This study aims to evaluate the subacute toxic effects of oil under different treatments on marine organism by simulating natural contaminative processes. In this study, 120# （RMD15） fuel oil was selected as the pol...This study aims to evaluate the subacute toxic effects of oil under different treatments on marine organism by simulating natural contaminative processes. In this study, 120# （RMD15） fuel oil was selected as the pollutant and marine medaka （Oryzias melastigma） embryos as the experimental organism. The developmental toxicity of different volume concentrations （0.05%, 0.2%, 1% and 5%） of water-accommodated fractions, biologically-enhanced water-accommodated fractions, and chemically-enhanced water-accommodated fractions on the embryos in different exposure time （8, 15 and 22 d） were compared and the content of relevant polycyclic aromatic hydrocarbons （PAHs） was studied （in dispersion and in vivo）. The subacute toxic effects were assessed in terms of antioxidant activities of enzymes （superoxide dismutase, catalase and glutathione S-transferase） and the blue sac disease （BSD） indexes.The results showed that the BSD indexes of the treatment groups were significantly higher than the respective control groups and showed positive correlations with both concentration and exposure time. The experiments with three antioxidant enzymes indicated that enzymatic activities of the embryos changed dramatically under the oxidation stress of petroleum hydrocarbons, especially after adding the dispersants. With the increase of petroleum hydrocarbon concentration and exposure time, the three enzymes showed different degrees of induction and inhibition effects.展开更多
Perfluorobutanesulfonate(PFBS)is an emerging pollutant capable of potently disrupting the sex and thyroid endocrine systems of teleosts.However,the hypoxic and temporal variation in PFBS endocrine disrupting toxicity ...Perfluorobutanesulfonate(PFBS)is an emerging pollutant capable of potently disrupting the sex and thyroid endocrine systems of teleosts.However,the hypoxic and temporal variation in PFBS endocrine disrupting toxicity remain largely unknown.In the present study,adult marine medaka were exposed to environmentally realistic concentrations of PFBS(0 and 10μg/L)under normoxia or hypoxia conditions for 7 days,aiming to explore the interactive behavior between PFBS and hypoxia.In addition,PFBS singular exposure was extended till 21days under normoxia to elucidate the time-course progression in PFBS toxicity.The results showed that hypoxia inhibited the growth and caused the suspension of egg spawn regardless of PFBS exposure.With regard to the sex endocrine system,7-day PFBS exposure led to an acute stimulation of transcriptional profiles in females,which,subsequently,recovered after the 21-day exposure.The potency of hypoxia to disturb the sex hormones was much stronger than PFBS.A remarkable increase in estradiol concentration was noted in medaka blood after hypoxia exposure.Changes in sex endocrinology of coexposed fish were largely determined by hypoxia,which drove the formation of an estrogenic environment.PFBS further enhanced the endocrine disrupting effects of hypoxia.However,the hepatic synthesis of vitellogenin and choriogenin,two commonly used sensitive biomarkers of estrogenic activity,failed to initiate in response to the estrogen stimulus.Compared to sex endocrine system,disturbances in thyroidal axis by PFBS or hypoxia were relatively mild.Overall,the present findings will advance our toxicological understanding about PFBS pollutant under the interference of hypoxia.展开更多
Neuropeptide Y receptor Y8(NPY8R)is a fish-specific receptor with two subtypes,NPY8AR and NPY8BR.Changes in expression levels during physiological processes or in vivo regulation after ventricular injection suggest th...Neuropeptide Y receptor Y8(NPY8R)is a fish-specific receptor with two subtypes,NPY8AR and NPY8BR.Changes in expression levels during physiological processes or in vivo regulation after ventricular injection suggest that NPY8BR plays an important role in feeding regulation;this has been found in only a few fish,at present.In order to better understand the physiological function of npy8br,especially in digestion,we used clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein 9(Cas9)technology to generate npy8br-/-japanese medaka(Oryzias latipes).We found that the deletion of npy8br in medaka larvae affected their feeding and digestion ability,ultimately affecting their growth.Specifically,npy8br deficiency in medaka larvae resulted in decreased feed intake and decreased expression levels of orexigenic genes(npy and agrp).npy8br-/-medaka larvae fed for 10 d(10th day of feeding)still had incompletely digested brine shrimp(Artemia nauplii)in the digestive tract 8 h after feeding,the messenger RNA(mRNA)expression levels of digestion-related genes(amy,lpl,ctra,and ctrb)were significantly decreased,and the activity of amylase,trypsin,and lipase also significantly decreased.The deletion of npy8br in medaka larvae inhibited the growth and significantly decreased the expression of growth-related genes(gh and igf1).Hematoxylin and eosin(H&E)sections of intestinal tissue showed that npy8br-/-medaka larvae had damaged intestine,thinned intestinal wall,and shortened intestinal villi.So far,this is the first npy8br gene knockout model established in fish and the first demonstration that npy8br plays an important role in digestion.展开更多
