RSV疫苗侯选株的安全与免疫原性

依据糖蛋白的不同,呼吸道合胞病毒(RSV)分A、B两个亚群,理想的疫苗应能同时抗A、B两个亚群。BBG2Na来源于RSV-A的G蛋白部分,是一个重组亚单位RSV疫苗侯选株。有趣的是,用明矾配制的BBG2Na在接种小鼠后初期能抗RSV-B的攻击。     

病毒虫传相关蛋白

昆虫传播的植物病毒种类多、危害大。病毒虫传包括获毒、携毒与传毒3个阶段,是病毒、昆虫、植物互作的复杂过程,其中涉及到多种蛋白质。本文对与昆虫传播病毒有关的蛋白质进行了综述,并分析了这些蛋白质研究的科学意义与发展趋势,为植物病毒病的防治研究提供了一些思路。     

杨树和冬小麦在短日照和寒冬中的胞间连丝动态(英文)

Electron microscopic observation revealed that poplar (Populus deltoides Marsh.) and winterwheat ( Triticum aestivum L. cv. Seward 80004) plasmodesmatal structures significantly changed undershort day (SD, 8 h light) and in winter period, and such changes differed also noticeably between these twowoody and herbaceous plants. Under long day (LD, 16 h light), many plasmodesmata with strong stainappeared in the cell wall of both poplar apical buds and winter wheat young leaf tissues, and connections ofcytoplasmic endoplasmic reticulum (ER) with the ER in some plasmodesmata were observed. In addition,the typical “neck type” plasmodesmata were observed in winter wheat young leaf tissues, and their centraldesmotubules (appressed-ER) could be clearly identified. Under SD, many poplar plasmodesmata showedonly a partial structure in the cell wall and appeared to be discontinued; some plasmodesmata swelled in themid-wall, forming the cavity, and no appressed-ER appeared, in winter wheat, however, no noticeablealterations of plasmodesmata occurred, and the plasmodesmatal structure essentially remained the sameas it was under LD. In winter period, poplar plasmodesmata had a similar morphology as those observedunder SD, however, winter wheat manifested at least two types of significant plasmodesmatal alterations:one plugged by electron-dense materials and the other of reduced neck region compared to those underLD. The above dynamic difference of the two species plasmodesmata under SD and winter period revealedthe difference of their dormancy development under those environmental conditions.     

LINGO-1:新发现的脑内神经再生抑制因子

在成年动物和人中枢神经系统 ,髓鞘内的神经再生抑制因子 (MAG、OMgp、Nogo等 )通过与神经元上的特异性受体复合体相互作用 ,启动对神经轴突再生的抑制 ;“Nogo 6 6受体”(Nogo 6 6receptor,即Nogoreceptor 1,NgR1)和“p75神经生长因子受体”是组成此受体复合体的两个关键亚单位 ;被Nogo等激活的受体复合体能活化“胞内骨架调节因子”———RhoA ,RhoA最终实现对轴突延长的抑制。美国学者最近发现 ,在转染后成功表达NgR1和p75的非神经细胞 (COS 7细胞 ) ,神经再生抑制因子OMgp不能激活NgR1和p75复合体、亦不能活化RhoA ,暗示神经…     

病毒诱导的PVX cp转基因沉默及其DNA甲基化

利用PCR方法获得了马铃薯X病毒(PVX)外壳蛋白(CP)基因(cp),并将其构建到植物表达载体中,利用农杆菌介导的叶盘法转化烟草(Nicotiana tabacum L.)。Northern杂交及Run on实验表明有3株转基因烟草发生了转录后基因沉默。发生沉默的cp基因的甲基化分析结果表明,发生转录后基因沉默的cp基因发生了不同程度的甲基化,说明DNA甲基化并没有完全抑制cp基因的转录。利用PVX病毒对外壳蛋白正常表达的转基因烟草进行接毒,Northern杂交检测结果表明,病毒诱导cp发生了基因沉默。进一步的Run on结果表明,转基因烟草中cp基因在沉默前后转录速率并没有发生变化,说明病毒诱导的沉默是一种转录后沉默。对cp基因沉默前后的甲基化分析表明,病毒的侵染导致了cp基因甲基化程度的增加。     

转新城疫病毒融合蛋白基因水稻植株的获得

以编码新城疫病毒融合蛋白(NDV—F)基因为外源基因,与玉米泛素蛋白(Ubi)启动子和农杆菌胭脂碱合成酶基因(NOS)终止子构建成嵌合基因,构建了适宜于农杆菌介导转化水稻的表达质粒pUNDV;并以潮霉素磷酸转移酶(HPT)基因作选择标记基因、β-半乳糖苷酸酶(GUS)基因作报告基因,借助于农杆菌介导转化水稻,获得了多株转基因植株。PCR分析和GUS活性检测结果证实含有NDV—F基冈的T—DNA已整合到水稻基因组中,为研制廉价的转基因水稻新城疫基因工程疫苗奠定了基础。