trans-Dominant Inhibition of Geminiviral DNA Replication by Bean Golden Mosaic Geminivirus rep Gene Mutants

ABSTRACT Geminiviruses are a group of single-stranded DNA viruses that cause major losses on a number of important crops throughout the world. Bean golden mosaic virus (BGMV) is a typical bipartite, whitefly-transmitted geminivirus that causes a severe disease on beans (Phaseolus vulgaris) in the Western Hemisphere. The lack of natural resistance to geminiviruses has led to attempts to engineer resistance, particularly through the use of pathogen-derived resistance strategies. The rep gene contains several conserved domains including nucleoside triphosphate (NTP)-binding and DNA-nicking domains and is the only geminiviral gene necessary for replication. Previous analysis by our group and others has demonstrated that the NTP-binding and DNA-nicking domains are necessary for geminiviral DNA replication. The ability of the rep gene and rep gene mutants to interfere with geminiviral DNA replication, when expressed in trans, was examined using a transient assay in a tobacco suspension cell culture system. Wild-type (wt) and mutant rep genes were cloned into plasmids under the control of the cauliflower mosaic virus 35S promoter for in planta expression and coinoculated into tobacco cells with infectious clones of various geminiviruses. The wt rep gene from BGMV-GA was able to support replication of BGMV-GA DNA-B. Several different rep gene mutants, with function-abolishing mutations in the NTP-binding or DNA-nicking domains, were potent trans-dominant inhibitors of geminiviral DNA replication.     

充满希望的目标工程——我省科技兴牧“双百”活动展望

为了贯落实党的十三届八中全会精神,加快农民致富奔小康的步伐,省委、省政府决定把1992年作为农村经济工作的“科技效益年”,以科技为动力,全面提高农业综合经济效益。省畜牧局决定在全省开展科技兴牧     

胜利乡发展养猪稳粮致富

胜利乡发展养猪稳粮致富李凯年（吉林省畜牧局长春１３００５１）胜利乡位于全国商品粮基地县吉林省梨树县境＊内，属于典型东北平原粮食产区。全乡１２个村１００个＊社，５０００户２３０００人，耕地７４５５公顷，粮食产量５０００＊万千克左右，其中９０％为玉米，是...     

西马特罗和鱼粉对羔羊性能、胴体特性和骨骼肌生长的影响

西马特罗(Cimaterol)是一种β-兴奋剂,化学名称为[CL263,780;(anthranilonitri-le,5—[1—hydroxy—2—(isopropylamino)ethyl]—)]。据报道可以改善肥育猪的胴体性状和成分,但对肥育羔羊的影响尚未见报道。另有报道,用2～8%鱼粉代替日粮中的大豆饼粉,可使羔羊的饲料转化率显著提高。为此,作者进行了两项试验,以确定短期与长期给羔羊饲喂西马特罗对其生长性能、胴体特性和骨骼肌生长的影响,以及西马特罗和用鱼粉代替日粮中部分大豆饼粉对     

种鸡感染螺旋体影响后裔质量

种鸡感染螺旋体影响后裔质量对禽肠道螺旋体病（ＡＩＳ）可以损害肠对类胡罗卜素和脂肪的吸收，降低产蛋量并伴有蛋黄色素沉着减少，已有过介绍。但是，本病是否影响感染ＡＩＳ父母代鸡群所产种蛋质量，尚不清楚。为了搞清这个问题，荷兰乌得勒支省立大学禽病系的Ｒ．Ｍ．...     

应用前列腺素F_(2α)治疗泌乳母牛的不发情

引言准确的发情检查是采用人工授精计划牛群中奶牛繁殖工作的主要决定性因素。最近的研究表明,至少40％的发情期未检出。未检出发情期的大多数母牛(90％)是发情周期正常的母牛。直肠检查揭示,报告处于乏情期的母牛有60～65％出现黄体。间隔2—4周用直肠触诊见到的黄体部位的变化是用其他试验检查母牛正常发情周期的一个指标。很少见有同一黄     