Benzo[a]pyrene(BaP),a ubiquitous pollutant,raises environmental health concerns due to induction of bone toxicity in the unexposed offspring.Exposure of F0 ancestor medaka(Oryzias latipes)to 1μg/L BaP for 21 days cau...Benzo[a]pyrene(BaP),a ubiquitous pollutant,raises environmental health concerns due to induction of bone toxicity in the unexposed offspring.Exposure of F0 ancestor medaka(Oryzias latipes)to 1μg/L BaP for 21 days causes reduced vertebral bone thickness in the unexposed F3 male offspring.To reveal the inherited modifications,osteoblast(OB)abundance and molecular signaling pathways of transgenerational BaP-induced bone thinning were assessed.Histomorphometric analysis showed a reduction in OB abundance.Analyses of the miRNA and mRNA transcriptomes revealed the dysregulation of Wnt signaling(frzb/ola-miR-1–3p,sfrp5/ola-miR-96–5p/miR-455–5p)and bone morphogenetic protein(Bmp)signaling(bmp3/ola-miR-96–5p/miR-181b-5p/miR-199a-5p/miR-205–5p/miR-455–5p).Both pathways are major indicators of impaired bone formation,while the altered Rank signaling in osteoclasts(c-fos/miR-205–5p)suggests a potentially augmented bone resorption.Interestingly,a typical BaP-responsive pathway,the Nrf2-mediated oxidative stress response(gst/ola-miR-181b-5p/miR-199a-5p/miR-205),was also affected.Moreover,mRNA levels of epigenetic modification enzymes(e.g.,hdac6,hdac7,kdm5b)were found dysregulated.The findings indicated that epigenetic factors(e.g.,miRNAs,histone modifications)may directly regulate the expression of genes associated with transgenerational BaP bone toxicity and warrants further studies.The identified candidate genes and miRNAs may serve as potential biomarkers for BaP-induced bone disease and as indicators of historic exposures in wild fish for conservation purposes.展开更多
Stem cells are present in developing embryos and adult tissues of multicellular organisms. Owing to their unique features, stem cells provide excellent opportunities for experimental analyses of basic developmental pr...Stem cells are present in developing embryos and adult tissues of multicellular organisms. Owing to their unique features, stem cells provide excellent opportunities for experimental analyses of basic developmental processes such as pluripotency control and cell fate decision and for regenerative medicine by stem cell-based therapy. Stem cell cultures have been best studied in 3 vertebrate organisms. These are the mouse, human and a small laboratory fish called medaka. Specifically, medaka has given rise to the first embryonic stem (ES) cells besides the mouse, the first adult testis-derived male stem cells spermatogonia capable of test-tube sperm production, and most recently, even haploid ES cells capable of producing Holly, a semi-cloned fertile female medaka from a mosaic oocyte created by microinjecting a haploid ES cell nucleus directly into a normal oocyte. These breakthroughs make medaka a favoring vertebrate model for stem cell research, the topic of this review.展开更多
Chinese medaka(Oryzias sinensis),widely distributed in the plateau lakes,Yunnan Province,which was the indicative specie for the habitat quality of riparian zone in the wetland ecosystems and also was the key specie i...Chinese medaka(Oryzias sinensis),widely distributed in the plateau lakes,Yunnan Province,which was the indicative specie for the habitat quality of riparian zone in the wetland ecosystems and also was the key specie in the lake ecosystems,and also was one of the fishes who suffered the severe invasion of alien species.There,we investigated that the genetic diversity and population structure of the wild Chinese medaka by using inter-simple sequence repeat(ISSR)analysis.The samples(20 individuals in total)of Chinese medaka in three populations in the drainage area of Dian Lake were obtained.The 7 ISSR primers were picked out to assess the genetic diversity.The ISSR primers combinations revealed 82.69%polymorphism,among 52 genetic loci amplified.The sum of effective number of alleles and observed number of alleles were 1.492 4 and 1.826 9,respectively.The Shannon genetic diversity and Nei genetic diversity indexes of all the populations were 0.434 5 and 0.289 7,respectively.The gene differentiation(GST)was 0.198 9,and the gene flow(NM)was 2.013 2.The AMOVA demonstrated that only 6.65%of genetic variance came from inter-population,and 93.35%of genetic variance came from intra-population.Phylogenetic tree showed that 20 individuals from 3 populations were clustering mixed each other.Also,the principal coordinate analysis(PCA)supported the cluster analysis results.These results indicated that the genetic diversity of Oryzias sinensis was at the middle level,and there was no obvious genetic differentiation among the three populations of Oryzias sinensis.展开更多
