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ABSTRACT:   Expressed sequence tag (EST) analysis is an efficient tool for gene discovery and for profiling gene expression. A cDNA library developed from messenger RNA of the Japanese flounder, Paralichthys olivaceus spleen was constructed by directional cloning, in order to isolate functional genes involved in immunity in fish. A total of 1010 ESTs from the library were sequenced and compared with sequences in the GenBank database. Of the 1010 ESTs, 618 ESTs (61%) were identified as being homologous with known genes from many organisms by BLAST searches, whereas 392 (39%) appeared to be unknown and are likely to represent newly described genes. Of the identified genes, 105 (17%) encoded proteins associated with cell/organism defence and homeostasis. Of these 105 genes, 21 were identified for the first time in Japanese flounder. These included macrophage inflammatory protein (MIP)-3 α, granulin-A, novel immune-type receptor (NITR), interferon regulatory factor (IRF)-10, presenilin-like protein-2, and antizyme inhibitor. A comparison of ESTs derived from spleen, kidney, liver and leukocytes suggested that expression of immune-related genes in different tissues, organs, or cells are different.  相似文献   

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ABSTRACT:   The nucleotide sequences of Japanese flounder Paralichthys olivaceus , major histocompatibility complex (MHC) cDNA, classical MHC class Iα, non-classical MHC class Iβ, MHC class IIα and IIβ, were determined. The domain structures and antigen binding motifs of vertebrate MHC are conserved in the Japanese flounder MHC. A phylogenetic analysis supports the classification of these genes into class I and class II MHC. Classical MHC class Iα was ubiquitously expressed, whereas the non-classical MHC class Iβ was expressed mainly in lymphoid organs, gills, intestine and stomach. The MHC classes IIα and IIβ were also ubiquitously expressed.  相似文献   

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ABSTRACT:    The 78-kDa glucose regulated protein (GRP78), a member of stress proteins, was cloned from a cDNA library of Japanese oyster Crassostrea gigas . The analysis on Japanese oyster GRP78 clone of approximately 2.6 kb revealed that the entire open reading frame was 1983 bp long and encoded 661 amino acid residues. At the DNA sequence level, the coding region of Japanese oyster GRP78 gene was 72, 62, and 62% identical to those of chicken GRP78, Japanese flounder HSP70, and Japanese flounder HSC71 genes, respectively. Deduced amino acid sequence of Japanese oyster GRP78 was 84, 62, and 62% identical to those of chicken GRP78, Japanese flounder HSP70, and Japanese flounder HSC71, respectively. Japanese oyster GRP78 contained an 18-residue sequence at the N-terminus that exhibits characteristics of a cleavable signal sequence. It also contained an ATPase domain, and a peptide-binding domain in addition to a Lys-Asp-Glu-Leu (KDEL) peptide motif that is involved in determining endoplasmic reticulum localization. Northern blot analysis showed that GRP78 mRNA was induced with heatshock treatment in the oyster tissues.  相似文献   

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采用抑制性消减杂交技术构建了三角帆蚌肝脏瘟病感染期抑制性消减cDNA文库。经检验,差异表达基因均被富集了 210倍左右,证明构建的 cDNA 消减文库具有很强的消减效率。PCR 鉴定发现,在随机挑取的阳性克隆中,95% 的克隆均含有 0.2~1.0 kb 的插入片段,这些片段可能是三角帆蚌瘟病病毒感染后差异表达基因的cDNA片段。测序共获得 214 个有效 cDNA 序列,分别属于8 大类,共 98 个基因。其中细胞分裂基因 2个、细胞结构与运动基因 9 个、代谢基因 10 个、信号传导基因 7 个、细胞防疫基因 10 个、基因与蛋白表达基因 20 个、未知功能蛋白基因 26 个,GenBank中找不到任何同源序列的基因 14 个。结果说明,构建的差异表达cDNA文库,可较好地反映三角帆蚌瘟病病毒对三角帆蚌影响的基因信息。  相似文献   

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The Japanese scallop Mizuhopecten yessoensis is one of the most important aquaculture mollusca in Japan and China. In the present study, a high‐quality cDNA library of the Japanese scallop was constructed from the kidney tissue. A total of 2919 expressed sequence tags longer than 100 bp were generated from this library. A cluster of 1440 unique sequences, which consisted of 258 contigs and 1182 singletons, was revealed. Based on blast searches, 882 (61.3%) genes had significant (E‐value <1e–5) matches to known sequences in public databases. Among them, >70 genes were involved in stress response, immunity and apoptosis. These results expanded our knowledge of the genetics and physiology of the Japanese scallop, and provided a useful resource for gene discovery for further research of this species.  相似文献   

