Developmental Expression of an Amphioxus (Branchiostoma belcheri) Gene Encoding a GATA Transcription Factor

GATA基因在脊椎动物和非脊椎动物的发育中行使重要的功能,该家族的成员在进化上也足非常保守的.脊椎动物的GATA基因分为两个亚群:GATA1/2/3和GATA4/5/6.通过生物信息分析,在文吕鱼的基因缓中找到了3个GATA基因:一个GATA1/2/3业家族基因,两个GATA4/5/6亚家族基因:还找到一个类GATA基因.还克隆了白氏文昌鱼(Branchiostoma belcheri)GATA123的一段序列,并研究了它在早期胚胎发育中的表达图式.结果表明GATA123在原肠胚的中内胚层表达,而在神经胚晚期和幼体早期,GATA123在脑泡和消化道中部区域表达.这种表达模式与头部发育的重要基因Otx相类似.结果提示在文吕鱼脑泡的发育过程中GATA123和Otx很可能共同发挥着重要的作用.

Cloning and characterization of the first amphibian bradykinin gene

More than ten bradykinin-related peptides and their cDNAs; have been identified from amphibians, but their genes are unknown. In present study, four cDNAs encoding one, two, four and six copies of bradykinin-related peptides were cloned from the frog (Odorrana grahami) skin cDNA library, respectively. Three bradykinin-related peptides (bradykinin, Thr6-bradykinin, Leu5Thr6-bradykinin) were deduced from these four cDNA sequences. Based on the cDNA sequence, the gene sequence encoding an amphibian bradykinin-related peptide from O. grahami was determined. It is composed of 7481 base pairs including two exons and two introns. The first exon codes signal peptide and the second exon codes acidic spacer peptide and Thr6-bradykinin. The promoter region of the bradykinin gene contains several putative recognition sites for nuclear factors, such as SRY, GATA-1, LYF-1, DeltaE, CDXA, NKX-2.5, MIF1 and S8. The current work may facilitate to understand the regulation and possible functions of amphibian skin bradykinin-related peptides. (C) 2009 Elsevier Masson SAS. All rights reserved.

中华绒螯蟹微卫星单引物扩增产物的初步分析

采用人工合成的 6个串联重复寡聚核苷酸单引物 ,以及 2个加锚的二核苷酸引物 ,利用SPAR和ASSR技术 ,对中华绒螯蟹 (Eriocheirsinensis)基因组进行PCR扩增 ,结果发现 ,对于GC含量丰富的三、四核苷酸引物如(CGA) 5、(GACA) 4 ,在不同退火温度的PCR反应中 ,都能扩增出清晰的条带 ,可以作为PCR扩增引物 ;反之 ,GC含量 <5 0 %的 (CATA) 4 和 (GATA) 4 很难检测到扩增产物 ;在基本PCR条件下 ,2个加锚的二核苷酸引物能扩增出可分辨的条

Expression pattern, cellular localization and promoter activity analysis of ovarian aromatase (Cyp19a1a) in protogynous hermaphrodite red-spotted grouper

Aromatase plays a key role in sex differentiation of gonads. In this study, we cloned the full-length cDNA of ovarian aromatase from protogynous hermaphrodite red-spotted grouper (Epinephelus akaara), and prepared the corresponding anti-EaCyp19a1a antiserum. Western blot and immunofluorescence studies revealed ovary-specific expression pattern of EaCyp19a1a in adults and its dynamic expression change during artificial sex reversal. EaCyp19a1a was expressed by follicular cells of follicular layer around oocytes because strong EaCyp19a1a immunofluorescence was observed in the cells of ovaries. During artificial sex reversal, EaCyp19a1a expression dropped significantly from female to male, and almost no any positive EaCyp19a1a signal was observed in testicular tissues. Then, we cloned and sequenced a total of 1967 bp T-flanking sequence of EaCyp19a1a promoter, and showed a number of potential binding sites for some transcriptional factors, such as SOX5, GATA gene family, CREB, AP1, FOXL1, C/EBP, ARE and SF-1. Moreover, we prepared a series of 5' deletion promoter constructs and performed in vitro luciferase assays of EaCyp19a1a promoter activities. The data indicated that the CREB regulation region from -1010 to -898 might be a major cis-acting element to EaCyp19a1a promoter, whereas the elements GATA and SOX5 in the region from -1216 to -1010 might be suppression elements. Significantly, we found a common conserved sequence region in the fish ovary-type aromatase promoters with identities from 93% to 34%. And, the motifs of TATA box, SF-1, SOX5, and CREB existed in the region and were conserved among the most of fish species. (C) 2009 Elsevier Ireland Ltd. All rights reserved.