Based on the simulative exposure experiments of nitrobenzene to two small experimental fishes, Medaka (Oryzias latipes) and Chinese Rare Minnow (Gobiocypris rarus), it was found that nitrobenzene could decrease in a l...Based on the simulative exposure experiments of nitrobenzene to two small experimental fishes, Medaka (Oryzias latipes) and Chinese Rare Minnow (Gobiocypris rarus), it was found that nitrobenzene could decrease in a linear way in the static aquatic system. Both fishes could accumulate dose-related levels of nitrobenzene quickly and eliminate the compound rapidly when they were transferred to clean water. The Chinese rare minnow showed more sensitivity to the acute toxicity exposure of nitrobenzene than Medaka. Typical molecular biomarkers in oxidative defense system including superoxide dismu- tase (SOD), catalase (CAT) showed the chemical induced alterations. The changes of acetylcholi- nesterase (AChE) activities indicated that nitrobenzene might affect the normal neural function. Nitro- benzene exposure could also lead to obvious damaging effects on the target organs, such as gill and liver by hitopathological studies.展开更多
The gonad specific expression of insulin-like growth factor 3(igf3)has suggested an important role of igf3 in fish reproduction.In this study,medaka igf3 was isolated and its expression patterns were compared with igf...The gonad specific expression of insulin-like growth factor 3(igf3)has suggested an important role of igf3 in fish reproduction.In this study,medaka igf3 was isolated and its expression patterns were compared with igf1,and germ cell gene vasa in adult medaka ovary.Molecular cloning and sequencing showed that the open reading frame(ORF)of medaka igf3 was comprised of 501 nucleotides and encoded 166 amino acid residues.Reverse transcription polymerase chain reaction(RT-PCR)analysis showed that igf3 RNA was specifically expressed in developing embryos and adult gonads of both sexes.Real time quantitative PCR(q-PCR)indicated that igf3 expression was gradually increased during oogenesis,and reached its highest level at stage V.Using Chromogenic and fluorescent in situ hybridization,igf3 was shown to be present in the germ cells of oogonia and in oocytes at stages I-III,as well as abundant in granulosa cells and theca cells of oocytes at stages IV-V.In addition,igf3 and igf1 were expressed mutually in the outer theca cells of stage V oocytes in ovary.Collectively,we demonstrated that gonad specific igf3 could mark medaka ovarian somatic cells and germ cells.These findings highlight the importance of igf3 during ovarian development.展开更多
Difenoconazole（DFZ） is a triazole fungicide which has been detected in the aquatic environment, including estuaries and embayments. However, few studies addressing the reproductive toxicity and transgenerational eff...Difenoconazole（DFZ） is a triazole fungicide which has been detected in the aquatic environment, including estuaries and embayments. However, few studies addressing the reproductive toxicity and transgenerational effects of DFZ on marine fishes are available.The present study was conducted to investigate the effects of DFZ on male marine medaka（Oryzias melastigma）. After exposure of the embryo to 1, 10, 100 and 1000 ng/L DFZ for180 days, the gonadosomatic index was significantly decreased in the 1000 ng/L treatment.The number of sperm was reduced while the abundances of spermatocytes and spermatogonia in the testes were increased in all the treatments. The m RNA levels of salmontype gnrh（sgnrh）, the luteinizing hormone（lhβ） and the follicle-stimulating hormone（fshβ）genes in the brain all exhibited a significant down-regulation, the expression of androgen receptors（arα and arβ） was decreased and that of estrogen receptor β and cytochrome P450 aromatase（cyp19 B） was increased in the testes. The expression levels of cyp19 A and cyp19 B were increased in the liver. The decrease of ars m RNA levels might be one of the reasons causing the reduction of sperm. The down-regulation of sgnrh, lhβ and fshβ m RNA levels suggested that DFZ might impact the spermatogenesis via the brain–pituitary–gonad pathway. The decrease of the fertilization success, the hatch ability and the swim-up success in the F1 generation indicated that DFZ pollution at environmental levels might cause a decrease of wild fish populations.展开更多
Generation of mutants with clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein 9(Cas9)is commonly carried out in fish species by co-injecting a mixture of Cas9 messenger RNA(mRN...Generation of mutants with clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein 9(Cas9)is commonly carried out in fish species by co-injecting a mixture of Cas9 messenger RNA(mRNA)or protein and transcribed guide RNA(gRNA).However,the appropriate expression system to produce functional gRNAs in fish embryos and cells is rarely present.In this study,we employed a poly-transfer RNA(tRNA)-gRNA(PTG)system driven by cytomegalovirus(CMV)promoter to target the medaka(Oryzias latipes)endogenous gene tyrosinase(tyr)or paired box 6.1(pax6.1)and illustrated its function in a medaka cell line and embryos.The PTG system was combined with the CRISPR/Cas9 system under high levels of promoter to successfully induce gene editing in medaka.This is a valuable step forward in potential application of the CRISPR/Cas9 system in medaka and other teleosts.展开更多
