公选课“微生物与人类”的教学实践

根据开设公选课"微生物与人类"的教学实践,介绍了利用公选课传授微生物知识的方式和特点.在教学过程中,首先根据非生物专业学生的特点精选教学内容,然后采取分专题讲授、参观、实验等多种教学方法增强学生的学习兴趣和教学效果,达到提高非生物专业学生科学素质的目的.     

记一节由学生设计的实验课

中学生物学教学大纲,要求学生要能比较系统地掌握关于植物和动物的形态结构、生理、分类、遗传和变异、生物进化和生态学等方面的基础知识.并掌握使用显微镜、制作装片、徒手切片、做简单生理实验和采集制作动植标本等技能.怎样才能达到这一要求?我认为从初中一年级起,就要重视培养学生学习植物学的兴趣和爱好,提高他们学习植物学的主动性和积极性.为此,我根据多年教学的体会,结合初一学生的好奇心强、求知欲高、喜欢观察和实验等特点,在教学中增加了胞间连丝和细胞吸水等十多个分组实验.并要求学生年末每人制作一     

高等农业院校微生物学实验课程教学改革探讨

微生物学实验技术的夯实和拓展是巩固和完善理论教学的重要保障,在引导高等农业院校学生认识和应用微生物过程中具有不可替代的作用.结合微生物学实验课程特点,针对微生物学实验教学采取了一系列改革措施,包括课程准备、学生分组管理、实验教学内容设计与考核方式等环节,以期探索提高实验教学效果的可行途径.结果表明,有效管理实验教学环节...     

涡虫在研究药物成瘾机制中的应用

药物成瘾危害人类健康并带来经济和社会问题,而滥用药物所造成的身体损害、身体依赖和戒断综合征的治疗等问题的解决仍存在困难.涡虫具有原始的中枢神经系统,其神经递质系统与哺乳类相似,具有易观察可量化的戒断反应,具有易饲养、低成本、无伦理问题等优于哺乳类实验动物的特点,因而迅速成为新的神经药理学在体动物实验模型.本文对涡虫的优点及其在药物成瘾机制等方面的研究进展进行综述,为药物成瘾机制及其治疗的研究提供新的思路.     

优化实验教学 促进概念生成

以"探究小肠适于消化吸收的特点"实验为例,从实验目的、实验材料和步骤、学习过程等方面进行了优化,从而提高实验效率,促进课堂概念的生成。     

脊髓薄片器官型培养技术的研究进展

脊髓薄片器官型培养技术是一项借助体外器官培养技术,通过活体切片机、微孔膜技术的应用,将脊髓一部分分离出来进行培养、研究的技术,该技术具有操作简单,观察直观,且可长时间进行体外实验,便于施加实验因素等特点,为体外研究脊髓的生理、病理变化提供了更多的技术支持和新的途径,但是该项技术在国内目前应用、报道很少,而其应用价值极高,故本文就脊髓薄片器官型培养技术的发展、特点、方法、注意事项、应用等方面对该项技术做一综述.     

几种DNA提取方法的比较

介绍了3种适合中学生物学实验的DNA提取方法。并针对中学实验的特点比较了它们在实验材料、实验步骤、实验时间和实验效果等方面的优缺点,对中学生物学实验的开展提供了基础资料。     

鹌鹑、果蝇遗传实验价值的比较研究

果蝇是生物学科遗传实验的经典材料,鹌鹑是新近开发的实验动物。对两者的实验价值进行比较研究结果表明：果蝇具有生活史短、繁殖率高、性状突出,在教学实验中还表现出知识性强,实验面宽等特点;鹌鹑具有直观性强、时代间隔短、繁殖率高、贴近生活、服务生产、供人观赏、饲养简便、遗传性状突出、知识性强等特点。同时,两者也都有不足。通过比较研究为合理安排生物实验课,进行校本实验开发提供科学依据。     

植物实时荧光定量PCR内参基因的特点及选择

实时荧光定量PCR(qRT-PCR)具有灵敏度高、特异性强、重复的动态定量范围和高通量等优点,是进行植物基因表达和转录分析最常用的技术手段之一.选择合适的内参基因是正确运用实时荧光定量PCR分析目标基因表达变化的前提.近年来,大量研究表明,内参基因的选择应取决于研究者的实验条件;随着实验条件的变化,内参基因的选择也随之变化.因此,实时荧光定量PCR结果分析的准确性在很大程度上依赖于所选择的内参基因是否适合.该文从内参基因的选择、常用内参基因的特点、新内参基因的挖掘、应用内参基因组合的优点和内参基因的稳定性评价等几方面进行综述,以期为研究者在实验中选择合适的内参基因提供参考和理论依据.     

