was impaired by MPTP.CBL treatment significantly restored the level of glutathione,superoxide dismutase,and catalase while reducing malondialdehyde level.It also reduced the level of pro-inflammatory mediators interleukin-1β,interleukin-6,and tumor necrosis factor-αin the MPTP-induced PD in the zebrafish model.In histopathological evaluation,pyknotic cells and signs of inflammation were significantly reduced in CBL-treated groups.A significant dose-dependent reduction in glutamate,along with elevations in dopamine,gamma-aminobutyric acid,serotonin,and noradrenaline,was observed in zebrafish treated with CBL.An immunohistochemistry analysis demonstrated that Akt was phosphorylated promptly by CBL,which was downregulated in MPTP-induced PD in zebrafish.Conclusions:These findings suggest that CBL exerts a neuroprotective effect through activation of Akt and may hold therapeutic potential for the treatment of this devastating neurological condition.展开更多
Objective:To examine the effect of the methanolic extract of Salacia fruticosa in a zebrafish model of scopolamine-induced Alzheimer’s disease.Methods:High-resolution liquid chromatography-mass spectrometry was used ...Objective:To examine the effect of the methanolic extract of Salacia fruticosa in a zebrafish model of scopolamine-induced Alzheimer’s disease.Methods:High-resolution liquid chromatography-mass spectrometry was used to characterize the phytochemical constituents of Salacia fruticosa methanolic extract.The drug-likeness of these compounds was determined via the DruLiTo tool,and their acetylcholinesterase(AChE)binding affinities were studied by molecular docking.In in vivo studies,adult zebrafish were treated with 3.125,6.25,and 12.5 mg/L of the extract for seven days and then immersed in scopolamine(100μM/L)to induce cognitive deficits.T-maze and novel object recognition tests were used for behavioral studies.In addition,the activities of AChE,antioxidant enzymes,and myeloperoxidase were determined in brain tissue of zebrafish.Results:High-resolution liquid chromatography-mass spectrometry revealed that 40 phytoconstituents were present in the methanolic extract of Salacia fruticosa,and 27 compounds met Lipinski's rule of five,indicating good drug-likeness.Some compounds such as stylopine,p-coumaroylagmatine,and(-)-heliannuol E,demonstrated high AChE binding affinity.Moreover,pretreatment with the extract significantly mitigated zebrafish cognitive decline,as indicated by increased time spent at the novel object in novel object recognition test,as well as increased time spent and decreased latency in the green arm(P<0.001).The extract also markedly lowered malondialdehyde and myeloperoxidase levels and AChE activity,and enhanced glutathione peroxidase and superoxide dismutase activities(P<0.001)in zebrafish with scopolamine-induced Alzheimer’s disease.Histopathological studies revealed that Salacia fruticosa extract ameliorated scopolamine-induced abnormalities in neuronal cell morphology.Conclusions:Pretreatment with the methanolic extract of Salacia fruticosa reduces cognitive impairment,enhances antioxidants,and attenuates oxidative stress,highlighting its potential as a preventive agent for Alzheimer’s disease.展开更多
The interaction between nanoparticles (NPs) and pollutants affects their bioavailability and toxicity.However,the processes by which NPs and pollutants change in vivo have rarely been explored.Here,using laser ablatio...The interaction between nanoparticles (NPs) and pollutants affects their bioavailability and toxicity.However,the processes by which NPs and pollutants change in vivo have rarely been explored.Here,using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS),we found that both nanoplastics and ZnO NPs caused more Cd to accumulate in zebrafish larvae,but with distinct pathways.Nanoplastics could adsorb Cd^(2+) and transfer it into the larvae through the“Trojan horse”effect.The coexposure of nanoplastics and Cd^(2+) caused Cd to accumulate in the abdomen where the nanoplastics were located without dissociation,showing a lower toxic effect than Cd^(2+) exposure alone.ZnO NPs weakly adsorbed Cd^(2+),but they increased the Zn and Cd contents in larvae by enhancing the expression of metal transporters.The coexposure of ZnO and Cd^(2+) evenly distributed Cd in the larvae,revealing a more severe toxic effect than Cd^(2+) exposure alone.Our results demonstrated the changing bioavailability and toxicity of Cd induced by different NPs.This also shows the vital role LA-ICP-MS plays in revealing the relationship between toxicity and bioavailability.In addition,the long-term effect of bioavailability on heavy metal toxicity and nanosafety deserves further investigation.展开更多
Pyrrolizidine alkaloids(PAs)are natural toxins generated as secondarymetabolites in plants,predominantly consisting of unsaturated PAs with diverse toxicities,such as hepatotoxicity.Echimidine,a prominent PA,is believ...Pyrrolizidine alkaloids(PAs)are natural toxins generated as secondarymetabolites in plants,predominantly consisting of unsaturated PAs with diverse toxicities,such as hepatotoxicity.Echimidine,a prominent PA,is believed to exert various toxicological effects,including survival inhibition and induction of apoptosis of hepatocytes.However,the effects of echimidine on development remain unclear.We selected three concentrations of 0.02,0.2,and 2 mg/L to investigate the developmental toxicity of echimidine on zebrafish embryos.After a 7-day exposure,we observed hyperactivity and anxiety-like behavior in zebrafish larvae.Furthermore,we found that echimidine exposure significantly promoted embryonic motor neurodevelopment in geneticallymodified zebrafish.Next,we detected that echimidine exposure significantly increased the content of the excitatory neurotransmitter acetylcholine(ACh),accompanied by a significant decrease in acetylcholinesterase(AChE)activity.Conversely,echimidine led to a significant reduction in the content of the sedative neurotransmitterγ-aminobutyric acid(GABA),accompanied by abnormal gene expression of enzymes related to GABA synthesis.Moreover,we elucidated the strong direct binding of echimidine to zebrafish and human AChE protein through molecular docking.In summary,our study found that echimidine induced ACh accumulation possibly by inhibiting AChE activity,leading to motor neurodevelopmental abnormalities and hyperactivity in zebrafish larvae.This work provides important scientific knowledge on the effects and mechanisms of PAs on neural development,which is helpful for controlling the risk of PAs in food and protecting public health.展开更多
Arsenic(As)and chromium(Cr)are two harmful toxicants as well as carcinogens which can coexist in polluted surface water and groundwater.This coexistence leads to mixture effects in animals including fish.Both of these...Arsenic(As)and chromium(Cr)are two harmful toxicants as well as carcinogens which can coexist in polluted surface water and groundwater.This coexistence leads to mixture effects in animals including fish.Both of these heavy metals are reported to manifest reactive oxygen species(ROS)mediated toxicity.Though individual neurotoxic effects have been reported,their mixture effects,its mechanism and cellular responses against oxidative stress and DNA damages remain unknown.The present study evaluated the individual and mixture effects of As and Cr at their environmentally relevant concentrations in zebrafish(Danio rerio)brain after 15,30 and 60 days of exposure.Nrf2,a transcription factor is involved in the expressional regulation of enzymes needed to maintain cellular redox homeostasis.This study reported the expressional pattern of Nrf2 and its associated xenobiotic metabolizing enzyme Nqo1 and other markers of oxidative stress such as ROS generation,reduced glutathione level,lipid peroxidation and catalase activity.Increased malondialdehyde(MDA)content,glutathione level,and catalase activity indicated oxidative stress in exposed groups.In addition,this study revealed expressional alterations of neurotoxicity marker(ache),DNA repair(ogg1,apex1,creb1,polb,mlh1,msh2 and msh6)and tumor suppressor(p53,brca2)genes.Results of ROS generation,MDA level,histopathological analysis,gene expression and immunofluorescence study confirmed that As and Cr did not show antagonistic effects in combination rather indicated additive effects which was dose-dependent but not always linear.展开更多