Microsatellite marker isolation and cultured strain identification in Carassius auratus gibelio

Microsatellites have become the preferred molecular markers for strain selection and genetic breeding in fish. In this study a total of 105 microsatellites were isolated and identified in gibel carp (Carassius auratus gibelio) by microsatellite sequence searches in GenBank and other databases and by screening and sequencing of positive clones from the genomic library enriched for AG and GATA repeats. Moreover, nineteen microsatellites were randomly selected to design locus-specific primer pairs, and these were successfully used to identify and discriminate different cultured strains of gibel carp including strains A, D, L, and F. Three different types of microsatellite pattern were distinguished by the number and length of fragments amplified from the 19 primer pairs, and some microsatellite primer pairs were found to produce different microsatellite patterns among strains and strain-specific fragments. In addition, some duplicated alleles were also detected in two microsatellite patterns. Therefore, the current study provides direct molecular markers to discriminate among different cultured strains for selective breeding and aquaculture practice of gibel carp.

Cloning, characterization and expression analysis of SIMP (source of immunodominant MHC-associated peptides) in grass carp Ctenopharyngodon idella

SIMP (source of immunodominant MHC-associated peptides) plays a key rote in N-linked glycosylation with the active site of oligosaccharyltransferase, being the source of MHC-peptides in the MHC I presentation pathway. In the present study, the SIMP gene has been cloned from grass carp Ctenopharyngodon idella by rapid amplification of cDNA ends (RACE). The full length of the cDNA sequence is 4384 bp, including a 1117 bp 5' UTR (untranslated region), a 2418 bp open reading frame, and a 849 bp 3' UTR. The deduced amino acids of the grass carp SIMP (gcSIMP) are a highly conserved protein with a STT3 domain and 11 transmembrane regions. The gcSIMP spans over more than 24,212 bp in length, containing 16 exons and 15 introns. Most encoding exons, except the first and the 15th, have the same length as those in human and mouse. The gcSIMP promoter contains many putative transcription factor binding sites, such as Oct-1, GCN4, YY1, Sp1, Palpha, TBP, GATA-1, C/EBP beta, and five C/EBP alpha binding sites. The mRNA expression of gcSIMP in different organs was examined by real-time PCR. The gcSIMP was distributed in all the organs examined, with the highest level in brain, followed by the level in the heart, liver, gill, trunk kidney, muscle, head kidney, thymus, and the lowest level in spleen. Furthermore, the recombinant gcSIMP has been constructed successfully and expressed in Escherichia coli by using pQE-40 vector, and the polyclonal antibody for rabbit has been successfully obtained, which was verified to be specific. Identification of gcSIMP will help to explore the function in fish innate immunity. (c) 2007 Elsevier Ltd. All rights reserved.

Molecular cloning, promoter analysis and induced expression of the complement component C9 gene in the grass carp Ctenopharyngodon idella

Complement-mediated killing of pathogens through lytic pathway is an important effector mechanism of innate immune response. C9 is the ninth member of complement components, creating the membrane attack complex (MAC). In the present study, a putative cDNA sequence encoding the 650 amino acids of C9 and its genomic organization were identified in grass carp Ctenopharyngodon idella. The deduced amino acid sequence of grass carp C9 (gcC9) showed 48% and 38.5% identity to Japanese flounder and human C9, respectively. Domain search revealed that gcC9 contains a LDL receptor domain, an EGF precursor domain, a MACPF domain and two TSP domain located in the N-terminal and C-terminal, respectively. Phylogenetic analysis demonstrated that gcC9 is clustered in a same clade with Japanese flounder, pufferfish and rainbow trout C9. The gcC9 gene consists of 11 exons with 10 introns, spacing over approximately 7 kb of genomic sequence. Analysis of gcC9 promoter region revealed the presence of a TATA box and some putative transcription factor such as C/EBP, HSF, NF-AT, CHOP-C, HNF-3B, GATA-2, IK-2, EVI- 1, AP-1, CP2 and OCT-1 binding sites. The first intron region contains C/EBPb, HFH-1 and Oct-1 binding sites. RT-PCR and Western blotting analysis demonstrated that the mRNA and protein of gcC9 gene have similar expression patterns, being constitutively expressed in all organs examined of healthy fish, with the highest level in hepatopancreas. By real-time quantitative RT-PCR analysis, gcC9 transcripts were significantly up-regulated in head kidney, spleen, hepatopancreas and down-regulated in intestine from inactivated fish bacterial pathogen Flavobacterium columnare-stimulated fish, demonstrating the role of C9 in immune response. (c) 2007 Elsevier B.V. All rights reserved.