In mammals,lipoprotein lipase(LPL)has been found to play an important role in lipid mentalismand deposition.LPL deficiency in humans(Homo sapiens)and mice(Mus musculus)tends to cause hypertriglyceridemia.The lpl gene ...In mammals,lipoprotein lipase(LPL)has been found to play an important role in lipid mentalismand deposition.LPL deficiency in humans(Homo sapiens)and mice(Mus musculus)tends to cause hypertriglyceridemia.The lpl gene is not expressed in adult mammalian liver,but is in adult fish liver.The functions provided by the lpl gene are diverse in vertebrates.Here,we knocked out the lpl gene in Japanese medaka(Oryzias latipes)with the CRISPR/Cas9 system.The lpl-knockout(KO)homozygous individuals showed severe developmental defects with an extremely emaciated and deformedbody and onlyaccounted for about5%of the F2fish.This is consistentwiththefindings inmicebut disaccords with the results for zebrafish(Danio rerio).Compared with wild-type(WT)madaka,the mRNA level of lpl in lpl-KO heterozygous mutant was significantly higher in the muscle,showed no significant difference in the liver,and was significantly lower in the heart.Under lpl heterozygous deficiency,the relative area of Oil RedO and triglycerides(TG)level in the liver,heart and muscle tissue covaried with levels of lpl mRNA in medaka.The lpl heterozygous deficiency did not affect the levelsofTG,low-density lipoprotein cholesterol(LDL-C),high-density lipoprotein cholesterol(HDL-C)and total cholesterol(TC)in the plasma of medaka,which is inconsistent with the findings in mammals.In general,the lpl gene plays an important role in the growth and development and is closely related to lipid deposition of medaka.展开更多
Numerous studies have showed that sox3 is involved in neurogenesis and sex differentiation in vertebrates.However,the accurate expression pattern is still unclear in fish.In this study,medaka sox3 was isolated and its...Numerous studies have showed that sox3 is involved in neurogenesis and sex differentiation in vertebrates.However,the accurate expression pattern is still unclear in fish.In this study,medaka sox3 was isolated and its expression patterns were compared with germ cell gene vasa in adult gonads.By reverse transcription-polymerase chain reaction(RT-PCR)analysis,sox3 RNA expression was detected in the brain,eyes and gonads.By chromogenic and fluorescent in situ hybridization,sox3 was present in the oogonia and early stages of oocytes as well as granulosa cells and theca cells in the later stages;in the testis,sox3 was occurred in the Sertoli cells and sperm with a specific signal in the location of chromatid body of sperm;in the embryos,sox3 was expressed in the central nervous.These results suggest that medaka sox3 gene was occurred in somatic and germ cells in adult gonads of both sexes,involved in the process of spermatogenesis,as well as the development of the nervous system.This study provides a precise expression pattern of sox3 and suggests that sox3 may be involved in gonadal and nervous system development of fish.展开更多
Germ cells of many organisms exhibit a unique perinuclear cytoplasmic cloud-like structure called the chromatoid body(CB).Specific components of the CB,such as vasa,are crucial for germline development.Herein we ident...Germ cells of many organisms exhibit a unique perinuclear cytoplasmic cloud-like structure called the chromatoid body(CB).Specific components of the CB,such as vasa,are crucial for germline development.Herein we identify another component of the CB,the Oryzias latipes gcnf homolog(Olgcnf).By reverse transcription polymerase chain reaction(RT-PCR),Olgcnf transcript was restricted to gonads in the adult tissues and was maternally provided and persisted throughout embryogenesis.By in situ hybridization on gonadal sections,Olgcnf transcript was restricted to germ cells.In the ovary,Olgcnf was predominantly expressed in the early stages of oocytes.In the testis,Olgcnf showed dynamic expression in round spermatids and sperm,accumulated in the CB during spermatid morphogenesis and concentrated in elongated spermatids of acrosome cap region and flagellar manchette.Moreover,Olgcnf was colocalized with vasa,which is the best-characterized component of the CB.Therefore,Olgcnf is specific to germ cells of both sexes and is a component of the CB during spermiogenesis.展开更多
基金The National Natural Science Foundation of China under contract No.41276105/D0608