The visual system of teleost fish grows continuously,which is a useful model for studying regeneration of the central nervous system.Glial cells are key for this process,but their contribution is still not well define...The visual system of teleost fish grows continuously,which is a useful model for studying regeneration of the central nervous system.Glial cells are key for this process,but their contribution is still not well defined.We followed oligodendrocytes in the visual system of adult zebrafish during regeneration of the optic nerve at 6,24,and 72 hours post-lesion and at 7 and 14 days post-lesion via the sox10:tagRFP transgenic line and confocal microscopy.To understand the changes that these oligodendrocytes undergo during regeneration,we used Sox2 immunohistochemistry,a stem cell marker involved in oligodendrocyte differentiation.We also used the Click-iT™ Plus TUNEL assay to study cell death and a BrdU assay to determine cell proliferation.Before optic nerve crush,sox10:tagRFP oligodendrocytes are located in the retina,in the optic nerve head,and through all the entire optic nerve.Sox2-positive cells are present in the peripheral germinal zone,the mature retina,and the optic nerve.After optic nerve crush,sox10:tagRFP cells disappeared from the optic nerve crush zone,suggesting that they died,although they were not TUNEL positive.Concomitantly,the number of Sox2-positive cells increased around the crushed area,the optic nerve head,and the retina.Then,between 24 hours post-lesion and 14 days post-lesion,double sox10:tagRFP/Sox2-positive cells were detected in the retina,optic nerve head,and whole optic nerve,together with a proliferation response at 72 hours post-lesion.Our results confirm that a degenerating process may occur prior to regeneration.First,sox10:tagRFP oligodendrocytes that surround the degenerated axons stop wrapping them,change their“myelinating oligodendrocyte”morphology to a“nonmyelinating oligodendrocyte”morphology,and die.Then,residual oligodendrocyte progenitor cells in the optic nerve and retina proliferate and differentiate for the purpose of remyelination.As new axons arise from the surviving retinal ganglion cells,new sox10:tagRFP oligodendrocytes arise from residual oligodendrocyte progenitor cells to guide,nourish and myelinate them.Thus,oligodendrocytes play an active role in zebrafish axon regeneration and remyelination.展开更多
Congenital disorders of glycosylation(CDG)are a cluster of monogenic disorders resulting from defects in glycosylation.FCSK encodes fucokinase,an enzyme that catalyzes the phosphorylation of L-fucose to generate fucos...Congenital disorders of glycosylation(CDG)are a cluster of monogenic disorders resulting from defects in glycosylation.FCSK encodes fucokinase,an enzyme that catalyzes the phosphorylation of L-fucose to generate fucose-1-phosphate,an important step in fucosylation.Mutations in FCSK lead to CDG with an autosomal recessive inheritance pattern,primarily manifesting as developmental delay,hypotonia,and brain abnormalities.However,no fcsk mutant animal models have yet been established.This study constructed the first fcsk knockout(fcsk^(-/-))zebrafish model using CRISPR/Cas9 technology.Notably,fcsk^(-/-)zebrafish exhibited impaired growth,characterized by delayed epiboly and DNA accumulation during early embryonic development,as well as brain atrophy in adulthood.Larval-stage fcsk^(-/-)zebrafish displayed locomotor deficits and increased susceptibility to pentylenetetrazole-induced seizures.In adulthood,fcsk^(-/-)zebrafish showed neurodevelopmental abnormalities,including increased anxiety,decreased aggression,reduced social preference,and impaired memory.Additionally,total protein fucosylation was markedly reduced in fcsk^(-/-)zebrafish,accompanied by decreased expression of pofut2,which encodes protein Ofucosyltransferase 2,an enzyme involved in the fucosylation salvage pathway.Apoptotic activity was elevated in the midbrain-hindbrain boundary(MHB)of fcsk^(-/-)zebrafish.Supplementation with GDP-L-fucose or the human FCSK gene restored developmental defects and total protein fucosylation in fcsk^(-/-)zebrafish.RNA sequencing revealed dysregulated gene expression associated with glycosylation,apoptosis,and neurodegenerative diseases.These findings suggest that fcsk^(-/-)zebrafish exhibit neurodevelopmental disorders,providing the first fcsk gene knockout animal model and offering a platform for investigating the molecular underpinnings of the disease and facilitating drug screening efforts.展开更多
The cell fate of primordial germ cell(PGC)in zebrafish is pre-determined by maternally deposited germ plasm,which is packaged into ribonucleoprotein complex in oocytes and inherited into PGC-fated cells in embryos.How...The cell fate of primordial germ cell(PGC)in zebrafish is pre-determined by maternally deposited germ plasm,which is packaged into ribonucleoprotein complex in oocytes and inherited into PGC-fated cells in embryos.However,the maternal factors regulating the assembly of germ plasm and PGC development remain poorly understood.In this study,we report that the maternal transcription factor Znf706 regulates the assembly of germ plasm factors into a granule-like structure localized perinuclearly in PGC during migration.Maternal and zygotic mutants of znf706 exhibit deficient germ plasm scattering at the early embryonic stage,decreased PGC numbers with some mislocation during PGC migration,and a lower female ratio in adulthood.Notably,the implementation of Znf706 CUT&Tag and RNA-seq on immature oocytes uncovers that Znf706 in stage I oocytes may promote transcription of several mitochondrial genes in addition to other functions.Hence,we propose that Znf706 is implicated in germ plasm assembly and PGC development in zebrafish.展开更多
With diabetes currently affecting 537 million people globally,innovative research approaches are urgently required.Zebrafish(Danio rerio)has emerged as a pivotal model organism in diabetes research,particularly valuab...With diabetes currently affecting 537 million people globally,innovative research approaches are urgently required.Zebrafish(Danio rerio)has emerged as a pivotal model organism in diabetes research,particularly valuable for developmental biology studies and preclinical therapeutic validation.Its rapid life cycle,optical transparency,and genetic tractability collectively enable efficient longitudinal observation of pathological progression and pharmacological responses.Utilizing zebrafish models,researchers have elucidated fundamental mechanisms governing islet development,β-cell dysfunction,and metabolic dysregulation.These experimental systems have significantly advanced our understanding of various diabetes subtypes,including type 1,type 2,gestational,and monogenic forms,while also facilitating mechanistic studies of diabetic complications such as retinopathy and nephropathy.Recent model refinements,particularly in simulating monogenic disorders and pregnancy-associated metabolic changes,promise to deepen our comprehension of disease pathophysiology and therapeutic interventions.Nevertheless,a persistent limitation lies in their incomplete recapitulation of human-specific physiological complexity and multi-organ metabolic interactions,factors that may influence translational applicability.Despite these constraints,zebrafish-based research continues to provide an indispensable platform for diabetes investigation,holding significant promise for alleviating the escalating global burden of this metabolic disorder.展开更多