Isolation and characterization of polymorphic microsatellites in a Yangtze River fish, brass gudgeon (Coreius heterodon Bleeker)

The brass gudgeon (Coreius heterodon) is a fish of economic importance in the Yangtze River. From a (GATA)(n)-enriched genomic library, 25 microsatellites were developed by employing the fast isolation by AFLP of sequences containing repeats (FIASCO) protocol. Nine loci exhibited polymorphism with two to 12 alleles (mean 3.9 alleles/locus) in a test population, and observed heterozygosity ranged from 0.1111 to 0.9630 (mean 0.4426). Three of the nine loci showed polymorphism in a congeneric species, the largemouth bronze gudgeon Coreius guichenoti. These loci should provide sufficient level of genetic diversity to evaluate the fine-scale population structure of C. heterodon.

Characterization and expression analysis of TNF-related apoptosis inducing ligand (TRAIL) in grass carp Ctenopharyngodon idella

TRAIL (Apo2 ligand) described as a type II transmembrame protein belonging to the TNF superfamily can induce apoptotic cell death in a variety of cell types. In the present study, a putative cDNA sequence encoding the 299 amino acids of TRAIL (GC-TRAIL) and its genomic organization were identified in grass carp Ctenopharyngodon idella. The predicted GC-TRAIL sequence showed 44 and 41% identities to chicken and human TRAILs, respectively. In a domain search, a tumor necrosis factor homology domain (THD) was identified in the C-terminal portion of TRAILs. The GC-TRAIL gene consists of five exons, with four intervening introns, spaced over approximately 4 kb of genomic sequence. Analysis of GC-TRAlL promoter region revealed the presence of a number of putative transcription factor binding sites, such as Sp1, NF-kappaB, AP-1, GATA, NFAT, HNF, STAT, P53 and IRFI sequences which are important for the expression of other TNF family members. Phylogenetic analysis placed GC-TRAIL and the putative zebrafish (Danio rerio) TRAIL obtained from searching the zebrafish database into one separate cluster near mammalian TRAIL genes, but apart from the reported zebrafish TRAIL-like protein, indicating that the GC-TRAIL is an authentic fish TRAIL. Expression analysis revealed that GC-TRAIL is expressed in many tissues, such as in gills, liver, trunk kidney, head kidney, intestine and spleen. (c) 2005 Elsevier B.V. All rights reserved.

Isolation and characterization of microsatellites in Chinese sturgeon, Acipenser sinensis

From (GATA)(n) and (AAAG)(n) enriched genomic libraries for the Chinese sturgeon (Acipenser sinensis), 50 primer pairs were developed using the fast isolation by AFLP of sequences containing repeats (FIASCO) protocol. Forty-six primer pairs exhibited highly polymorphic with two to 11 alleles per locus, while the rest four displayed monomorphic. These markers yielded 246 alleles in a survey of eight specimens of wild A. sinensis. Average observed heterozygosity ranged from 0.13 to 1.00. These loci should provide sufficient levels of genetic diversity to allow parentage analysis for artificial stocking management and delineation of fine-scale population structure.

Characterization of two genes encoding leucine-rich repeat-containing proteins in grass carp Ctenopharyngodon idellus