文摘This study aims to evaluate the subacute toxic effects of oil under different treatments on marine organism by simulating natural contaminative processes. In this study, 120# （RMD15） fuel oil was selected as the pollutant and marine medaka （Oryzias melastigma） embryos as the experimental organism. The developmental toxicity of different volume concentrations （0.05%, 0.2%, 1% and 5%） of water-accommodated fractions, biologically-enhanced water-accommodated fractions, and chemically-enhanced water-accommodated fractions on the embryos in different exposure time （8, 15 and 22 d） were compared and the content of relevant polycyclic aromatic hydrocarbons （PAHs） was studied （in dispersion and in vivo）. The subacute toxic effects were assessed in terms of antioxidant activities of enzymes （superoxide dismutase, catalase and glutathione S-transferase） and the blue sac disease （BSD） indexes.The results showed that the BSD indexes of the treatment groups were significantly higher than the respective control groups and showed positive correlations with both concentration and exposure time. The experiments with three antioxidant enzymes indicated that enzymatic activities of the embryos changed dramatically under the oxidation stress of petroleum hydrocarbons, especially after adding the dispersants. With the increase of petroleum hydrocarbon concentration and exposure time, the three enzymes showed different degrees of induction and inhibition effects.
基金supported by the National Natural Science Foundation of China (Nos.22006159 and 31971236)the Research Grants Council Theme-Based Research Scheme (No.T21-602/16-R)+1 种基金the Natural Science Foundation of Hubei Province,China (No.2021CFA086)the State Key Laboratory of Freshwater Ecology and Biotechnology (No.2022FBZ02)。
文摘Perfluorobutanesulfonate(PFBS)is an emerging pollutant capable of potently disrupting the sex and thyroid endocrine systems of teleosts.However,the hypoxic and temporal variation in PFBS endocrine disrupting toxicity remain largely unknown.In the present study,adult marine medaka were exposed to environmentally realistic concentrations of PFBS(0 and 10μg/L)under normoxia or hypoxia conditions for 7 days,aiming to explore the interactive behavior between PFBS and hypoxia.In addition,PFBS singular exposure was extended till 21days under normoxia to elucidate the time-course progression in PFBS toxicity.The results showed that hypoxia inhibited the growth and caused the suspension of egg spawn regardless of PFBS exposure.With regard to the sex endocrine system,7-day PFBS exposure led to an acute stimulation of transcriptional profiles in females,which,subsequently,recovered after the 21-day exposure.The potency of hypoxia to disturb the sex hormones was much stronger than PFBS.A remarkable increase in estradiol concentration was noted in medaka blood after hypoxia exposure.Changes in sex endocrinology of coexposed fish were largely determined by hypoxia,which drove the formation of an estrogenic environment.PFBS further enhanced the endocrine disrupting effects of hypoxia.However,the hepatic synthesis of vitellogenin and choriogenin,two commonly used sensitive biomarkers of estrogenic activity,failed to initiate in response to the estrogen stimulus.Compared to sex endocrine system,disturbances in thyroidal axis by PFBS or hypoxia were relatively mild.Overall,the present findings will advance our toxicological understanding about PFBS pollutant under the interference of hypoxia.
基金supported by the National Natural Science Foundation of China(No.31972809)the Key Research&Development Program of Hubei Province(No.2022BBA0051),China.
文摘Neuropeptide Y receptor Y8(NPY8R)is a fish-specific receptor with two subtypes,NPY8AR and NPY8BR.Changes in expression levels during physiological processes or in vivo regulation after ventricular injection suggest that NPY8BR plays an important role in feeding regulation;this has been found in only a few fish,at present.In order to better understand the physiological function of npy8br,especially in digestion,we used clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein 9(Cas9)technology to generate npy8br-/-japanese medaka(Oryzias latipes).We found that the deletion of npy8br in medaka larvae affected their feeding and digestion ability,ultimately affecting their growth.Specifically,npy8br deficiency in medaka larvae resulted in decreased feed intake and decreased expression levels of orexigenic genes(npy and agrp).npy8br-/-medaka larvae fed for 10 d(10th day of feeding)still had incompletely digested brine shrimp(Artemia nauplii)in the digestive tract 8 h after feeding,the messenger RNA(mRNA)expression levels of digestion-related genes(amy,lpl,ctra,and ctrb)were significantly decreased,and the activity of amylase,trypsin,and lipase also significantly decreased.The deletion of npy8br in medaka larvae inhibited the growth and significantly decreased the expression of growth-related genes(gh and igf1).Hematoxylin and eosin(H&E)sections of intestinal tissue showed that npy8br-/-medaka larvae had damaged intestine,thinned intestinal wall,and shortened intestinal villi.So far,this is the first npy8br gene knockout model established in fish and the first demonstration that npy8br plays an important role in digestion.
