牛病毒性腹泻病毒P125基因重要区的比较与分析

根据牛病毒性腹泻病毒（ＢＶＤＶ）ＮＡＤＬ株的序列，以计算机辅助设计，化学合成１对引物（Ｗ１／Ｗ２）；应用ＲＴ－ＰＣＲ对国内不同地区分离的４株ＢＶＤＶ的Ｐ１２５基因外源序列插入区进行了扩增，并将扩增的片段进行克隆和序列测定，同时以ＤＮＡＳＩＳ和ＰＲＯＳＩＳ计算机软件将测定的核苷酸序列及推导的氨基酸序列进行比较分析。结果证实，国内分离的４株ＢＶＤＶ在这一区域中既没有外源序列的插入，也没有基因重组、基因重排或基因缺失，但存在某些核苷酸和氨基酸的替换，表明病毒的致细胞病变作用除与外源序列的插入、基因重组、基因重排或基因缺失有关外，可能还存在其他机制。核苷酸序列的同源性及系统树分析的结果表明，国内的ＢＶＤＶ毒株存在Ｉａ和Ｉｂ２个基因亚型，它们均属基因Ｉ型ＢＶＤＶ     

影响胚胎移植成功率的主要因素

本文针对在胚胎移植过程中可能预见的各种影响胚胎移植技术的实施的因素进行了较为全面的分析,并针对不同影响因素提出了自己独特的见解,以期在生产实践中对胚胎移植技术的应用和推广有所借鉴。     

早熟桃新品种‘美瑞’

‘美瑞’是从引自美国的桃品系‘美P3’的自然实生后代中选出的早熟新品种。花蔷薇形,花粉多。果实近圆形,平均单果质量203 g,大果297 g;果面深红色;果肉淡绿至黄白色,硬溶质,硬度高,风味甜,可溶性固形物含量12.1%。粘核。果实发育期89 d。产量较高,盛果期30 t ? hm-2以上。     

狂犬病病毒糖蛋白转基因小鼠的构建研究

将狂犬病病毒糖蛋白ｃＤＮＡ ＢｇｌⅡ（１．６７ｋｂ）片段正向插入ｐＭＴ０１０／Ａ＾＋ＢａｍＨⅠ切点，构建重组质粒ｐＭＴ０１０／Ａ＾＋－Ｒｇｐ，用ＥｃｏＲⅠ＋ＳａｌⅠ对ｐＭＴ０１０／Ａ＾＋－Ｒｇｐ进行双酶切后，回收含有狂犬病病毒糖蛋白ｃＤＮＡ和绵羊ＭＴ启动子的２．７６ｋｂ片段，通过显微注射技术将该片段注入小鼠单细胞受精卵雄前核内，在进行胚胎移植后，获得４４只小鼠，经ＰＣＲ、Ｓｏｕｔｈｅｒｎ杂交及原位     

洞庭湖湿地虉草替代大白菜对肉兔生产性能的影响

试验采用48只青年期(40～45日龄、体重约800 g)发育良好、健康无病的新西兰肉兔,随机分为4组:1组饲喂基础日粮,2～4组分别用占日粮5%,15%和25%的虉草Phalaris arundinacea代替日粮中等量的大白菜,试验期35 d.试验结果表明:各组间兔的日增重、屠宰率、料肉比等指标差异均不显著(P＞0.05),可见虉草代替大白菜不影响兔的生长,以15%的替代量的3组增重效果最佳,经济效益最好.     

