猪圆环病毒2型分离株的基因组克隆、序列测定与分析

设计合成两对覆盖PCV2基因组奎长的引物，对PCV2分离株S2、P11、L进行全基因测序。将所测序列与GenBank上已公布的PCV2毒株序列进行同泺性比较，并绘制系统发育进化树。结果显示。所测毒株与其它地城的24株PCV2分离株的基因组序列同源性很高。3个分离株之问的奎基因核苷酸同源性在95.4％-99.3％。序列分析表明欧洲分离株和美洲分离株分别构成PCV2的两个夫的分支：欧洲系和美洲系。S2、P11属于欧洲系，L属于美洲系。     

猪圆环病毒2型疫苗的研究进展

猪圆环病毒2型(PCV-2)是引起断奶仔猪多系统衰竭综合征(PMWS)的主要病原,给全球养猪业造成了巨大经济损失。PCV-2感染可破坏动物机体的免疫系统,造成严重的免疫抑制,容易诱发多种细菌及病毒的混合感染与继发感染,给疾病的诊断和治疗带来巨大的困难。疫苗免疫接种是防控PCV-2感染的有效手段,近年来,全球市场上已先后推出PCV-2灭活疫苗、亚单位疫苗和嵌合疫苗,实验室也致力于研究新型活载体疫苗、核酸疫苗、标记疫苗和小RNA分子疫苗等,文章就PCV-2疫苗的研究进展进行综述,为有效防控猪圆环病毒病提供参考。     

猪圆环病毒的研究进展

<正>猪圆环病毒(Porcine circovirus,PCV)是迄今为止发现的最小的一种脊椎动物病毒。可根据PCV致病性、抗原性及核苷酸序列的差异,将PCV划分成了无致病性(或PK-15源性)的猪圆环病毒1型(PCV1)和有致病性     

猪圆环病毒的致病机理

猪圆环病毒（PCV2）是近年来发现的一种新病毒。该病毒主要侵害哺乳仔猪和育肥猪。主要引起猪断奶后多系统衰竭综合症（PMWS）、猪皮炎肾炎综合症（PDNS）、增生性坏死性肺炎（PNP）、猪呼吸道病综合症（PRDC）、繁殖障碍、先天性颤抖、肠炎等疾病。严重影响猪生长发育。且致死率较高，此病可引起典型的临床症状和病理变化。其典型的临床症状为患猪体质不良、皮肤苍白或有黄疸、消瘦、死亡等，病理特征主要为全身器官的炎性变化。该病自1991年开始报道以来．已成为严重影响养猪业发展的传染病之一，引起了世界许多国家兽医工作者的高度重视。     

上海地区猪2型圆环病毒病的流行病学调查和病毒基因型分析

为了解上海地区猪2型圆环病毒病的流行现状,于2010~2014年间开展了流行病学调查和分离毒株的基因型分析,结果表明发病场户构成比例中,规模猪场占62.1%,专业养猪户占37.9%;PCV2引发的临床病症中,PMWS比例最高,占58.6%;PDNS次之,占24.1%,其它病症占17.2%;经对不同季节发病情况的统计,冬季发病比例最高,达44.8%,夏季次之,占27.6%,春季和秋季则分别占17.2%和10.4%。经对29个PCV2感染病例的病原学检测结果分析,平均混合感染率达到53.1%。经对病原学阳性样本的基因型分析,以PCV-2b感染为主,所占比例为93.1%;其次为PCV-2a,占6.9%。     

猪圆环病毒2型PCR检测方法的建立

根据猪圆环病毒2型(PCV2)的基因序列,设计一对能特异性扩增PCV2ORF2基因的引物,通过对PCR方法的优化,建立了快速的PCR检测方法用于病料中PCV2感染的检测。用本方法对猪瘟病毒(HCV)、猪繁殖与呼吸综合征病毒(PRRSV)、猪伪狂犬病毒(PRV)进行了扩增,均未有条带出现,表明该方法具有良好的特异性;敏感性试验表明,该方法能够检测到的最低DNA模板浓度为1.0×10-5ng/μL;重复性试验表明,该方法具有良好的稳定性。     

猪圆环病毒的致病机理

猪圆环病毒(PCV2)是近年来发现的一种新病毒。该病毒主要侵害哺乳仔猪和育肥猪。主要引起猪断奶后多系统衰竭综合症(PMWS)、猪皮炎肾炎综合症(PDNS)、增生性坏死性肺炎(PNP)、猪呼吸道病综合症(PRDC)、繁殖障碍、先天性颤抖、肠炎等疾病。严重影响猪生长发育,且致死率较高,此病可引起典型的临床症状和病理变化。其典型的临床症状为患猪体质不良、皮肤苍白或有黄疸、消瘦、死亡等,病理特征主要为全身器官的炎性变化。该病自1991年开始报道以来,已成为严重影响养猪业发展的传染病之一,引起了世界许多国家兽医工作者的高度重视。     