In adult mammals,optic nerve injury leads to irreversible vision loss due to its extremely limited regenerative capacity.In contrast,adult zebrafish possess a robust capacity for spontaneous visual system regeneration...In adult mammals,optic nerve injury leads to irreversible vision loss due to its extremely limited regenerative capacity.In contrast,adult zebrafish possess a robust capacity for spontaneous visual system regeneration,although the spatiotemporal coordination of recovery across the retina,optic nerve,and brain remains poorly understood.In the present study,the regenerative dynamics following optic nerve transection were systematically characterized in adult zebrafish over a 5 week period using hematoxylin-eosin staining,immunohistochemistry,transmission electron microscopy,single-cell RNA sequencing,and optokinetic response(OKR)behavioral assessments.At 1 week post-injury(1 wpi),retinal ganglion cell depletion was evident but showed significant recovery by 2 wpi.Concurrently,the injured optic nerve displayed a marked increase in diameter and cell number at 2 wpi,including widespread expression of proliferating cell nuclear antigen,consistent with heightened proliferative activity.Single-cell transcriptomic profiling at 2 wpi revealed five principal cell populations:fibroblasts,mural cells,immune cells,mature oligodendrocytes,and myelin-forming oligodendrocytes.By 4-5 wpi,remyelination within the optic nerve and re-establishment of synaptic architecture in the optic tectum were strongly correlated with functional restoration of OKR behavior.These findings provide a comprehensive spatiotemporal framework of visual pathway regeneration in zebrafish,establishing a valuable model for elucidating conserved mechanisms of neural repair with translational potential for human vision restoration.展开更多
Because the physiological characteristics and melanin regulation mechanism of zebrafish are highly similar with those of humans,it is of high reference value to use zebrafish model in the evaluation of cosmetic whiten...Because the physiological characteristics and melanin regulation mechanism of zebrafish are highly similar with those of humans,it is of high reference value to use zebrafish model in the evaluation of cosmetic whitening efficacy.In this study,zebrafish embryos are used as biological models to evaluate the whitening efficacy of six kinds of cosmetics raw materials,such as antioxidant,preservative and essence,and the formula of facial cleanser and facial mask products,and the limitations of the zebrafish melanin production grayscale detection method in practical application are discussed.The results show that the selection of different types of components can also reduce the production of melanin and show whitening effect.It can be seen that the gray scale method of melanin production in zebrafish is suitable for the evaluation of the efficacy of raw materials.In practical application,due to the complexity of the formula,the toxic effects of different types of ingredients may interfere with the melanin generation of zebrafish,affecting the judgment and evaluation of whitening efficacy.For the detection of whitening efficacy of products,a comprehensive evaluation system should be built together with other methods to accurately evaluate the whitening efficacy.展开更多
Single-base editors,including cytosine base editors(CBEs)and adenine base editors(ABEs),facilitate accurate C·G to T·A and A·T to G·C,respectively,holding promise for the precise modeling and treat...Single-base editors,including cytosine base editors(CBEs)and adenine base editors(ABEs),facilitate accurate C·G to T·A and A·T to G·C,respectively,holding promise for the precise modeling and treatment of human hereditary disorders.Efficient base editing and expanded base conversion range have been achieved in human cells through base editors fusing with Rad51 DNA binding domain(Rad51DBD),such as hyA3A-BE4max.Here,we show that hyA3A-BE4max catalyzes C-to-T substitution in the zebrafish genome and extends editing positions(C_(12)-C_(16))proximal to the protospacer adjacent motif.We develop a codon-optimized counterpart zhyA3A-CBE5,which exhibits substantially high C-to-T conversion with 1.59-to 3.50-fold improvement compared with the original hyA3A-BE4max.With these tools,disease-relevant hereditary mutations can be more efficaciously generated in zebrafish.We introduce human genetic mutation rpl11^(Q42*)and abcc6a^(R1463C) by zhyA3A-CBE5 in zebrafish,mirroring Diamond-Blackfan anemia and Pseudoxanthoma Elasticum,respectively.Our study expands the base editing platform targeting the zebrafish genomic landscape and the application of single-base editors for disease modeling and gene function study.展开更多
The liver is a key endoderm-derived multifunctional organ within the digestive system.Prospero homeobox 1(Prox1)is an essential transcription factor for liver development,but its specific function is not well understo...The liver is a key endoderm-derived multifunctional organ within the digestive system.Prospero homeobox 1(Prox1)is an essential transcription factor for liver development,but its specific function is not well understood.Here,we show that hepatic development,including the formation of intrahepatic biliary and vascular networks,is severely disrupted in prox1a mutant zebrafish.We find that Prox1a is essential for liver growth and proper differentiation but not required for early hepatic cell fate specification.Intriguingly,prox1a depletion leads to ectopic initiation of a Cdx1b-mediated intestinal program and the formation of intestinal lumen-like structures within the liver.Morpholino knockdown of cdx1b alleviates liver defects in the prox1a mutant zebrafish.Finally,chromatin immunoprecipitation analysis reveals that Prox1a binds directly to the promoter region of cdx1b,thereby repressing its expression.Overall,our findings indicate that Prox1a is required to promote and protect hepatic development by repression of Cdx1b-mediated intestinal cell fate in zebrafish.展开更多
Acute mitochondrial damage and the energy crisis following axonal injury highlight mitochondrial transport as an important target for axonal regeneration.Syntaphilin(Snph),known for its potent mitochondrial anchoring ...Acute mitochondrial damage and the energy crisis following axonal injury highlight mitochondrial transport as an important target for axonal regeneration.Syntaphilin(Snph),known for its potent mitochondrial anchoring action,has emerged as a significant inhibitor of both mitochondrial transport and axonal regeneration.Therefore,investigating the molecular mechanisms that influence the expression levels of the snph gene can provide a viable strategy to regulate mitochondrial trafficking and enhance axonal regeneration.Here,we reveal the inhibitory effect of microRNA-146b(miR-146b)on the expression of the homologous zebrafish gene syntaphilin b(snphb).Through CRISPR/Cas9 and single-cell electroporation,we elucidated the positive regulatory effect of the miR-146b-snphb axis on Mauthner cell(M-cell)axon regeneration at the global and single-cell levels.Through escape response tests,we show that miR-146b-snphb signaling positively regulates functional recovery after M-cell axon injury.In addition,continuous dynamic imaging in vivo showed that reprogramming miR-146b significantly promotes axonal mitochondrial trafficking in the pre-injury and early stages of regeneration.Our study reveals an intrinsic axonal regeneration regulatory axis that promotes axonal regeneration by reprogramming mitochondrial transport and anchoring.This regulation involves noncoding RNA,and mitochondria-associated genes may provide a potential opportunity for the repair of central nervous system injury.展开更多