体现不同专业特色的微生物学实验教学改革研究

总结了微生物学实验教学的改革与实践.根据专业特点设置基础验证性实验以加强基本操作技能训练,开设有专业特色的综合、设计性实验强化学生综合实践能力培养,利用创新性实验促进培养学生创新能力,并依托网络化的实验教学信息平台与完善的实验室管理制度实施开放实验,构建了体现专业特色的微生物学实验教学体系.实践证明,体现专业特色的微生物学实验教学改革,提高了实验效率与实验教学质量.     

北京地区实验树晌的饲养管理方法

树鼩作为低等灵长类动物,在生物学研究中的价值日益引起研究者重视,将其作为实验动物的实验需求越来越多。作为南方亚热带动物,树嗣如何适应北方地区的生活是北方地区将其用作实验动物的前提。本实验室探索出适宜树购居住的饲养笼具,确定了饲养环境温度、湿度、光照时间、噪声及通风等条件,制定了规范化的卫生管理标准,建立了北京地区长期人工培育树晌的饲养管理方法,为今后利用树嗣进行中医药病证结合动物模型的研究奠定了基础。     

Creating animal models,why not use the Chinese tree shrew (Tupaia belangeri chinensis)?

The Chinese tree shrew (Tupaia belangeri chinensis),a squirrel-like and rat-sized mammal,has a wide distribution in Southeast Asia,South and Southwest China and has many unique characteristics that make it suitable for use as an experimental animal.There have been many studies using the tree shrew (Tupaia belangen) aimed at increasing our understanding of fundamental biological mechanisms and for the modeling of human diseases and therapeutic responses.The recent release of a publicly available annotated genome sequence of the Chinese tree shrew and its genome database (www.treeshrewdb.org) has offered a solid base from which it is possible to elucidate the basic biological properties and create animal models using this species.The extensive characterization of key factors and signaling pathways in the immune and nervous systems has shown that tree shrews possess both conserved and unique features relative to primates.Hitherto,the tree shrew has been successfully used to create animal models for myopia,depression,breast cancer,alcohol-induced or non-alcoholic fatty liver diseases,herpes simplex virus type 1 (HSV-1) and hepatitis C virus (HCV) infections,to name a few.The recent successful genetic manipulation of the tree shrew has opened a new avenue for the wider usage of this animal in biomedical research.In this opinion paper,I attempt to summarize the recent research advances that have used the Chinese tree shrew,with a focus on the new knowledge obtained by using the biological properties identified using the tree shrew genome,a proposal for the genome-based approach for creating animal models,and the genetic manipulation of the tree shrew.With more studies using this species and the application of cutting-edge gene editing techniques,the tree shrew will continue to be under the spot light as a viable animal model for investigating the basis of many different human diseases.     

树鼩载脂蛋白E的cDNA和蛋白质结构分析

以从树肝脏mRNA逆转录得到的Ⅰ链cDNA为模板 ,运用SMARTRACEPCR技术 ,扩增得到树载脂蛋白E(apoE)cDNA序列 ,并推导出apoE蛋白质的氨基酸序列 .利用分子生物学软件包PCGENE对氨基酸序列和二级结构进行分析和比较 .结果表明 ,树apoEcDNA序列 (作为新基因已被GenBank接收 ,登录号为AF 30 3830 )由 1138bp构成 ,其中 5′非翻译区 6 4bp ,3′非翻译区 135bp ,939bp组成一个完整开放阅读框架 ,与人apoEcDNA的同源性为 86 % .编码 313个氨基酸组成的apoE前体 ,包含 18个氨基酸构成的信号肽和 2 95个氨基酸组成的成熟蛋白 .与人apoE氨基酸序列的同源性为 78% .树apoE与人及其它种属动物apoE在氨基酸组成上相近 ,但比人apoE少4个氨基酸 ,比动脉粥样硬化易感动物家兔apoE多 2个氨基酸 .经Garnier法预测 ,树apoE蛋白二级结构与人apoE相似 ,螺旋构象 (helical) 6 9 9% ,伸展构象 (extended) 16 6 % ,转角构象 (turn)6 0 % ,无规则卷曲 (coil) 7 6 % .     