The cDNAs and genes of two different types of leucine- rich repeat-containing proteins from grass carp ( Ctenopharyngodon idellus) were cloned. Homology search revealed that the two genes, designated as GC-GARP and GC-LRG, have 37% and 32% deduced aminoacid sequence similarities with human glycoprotein A repetitions predominant precursor ( GARP) and leucine-rich alpha2-glycoprotein (LRG), respectively. The cDNAs of GC-GARP and GC-LRG encoded 664 and 339 amino acid residues, respectively. GC-GARP and GC-LRG contain many distinct structural and/or functional motifs of the leucine- rich repeat (LRR) subfamily, such as multiple conserved 11-residue segments with the consensus sequence LxxLxLxxN/CxL ( x can be any amino acid). The genes GC-GARP and GC-LRG consist of two exons, with 4,782 bp and 2,119 bp in total length, respectively. The first exon of each gene contains a small 5'-untranslated region and partial open reading frame. The putative promoter region of GC-GARP was found to contain transcription factor binding sites for GATA-1, IRF4, Oct-1, IRF-7, IRF-1, AP1, GATA-box and NFAT, and the promoter region of GC-LRG for MYC-MAX, MEIS1, ISRE, IK3, HOXA9 and C/EBP alpha. Phylogenetic analysis showed that GC-GARP and mammalian GARPs were clustered into one branch, while GC-LRG and mammalian LRGs were in another branch. The GC-GARP gene was only detected in head kidney, and GC-LRG in the liver, spleen and heart in the copepod ( Sinergasilus major)- infected grass carp, indicating the induction of gene expression by the parasite infection. The results obtained in the present study provide insight into the structure of fish LRR genes, and further study should be carried out to understand the importance of LRR proteins in host - pathogen interactions.

文昌鱼Dkk和Kremen基因家族表达图谱和功能的研究

文昌鱼长期作为脊索动物的祖先模型被研究。它与脊椎动物发育机制的比较为后者的发生和进化提供了大量证据。Wnt信号通路在动物胚胎发育中行使着多样而重要的功能：如胚胎轴系的建立，胚层分化，神经图式形成等。在腔肠动物胚胎发育的早期，Wnt/β-catenin主要参与动植物半球极性的形成和胚层分化——很可能是Wnt通路的祖先功能。而在高等脊椎动物胚胎发育的早期，Wnt/β-catenin通路对于背腹轴、前后轴和左右轴极性的建立发挥着至关重要的作用。我们的研究主要集中在文昌鱼Wnt/β-catenin信号通路的两种调节因子Dickkopf（Dkk）和Kremen，以探明这些Wnt信号调节因子的祖先功能，以及在脊椎动物中获得新功能的进化历程。分泌性蛋白Dkk是Wnt信号通路的抑制因子，协同它的高亲和性受体Kremen，在两栖类胚胎头部的发育中起着关键作用。基于脊椎动物Dkk和kremen的报道以及佛罗里达文昌鱼基因组序列信息，我们运用分子克隆的方法，得到白氏文昌鱼Dkk家族的两个基因：BbDkk124和BbDkk3，以及Kremen家族的5个基因：BbKremen-a，BbKremen-c，BbKremen-d，BbKremen-e，BbKremen-g，用整体胚胎原位杂交的方法研究了它们的表达图谱，并在293T细胞和非洲爪蟾胚胎这两个系统中检测了它们对Wnt信号活性的影响和胚胎发育表型的影响。结果表明文昌鱼Dkk和Kremen的表达区域与脊椎动物的同源基因并不相同，出现了较大分歧，但BbDkk124作为Wnt信号抑制因子的功能是保守的。Kremen家族的两个基因BbKremen-e和BbKremen-g在293T细胞内对Wnt通路的影响不显著，而在非洲爪蟾系统中，引起胚胎不同的畸形表型。我们的实验结果为脊椎动物Dkk和Kremen 基因家族的进化提供了一些资料。 此外我们还研究了文昌鱼GATA家族的基因，这个家族在脊椎动物和非脊椎动物的发育中行使重要的动能，在进化上也是非常保守的。脊椎动物的GATA基因分为两个亚群：GATA1/2/3和GATA4/5/6。通过生物信息分析，我们在文昌鱼的基因组中找到了三个GATA基因：一个GATA1/2/3亚家族基因，两个GATA4/5/6亚家族基因，另外还找到一个类GATA基因。我们克隆了白氏文昌鱼GATA123的一段序列并研究了它在早期胚胎发育中的特异性表达。结果表明GATA123在原肠胚的中内胚层表达，而在神经胚晚期和幼体早期，GATA123在脑泡和消化道中部区域表达。这种表达模式与头部发育的重要基因Otx相类似。我们的研究结果提示在文昌鱼脑泡的发育过程中GATA123和Otx很可能协同发挥着重要的作用。

