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Pituitary adenylate cyclase activating polypeptide(PACAP)and growth hormone-releasing hormone(GHRH)play important roles in the GH/IGF growth axis in fishes.To determine whether epigenetic change is involved in the regulation of pacap and ghrh responses to low salinity stress in Cynoglossus semilaevis,the correlation between growth traits,DNA methylation status and gene expression level in low salinity(15,S15)and optimal salinity(30,S30)at day 7(D7)and day 60(D60)were analyzed.Results showed that exposure to low salinity for 60 days attenuated C.semilaevis growth rate.Under low salinity,DNA methylation level of pacap promoter increased in females and decreased in males at day 7,but inverted at day 60.Additionally,pacap expression was up-regulated in both males and females.The pacap promoter methylation level was higher and expression level was lower in female than in male.The results suggest that pacap promoter methylation level is negatively correlated to mRNA level and positively correlated to body weight,while gene expression level is negatively related with body weight.With the decrease of salinity,DNA methylation level of ghrh promoter and exon1,as well as its gene expression displayed minor changes.Overall,pacap gene seems to play an important role in fish growth,contributing to female growth superiority,while ghrh gene seems not pertinent under salinity stress.The results indicate that low salinity potentially affects fish growth through regulating DNA methylation in pacap promoter.This study expands the understanding of the molecular mechanism of how salinity modulates fish growth from the epigenetic perspective.  相似文献   

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A novel immune-related gene was expressed in Japanese flounder (Paralichthys olivaceus) injected with Vibrio anguillarum. The complete cDNA contained a 169 bp 5’UTR, a 336 bp open reading frame (ORF) encoding 111 amino acids and a 556bp 3’UTR. Six exons and five introns were identified in the PoIR2 gene. Blastp similarity comparison showed its encoding protein had 50% similarity to Danio rerio neuromedin S (NMS), but further alignment indicated they did not have NMS C-terminal conservational signature domain. So it was not defined as an NMS homologue. Protein structure analysis indicated it had a 26aa signal peptide and was a secretory pathway protein. RT-PCR demonstrated that the expression of PoIR2 was quickly induced and drastically increased in liver, kidney, spleen, gills, intestine, heart, and skeletal muscle after infected with V. anguillarum. These results indicated that the PoIR2 might play some important role in Japanese flounder immune response system. This gene was named PoIR2 (P.olivaceus immune-related gene 2, GenBank accession number: EU224372). The mature PoIR2 peptide was expressed in BL21(DE3) pLysS using pET-32a(+) vector and a great part of the recombinant mature peptide existed as soluble type.  相似文献   

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Salinity is a crucial environmental stress that severely affects fish growth and survival.Under environmental stress,DNA methylation plays an important role in gene expression and genome function.To better understand the epigenetic regulation mechanism of igf2 under low salinity stress,we analyzed the DNA methylation at 5’UTR,exon1,intron1,and exon2,and analyzed the relationship of DNA methylation with mRNA abundance as well as the special single CpG sites methylation patterns of igf2 in the liver of half smooth tongue sole under low salinity(15)for 0,7,and 60 d.When exposed to low salinity,DNA methylation at 5’UTR and exon2 remained stable,while it was up-regulated firstly and then down-regulated at exon1 and intron1.Some single CpG sites of igf2 associated with low salinity,and most of these sites with significantly changed methylation levels(P<0.05)are located in intron1 area.The discrepant variation of single CpG sites methylation levels and igf2 expression further revealed that females and males showed different response to low salinity.Remarkably,the 38-CpG site of intron1 servers as a sexual marker.Additionally,our integrative analysis demonstrated that regional DNA of igf2 methylation had highly complex interplay on gene expression.The single CpG sites in intron1 were indispensable epigenetic markers under external environmental stress.Above all,to resist the low salinity stress,half smooth tongue sole liver can regulate the expression of igf2 through methylation of CpG sites in intron1.  相似文献   

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The complement system plays a crucial role in the innate immune system of animals. It can be activated by distinct yet overlapping classical, alternative and lectin pathways. In the alternative pathway, complement factor B(Bf) serves as the catalytic subunit of complement component 3(C3) convertase, which plays the central role among three activation pathways. In this study, the Bf gene in sea cucumber(Apostichopus japonicus), termed Aj Bf, was obtained by rapid amplification of c DNA ends(RACE). The full-length c DNA of Aj Bf was 3231 bp in length barring the poly(A) tail. It contained an open reading frame(ORF) of 2742 bp encoding 913 amino acids, a 105 bp 5'-UTR(5'-terminal untranslated region) and a 384 bp 3'-UTR. Aj Bf was a mosaic protein with six CCP(complement control protein) domains, a VWA(von Willebrand factor A) domain, and a serine protease domain. The deduced molecular weight of Aj Bf protein was 101 k Da. Quantitative real time PCR(q RT-PCR) analysis indicated that the expression level of Aj Bf in A. japonicus was obviously higher at larval stage than that at embryonic stage. Expression detection in different tissues showed that Aj Bf expressed higher in coelomocytes than in other four tissues. In addation, Aj Bf expression in different tissues was induced significantly after LPS or Poly I:C challenge. These results indicated that Aj Bf plays an important role in immune responses to pathogen infection.  相似文献   

