猪圆环病毒II型结构蛋白的二级结构及其B细胞抗原表位预测

本研究以猪圆环病毒(porcine circovirus,PCV)II型的基因组序列为材料,采用Garnier-Robson方法、Chou-Farplus方法和Karplus-Schulz方法预测了其结构蛋白的二级结构,用Kyte-Doolittle方法对结构蛋白的亲水性进行了分析,用Emini方法预测了结构蛋白的表面可能性,以Jameson-Wolf方法预测了蛋白的抗原指数。然后综合评价了PCV-2型结构蛋白的B细胞抗原表位。结果表明,PCV-2结构蛋白形成α螺旋结构的能力较差,但是该蛋白含有较多的β折叠和转角结构,因而该蛋白具有丰富的二级结构。分析结果还表明结构蛋白具有多处抗原指数较高的区段,其中羧基端含有潜在的B细胞优势抗原表位,因此其在免疫学中的地位也应当引起重视。本研究将为猪圆环病毒的反向疫苗学的研究提供一定的理论依据。     

动物基因打靶技术的原理与应用

基因打靶是利用同源重组的原理 ,定点修饰目的基因组上特定位点的基因 ,定向地改变生物遗传特性的方法 ,作为新兴的遗传工具 ,它有着广泛的应用前景。     

甘肃高山细毛羊妊娠母羊营养需要量估测

借助其他品种绵羊营养需要的一些研究方法,结合甘肃高山细毛羊四季牧草干物质采食量、营养物质摄入量、采食牧草营养成分、牧草营养物质消化率以及生产相关数据,采用析因法估测甘肃高山细毛羊能量和蛋白质需要量:成年母羊维持代谢能需要量为6.58 MJ/d(每kg代谢体重维持代谢能需要为0.417 MJ/W^0.75),维持蛋白质需要量107.62 g/d;妊娠前期代谢能需要量为12.54 MJ/d,粗蛋白质需要量125.19 g/d;妊娠后期代谢能需要量为12.86 MJ/d,粗蛋白质需要量为146 g/d;通过对比研究表明,甘肃高山细毛羊成年母羊钙需要量约为8.22~9.61 g/d,磷需要量为4.98~5.87 g/d,食盐需要量为9~16 g/d。     

营养水平对仔猪断奶综合征的影响

试验选取杜×长×大三元杂交仔猪,随机分为2个处理组,每个处理3个重复,每个重复10头仔猪.试验组饲喂5008配合日粮.对照组饲喂5000配合日粮.针对仔猪断奶综合征的表现特征,分别测定各组猪生长性能和腹泻率等指标.试验结果表明,饲粮中合有高水平的蛋白质及能量对断奶仔猪有促生长作用,可缓解仔猪断奶综合征的发生.     

日粮营养代谢与基因表达的研究进展

动物日粮营养代谢能够影响基因的表达,研究表明:通过改变日粮的营养水平可以调节动物体内相关基因的表达,从而使动物处于最佳的生长状态。本文就碳水化合物、脂肪和脂肪酸、蛋白质等营养素对基因表达的调控进行了综述。     

The role of green roofs in mitigating Urban Heat Island effects in the metropolitan area of Adelaide,South Australia

Changing an urban environment and replacing vegetated surfaces with low albedo materials is one of the reasons for increasing temperatures in an urban environment and consequently also one of the key causes of urban heat island effects. In this study, an experimental investigation at the micro-scale and also a numerical simulation at the macro-scale of a typical urban environment in Adelaide were conducted to estimate the potential for mitigating the UHI effect. The results showed that existing low albedo materials such as asphalt, metal roofs and brick pavements contribute to the heat island potential. Also, urban development and a lack of natural vegetation contribute to increased temperatures in cities. The ability of two types of extensive and intensive green roofs to reduce the surrounding micro-climate temperature were monitored. The results showed that they have significant cooling effects in summer time and could behave as an insulation layer to keep buildings warmer in the winter. Furthermore, different scenarios of adding green roofs to the Adelaide urban environment were investigated using the Envi–MET model. The scenario modelling of adding green roofs in a typical urban area in Adelaide, Australia, supported the hypothesis that this can lead to reductions in energy consumption in the Adelaide urban environment. Also an increased use of other water sensitive urban design technologies such as green walls and street trees together with the adoption of high albedo materials is recommended for achieving the optimum efficiency in terms of reducing urban temperatures and mitigating urban heat island effects.     