猪圆环病毒2型疫苗的应用与研究现状

猪圆环病毒病2型是主要侵害哺乳仔猪、育肥猪及怀孕母猪的免疫抑制性疾病。该病毒可诱发多种病毒、细菌的混合感染和继发感染,给养猪业造成巨大的经济损失,对此病的研究特别是对其疫苗的研究正日益受到关注。到目前为止,部分疫苗已在临床试验中取得成功,有的已投入应用,其他候选疫苗也正在积极研究中。文章就近年来国内外各类猪圆环病毒疫苗2型的的应用与研究现状作一综述。     

猪圆环病毒2型及其混合感染

猪圆环病毒2型是圆环病毒科圆环病毒属成员,通过与多种病原混合感染的方式协同致病,主要参与断奶仔猪多系统衰竭综合征、呼吸道疾病综合征、母猪繁殖障碍综合征、猪皮炎与肾病综合征等的致病过程,给养猪生产带来巨大损失。文章对猪圆环病毒2型参与引起的主要疾病及其与不同病原混合感染时的临床症状和病理变化进行了综述。     

猪圆环病毒病的防治

猪圆环病毒病在我国猪场广泛存在,主要发生在哺乳期和保育期的仔猪,一般于断奶后2~3 d开始发病,急性发病猪群中,病死率超过20%。严重的高达60%以上。将成为在今后很长一段时间内困扰我国养猪业的主要问题之一。     

一起猪圆环病毒病并发猪瘟诊断分析

某市某猪场发生了一起以断奶后保育猪突然发病,发热,皮肤发红,贫血,下痢,衰竭为主要症状,发病率和死亡率很高的急性传染病,经流行病学调查、临床症状、剖检变化、实验室检查等综合诊断,确诊为猪圆环病毒病并发猪瘟混合感染,通过采取合理用药和防制措施,病情得到较好的控制。     

猪繁殖与呼吸综合征病毒实验室诊断技术的研究

猪繁殖与呼吸综合征病毒(porcine reproductive and respiratorysyndrome virus,PRRSV)是一种严重危害种公猪和繁殖母猪及其仔猪的一种接触性传染病,是我国重要猪病病原体之一。为了预防和控制该病,建立有效实用的诊断技术是一个重要环节,文章就其免疫学诊断和分子生物学诊断的进展情况做一综述。     

猪繁殖与呼吸综合征病毒的分子生物学

猪繁殖与呼吸综合征是由猪繁殖与呼吸综合征病毒引起的猪的一种传染病,目前在世界各地均有发生和流行,是危害养猪业最为严重的疾病之一。PRRSV也是造成2006年以来我国猪高热病的主要病原。本文对猪繁殖与呼吸综合征病毒的病毒形态和理化特性、基因组结构、病毒蛋白及功能,基因组的变异,分子生物学诊断等五个方面的研究进展作了综述。     

海蜇(Rhopilema esculentum)磷脂酶A2基因的cDNA、基因组克隆与表达分析

本研究利用RACE和RT-PCR技术克隆了海蜇(Rhopilema esculentum)磷脂酶A2基因(Re-PLA2-1)的cDNA及基因组序列,并分析了其mRNA在海蜇不同发育阶段的表达.Re-PLA2-1基因的cDNA全长为824 bp,包括了48 bp的5'非编码区、504 bp的开放阅读框及272 bp的3'非翻译区.SMART分析显示,Re-PLA2-1为分泌蛋白,包括了一个由19个氨基酸组成的信号肽和一个由118个氨基酸组成的磷脂酶A2结构域.多序列比对和系统进化分析显示,Re-PLA2-1基因与来自星状海葵(Nematostella vectensis)、僧袍芋螺(Conus magus)、长牡蛎(Crassostrea gigas)等磷脂酶A2的相似性较高,共同聚类为pfam09056 GIX PLA2分支,均包含pfam09056家族成员酶活性所必需的Ca2+结合位点、活性催化位点和PLA2结构域所必需形成二硫键的半胱氨酸.Re-PLA2-1基因组全长为2671 bp,由4个外显子和3个内含子组成.RT-PCR结果显示,Re-PLA2-1基因在海蜇4个发育阶段均有表达,其中,横裂体阶段的表达量最高,碟状体阶段最低.这些研究结果为进一步了解海蜇磷脂酶A2毒素的生物功能奠定了基础.     

The effects of elevated pCO2 on growth,shell production and metabolism of cultured juvenile abalone,Haliotis iris

Reduced seawater pH and elevated pCO₂ are important considerations in tank‐based abalone aquaculture, while sea‐based farms may be at risk to ocean acidification reductions in pH. Juvenile Haliotis iris (5–13 and 30–40 mm shell length) were reared in two, 100‐day experiments at ambient pH_nbs (~ 8.1, 450 μatm CO₂), pH 7.8 (~1000 μatm CO₂) and pH 7.6 (~1600 μatm CO₂). Seawater pH was measured and adjusted automatically by bubbling CO₂ into water in replicated flow through tanks. Two separate trials were run, in winter (8.8°C) and summer (16.5°C). Survival and growth were monitored every 30 days, and post experiment measurements of morphometrics and respiration rate undertaken. Growth of shell length and wet weight were negatively affected by reduced pH, with a 2 to 3‐fold reduction in growth of both size classes between ambient and pH 7.6 treatments in the summer experiment. For small juveniles, growth reductions were in conjunction with decreases to shell weight, while large juveniles showed greater resilience in shell production. No changes to respiration rate occurred, suggesting that juveniles may maintain physiological functioning while tolerating dissolution pressure or that they are unable to upregulate metabolism to compensate for pH effects. These data show that CO₂ driven reductions in pH can impact growth, metabolism and biomineralization of abalone, and indicate that water quality and ocean acidification are of importance in aquaculture of the species.     