基金supported by the Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(No.SMSEGL20SC02)the National Natural Science Foundation of China(No.41977371)+1 种基金a Project grant from the Shenzhen and Technology Innovation Commission(No.JCYJ20170818094137791)supported by the National Institute of Environmental Health Sciences of the National Institutes of Health under award number 1R15ES032936-01.
文摘Benzo[a]pyrene(BaP),a ubiquitous pollutant,raises environmental health concerns due to induction of bone toxicity in the unexposed offspring.Exposure of F0 ancestor medaka(Oryzias latipes)to 1μg/L BaP for 21 days causes reduced vertebral bone thickness in the unexposed F3 male offspring.To reveal the inherited modifications,osteoblast(OB)abundance and molecular signaling pathways of transgenerational BaP-induced bone thinning were assessed.Histomorphometric analysis showed a reduction in OB abundance.Analyses of the miRNA and mRNA transcriptomes revealed the dysregulation of Wnt signaling(frzb/ola-miR-1–3p,sfrp5/ola-miR-96–5p/miR-455–5p)and bone morphogenetic protein(Bmp)signaling(bmp3/ola-miR-96–5p/miR-181b-5p/miR-199a-5p/miR-205–5p/miR-455–5p).Both pathways are major indicators of impaired bone formation,while the altered Rank signaling in osteoclasts(c-fos/miR-205–5p)suggests a potentially augmented bone resorption.Interestingly,a typical BaP-responsive pathway,the Nrf2-mediated oxidative stress response(gst/ola-miR-181b-5p/miR-199a-5p/miR-205),was also affected.Moreover,mRNA levels of epigenetic modification enzymes(e.g.,hdac6,hdac7,kdm5b)were found dysregulated.The findings indicated that epigenetic factors(e.g.,miRNAs,histone modifications)may directly regulate the expression of genes associated with transgenerational BaP bone toxicity and warrants further studies.The identified candidate genes and miRNAs may serve as potential biomarkers for BaP-induced bone disease and as indicators of historic exposures in wild fish for conservation purposes.
基金supported by the Biomedical Research Council of Singapore (Grant Nos. R-05-1-21-19-404, R-08-1-21-19-585 and SBIC-SSCC-002-2007)the Ministry of Education of Singapore (Grant No. R-154-000-285-112)the National University of Singapore (Grant No. R-154-000-153-720)
文摘Stem cells are present in developing embryos and adult tissues of multicellular organisms. Owing to their unique features, stem cells provide excellent opportunities for experimental analyses of basic developmental processes such as pluripotency control and cell fate decision and for regenerative medicine by stem cell-based therapy. Stem cell cultures have been best studied in 3 vertebrate organisms. These are the mouse, human and a small laboratory fish called medaka. Specifically, medaka has given rise to the first embryonic stem (ES) cells besides the mouse, the first adult testis-derived male stem cells spermatogonia capable of test-tube sperm production, and most recently, even haploid ES cells capable of producing Holly, a semi-cloned fertile female medaka from a mosaic oocyte created by microinjecting a haploid ES cell nucleus directly into a normal oocyte. These breakthroughs make medaka a favoring vertebrate model for stem cell research, the topic of this review.