海湾扇贝超氧化物歧化酶家族基因结构、表达和多态性分析

海湾扇贝Argopecten irradian Lamarck于1982年从美国引种到中国，由于具有较快的生长速度和很高的经济效益，海湾扇贝成为中国最主要的养殖贝类之一。近年来海湾扇贝养殖遇到了死亡率高等问题，深入开展海湾扇贝功能基因的研究，尤其是免疫相关基因及其机制研究并在此基础上寻找扇贝疾病防治的有效方法对海湾扇贝的健康养殖十分重要。 对于贝类免疫系统来说，其血细胞在先天性免疫防御中起着重要的作用。当受到外界病原侵染时，贝类血细胞的一个重要免疫反应就是吞噬作用。在吞噬病原过程中，受到病原侵染的贝类还会产生其他多种免疫反应，这些免疫反应将消耗大量的能量（ATP），产能的呼吸链会加速运转，由此也会引发与呼吸链相耦联的活性氧（ROS）的大量产生。这些活性氧具有极强的反应特性，能破坏病原微生物的结构和功能分子，实现对入侵病原的杀灭。利用活性氧对被吞噬的病原进行杀灭，这是吞噬作用消除病原抵御侵染的重要机制。但由于活性氧分子反应的非特异性，它们也会破坏宿主机体细胞内的功能蛋白分子、不饱和脂肪酸分子和核酸等，对细胞造成严重的伤害，进而导致机体生理机能的损伤和免疫系统的破坏。所以，及时消除病原感染机体内过量产生的ROS，维持相关细胞的正常代谢，对提高机体抵抗力和免疫力具有重要的作用。O2-是生物体内产生的第一种活性氧分子，其他的活性氧分子也是由它衍生而来，消除过量O2-是消除过量活性氧危害的第一步也是关键一步。生物体内，超氧化物歧化酶（SOD）是催化O2-发生歧化反应，消除O2-的关键酶。 首先，本文通过RACE方法获得了海湾扇贝SOD家族全部三种基因的cDNA全长并对其进行了序列的生物信息学分析，海湾扇贝AiCuZnSOD全长cDNA为1047个碱基，其中开放阅读框为459个碱基，编码152个氨基酸，与栉孔扇贝Chlamys farreri的CuZnSOD相似度为77.5%，与长牡蛎Crassostrea gigas的相似度为75%，与人的相似度为74.7%。AiMnSOD全长cDNA为1207个碱基，其中开放阅读框为678个碱基，编码226个氨基酸，序列比对结果发现AiMnSOD的氨基酸序列与虾夷扇贝Mizuhopecten yessoensis和皱纹盘鲍Haliotis discus hannai的相似度分别为85%和78.4%，与哺乳动物相似度也在68%~72%之间。AiECSOD全长cDNA为893个碱基，其中开放阅读框为657个碱基，编码218个氨基酸。AiECSOD与其它物种ECSOD相似度比较低。与线虫Brugia pahangi的相似度为27.9%，与疟蚊Anopheles gambiae的相似度为31.4%，与斑马鱼Danio rerio的相似度为27.8%，与人的相似度也只有28.6%，与同是贝类的长牡蛎ECSOD也只有28.1%的相似性。主要原因是AiECSOD的信号肽和肝磷脂结合区域在各物种中无同源性。 其次，采用qRT-PCR（quantitative real time PCR）方法分析三种SOD基因在不同组织中的表达情况，结果表明三种SOD基因的组织表达有所差异。AiCuZnSOD基因在鳃中表达水平最高，其次是血细胞和性腺，在外套膜、闭壳肌和肝胰脏表达水平较低。AiMnSOD基因在鳃中表达水平最高，其次是外套膜，在血细胞、性腺，而在肝胰脏和闭壳肌表达较弱。AiECSOD基因在血细胞中表达水平最高，其次是肝胰脏，在鳃、闭壳肌表达水平较低，而性腺和外套膜没有检测到。同时，采用qRT-PCR对鳗弧菌Vibrio angullarum感染后海湾扇贝血细胞中三种SOD基因mRNA表达变化进行了检测。AiCuZnSOD表达量在各个时间段没有显著差异(P > 0.05)。AiMnSOD的表达量在1.5 h时略有下降，在3 h时达到最高表达量，是空白组（0h）的3倍(P < 0.01)，从6 h到24 h表达量逐渐下降，24 h时表达量是空白组的1.6倍，24 h到48 h又稍有升高。AiECSOD的表达量在1.5 h时有所下降，是空白组的0.3倍（P < 0.05)，随后逐渐升高，在12 h时达到最高表达量，是空白组（0h）的4.5倍（P < 0.01），从24 h到48 h表达量逐渐下降并恢复到空白组的水平。在对照组，各个时间点没有显著差异（P > 0.05）。在鳗弧菌感染后，海湾扇贝三种SOD的表达并不一致，且差异比较显著。AiCuZnSOD被认为是构成性表达基因，其受外界刺激的影响最小，AiMnSOD和AiECSOD受刺激后表达上调比较明显。 第三，采用Genome-walking的方法得到了海湾扇贝三种SOD基因的基因组全长和近端启动子序列并对其进行了相关分析。AiCuZnSOD的基因组序列全长为4279bp，包含有4个外显子和3个内含子。AiMnSOD的基因组序列全长为10692bp，包含有4个外显子和3个内含子。AiECSOD的基因组序列全长为5276bp，包含有5个外显子和4个内含子。三种基因外显子和内含子的结合处序列遵循-AT/GT-原则。我们把海湾扇贝SOD家族的三个基因的近端启动子进行了比较分析。发现三种SOD在靠近起始密码子的位置都有Oct-1结合位点。三种SOD共有的转录位点有：Oct-1、C/EBPalp、Oct2.1、Sp-1和GATA-1。AiCuZnSOD和AiMnSOD共有的转录位点有：ICSBP、Ftz、TATA-box、C/EBPbeta和Antp。AiCuZnSOD和AiECSOD共有的转录位点有：AP-1和NFκB。AiMnSOD和AiECSOD共有的转录位点有：GR和ER。AiCuZnSOD独有的位点有：SRF、YY-1和NF-1。AiMnSOD独有的位点有：HNF-1、Hb、MEB、NF-muE1、Pit-1a和Eve。AiECSOD独有的位点有：CREB、RATA-alph、Kruppel-like和AP-3。 此外，通过构建原核表达载体，本研究对AiCuZnSOD和AiECSOD基因进行了体外重组表达，并对纯化的重组蛋白进行了酶活分析。酶活分析表明，重组AiCuZnSOD蛋白有较高的酶活和稳定性。 最后，我们对海湾扇贝三种SOD基因的部分区域，包括启动子、编码区，部分内含子区域进行了SNP检测，并对SOD基因部分SNP位点多态性和鳗弧菌敏感性进行了相关分析。三种SOD基因中，我们共发现了59个SNP位点，其中AiECSOD的SNP位点最多，特别是在启动子区，AiCuZnSOD和AiMnSOD多态性较低。其中AiCuZnSOD启动子区的-1739 T-C 位点的基因型和等位基因，AiECSOD启动子区的-498 A-T和-267 G-A等位基因频率，AiECSOD的第一个外显子38 Thr-Lys的多态性在敏感和抗菌群体中存在显著差异（P < 0.05）。