Pharyngeal cartilage morphogenesis is crucial for the formation of craniofacial structures.Cranial neural crest cells are specified at the neural plate border,migrate to pharyngeal arches,and differentiate into pharyn...Pharyngeal cartilage morphogenesis is crucial for the formation of craniofacial structures.Cranial neural crest cells are specified at the neural plate border,migrate to pharyngeal arches,and differentiate into pharyngeal chondrocytes,which subsequently flatten,elongate,and stack like coins during maturation.Although the developmental processes prior to chondrocyte maturation have been extensively studied,their subsequent changes in morphology and organization remain largely elusive.Here,we show that wnt2bb is expressed in the pharyngeal ectoderm adjacent to the chondrogenic precursor cells in zebrafish.Inactivation of Wnt2bb leads to a reduction in nuclearβ-catenin,which impairs chondrogenic precursor proliferation and disrupts chondrocyte morphogenesis and organization,eventually causing a severe shrinkage of pharyngeal cartilages.Moreover,the decrease ofβ-catenin in wnt2bb^(-/-)mutants is accompanied by the reduction of Yap expression.Reactivation of Yap can restore the proliferation of chondrocyte progenitors as well as the proper size,shape,and stacking of pharyngeal chondrocytes.Our findings suggest that Wnt/β-catenin signaling promotes Yap expression to regulate pharyngeal cartilage formation in zebrafish.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.12205006)the Excellent Youth Scientific Research Project of Anhui Province,China(Grant No.2022AH030107)。
文摘Zebrafish are increasingly being utilized as a laboratory animal species to study various biological processes,both normal and pathological.It is crucial to comprehend the dynamics of zebrafish locomotion and put forth realistic models since their locomotion characteristics are employed as feedback indicators in diverse experiments.In this study,we conducted experimental research on the locomotion of zebrafish across various spatial sizes,focusing on the analysis of motion step size and motion direction.The results indicated that the motion step exhibits long-range correlations,the motion direction shows unbiased randomness,and the data characteristics are not influenced by spatial size.The dynamic mechanisms are complicated dynamical processes rather than fractional Brownian or Lévy processes motion.Based on the experimental results,we proposed a model for describing the movement of zebrafish in a circular container.Our findings shed light on the locomotion characteristics of zebrafish,and have the potential to benefit both the biological outcomes of animal tests and the welfare of the subjects.
基金supported by the National Natural Science Foundation of China(Nos.22276117 and 22076108)the Science and Technology Innovation Talent Team Project of Shanxi Province(No.202204051002024).
文摘Phenanthrene(Phe)is one of the common polycyclic aromatic hydrocarbons in the environment,and recent studies show that it can cause cardiac developmental toxicity and immunotoxicity.However,it is still unknown whether it can affect the hematopoietic development in aquatic organisms.To address this question,zebrafish(Danio rerio)were chronically exposed to Phe at different concentrations.We found that Phe caused structural damage to the renal tubules in the kidney,induced malformed erythrocytes in peripheral blood,and decreased the proportion of myeloid cells in adult zebrafish,suggesting possible negative impacts that Phe posed to hematopoietic development.Then,using in situ hybridization technology,we found that Phe decreased the expression of primitive hematopoietic marker genes,specifically gata1 and pu.1,accompanied by an obstruction of primitive erythrocyte circulation.Furthermore,Phe impaired definitive hematopoiesis,increased aberrations of the transient hematopoietic site(PBI),and reduced the generation of hematopoietic stem cells,ultimately influencing the number of erythrocytes and myeloid cells.The findings suggested that Phe could induce hematopoietic toxicity in zebrafish embryos and pose unknown ecological risks.
基金supported by the Research Funds of the Center for Advanced Interdisciplinary Science and Biomedicine of IHM,No.QYZD20220002the National Natural Science Foundation of China,No.82071357a grant from the Ministry of Science and Technology of China,No.2019YFA0405600 (all to BH)。
文摘Rab5 is a GTPase protein that is involved in intracellular membrane trafficking. It functions by binding to various effector proteins and regulating cellular responses, including the formation of transport vesicles and their fusion with the cellular membrane. Rab5 has been reported to play an important role in the development of the zebrafish embryo;however, its role in axonal regeneration in the central nervous system remains unclear. In this study, we established a zebrafish Mauthner cell model of axonal injury using single-cell electroporation and two-photon axotomy techniques. We found that overexpression of Rab5 in single Mauthner cells promoted marked axonal regeneration and increased the number of intra-axonal transport vesicles. In contrast, treatment of zebrafish larvae with the Rab kinase inhibitor CID-1067700markedly inhibited axonal regeneration in Mauthner cells. We also found that Rab5 activated phosphatidylinositol 3-kinase(PI3K) during axonal repair of Mauthner cells and promoted the recovery of zebrafish locomotor function. Additionally, rapamycin, an inhibitor of the mechanistic target of rapamycin downstream of PI3K, markedly hindered axonal regeneration. These findings suggest that Rab5 promotes the axonal regeneration of injured zebrafish Mauthner cells by activating the PI3K signaling pathway.
基金supported by European Regional Development Funds RE0022527 ZEBRATOX(EU-Région Réunion-French State national counterpart,to Nicolas Diotel and Jean-Loup Bascands).
文摘After brain damage,regenerative angiogenesis and neurogenesis have been shown to occur simultaneously in mammals,suggesting a close link between these processes.However,the mechanisms by which these processes interact are not well understood.In this work,we aimed to study the correlation between angiogenesis and neurogenesis after a telencephalic stab wound injury.To this end,we used zebrafish as a relevant model of neuroplasticity and brain repair mechanisms.First,using the Tg(fli1:EGFP×mpeg1.1:mCherry)zebrafish line,which enables visualization of blood vessels and microglia respectively,we analyzed regenerative angiogenesis from 1 to 21 days post-lesion.In parallel,we monitored brain cell proliferation in neurogenic niches localized in the ventricular zone by using immunohistochemistry.We found that after brain damage,the blood vessel area and width as well as expression of the fli1 transgene and vascular endothelial growth factor(vegfaa and vegfbb)were increased.At the same time,neural stem cell proliferation was also increased,peaking between 3 and 5 days post-lesion in a manner similar to angiogenesis,along with the recruitment of microglia.Then,through pharmacological manipulation by injecting an anti-angiogenic drug(Tivozanib)or Vegf at the lesion site,we demonstrated that blocking or activating Vegf signaling modulated both angiogenic and neurogenic processes,as well as microglial recruitment.Finally,we showed that inhibition of microglia by clodronate-containing liposome injection or dexamethasone treatment impairs regenerative neurogenesis,as previously described,as well as injury-induced angiogenesis.In conclusion,we have described regenerative angiogenesis in zebrafish for the first time and have highlighted the role of inflammation in this process.In addition,we have shown that both angiogenesis and neurogenesis are involved in brain repair and that microglia and inflammation-dependent mechanisms activated by Vegf signaling are important contributors to these processes.This study paves the way for a better understanding of the effect of Vegf on microglia and for studies aimed at promoting angiogenesis to improve brain plasticity after brain injury.