基金Under the auspices of Special Program for Key Basic Research Project of the Ministry of Science and Technology,China(973 Program)(2012CB426509)General Project of Research Foundation of Yunnan Provincial Education Department(2014Y335)Research Staring Foundation of Southwest Forestry University(111041)
文摘Chinese medaka(Oryzias sinensis),widely distributed in the plateau lakes,Yunnan Province,which was the indicative specie for the habitat quality of riparian zone in the wetland ecosystems and also was the key specie in the lake ecosystems,and also was one of the fishes who suffered the severe invasion of alien species.There,we investigated that the genetic diversity and population structure of the wild Chinese medaka by using inter-simple sequence repeat(ISSR)analysis.The samples(20 individuals in total)of Chinese medaka in three populations in the drainage area of Dian Lake were obtained.The 7 ISSR primers were picked out to assess the genetic diversity.The ISSR primers combinations revealed 82.69%polymorphism,among 52 genetic loci amplified.The sum of effective number of alleles and observed number of alleles were 1.492 4 and 1.826 9,respectively.The Shannon genetic diversity and Nei genetic diversity indexes of all the populations were 0.434 5 and 0.289 7,respectively.The gene differentiation(GST)was 0.198 9,and the gene flow(NM)was 2.013 2.The AMOVA demonstrated that only 6.65%of genetic variance came from inter-population,and 93.35%of genetic variance came from intra-population.Phylogenetic tree showed that 20 individuals from 3 populations were clustering mixed each other.Also,the principal coordinate analysis(PCA)supported the cluster analysis results.These results indicated that the genetic diversity of Oryzias sinensis was at the middle level,and there was no obvious genetic differentiation among the three populations of Oryzias sinensis.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 40503014 and 40590392)Chinese Academy of Sciences (Grant No. KJCX2-SW- H06, KZCX2-YW-402)Beijing Nova Programme (Grant No. 2004A51)
文摘Based on the simulative exposure experiments of nitrobenzene to two small experimental fishes, Medaka (Oryzias latipes) and Chinese Rare Minnow (Gobiocypris rarus), it was found that nitrobenzene could decrease in a linear way in the static aquatic system. Both fishes could accumulate dose-related levels of nitrobenzene quickly and eliminate the compound rapidly when they were transferred to clean water. The Chinese rare minnow showed more sensitivity to the acute toxicity exposure of nitrobenzene than Medaka. Typical molecular biomarkers in oxidative defense system including superoxide dismu- tase (SOD), catalase (CAT) showed the chemical induced alterations. The changes of acetylcholi- nesterase (AChE) activities indicated that nitrobenzene might affect the normal neural function. Nitro- benzene exposure could also lead to obvious damaging effects on the target organs, such as gill and liver by hitopathological studies.
基金This work was supported by the National Natural Science Foundation of China(31672700)National Key R&D Program of China(2018YFD0901205).
文摘The gonad specific expression of insulin-like growth factor 3(igf3)has suggested an important role of igf3 in fish reproduction.In this study,medaka igf3 was isolated and its expression patterns were compared with igf1,and germ cell gene vasa in adult medaka ovary.Molecular cloning and sequencing showed that the open reading frame(ORF)of medaka igf3 was comprised of 501 nucleotides and encoded 166 amino acid residues.Reverse transcription polymerase chain reaction(RT-PCR)analysis showed that igf3 RNA was specifically expressed in developing embryos and adult gonads of both sexes.Real time quantitative PCR(q-PCR)indicated that igf3 expression was gradually increased during oogenesis,and reached its highest level at stage V.Using Chromogenic and fluorescent in situ hybridization,igf3 was shown to be present in the germ cells of oogonia and in oocytes at stages I-III,as well as abundant in granulosa cells and theca cells of oocytes at stages IV-V.In addition,igf3 and igf1 were expressed mutually in the outer theca cells of stage V oocytes in ovary.Collectively,we demonstrated that gonad specific igf3 could mark medaka ovarian somatic cells and germ cells.These findings highlight the importance of igf3 during ovarian development.
基金supported by the National Natural Science Foundation of China (No. 41376118)
文摘Difenoconazole（DFZ） is a triazole fungicide which has been detected in the aquatic environment, including estuaries and embayments. However, few studies addressing the reproductive toxicity and transgenerational effects of DFZ on marine fishes are available.The present study was conducted to investigate the effects of DFZ on male marine medaka（Oryzias melastigma）. After exposure of the embryo to 1, 10, 100 and 1000 ng/L DFZ for180 days, the gonadosomatic index was significantly decreased in the 1000 ng/L treatment.The number of sperm was reduced while the abundances of spermatocytes and spermatogonia in the testes were increased in all the treatments. The m RNA levels of salmontype gnrh（sgnrh）, the luteinizing hormone（lhβ） and the follicle-stimulating hormone（fshβ）genes in the brain all exhibited a significant down-regulation, the expression of androgen receptors（arα and arβ） was decreased and that of estrogen receptor β and cytochrome P450 aromatase（cyp19 B） was increased in the testes. The expression levels of cyp19 A and cyp19 B were increased in the liver. The decrease of ars m RNA levels might be one of the reasons causing the reduction of sperm. The down-regulation of sgnrh, lhβ and fshβ m RNA levels suggested that DFZ might impact the spermatogenesis via the brain–pituitary–gonad pathway. The decrease of the fertilization success, the hatch ability and the swim-up success in the F1 generation indicated that DFZ pollution at environmental levels might cause a decrease of wild fish populations.
基金This study was supported by the National Natural Science Foundation of China(Nos.31771648 and 31672653)the Scientific Research Foundation of Jimei University(No.ZQ2020003)the National Key Basic Research Program of China(No.2013CB967700).