Cloning, characterization, and expression analysis of extracellular copper/zinc superoxide dismutase gene from bay scallop Argopecten irradians

Extracellular superoxide dismutase (ECSOD) is a major extracellular antioxidant enzyme that protects organs from damage by reactive oxygen species (ROS). We cloned a novel ECSOD from the bay scallop Argopecten irradians (AiECSOD) by 3' and 5' RACE. The full-length cDNA of AiECSOD was 893 bp with a 657 bp open reading frame encoding 218 amino acids. The deduced amino acid sequence contained a putative signal peptide of 20 amino acids, and sequence comparison showed that AiECSOD had low degree of homology to ECSODs of other organisms. The genomic length of the AiECSOD gene was about 5276 bp containing five exons and six introns. The promoter region contained many putative transcription factor binding sites such as c-Myb, Oct-1, Sp1, Kruppel-like, c-ETS, NF kappa B, GATA-1, AP-1, and Ubx binding sites. Furthermore, tissue-specific expressions of AiECSOD and temporal expressions of AiECSOD in haemocytes of bay scallops challenged with bacteria Vibrio anguillarum were quantified using qRT-PCR. High levels of expression were detected in haemocytes, but not in gonad and mantle. The expression of AiECSOD reached the highest level at 12 h post-injection with V. anguillarum and then returned to normal between 24 h and 48 h post-injection. These results indicated that AiECSOD was an inducible protein and that it may play an important role in the immune responses against V anguillarum. Crown Copyright (C) 2008 Published by Elsevier Ltd. All rights reserved.