对猪伪狂犬病亚单位疫苗的评价

伪狂犬病是由侵袭大多数温血动物的疱疹病毒所致。在猪,该病毒侵袭呼吸道和生殖、神经系统。幼猪、乳猪的发病率和死亡率几达100％。超过6周令的猪发病率有所不同,虽依毒株而定,但死亡率一般不高。猪为该病毒的自然宿主和贮主。而其他种动物被侵袭时,则一般称为“死亡终端”(“dead end”)宿主。在该病的短期病程中,患猪易发生严重的急性致死性脑炎和排少量或不排病毒的局部剧烈搔痒。在该病存活的猪易发生潜伏感染,并可随着条     

Effects of phenobarbitone on serum biochemical tests in dogs

OBJECTIVES: To investigate effects of phenobarbitone on serum activities of alanine aminotransferase, alkaline phosphatase and gamma-glutamyl transferase and concentrations of bilirubin, albumin, cholesterol and total protein in dogs. ANIMALS: Ten crossbreed experimental dogs and 10 client-owned dogs of mixed breeds treated chronically with phenobarbitone to control seizures. PROCEDURES: Experimental dogs were allocated to treatment (6 mg/kg oral phenobarbitone, n = 6) and control (no treatment, n = 4) groups in which serum biochemical tests were performed at intervals during a 3-month period. Biochemical tests were performed once on the 10 epileptic dogs. RESULTS: Phenobarbitone caused increased serum alkaline phosphatase activity but did not affect gamma-glutamyl transferase activity or bilirubin, cholesterol, albumin and total protein concentrations. Phenobarbitone had minimal effect on alanine aminotransferase activity. CONCLUSIONS: Individual dogs treated with phenobarbitone may have small increases in serum alanine aminotransferase activity and variable increases in alkaline phosphatase activity but are unlikely to have alterations in gamma-glutamyl transferase activity or bilirubin, cholesterol, albumin or total protein concentrations.     

Medical treatment of cholangiohepatitis and cholelithiasis in mature horses: 9 cases (1991-1998)

The medical approach to treatment of cholangiohepatitis and cholelithiasis in 9 horses is described. Seven horses were treated successfully and returned to normal use, with a minimum follow-up period of 12 months. Long-term antimicrobial therapy was believed to be critical in those cases that survived, with a median treatment duration of 51 days (range 17-124 days). Treatment failure was associated with severe periportal and bridging hepatic fibrosis from biopsy material obtained at admission in 2 horses, one of whom also presented with hyperammonaemic hepatic encephalopathy. Transabdominal ultrasound was used diagnostically in each case to obtain hepatic biopsy material for histopathology and bacterial culture, to evaluate hepatic size and echogenicity and to identify and monitor the dissolution of hepatoliths. Histologically, all horses had evidence of suppurative cholangiohepatitis with varying degrees of periportal and bridging fibrosis. Discrete hyperechoic calculi were identified in 4 cases, but all horses had ultrasonographic evidence of biliary obstruction with numerous dilated bile ducts. Aerobic and anaerobic cultures of liver biopsy material were negative from 7 horses, but 2 different species of Escherichia coli were obtained from one horse, and Bacteroides vulgatus and Escherichia coli were isolated from another. In all 7 horses that survived, clinical recovery was seen before normalisation of biochemical indices of hepatobiliary function including gammaglutamyl transaminopeptidase (GGT), alkaline phosphatase (AP), bile acids and serum bilirubin. Serum GGT levels were monitored extensively as a marker of hepatobiliary disease and actually increased during the initial period of clinical improvement in horses that recovered. Supportive medical therapy with i.v. fluids was also a critical part of the therapy of several cases in this report, both acutely and in the management of chronic cases that deteriorated clinically during treatment. Previous therapeutic failures may well be related to treatment periods of inadequate duration, and the authors recommend that antimicrobial therapy should be continued until GGT values are normal.     

我国现代畜牧业发展必须跨越5大障碍

2007年1月29日,中共中央的"一号文件"发出了"积极发展现代农业,扎实推进社会主义新农村建设"的动员令.发展现代畜牧业是我国畜牧业发展的必然趋势,也是发展现代农业和建设社会主义新农村的重要内容与客观要求.从我国的实际情况看,从传统畜牧业向现代畜牧业转变必须跨越5大障碍.