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The myosin heavy chain (MyHC) is one of the major structural and contracting proteins of muscle. We have isolated the cDNA clone encoding MyHC of the grass carp, Ctenopharyngodon idella. The sequence comprises 5 934 bp, including a 5 814 bp open reading frame encoding an amino acid sequence of 1 937 residues. The deduced amino acid sequence showed 69% homology to rabbit fast skeletal MyHC and 73%–76% homology to the MyHCs from the mandarin fish, walleye pollack, white croaker, chum salmon, and carp. The putative sequences of subfragment-1 and the light meromyosin region showed 61.4%–80% homology to the corresponding regions of other fish MyHCs. The tissue-specific and developmental stage-specific expressions of the MyHC gene were analyzed by quantitative real-time PCR. The MyHC gene showed the highest expression in the muscles compared with the kidney, spleen and intestine. Developmentally, there was a gradual increase in MyHC mRNA expression from the neural formation stage to the tail bud stage. The highest expression was detected in hatching larva. Our work on the MyHC gene from the grass carp has provided useful information for fish molecular biology and fish genomics.  相似文献   

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采用相关序列扩增多态性(sequence-realted amplified polymorphism,SRAP)技术分析野生草鱼和家养草鱼,并筛选与草鱼种质退化相关的分子遗传标记。共进行88对引物组合的检测,产生标记数目共计905个。依据标记在群体中出现的频率和变化规律,共筛选出21个可能与种质相关的特异性标记,对这些特异性标记进行测序并将测序结果进行BLAST分析,发现测得片段中有8个片段能在GeneBank中找到同源性较高的序列,而其他片段与数据库中序列的相似性较低。  相似文献   

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DAX1, a member of nuclear receptor superfamily, has a function in the sex determination and gonadal differentiation of several vertebrate species. However, little information about DAX1 of invertebrates is available. Here we cloned a homolog of scallop (Chlamys farreri Jones and Preston 1904) dax1, Cf-dax1, and determined its expression characteristics at mRNA and protein levels. The cDNA sequence of Cf-dax1 was 2093 bp in length, including 1404 bp open reading frame (ORF) encoding 467 amino acids. Unlike those of vertebrates, no conserved LXXLL-related motif was found in the putative DNA binding region of Cf-DAX1. Fluorescence in situ hybridization showed that Cf-dax1 located on the short arm of a pair of subtelocentric chromosomes. Tissue distribution analysis using semi-quantitative RT-PCR revealed that Cf-dax1 expressed widely in adult scallop tissues, with the highest expression level found in adductor muscle, moderate level in mantle, gill and testis, and low level in kidney, ovary and hepatopancreas. The result of quantitative real-time PCR indicated that the expression of Cf-dax1 was significantly higher (P<0.05) in testis than in ovary at the same stage, showing a sex-dimorphic expression pattern. Furthermore, immunohistochemical detection found that Cf-DAX1 mainly located in spermatogonia and spermatocytes of testis and in oogonia and oocytes of ovary, implying that DAX1 may involve in gametogenesis of bivalves.  相似文献   

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Increasingly arisen environmental constraints may contribute to heritable phenotypic variation including methylation changes,which can help the animals with development,growth and survival.In this study,we assessed the DNA methylation levels in three tissues(gonad,kidney and gill) of half smooth tongue sole under the salinity stress.The methylation-sensitive amplification polymorphism(MSAP) technique was applied to illustrate the regulation of epigenetic mechanism in environmental stimuli.Fish were subjected to 15 salinity treatment for 7 and 60 days,respectively.A total of 11259 fragments were amplified with 8 pairs of selective primers.The levels of methylated DNA in different tissues of females and males without salinity stress were analyzed,which were 32.76% and 47.32% in gonad;38.13% and 37.69% in kidney;37.58% and 34.96% in gill,respectively.In addition,the significant difference was observed in gonad between females and males,indicating that discrepant regulation in gonadal development and differentiation may involve sex-related genes.Further analysis showed that total and hemi-methylation were significantly decreased under 15 salinity for 7 days,probably resulting in up-regulating salt-tolerance genes expression to adjust salt changing.With the adjustment for 60 days,total and hemi-methylation prominently went back to its normal levels to obtain equilibrium.Particularly,full methylation levels were steady along with salinity stress to maintain the stability of gene expression.Additionally,the data showed that gonads in females and gills in males were superior in adaptability.As a result,DNA methylation regulates tissue-specific epiloci,and may respond to salinity stress by regulating gene expression to maintain animal survival and activity.  相似文献   