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ABSTRACT:   Interleukin-1β (IL-1β) cDNA of Japanese flounder was found to consist of 1329 bp, encoded 247 amino acid residues. Among the fish IL-1β in the databases, the one with the highest identity of Japanese flounder IL-1β was that of seabass (62% identity). The expression of IL-1β was induced by treatment with concanavalin A (ConA)/phorbol myristate acetate (PMA) and lipopolysaccharide. The copy number of IL-1β mRNA was increased 30-fold after stimulation with ConA/PMA. Of 871 cDNA on a microarray, 93 genes (10.7%) were up-regulated or down-regulated by IL-1β at 1, 3 and 7 days post-injection. The induced gene expression was highest on day 1 followed by day 3 and day 7. A total of 7% of known and 3.7% of unknown genes of the 871 tested genes were differentially expressed. Of the genes tested, 7.4% were up-regulated and 3.3% were down-regulated. Cytokine genes such as tumor necrosis factor, granulocyte colony stimulating factor and chemokine receptor A were induced in response to IL-1β. Cell surface antigens such as IgM, MHC class I and CD20 receptor were up-regulated. Signal transduction genes such as Toll-like receptor 1 and SH3P2 were also up-regulated. The glucocorticoid receptor and cAMP early repressor were down-regulated in our microarray analysis.  相似文献   

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ABSTRACT:   Seasonal changes in the infection state of marine birnavirus (MABV) in Japanese flounder Paralichthys olivaceus and in rearing sea water are described. Sea water and 10–11 healthy fish were sampled monthly from April 2002 to February 2003. The MABV genome was detected throughout the year in > 80% of the fish examined at each sampling. The virus was isolated from the liver, kidney, and spleen, but not from the brain. The detection rate in each organ increased from April to October, and then decreased. Detection of virus antigen by the indirect fluorescent antibody technique also showed that the virus was present from spring to autumn (June–September) in the liver, kidney, and spleen, but not the brain. Sequence analysis of the MABV genome at the VP2–NS region revealed two specific mutations compared to the standard yellowtail strain (Y-6). It is suggested that the infection state of MABV in Japanese flounder changes to a latent or persistent infection after autumn. MABV was detected in sea water between September and February, suggesting that virus particles in the environment are relatively higher during cool seasons.  相似文献   

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ABSTRACT:   The effect of dietary taurine on juvenile Japanese flounder was determined by feeding three taurine-supplemented experimental diets (TAU) and a commercial diet (CD) to evaluate a practical diet for juvenile Japanese flounder. Juvenile Japanese flounder were reared on the three experimental diets supplemented with taurine at 0, 0.5, 1.0% and CD. These diets were fed to juvenile Japanese flounder of an initial mean body weight of 0.2 g for 6 weeks at 20°C and the taurine contents of the whole body and tissues were analyzed. The final average body weight of juvenile Japanese flounder fed the 1.0% TAU was significantly higher than that of the other groups. Taurine contents in the whole body and tissues increased with the increase in dietary taurine level. These results indicate that juvenile Japanese flounder require at least 15 mg/g taurine in the diet, even though a combined mix of fish, krill and squid meal was the main protein source in the experimental diets.  相似文献   

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ABSTRACT:     The acute toxicities of boron were examined for Japanese flounder Paralichthys olivaceus and red sea bream Pagrus major in terms of fish size and water temperature. Japanese flounder of 0.1–70.0 g and red sea bream of 0.6–20.3 g were exposed to different concentrations of boron for 96 h at 20°C under semi-static conditions. In both fish species, the median lethal concentration (LC50) for 96 h of boron increased linearly with increasing fish size, ranging from 108 to 252 mg B/L for the flounder, and from 97 to 172 mg B/L for the sea bream. The effect of water temperature on acute toxicity was examined for Japanese flounder of 0.6 and 1.5 g at 10, 15, 20 and 25°C, and for red sea bream of 0.6 and 2.4 g at 12, 15, 20 and 25°C. The toxicity of boron for the flounder increased linearly with increasing water temperature. The 96 h LC50 values ranged from 299 to 108 mg B/L for the 0.6 g flounder and from 350 to 113 mg B/L for the 1.5 g flounder. A similar trend was shown for the 2.4 g red sea bream; however, the relationship for the 0.6 g red sea bream was not significant.  相似文献   