凡纳滨对虾E75基因可变剪切形式的鉴定与分析

E75是对虾蜕皮激素信号通路的关键调控因子。为了深入了解E75基因的结构和功能,本实验从转录组数据中筛选得到注释为凡纳滨对虾E75基因的转录本,经与基因组序列比对分析,鉴定发现凡纳滨对虾E75基因至少存在6种可变剪接体,分别命名为LvE75-1、LvE75-2、LvE75-3、LvE75-4、LvE75-5和LvE75-6。其中LvE75-1/2/4/5/6均包含DBD和LBD结构域,与果蝇E75A/C有相同的结构域,而LvE75-3仅包含LBD结构域,与果蝇E75D相同。在凡纳滨对虾蜕皮过程中,LvE75-1/2/3/4在D3～D4时期高表达,而LvE75-5和LvE75-6表达量很低。在成体组织中,LvE75各种剪切形式在所有检测的组织中均有表达,且在表皮、肠和鳃中表达较高,在肝胰脏、血细胞和淋巴组织中仅LvE75-3表达较高。实验通过双链RNA干扰LvE75基因的表达,在干扰样品中,检测到Halloween基因中的spo、phm和dib表达下调,shd表达上调,表明LvE75可能通过调控Halloween基因的表达来影响蜕皮激素的合成;同时E75基因的干扰也使同为蜕皮激素早期应答基因的Br-C基因和Ftz-F1基因表达下调,HR3基因表达上调,表明LvE75基因对蜕皮信号通路上下游基因均有作用。在LvE75基因持续干扰12 d后,凡纳滨对虾的蜕皮率显著低于对照组,而死亡率显著高于对照组,说明LvE75基因对凡纳滨对虾的蜕皮和生存具有重要作用。     

Binding characteristics of the Zn-binding membrane protein from common carp

ABSTRACT:    This study incorporated the 43 kDa Zn-binding membrane protein isolated from common carp into liposome. The specificity and strength of the binding of ⁶⁵Zn to the 43 kDa protein-liposomes, and the binding of the ⁶⁵Zn-labeled 43 kDa protein-liposomes to laminin were studied. It was found that ⁶⁵Zn was bound to the external side of the 43 kDa protein-liposomes. Specific binding of ⁶⁵Zn to the protein-liposomes was detected. The binding parameter of Zn to the protein was found to be: maximum binding site (N_max), 76.7 pmole/µg protein (approx. 3 mole of Zn²⁺/mole); and equilibrium dissociation constant (Kd), 0.19 µM. Of the cations introduced (Ca²⁺, Cd²⁺,Co²⁺, Cr²⁺, Cu²⁺, Fe²⁺, Hg²⁺, Mg²⁺, Mn²⁺, Ni²⁺, Pb²⁺), only Co²⁺ competed significantly with Zn. The protein-liposomes were also found to bind specifically to laminin with a N_max of 1.1 pmole/µg laminin, and Kd of 4.79 µM. No significant protein-liposome binding occurred to other extracellular matrix proteins (fibronectin, fibrinogen or vitronectin). Furthermore, the binding was specifically inhibited by the Arg-Gly-Asp (RGD) peptide or GRGDSPG, while two other analogs (GRGESPG and GRADSPG) were without effect.     

布鲁菌感染小鼠RAW264．7细胞对IRGl基因的表达调控作用

针对小鼠RAW264．7细胞IRGl基N设计4个RNA干扰靶位,筛选出最佳干扰序列构建shRNA慢病毒载体质粒并包装获得慢病毒颗粒,进而经嘌呤霉素筛选获得稳转细胞系,实现IRGl基因在RAW264．7细胞基因表达的沉默。并通过布鲁菌l6M株及M5株感染基因沉默细胞对IRGl基因在布鲁菌感染中的作用进行研究。结果表明,慢病毒介导的shRNA高效、稳定地沉默了IRGl基因的表达,布鲁菌侵染RAW264．7细胞后IRGl基因表达上调。未试验为1RG1基因及相美调控基因抗布鲁菌病作用研究奠定了基础。     

补铁剂及多肽铁复合物的研究进展

缺铁性贫血作为贫血中最常见的一种,越来越受到人们的关注。随着营养与健康需求的变化和安全意识的 增强,人们致力于补铁效果好、吸收好、副作用小、安全性更高的口服补铁剂的研发。本文对补铁剂的发展和相关 研究进行综述,概述新型补铁剂的研究进展,全面阐述多肽铁复合物蛋白琥珀酸铁的原料来源、结构、机理、制 备、应用、消化吸收机制,对多肽铁复合物和蛋白琥珀酸铁的发展前景进行展望,以期对补铁剂的研究与发展提供 理论依据。