基金financially supported by the Zhejiang Zhongmengchang Health Technology Co.,Ltd.
文摘Increased accumulation of oxytetracycline(OTC)in environmental water bodies could potentially lead to its accumulation in human body,thereby damaging human intestinal tract.Dietary interventions could be helpful for recovery of intestinal morphology and function.Therefore,this study set zebrafish as model to explore the potential of kefir supplementation in the recovery of intestinal damage caused by exposure to OTC.In experiments by zebrafish,the rearing units used were glass tanks,each with volume of 5 L.The tanks were stocked with 12 zebrafish each.For each treatment,there were 8 replicate tanks.The zebrafish were treated with OTC followed by the addition of kefir to the food.The results showed positive improvements with kefir supplementation.Kefir treatment mitigated intestinal inflammation by reducing the levels of TNF-α,IL-6,and IL-1β;enhancing the activity of the antioxidant enzymes catalase,superoxide dismutase,glutathione peroxidase and increasing the gene expression of intestinal tight junction proteins(ZO-1a and ZO-1b).These effects were beneficial for reversing reduced integrity of intestinal barrier caused by OTC.Moreover,kefir helped to reverse the disruption of gut microbiota caused by OTC and further impacted host metabolism.Specifically,Lactobacillus kefiranofaciens and Lactobacillus kefiri,which were derived from the kefir microbiota,were found to be enriched in the zebrafish intestine.This helped to inhibit the increased abundance of some Proteobacteria species induced by OTC treatment.Liver metabolomics analysis revealed that kefir improved OTC-induced disruptions in the tricarboxylic acid cycle,glycerophospholipid and amino acid metabolism.The differentially abundant metabolites identified included a total of 80 types after OTC exposure,with the abundance of 74 kinds significantly reversed following kefir treatment.Correlation analysis revealed that certain Proteobacteria species and above Lactobacillus species were closely linked with metabolic inhibition in zebrafish caused by OTC and metabolic restoration caused by kefir treatment,respectively.
基金funded by ICMR,New Delhi(Grant No.45/29/2022-PHA/BMS).
文摘Objective:To investigate the effect of cerebrolysin(CBL)on motor impairment,neuroinflammation,oxidative stress,and neurotransmitter profile in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-induced Parkinson’s disease(PD)in zebrafish.Methods:In the current study,zebrafish were treated with CBL at doses of 1.25,2.5,and 5 mL/kg body weight for 7 consecutive days.MPTP(20 mg/kg body weight)was administered on alternative days-1st,3rd,5th,and 7th.On day 7,zebrafish were sacrificed,and their brains were isolated for biochemical,neurochemical,histopathological,IHC,and neurotransmitter analysis.Results:The treatment with CBL significantly increased total distance traveled and the number of entries in the top zone,which was impaired by MPTP.CBL treatment significantly restored the level of glutathione,superoxide dismutase,and catalase while reducing malondialdehyde level.It also reduced the level of pro-inflammatory mediators interleukin-1β,interleukin-6,and tumor necrosis factor-αin the MPTP-induced PD in the zebrafish model.In histopathological evaluation,pyknotic cells and signs of inflammation were significantly reduced in CBL-treated groups.A significant dose-dependent reduction in glutamate,along with elevations in dopamine,gamma-aminobutyric acid,serotonin,and noradrenaline,was observed in zebrafish treated with CBL.An immunohistochemistry analysis demonstrated that Akt was phosphorylated promptly by CBL,which was downregulated in MPTP-induced PD in zebrafish.Conclusions:These findings suggest that CBL exerts a neuroprotective effect through activation of Akt and may hold therapeutic potential for the treatment of this devastating neurological condition.
基金funded by King Saud University,Riyadh,Saudi Arabia,Project Number(RSPD2025R709).
文摘Objective:To examine the effect of the methanolic extract of Salacia fruticosa in a zebrafish model of scopolamine-induced Alzheimer’s disease.Methods:High-resolution liquid chromatography-mass spectrometry was used to characterize the phytochemical constituents of Salacia fruticosa methanolic extract.The drug-likeness of these compounds was determined via the DruLiTo tool,and their acetylcholinesterase(AChE)binding affinities were studied by molecular docking.In in vivo studies,adult zebrafish were treated with 3.125,6.25,and 12.5 mg/L of the extract for seven days and then immersed in scopolamine(100μM/L)to induce cognitive deficits.T-maze and novel object recognition tests were used for behavioral studies.In addition,the activities of AChE,antioxidant enzymes,and myeloperoxidase were determined in brain tissue of zebrafish.Results:High-resolution liquid chromatography-mass spectrometry revealed that 40 phytoconstituents were present in the methanolic extract of Salacia fruticosa,and 27 compounds met Lipinski's rule of five,indicating good drug-likeness.Some compounds such as stylopine,p-coumaroylagmatine,and(-)-heliannuol E,demonstrated high AChE binding affinity.Moreover,pretreatment with the extract significantly mitigated zebrafish cognitive decline,as indicated by increased time spent at the novel object in novel object recognition test,as well as increased time spent and decreased latency in the green arm(P<0.001).The extract also markedly lowered malondialdehyde and myeloperoxidase levels and AChE activity,and enhanced glutathione peroxidase and superoxide dismutase activities(P<0.001)in zebrafish with scopolamine-induced Alzheimer’s disease.Histopathological studies revealed that Salacia fruticosa extract ameliorated scopolamine-induced abnormalities in neuronal cell morphology.Conclusions:Pretreatment with the methanolic extract of Salacia fruticosa reduces cognitive impairment,enhances antioxidants,and attenuates oxidative stress,highlighting its potential as a preventive agent for Alzheimer’s disease.
基金financially supported by the National Natural Science Foundation of China(NSFC,Nos.22174103 and 21575107)。
文摘The interaction between nanoparticles (NPs) and pollutants affects their bioavailability and toxicity.However,the processes by which NPs and pollutants change in vivo have rarely been explored.Here,using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS),we found that both nanoplastics and ZnO NPs caused more Cd to accumulate in zebrafish larvae,but with distinct pathways.Nanoplastics could adsorb Cd^(2+) and transfer it into the larvae through the“Trojan horse”effect.The coexposure of nanoplastics and Cd^(2+) caused Cd to accumulate in the abdomen where the nanoplastics were located without dissociation,showing a lower toxic effect than Cd^(2+) exposure alone.ZnO NPs weakly adsorbed Cd^(2+),but they increased the Zn and Cd contents in larvae by enhancing the expression of metal transporters.The coexposure of ZnO and Cd^(2+) evenly distributed Cd in the larvae,revealing a more severe toxic effect than Cd^(2+) exposure alone.Our results demonstrated the changing bioavailability and toxicity of Cd induced by different NPs.This also shows the vital role LA-ICP-MS plays in revealing the relationship between toxicity and bioavailability.In addition,the long-term effect of bioavailability on heavy metal toxicity and nanosafety deserves further investigation.
