Lentivirus-mediated calcitonin gene-related peptide transfection enhances endothelial differentiation of rat bone marrow mesenchymal stem cells

AIM：To study the effect of calcitonin gene-related peptide (CGRP) gene transfection mediated by lentivirus on the differentiation of rat bone marrow mesenchymal stem cells (MSCs) to endothelial cells. METHODS：Rat bone marrow MSCs were isolated by density gradient centrifugation combined with adherence method. Recombinant lentivirus vector carrying CGRP gene (Lenti-CGRP) was transfected into the MSCs. The secretion of CGRP in culture supernatants of the transfected MSCs was detected using ELISA method. The cells at passage 3 were divided into three groups: CGRP group (MSCs transfected with Lenti-CGRP), CGRP+CGRP8-37 (an antagonist of CGRP receptor) group and control group (MSCs transfected with PBS). The differentiation of the MSCs was detected by immunocytochemical staining for CD31 and factor Ⅷ-related antigen. The proliferation of the cells was measured by cell counting, and the angiogenic ability of the cells was analyzed using Matrigel assay. RESULTS：The proportion of CD31-and factor Ⅷ-related antigen-positive cells in CGRP and CGRP+CGRP8-37 groups was larger than that in control group (P<0.05). The numbers of the cells in CGRP and CGRP+CGRP8-37 groups were significantly increased compared with control group (P<0.05). Lumen-like structures were observed in CGRP and CGRP+CGRP8-37 groups. The above indexes in CGRP+CGRP8-37 group were reduced compared with CGRP group. CONCLUSION: Transfection with CGRP gene induces rat bone marrow MSCs to differentiate into endothelial cells and enhances their proliferation, suggesting that CGRP may play a role in the regulation of angiogenesis.     

Effects of temperature and humidity on the contact angle of pesticide droplets on rice leaf surfaces

The effects of external factors such as temperature, humidity, pesticide formulation, and pesticide concentration on the contact angle of pesticide droplets on rice leaf surfaces were analyzed. The experiments showed that there were significant differences in the contact angles of droplets on the leaf surfaces under different temperatures and humidity. As the ambient temperature increased, the contact angle first decreased and then increased, reaching a minimum value at 25°C. With a gradual increase in humidity, the contact angle significantly increased and reached a maximum at 100% humidity. Finally, it was concluded that both the formulation and concentration of the pesticide had a significant effect on the contact angle of droplets on rice leaf surfaces. The experiments also illustrated that the effects of the pesticide formulation and concentration on the contact angle were more significant than those of temperature and humidity.     

云南省德宏州发现3种草地贪夜蛾幼虫寄生蜂

重大迁飞性害虫草地贪夜蛾Spodoptera frugiperda(J.E.Smith)自2019年1月入侵我国以来,已对我国粮食安全构成重大威胁。为加速对我国草地贪夜蛾寄生性天敌资源的发掘与防治潜能的评估,我们于2019年9月-11月对云南省德宏州玉米和小麦上草地贪夜蛾的寄生性天敌开展田间调查并对采集到的天敌进行分子鉴定。共发现3种草地贪夜蛾幼虫寄生蜂,分别为斯氏侧沟茧蜂Microplitis similis Lyle、半闭弯尾姬蜂Diadegma semiclausum Hellen和斜纹夜蛾长距姬小蜂Euplectrus laphygmae Ferrière,田间最高自然寄生率分别为12.00%、22.30%和5.33%。另外,田间调查发现在玉米和大豆上斯氏侧沟茧蜂还可寄生与草地贪夜蛾同属的斜纹夜蛾S.litura幼虫;在大豆和杂草上斜纹夜蛾长距姬小蜂可寄生甜菜夜蛾S.exigua幼虫。本研究将为今后开展草地贪夜蛾天敌昆虫的保护和利用提供重要参考。     

成年黄山短尾猴春季昼间行为时间分配

2007年3～5月,采用焦点动物取样法对黄山野生猴谷YA1群黄山短尾猴成年个体行为时间分配进行系统观察.数据分析显示:黄山短尾猴成年个体日活动行为主要为休息(59.72%)、理毛(17.50%)和觅食(14.82%),其他行为如漫游(5.86%)、玩耍(0.04%)和其他(1.64%)时间花费较少,觅食高峰与投喂时间基本一致.老年组个体比成年组个体花费较多的时间用于休息(Z=-5.811,P＜0.01)和理毛(Z=-4.913,P＜0.01),较少时间漫游(Z=-3.989,P＜0.01).雄性个体花费较多时间休息(Z=-3.577,P＜0.01)而雌性个体花费大量时间进行理毛(Z=-3.134,P＜0.01).哺乳期雌性漫游行为(Z=-2.9541,P＜0.01)低于非哺乳期雌性个体,其他行为(Z=-2.9541,P＜0.01)明显高于非哺乳期雌性,而觅食行为(Z=-0.1773,P＞0.05)无显著差异性.结果表明人工投喂是导致其行为时间分配的主要原因.     

猪蓝耳病病毒感染野猪病例的实验室检测

应用猪蓝耳病、猪瘟RT-PCR检测试剂盒对疑似猪蓝耳病病毒、猪瘟病毒混合感染野猪病料进行检测,并对阳性材料进行病原特征基因序列测定与分析,结果显示:送检病料存在猪蓝耳病病毒感染,但不存在猪瘟病毒感染;对猪蓝耳病病毒流行株NPS2基因分析表明,野猪源蓝耳病病毒NPS2基因与家猪源同源性达95.2%以上,是存在基因缺失的高致病性猪蓝耳病病毒。研究结果说明,高致病性猪蓝耳病病毒可引起野猪发病,应采取相应疫苗免疫进行防控。     

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     

平菇菌盖超微结构的研究

利用透射电镜，对平菇菌盖的超微结构进行了观察。平菇成熟菌丝细胞有完整的双层细胞壁结构，内含细胞膜，线粒体，细胞核，内质网，泡囊，核糖体，糖原、须边体及典型的桶孔隔膜，有的细胞中，糖原颗粒了聚集在细胞质中，泡囊中也含有大量颗粒。线粒体膜，核膜，孢子膜均为双层，轮廓清晰。孢子中有线粒体、核、泡囊、核糖体、内质网。老化菌丝内有较大液泡，不见各种细胞器。     

湖南省某生猪批发市场疫病传播风险评估

为评估湖南省某生猪批发市场猪群疫病的发生风险,找出可能的风险因素,便于提出针对性预防措施,采用自行设计的调查问卷,结合访谈和现场调查,对27户经营户进行了调查,并将调查结果和调运数据相结合进行了疫病传播风险定性评估。结果显示:该市场疫病传入的可能性"高",内部传播的可能性"中等",疫病传出的可能性"高"。生猪调运频次多、数量大,经纪人行为复杂,运输车辆清洗消毒不彻底是可能的风险因素。评估结果提示,应尽量减少经纪人行为影响,重点加强对运输车辆的清洗消毒。     

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