Effect of follistatin on pre‐implantational development of pig parthenogenetic embryos

The present study was designed to explore effects of follistatin (FST) on pre‐implantational development of parthenogenetically activated embryos (PAEs) in pigs. First, we investigated the FST messenger RNA expression level and dynamic FST protein expression patterns in porcine oocytes and PAEs. Then, PAEs were placed in embryo culture medium supplemented with 10 ng/mL of FST‐288, FST‐300, and FST‐315. Next, PAEs were cultured with 0, 1, 10 and 100 ng/mL of FST‐315 protein throughout the in vitro culture (IVC) duration. Further, 10 ng/mL of FST‐300 was added from the start of IVC in which PAEs were treated for 30, 48 and 60 h. The results showed that 1 ng/mL FST‐315 could significantly increase the total cell numbers of blastocyst and trophectoderm cell number in PAEs. Exogenous FST‐300 supplementation could significantly promote the early cleavage divisions and improve the blastocyst formation rate of porcine embryos. FST‐300 appeared to affect early embryonic development before activation of the embryonic genome. In all, the study confirmed for the first time that FST plays a role in promoting early embryonic development in pigs, which differed with different FST subtypes. FST‐300 could facilitate the initial cleavage time and improve the blastocyst formation rate, and FST‐315 could improve the blastocyst quality.     

重组逆转录病毒载体的包装

将3.7kb的LacZ基因片段克隆到含标志基因Neo的逆转录病毒载体，pLXSN与pLNCX的多克隆位点，构建了含有LacZ基因的重组逆转录病毒载体pLLSN和pLNCL.在测定了G418对饥装细胞系PA317的最小致剂量后（最小致死剂量为0.3g/L），通过脂质体Lipofectin与磷酸钙2种介质，分别将2种重组逆转录病毒载体导入包装细胞系PA317进行包装，并以0.3g/L，的G418进行筛选，得到多个G418抗性克隆，经扩大培养，传代，分别得到包装pLLSN与pLNCL的2株阳性细胞，电镜下可见阳性细胞的培养上清中具有逆转录病毒形态特征的成熟病毒粒子，本0研究为运用逆转录病毒载体系统，解决转角因效率低的问题奠定了基础。     

早熟金针菇新品种G1的杂交选育

以金针菇菌株F3-31和FM-83为亲本,经过杂交选育出优良白色金针菇菌株G1.以菌丝生长速度、生长势、产量、子实体农艺性状及栽培周期等为指标,对金针菇菌株G1与其亲本进行比较.试验结果表明,G1菌丝生长速度快且生长势旺盛;平均单瓶产量达216 g,比亲本分别增产54 g、20 g,生物转化率也比亲本菌株高,达到72%;栽培周期43 d,比亲本分别缩短1 d、6 d;子实体各项农艺性状优良,是适于金针菇工厂化栽培的早熟白色优良菌株.     

Research Progress on Bacterial Resistance in Environment

Antibiotic resistance genes have become a recognized environmental pollutant, threatening the ecological safety and human health. The application of antibiotics in the clinical and animals breeding, making the environmental microorganisms living with the impact of the residue of antibiotics and elements of resistance genetic and leading to antibiotic resistant bacteria to gain a competitive advantage and destroyed the stability of ecosystem. In this paper, we expounded the concept of resistance gene transmission by the view of macro environment. Through analyzing the mechanism of resistance development,environmental pollution caused by drug resistance and the impact of environmental microorganism for drug resistance, we clarified the key role of the environment in the development of the characteristics of bacterial resistance and analysis environmental resistance.Such as the ecological diversity of flora, the types and the spread of resistant bacteria, the residues of antibiotics and the transmission of the resistance genes.     

东莞市动物防疫检疫信息化管理的探讨

跨入21世纪,人类已进入信息化时代。在动物防疫检疫工作中,引用信息化管理,是新形势下动物防疫管理工作的必然要求,对提高动物防疫管理水平,确保动物防疫各项措施落实,实时掌握动物防疫工作动态,保障监督工作到位,提高管理绩效,推动动物防疫管理工作规范化、程序化、制度化起到重要作用。鉴于目前动物防疫管理工作中引用信息化程度不高,尚处于起步探索阶段,因此,东莞市兽医防疫检疫站从2004年起,对在动物防疫管理工作中引入信息化管理进行专题研究,研究开发了“动物防疫检疫管理系统”,成功应用于我市动物防疫管理工作中并发挥了重要作用。…