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ABSTRACT:   In order to construct a simple sequence repeat (SSR)-based genetic linkage map and to promote molecular marker-assisted selection (MAS) in scallop breeding, the methods of Fast Isolation by AFLP of Sequences COntaining repeats (FIASCO)-colony hybridization and expressed sequence tag (EST) database mining were modified and used to develop 95 novel microsatellite markers for Zhikong scallop. The SSR-enriched library constructed by the FIASCO method consisted of 830 clones, and 295 (35.5%) positive clones were identified after colony hybridization. One hundred and fifty clones were randomly sequenced and the results showed all clones contained at least one microsatellite. Of 91 primer pairs designed, 72 were amplified scorable polymerase chain reaction (PCR) products and 70 were polymorphic with the allele number range of 3–16 alleles/locus (average 7.0 alleles/locus). When EST database mining was performed, 66 microsatellites containing ESTs were identified from 3467 sequences deposited in GenBank. Based on cluster analysis of length and GC content of the flanking regions, 47 primer pairs were designed and 23 scorable EST SSRs were obtained. Compared with genomic SSRs developed in this study, EST SSRs showed lower genetic variability with an average of 4.2 alleles/locus. The results in the present study demonstrate that modified FIASCO-colony hybridization is an efficient and low-cost method for the isolation of large numbers of microsatellite markers for scallop species.  相似文献   

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抑制差减杂交法克隆牙鲆变态早期差异表达的基因   总被引:2,自引:0,他引:2  
为了克隆变态早期牙鲆头部差异表达的基因,采用抑制差减杂交法,以变态前的仔鱼头部表达的RNA作为驱动RNA,建立了牙鲆变态早期的差减cDNA文库,并利用相对定量RT-PCR对其进行了筛选。差减库的平均插入片段558bp左右,阳性率为81.8%。随机测定的45个克隆,在剔除假阳性克隆后,共得到22个不同的基因,其中13个为已知cDNA的同源基因,而另外9个为已知蛋白的同源基因,分别为prolactin receptor-like,COL1A1,M3-muscarinic receptor,Sfrs3,tropomyosin,ribosomal protein L27,ribosomal [rpteom S12,GAPDH,COL1A3。在所有22个基因中,COL1A1基因在差减库中的分布频率最高,为22.2%。RT-PCR检测结果表明,在所检测的11个基因中,所有基因在右眼移动前后的牙鲆头部均有表达,只是体现在表达水平上的不同。  相似文献   

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Expressed sequence tag (EST) analysis is an efficient tool for gene discovery and for profiling gene expression. In order to isolate functional genes involved in immunity in fish, a cDNA library was constructed from red sea bream (Chrysophrys major) spleen by unidirectional cloning. A total of 2010 ESTs from the library was sequenced and compared with sequences in the GenBank database. Of the 2010 ESTs, 320 ESTs (15.9%) were identified as orthologs of known gene from other organisms by BLAST searches, whereas 1690 ESTs (84.1%) appeared to be unknown and are likely to represent newly described genes. These identified clones were derived from at least 81 genes, which were categorized into eight categories: 9 in cell structure/motility (11.1%), 14 in metabolism (17.3%), 8 in cell defense/immunity (10%), 5 in cell division (6.2%), 7 in cell signal transduction/communication (8.6%), 30 in gene/protein expression (37%), 5 hemoglobin (6.2%) and 3 genes lacking enough information to be classified (3.7%). Several important cDNAs involved in immune functions, such as immunoglobulin light chain (IgL), MHC class II, MHC class IIβ and RAP2c, were identified in red sea bream and compared for their structure with those from other organisms. Alignment showed that the red sea bream IgL precursor was closer to that of spotted wolfish than to that of yellowtail, Europe sea bass, orange spotted grouper, Atlantic salmon, channel catfish, fugu and sterlet. Phylogenetic analysis indicated that the red sea bream MHC II and MHC IIβ were more related to those from striped sea bass than to those from cichlid, flounder, salmonids, zebrafish and carp. High identity (over 92%) in deduced amino acid sequence of RAP2c between red sea bream and mammals implied that RAP2c gene was highly conserved during evolution.  相似文献   

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