基金supported by the Key Project at the Central Government Level:the ability establishment of sustainable use for valuable Chinese medicine resources(No.2060302)the National Natural Science Foundation of China(No.82104389)+2 种基金the Scientific and Technological Innovation Project of China Academy of Chinese Medical Sciences(No.CI2023E002)the High-level Key Discipline Program of National Administration of Traditional Chinese Medicine(No.ZYYZDXK-2023244)China Agricultural Research System of MOF and MARA(No.CARS-21).
文摘Pyrrolizidine alkaloids(PAs)are natural toxins generated as secondarymetabolites in plants,predominantly consisting of unsaturated PAs with diverse toxicities,such as hepatotoxicity.Echimidine,a prominent PA,is believed to exert various toxicological effects,including survival inhibition and induction of apoptosis of hepatocytes.However,the effects of echimidine on development remain unclear.We selected three concentrations of 0.02,0.2,and 2 mg/L to investigate the developmental toxicity of echimidine on zebrafish embryos.After a 7-day exposure,we observed hyperactivity and anxiety-like behavior in zebrafish larvae.Furthermore,we found that echimidine exposure significantly promoted embryonic motor neurodevelopment in geneticallymodified zebrafish.Next,we detected that echimidine exposure significantly increased the content of the excitatory neurotransmitter acetylcholine(ACh),accompanied by a significant decrease in acetylcholinesterase(AChE)activity.Conversely,echimidine led to a significant reduction in the content of the sedative neurotransmitterγ-aminobutyric acid(GABA),accompanied by abnormal gene expression of enzymes related to GABA synthesis.Moreover,we elucidated the strong direct binding of echimidine to zebrafish and human AChE protein through molecular docking.In summary,our study found that echimidine induced ACh accumulation possibly by inhibiting AChE activity,leading to motor neurodevelopmental abnormalities and hyperactivity in zebrafish larvae.This work provides important scientific knowledge on the effects and mechanisms of PAs on neural development,which is helpful for controlling the risk of PAs in food and protecting public health.
基金the Department of Zoology,Visva-Bharati for providing infrastructural supportSreejata Kamila is grateful to the Council of Scientific and Industrial Research(CSIR),India for Senior Research Fellowship(CSIR File No.09/202(0102)/2019-EMR-I)+2 种基金Koushik Kumar Dey acknowledges the Department of Biotechnology,New Delhi for research fellowship(No.BT/PR28560/AAQ/3/919/2018)Shehnaz Islam is thankful to Maulana Azad National Fellowship(UGC ref ID-201920–345938)India for her financial support.
文摘Arsenic(As)and chromium(Cr)are two harmful toxicants as well as carcinogens which can coexist in polluted surface water and groundwater.This coexistence leads to mixture effects in animals including fish.Both of these heavy metals are reported to manifest reactive oxygen species(ROS)mediated toxicity.Though individual neurotoxic effects have been reported,their mixture effects,its mechanism and cellular responses against oxidative stress and DNA damages remain unknown.The present study evaluated the individual and mixture effects of As and Cr at their environmentally relevant concentrations in zebrafish(Danio rerio)brain after 15,30 and 60 days of exposure.Nrf2,a transcription factor is involved in the expressional regulation of enzymes needed to maintain cellular redox homeostasis.This study reported the expressional pattern of Nrf2 and its associated xenobiotic metabolizing enzyme Nqo1 and other markers of oxidative stress such as ROS generation,reduced glutathione level,lipid peroxidation and catalase activity.Increased malondialdehyde(MDA)content,glutathione level,and catalase activity indicated oxidative stress in exposed groups.In addition,this study revealed expressional alterations of neurotoxicity marker(ache),DNA repair(ogg1,apex1,creb1,polb,mlh1,msh2 and msh6)and tumor suppressor(p53,brca2)genes.Results of ROS generation,MDA level,histopathological analysis,gene expression and immunofluorescence study confirmed that As and Cr did not show antagonistic effects in combination rather indicated additive effects which was dose-dependent but not always linear.
基金supported by the Lanzadera TCUE and C2 program(Universidad de Salamanca)(to ASL)the Spanish National Research Council(CSIC)funded by the Junta de Castilla y León and co-financed by the European Regional Development Fund(ERDF“Europe drives our growth”):Internationalization Project“CL-EI-2021-08-IBFG Unit of Excellence”,Grant(PID2022-138478OA-100)funded by MICIU/AEI/10.13039/501100011033 and,by FEDER,UE(to MGM)+3 种基金Junta de Castilla y León(SA225P23)Gerencia Regional de Salud(2701/A1/2023)(to AV)the Plan Especial Grado Medicina(USAL)(to CPM)a Ramón y Cajal researcher:Grant RYC2021-033684-I funded by MICIU/AEI/10.13039/501100011033 and,by European Union NextGenerationEU/PRTR.
文摘The visual system of teleost fish grows continuously,which is a useful model for studying regeneration of the central nervous system.Glial cells are key for this process,but their contribution is still not well defined.We followed oligodendrocytes in the visual system of adult zebrafish during regeneration of the optic nerve at 6,24,and 72 hours post-lesion and at 7 and 14 days post-lesion via the sox10:tagRFP transgenic line and confocal microscopy.To understand the changes that these oligodendrocytes undergo during regeneration,we used Sox2 immunohistochemistry,a stem cell marker involved in oligodendrocyte differentiation.We also used the Click-iT™ Plus TUNEL assay to study cell death and a BrdU assay to determine cell proliferation.Before optic nerve crush,sox10:tagRFP oligodendrocytes are located in the retina,in the optic nerve head,and through all the entire optic nerve.Sox2-positive cells are present in the peripheral germinal zone,the mature retina,and the optic nerve.After optic nerve crush,sox10:tagRFP cells disappeared from the optic nerve crush zone,suggesting that they died,although they were not TUNEL positive.Concomitantly,the number of Sox2-positive cells increased around the crushed area,the optic nerve head,and the retina.Then,between 24 hours post-lesion and 14 days post-lesion,double sox10:tagRFP/Sox2-positive cells were detected in the retina,optic nerve head,and whole optic nerve,together with a proliferation response at 72 hours post-lesion.Our results confirm that a degenerating process may occur prior to regeneration.First,sox10:tagRFP oligodendrocytes that surround the degenerated axons stop wrapping them,change their“myelinating oligodendrocyte”morphology to a“nonmyelinating oligodendrocyte”morphology,and die.Then,residual oligodendrocyte progenitor cells in the optic nerve and retina proliferate and differentiate for the purpose of remyelination.As new axons arise from the surviving retinal ganglion cells,new sox10:tagRFP oligodendrocytes arise from residual oligodendrocyte progenitor cells to guide,nourish and myelinate them.Thus,oligodendrocytes play an active role in zebrafish axon regeneration and remyelination.