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Increasingly arisen environmental constraints may contribute to heritable phenotypic variation including methylation changes, which can help the animals with development, growth and survival. In this study, we assessed the DNA methylation levels in three tissues (gonad, kidney and gill) of half smooth tongue sole under the salinity stress. The methylation-sensitive amplification polymorphism (MSAP) technique was applied to illustrate the regulation of epigenetic mechanism in environmental stimuli. Fish were subjected to 15 salinity treatment for 7 and 60 days, respectively. A total of 11259 fragments were amplified with 8 pairs of selective primers. The levels of methylated DNA in different tissues of females and males without salinity stress were analyzed, which were 32.76% and 47.32% in gonad; 38.13% and 37.69% in kidney; 37.58% and 34.96% in gill, respectively. In addition, the significant difference was observed in gonad between females and males, indicating that discrepant regulation in gonadal development and differentiation may involve sex-related genes. Further analysis showed that total and hemi-methylation were significantly decreased under 15 salinity for 7 days, probably resulting in up-regulating salt-tolerance genes expression to adjust salt changing. With the adjustment for 60 days, total and hemi-methylation prominently went back to its normal levels to obtain equilibrium. Particularly, full methylation levels were steady along with salinity stress to maintain the stability of gene expression. Additionally, the data showed that gonads in females and gills in males were superior in adaptability. As a result, DNA methylation regulates tissue- specific epiloci, and may respond to salinity stress by regulating gene expression to maintain animal survival and activity.  相似文献   

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【目的】哺乳动物pik3r1基因参与多种免疫途径,探索pik3r1基因在罗非鱼(Oreochromis)中的作用。【方法】克隆尼罗罗非鱼(Oreochromis niloticus)pik3r1(命名为On-pik3r1)cDNA全长,对该基因进行生物信息学分析,并运用荧光定量PCR方法分析无乳链球菌(Streptococcus agalactiae)刺激后On-pik3r1 mRNA在各组织种的表达模式。【结果与结论】On-pik3r1基因编码区2190 bp,编码729个氨基酸,5′端非编码区(UTR)为542 bp,3′UTR为2248 bp,理论分子质量为83.99 ku,等电点为5.73。On-pik3r1与斑马拟丽鱼(Maylandia zebra)相似性最高(98.53%),与其他物种的同源性在70%以上,表明pik3r1在物种进化过程中高度保守。On-pik3r1在健康尼罗罗非鱼各组织中均有表达,在肌肉中表达量最高,其次是鳃、皮肤,在胸腺中表达量最低。经灭活无乳链球菌刺激后,On-pik3r1表达量在肠道、鳃、脾脏、头肾、脑部等5个组织中均极显著下调(P<0.01),在胸腺中表现为4 h时极显著下调(P<0.01),24、48、72 h时为显著下调(P<0.05)。On-pik3r1参与了罗非鱼的对无乳链球菌的免疫应答过程。  相似文献   

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Half-smooth tongue sole (Cynoglossus semilaevis) is a promising species for aquaculture in China.The wild population of C. semilaevis is under threat from environmental factors. Microsatellite markers are very suitable for assessing genetic diversity. Four microsatellite-enriched libraries of half smooth tongue sole (Cynoglossus semilaevis) were constructed,from which 57 polymorphic microsatellites were isolated and characterized.The polymorphism of these microsatellites was assessed by genotyping in 30 ind...  相似文献   

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In most bacteria,plants and algae,fatty acid biosynthesis is catalyzed by a group of freely dissociable proteins known as the type II fatty acid synthase(FAS II) system.In the FAS II system,enoylacyl carrier protein reductase(ENR) acts as a determinant for completing the cycles of fatty acid elongation.In this study,the cDNA sequence of ENR,designated as IgENR,was isolated from the microalga Isochrysis galbana CCMM5001.RACE(rapid amplification of cDNA ends) was used to isolate the full-length cDNA of IgENR(1 503 bp),which contains an open reading frame(ORF) of 1 044 bp and encodes a protein of 347 amino acids.The genomic DNA sequence of IgENR is interrupted by four introns.The putative amino acid sequence is homologous to the ENRs of seed plants and algae,and they contain common coenzymebinding sites and active site motifs.Under different stress conditions,real-time quantitative polymerase chain reaction(RT-qPCR) showed the expression of IgENR was upregulated by high temperature(35℃),and downregulated by depleted nitrogen(0 mol/L).To clarify the mechanism of lipids accumulating lipids,other genes involved in lipids accumulation should be studied.  相似文献   

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