Molecular characterization of transformer‐2 gene in the mud crab Scylla paramamosain and its putative role in sexual development

Transformer‐2 (Tra‐2) is an mRNA splicing factor that acts in concert with Tra to regulate the female sexual development in Drosophila melanogaster. In decapods, as no Tra homologues have been identified, the role of Tra‐2 in sexual development is more often discussed accordingly. In the present study, the full‐length cDNA of Tra‐2 of the mud crab Scylla paramamosain (SpTra‐2) was cloned and characterized. The deduced amino acid sequence of SpTra‐2 contained an RNA‐recognition motif (RRM) flanking by two RS‐rich regions, which are the hallmarks of the Tra‐2 proteins. The SpTra‐2 mRNA was highly abundant in the hepatopancreas, muscles and androgenic glands of the male crabs, implying a potential role in male sexual development. The hypothesis was supported by the RNAi experiments, finding that the injection of SpTra‐2 dsRNA in vivo led to a decreased expression of SpIAG, a key gene in crustacean male sexual differentiation. The relationship between SpTra‐2 and SpIAG was further affirmed by eyestalk ablation (ESA) experiments, which caused SpTra‐2 expression earlier than SpIAG expression in both androgenic glands and hepatopancreas. In addition, treatment with SpTra‐2 dsRNA also reduced the mRNA level of SpSxl, but had no effects on SpDmrt expression, suggesting the sex determination system in S. paramamosain is different from that in D. melanogaster.     

Molecular cloning and characterization of p38 gene in the Chinese Mitten Crab,Eriocheir sinensis

p38 is an important component of the MAPK signaling pathways as a Ser/Thr protein kinase. We cloned the full length p38 (Es‐p38) cDNA sequence in Eriocheir Sinensis which contained a 1098‐nucleotide ORF that encoded a protein of 365 amino acids. Es‐p38 protein has a p38 MAPK functional domain (STKc_p38), it is a typical serine/threonine kinase and processes all p38 protein's conservative T‐G‐Y motif. Tissue expression of the Es‐p38 gene and expression during testis development stages were determined by quantitative real‐time PCR analysis. The results show that Es‐p38 gene is expressed in various tissues, but it expresses higher in the muscle, hepatopancreas, intestine, ovary and testis. The expression level of Es‐p38 gene at different stages of testis development shows no significant difference between the spermatocyte phase (July–August) and spermatid stage (August–October), but it rises significantly in the mid‐late period of sperm stage (December–January). This changing trend has a positive relationship with the E. Sinensis gonad development and reproduction stage, which preliminarily shows that Es‐p38 may function in the E. Sinensis testis development and the process of spermatogenesis.     

Molecular cloning,characterization and expression analysis of glucose transporters from Rachycentron canadum

It is very necessary to clarify the mechanism of carbohydrate metabolism in fish due to their poor ability to utilize carbohydrates. Glucose transporters (GLUTs) are important carriers involved in glucose transport across the plasma membrane, which is the first rate‐limiting step of carbohydrate metabolism. In this study, five glucose transporters (RcGLUT1, RcGLUT2, RcGLUT3, RcGLUT5 and RcGLUT9) were obtained from Rachycentron canadum. The complete cDNAs open reading frames (ORF) of RcGLUT1, RcGLUT2, RcGLUT3, RcGLUT5 and RcGLUT9 were 1,476 bp, 1,530 bp, 1,551 bp, 1,539 bp and 1,578 bp (GenBank accession no. MK560257 , MK560258 , MH184460 , MH184461 and MH184462 ), encoding 491, 509, 516, 512 and 525 amino acid (aa) residues respectively. All five RcGLUTs contained a Sugar_tr domain, which is an important feature of the GLUT gene family. The multiple sequence alignment and phylogenetic relationship analyses showed that RcGLUTs were highly conserved and homologous from fish to mammals. Examination of tissue distribution showed that RcGLUTs were expressed constitutively in R. canadum. RcGLUT1‐5 and RcGLUT9 had the highest expression in the foregut, kidneys, haemocytes, muscles, liver and heart respectively. All six RcGLUTs first increased to peak levels of expression and then reduced both in the liver and muscle after fasting. The exception is that the expression levels of RcGLUT4 and RcGLUT5 in muscle were significantly lower than the control. In response to hypoxia, only RcGLUT2 in the liver and muscle and RcGLUT9 in muscle were expressed at a significantly lower level relative to the control. In sum, all RcGLUTs in the liver and muscles showed significant changes in response to fasting and hypoxia, suggesting that GLUT genes may play a role in the response to common physiological stresses.