基金supported by the National Key R&D Program of China(2023YFC2706302)National Natural Science Foundation of China(81000079,81170165 and 81870959 to X.Z.)+1 种基金Program of HUST Academic Frontier Youth Team(2016QYTD02)Fundamental Research Funds for the Central Universities(HUST:2019JYCXJJ035)。
文摘Congenital disorders of glycosylation(CDG)are a cluster of monogenic disorders resulting from defects in glycosylation.FCSK encodes fucokinase,an enzyme that catalyzes the phosphorylation of L-fucose to generate fucose-1-phosphate,an important step in fucosylation.Mutations in FCSK lead to CDG with an autosomal recessive inheritance pattern,primarily manifesting as developmental delay,hypotonia,and brain abnormalities.However,no fcsk mutant animal models have yet been established.This study constructed the first fcsk knockout(fcsk^(-/-))zebrafish model using CRISPR/Cas9 technology.Notably,fcsk^(-/-)zebrafish exhibited impaired growth,characterized by delayed epiboly and DNA accumulation during early embryonic development,as well as brain atrophy in adulthood.Larval-stage fcsk^(-/-)zebrafish displayed locomotor deficits and increased susceptibility to pentylenetetrazole-induced seizures.In adulthood,fcsk^(-/-)zebrafish showed neurodevelopmental abnormalities,including increased anxiety,decreased aggression,reduced social preference,and impaired memory.Additionally,total protein fucosylation was markedly reduced in fcsk^(-/-)zebrafish,accompanied by decreased expression of pofut2,which encodes protein Ofucosyltransferase 2,an enzyme involved in the fucosylation salvage pathway.Apoptotic activity was elevated in the midbrain-hindbrain boundary(MHB)of fcsk^(-/-)zebrafish.Supplementation with GDP-L-fucose or the human FCSK gene restored developmental defects and total protein fucosylation in fcsk^(-/-)zebrafish.RNA sequencing revealed dysregulated gene expression associated with glycosylation,apoptosis,and neurodegenerative diseases.These findings suggest that fcsk^(-/-)zebrafish exhibit neurodevelopmental disorders,providing the first fcsk gene knockout animal model and offering a platform for investigating the molecular underpinnings of the disease and facilitating drug screening efforts.
基金supported by the National Natural Science Foundation of China(31988101 to A.M.)the National Key Research and Development Program of China(2023YFA1800300 to X.W.and 2018YFC1003304 to A.M.)the Yunnan Provincial Science and Technology Project at Southwest United Graduate School(202302A0370011 to A.M.).
文摘The cell fate of primordial germ cell(PGC)in zebrafish is pre-determined by maternally deposited germ plasm,which is packaged into ribonucleoprotein complex in oocytes and inherited into PGC-fated cells in embryos.However,the maternal factors regulating the assembly of germ plasm and PGC development remain poorly understood.In this study,we report that the maternal transcription factor Znf706 regulates the assembly of germ plasm factors into a granule-like structure localized perinuclearly in PGC during migration.Maternal and zygotic mutants of znf706 exhibit deficient germ plasm scattering at the early embryonic stage,decreased PGC numbers with some mislocation during PGC migration,and a lower female ratio in adulthood.Notably,the implementation of Znf706 CUT&Tag and RNA-seq on immature oocytes uncovers that Znf706 in stage I oocytes may promote transcription of several mitochondrial genes in addition to other functions.Hence,we propose that Znf706 is implicated in germ plasm assembly and PGC development in zebrafish.
基金Supported by Natural Science Foundation of Zhejiang Province,China,No.LQ24H070007。
文摘With diabetes currently affecting 537 million people globally,innovative research approaches are urgently required.Zebrafish(Danio rerio)has emerged as a pivotal model organism in diabetes research,particularly valuable for developmental biology studies and preclinical therapeutic validation.Its rapid life cycle,optical transparency,and genetic tractability collectively enable efficient longitudinal observation of pathological progression and pharmacological responses.Utilizing zebrafish models,researchers have elucidated fundamental mechanisms governing islet development,β-cell dysfunction,and metabolic dysregulation.These experimental systems have significantly advanced our understanding of various diabetes subtypes,including type 1,type 2,gestational,and monogenic forms,while also facilitating mechanistic studies of diabetic complications such as retinopathy and nephropathy.Recent model refinements,particularly in simulating monogenic disorders and pregnancy-associated metabolic changes,promise to deepen our comprehension of disease pathophysiology and therapeutic interventions.Nevertheless,a persistent limitation lies in their incomplete recapitulation of human-specific physiological complexity and multi-organ metabolic interactions,factors that may influence translational applicability.Despite these constraints,zebrafish-based research continues to provide an indispensable platform for diabetes investigation,holding significant promise for alleviating the escalating global burden of this metabolic disorder.
基金supported by National Key R&D Program of China(2021YFA1101200)National Natural Science Foundation of China(82171048+6 种基金81800842)Key R&D Program of Zhejiang Province(2021C03065)Key R&D Program of Wenzhou Eye Hospital(YNZD1201902)Key R&D Program of Wenzhou(ZY2022021)R&D Program of Wenzhou(H20220008)Research Initiation Funds from Wenzhou Eye Hospital(KYQD20221203)China Postdoctoral Science Foundation(2023M742674)。
文摘In adult mammals,optic nerve injury leads to irreversible vision loss due to its extremely limited regenerative capacity.In contrast,adult zebrafish possess a robust capacity for spontaneous visual system regeneration,although the spatiotemporal coordination of recovery across the retina,optic nerve,and brain remains poorly understood.In the present study,the regenerative dynamics following optic nerve transection were systematically characterized in adult zebrafish over a 5 week period using hematoxylin-eosin staining,immunohistochemistry,transmission electron microscopy,single-cell RNA sequencing,and optokinetic response(OKR)behavioral assessments.At 1 week post-injury(1 wpi),retinal ganglion cell depletion was evident but showed significant recovery by 2 wpi.Concurrently,the injured optic nerve displayed a marked increase in diameter and cell number at 2 wpi,including widespread expression of proliferating cell nuclear antigen,consistent with heightened proliferative activity.Single-cell transcriptomic profiling at 2 wpi revealed five principal cell populations:fibroblasts,mural cells,immune cells,mature oligodendrocytes,and myelin-forming oligodendrocytes.By 4-5 wpi,remyelination within the optic nerve and re-establishment of synaptic architecture in the optic tectum were strongly correlated with functional restoration of OKR behavior.These findings provide a comprehensive spatiotemporal framework of visual pathway regeneration in zebrafish,establishing a valuable model for elucidating conserved mechanisms of neural repair with translational potential for human vision restoration.