文摘Generation of mutants with clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein 9(Cas9)is commonly carried out in fish species by co-injecting a mixture of Cas9 messenger RNA(mRNA)or protein and transcribed guide RNA(gRNA).However,the appropriate expression system to produce functional gRNAs in fish embryos and cells is rarely present.In this study,we employed a poly-transfer RNA(tRNA)-gRNA(PTG)system driven by cytomegalovirus(CMV)promoter to target the medaka(Oryzias latipes)endogenous gene tyrosinase(tyr)or paired box 6.1(pax6.1)and illustrated its function in a medaka cell line and embryos.The PTG system was combined with the CRISPR/Cas9 system under high levels of promoter to successfully induce gene editing in medaka.This is a valuable step forward in potential application of the CRISPR/Cas9 system in medaka and other teleosts.
基金the National Natural Science Foundation of China(31972809)China Agriculture Research System(CARS-46)the National Key R&D Program of China(2019YFD0900500).
文摘In mammals,lipoprotein lipase(LPL)has been found to play an important role in lipid mentalismand deposition.LPL deficiency in humans(Homo sapiens)and mice(Mus musculus)tends to cause hypertriglyceridemia.The lpl gene is not expressed in adult mammalian liver,but is in adult fish liver.The functions provided by the lpl gene are diverse in vertebrates.Here,we knocked out the lpl gene in Japanese medaka(Oryzias latipes)with the CRISPR/Cas9 system.The lpl-knockout(KO)homozygous individuals showed severe developmental defects with an extremely emaciated and deformedbody and onlyaccounted for about5%of the F2fish.This is consistentwiththefindings inmicebut disaccords with the results for zebrafish(Danio rerio).Compared with wild-type(WT)madaka,the mRNA level of lpl in lpl-KO heterozygous mutant was significantly higher in the muscle,showed no significant difference in the liver,and was significantly lower in the heart.Under lpl heterozygous deficiency,the relative area of Oil RedO and triglycerides(TG)level in the liver,heart and muscle tissue covaried with levels of lpl mRNA in medaka.The lpl heterozygous deficiency did not affect the levelsofTG,low-density lipoprotein cholesterol(LDL-C),high-density lipoprotein cholesterol(HDL-C)and total cholesterol(TC)in the plasma of medaka,which is inconsistent with the findings in mammals.In general,the lpl gene plays an important role in the growth and development and is closely related to lipid deposition of medaka.
基金the National Key R&D Program of China(2018YFD0901205)National Natural Science Foundation of China(31672700).
文摘Numerous studies have showed that sox3 is involved in neurogenesis and sex differentiation in vertebrates.However,the accurate expression pattern is still unclear in fish.In this study,medaka sox3 was isolated and its expression patterns were compared with germ cell gene vasa in adult gonads.By reverse transcription-polymerase chain reaction(RT-PCR)analysis,sox3 RNA expression was detected in the brain,eyes and gonads.By chromogenic and fluorescent in situ hybridization,sox3 was present in the oogonia and early stages of oocytes as well as granulosa cells and theca cells in the later stages;in the testis,sox3 was occurred in the Sertoli cells and sperm with a specific signal in the location of chromatid body of sperm;in the embryos,sox3 was expressed in the central nervous.These results suggest that medaka sox3 gene was occurred in somatic and germ cells in adult gonads of both sexes,involved in the process of spermatogenesis,as well as the development of the nervous system.This study provides a precise expression pattern of sox3 and suggests that sox3 may be involved in gonadal and nervous system development of fish.
基金This work was supported by the National Natural Science Foundation of China(31672700)National Key R&D Program of China(2018YFD0901205).
文摘Germ cells of many organisms exhibit a unique perinuclear cytoplasmic cloud-like structure called the chromatoid body(CB).Specific components of the CB,such as vasa,are crucial for germline development.Herein we identify another component of the CB,the Oryzias latipes gcnf homolog(Olgcnf).By reverse transcription polymerase chain reaction(RT-PCR),Olgcnf transcript was restricted to gonads in the adult tissues and was maternally provided and persisted throughout embryogenesis.By in situ hybridization on gonadal sections,Olgcnf transcript was restricted to germ cells.In the ovary,Olgcnf was predominantly expressed in the early stages of oocytes.In the testis,Olgcnf showed dynamic expression in round spermatids and sperm,accumulated in the CB during spermatid morphogenesis and concentrated in elongated spermatids of acrosome cap region and flagellar manchette.Moreover,Olgcnf was colocalized with vasa,which is the best-characterized component of the CB.Therefore,Olgcnf is specific to germ cells of both sexes and is a component of the CB during spermiogenesis.