文摘Because the physiological characteristics and melanin regulation mechanism of zebrafish are highly similar with those of humans,it is of high reference value to use zebrafish model in the evaluation of cosmetic whitening efficacy.In this study,zebrafish embryos are used as biological models to evaluate the whitening efficacy of six kinds of cosmetics raw materials,such as antioxidant,preservative and essence,and the formula of facial cleanser and facial mask products,and the limitations of the zebrafish melanin production grayscale detection method in practical application are discussed.The results show that the selection of different types of components can also reduce the production of melanin and show whitening effect.It can be seen that the gray scale method of melanin production in zebrafish is suitable for the evaluation of the efficacy of raw materials.In practical application,due to the complexity of the formula,the toxic effects of different types of ingredients may interfere with the melanin generation of zebrafish,affecting the judgment and evaluation of whitening efficacy.For the detection of whitening efficacy of products,a comprehensive evaluation system should be built together with other methods to accurately evaluate the whitening efficacy.
基金supported by grants from Ministry of Science and Technology of the People's Republic of China(2018YFA0801004 and 2018YFA0800103)the National Natural Science Foundation of China(NSFC31530044,NSFC31970780,NSFC82202056).
文摘Single-base editors,including cytosine base editors(CBEs)and adenine base editors(ABEs),facilitate accurate C·G to T·A and A·T to G·C,respectively,holding promise for the precise modeling and treatment of human hereditary disorders.Efficient base editing and expanded base conversion range have been achieved in human cells through base editors fusing with Rad51 DNA binding domain(Rad51DBD),such as hyA3A-BE4max.Here,we show that hyA3A-BE4max catalyzes C-to-T substitution in the zebrafish genome and extends editing positions(C_(12)-C_(16))proximal to the protospacer adjacent motif.We develop a codon-optimized counterpart zhyA3A-CBE5,which exhibits substantially high C-to-T conversion with 1.59-to 3.50-fold improvement compared with the original hyA3A-BE4max.With these tools,disease-relevant hereditary mutations can be more efficaciously generated in zebrafish.We introduce human genetic mutation rpl11^(Q42*)and abcc6a^(R1463C) by zhyA3A-CBE5 in zebrafish,mirroring Diamond-Blackfan anemia and Pseudoxanthoma Elasticum,respectively.Our study expands the base editing platform targeting the zebrafish genomic landscape and the application of single-base editors for disease modeling and gene function study.
基金partially supported by grants from the National Key Research and Development Program of China and the National Natural Science Foundation of China(2018YFA0801000,32270889,2019YFA0802800,32070824,2015CB942800,2016YFA0100500,31871458,31671500,and 81371264)supported by Beijing Natural Science Foundation(5242009)a grant from the Fisheries Innovation Team of Beijing Agriculture Innovation Consortium(BAIC07-2023-02).
文摘The liver is a key endoderm-derived multifunctional organ within the digestive system.Prospero homeobox 1(Prox1)is an essential transcription factor for liver development,but its specific function is not well understood.Here,we show that hepatic development,including the formation of intrahepatic biliary and vascular networks,is severely disrupted in prox1a mutant zebrafish.We find that Prox1a is essential for liver growth and proper differentiation but not required for early hepatic cell fate specification.Intriguingly,prox1a depletion leads to ectopic initiation of a Cdx1b-mediated intestinal program and the formation of intestinal lumen-like structures within the liver.Morpholino knockdown of cdx1b alleviates liver defects in the prox1a mutant zebrafish.Finally,chromatin immunoprecipitation analysis reveals that Prox1a binds directly to the promoter region of cdx1b,thereby repressing its expression.Overall,our findings indicate that Prox1a is required to promote and protect hepatic development by repression of Cdx1b-mediated intestinal cell fate in zebrafish.
基金supported by the core facility Center for Life Sciences,University of Science and Technology of China,Research Funds of the Center for Advanced Interdisciplinary Science and Biomedicine of IHM(QYZD20220002)the National Natural Science Foundation of China(82071357)the Ministry of Science and Technology of China(2019YFA0405600).
文摘Acute mitochondrial damage and the energy crisis following axonal injury highlight mitochondrial transport as an important target for axonal regeneration.Syntaphilin(Snph),known for its potent mitochondrial anchoring action,has emerged as a significant inhibitor of both mitochondrial transport and axonal regeneration.Therefore,investigating the molecular mechanisms that influence the expression levels of the snph gene can provide a viable strategy to regulate mitochondrial trafficking and enhance axonal regeneration.Here,we reveal the inhibitory effect of microRNA-146b(miR-146b)on the expression of the homologous zebrafish gene syntaphilin b(snphb).Through CRISPR/Cas9 and single-cell electroporation,we elucidated the positive regulatory effect of the miR-146b-snphb axis on Mauthner cell(M-cell)axon regeneration at the global and single-cell levels.Through escape response tests,we show that miR-146b-snphb signaling positively regulates functional recovery after M-cell axon injury.In addition,continuous dynamic imaging in vivo showed that reprogramming miR-146b significantly promotes axonal mitochondrial trafficking in the pre-injury and early stages of regeneration.Our study reveals an intrinsic axonal regeneration regulatory axis that promotes axonal regeneration by reprogramming mitochondrial transport and anchoring.This regulation involves noncoding RNA,and mitochondria-associated genes may provide a potential opportunity for the repair of central nervous system injury.
基金support of the National Natural Science Foundation of China(32025014 and 32330029 to Q.W.)the National Key Research and Development Program of China(2020YFA0804000 to Q.W.)+2 种基金Guangdong Excellent Youth Team Project(2024B1515040019 to Q.W.)Guangzhou Science and Technology Plan Project(202201010323 to X.H.)the Fundamental Research Funds for the Central Universities(to Q.W.).
文摘Pharyngeal cartilage morphogenesis is crucial for the formation of craniofacial structures.Cranial neural crest cells are specified at the neural plate border,migrate to pharyngeal arches,and differentiate into pharyngeal chondrocytes,which subsequently flatten,elongate,and stack like coins during maturation.Although the developmental processes prior to chondrocyte maturation have been extensively studied,their subsequent changes in morphology and organization remain largely elusive.Here,we show that wnt2bb is expressed in the pharyngeal ectoderm adjacent to the chondrogenic precursor cells in zebrafish.Inactivation of Wnt2bb leads to a reduction in nuclearβ-catenin,which impairs chondrogenic precursor proliferation and disrupts chondrocyte morphogenesis and organization,eventually causing a severe shrinkage of pharyngeal cartilages.Moreover,the decrease ofβ-catenin in wnt2bb^(-/-)mutants is accompanied by the reduction of Yap expression.Reactivation of Yap can restore the proliferation of chondrocyte progenitors as well as the proper size,shape,and stacking of pharyngeal chondrocytes.Our findings suggest that Wnt/β-catenin signaling promotes Yap expression to regulate pharyngeal cartilage formation in zebrafish.