树鼩IgG纯化鉴定及其多克隆抗体制备和检测

目的:比较两种抗体纯化方法在分离纯化树鼩IgG抗体的应用,制备抗IgG的多克隆抗体及检测。方法:采用两种商品化IgG抗体纯化试剂盒分离树鼩血清IgG抗体,采用SDS-PAGE和蛋白定量测定提纯IgG。以树鼩IgG作为抗原,与等量弗氏完全佐剂(第一次)、弗氏不完全佐剂(第二次)混合皮下注射免疫兔,对分离血清进行多克隆抗体纯化及Western Blot检测及定量分析。结果:两种方法均能有效分离纯化树鼩IgG,在经过Montage PROSEP-A试剂纯化后的IgG在纯度和含量方面均优于Protein A/G Matrix试剂。通过纯化后的树鼩IgG免疫兔制备的抗IgG抗体能有效识别树鼩IgG。结论:纯化的树鼩IgG具有良好免疫原性,由此制备的抗体具有高度特异性。研究结果为利用树鼩作为实验动物提供了必要的实验基础。     

树鼩模型:抑郁症的社会竞争失败与学习和记忆的被捕获条件反射

最近基因组研究表明树鼩属于灵长类或是与灵长类亲缘关系最密切的姐妹种.因此,树鼩可能是应用于建立人类疾病动物模型的最佳动物之一.该文报道一种抑郁症的社会竞争失败病因学树鼩(Tupaia belangerichinensis)模型.一对雄性树鼩被饲养在一个双笼中,用网格把双笼隔开,网格上有一小门.适应1周后,把小门打开,这一对树鼩产生短暂的争斗,每天一次,连续21天.其中争斗失败者被称为服从者.这个过程可导致每天1 h的直接社交冲突和23 h的间接相互影响(比如通过气味、视觉等).与正常对照相比,失败者在第三周也就是社交冲突的最后一周显示了体重、自主活动、躲避行为、尿液皮质醇水平等的变化,并且这种改变可持续至少2周以上.此外,还报道全新的记忆模型,一种被捕获条件反射树鼩模型.在一个封闭的小房间中放置捕获笼,其中挂有一片苹果,小房间中有一只自由活动的树鼩.训练的前4次树鼩进入捕获笼吃苹果并不触发捕获笼关闭,但在第5次时触发捕获笼关闭,并持续一小时才释放树鼩.第1-5次树鼩进入捕获笼的延迟时时间作为适心性指标,其中第5次才是作为被捕获的一次学习训练.24 h后,测试树鼩进入捕获笼的延迟时间作为被捕获记忆能力指标.树鼩经过第5次被捕获训练,能形成很好的被捕获记忆,因为24 h后的延迟时间极人地增加.在训练前腹腔注射已知能阻断记忆形成的NMDA受体拮抗剂MK-801(0.2 mg/kg,腹腔注射),对适应指标没有显著影响,但足极大地缩短了24 h后测试的延迟时间,即阻断了被捕获记忆.这些结果表明了一种抑郁症的慢性社会竞争失败与学习和记忆的一次被捕获条件反射树鼩模型.这两种树趵模型对抑郁症与学习和记忆的机理研究、抗抑郁症新药的临床前药效学评价具有潜在的重要意义.

Abstract：

Recent genome studies indicate that tree shrew is in the order or a closest sister of primates, and thus may be one of the best animals to model human diseases. In this paper, we report on a social defeat model of depression in tree shrew (Tupaia belangeri chinensis). Two male tree shrews were housed in a pair-cage consisting of two independent cages separated by a wire mesh partition with a door connecting the two cages. After one week adaptation, the connecting door was opened and a brief fighting occurs between the two male tree shrews and this social conflict session consisted of 1 h direct conflict (fighting) and 23 h indirect influence (e.g. smell, visual cues) per day for 21 days. The defeated tree shrew was considered the subordinate. Compared with naive animals, subordinate tree shrews at the final week of social conflict session showed alterations in body weight, locomotion, avoidance behavior and urinary cortisol levels.Remarkably, these alterations persisted for over two weeks. We also report on a novel captive conditioning model of learning and memory in tree shrew. An automatic trapping cage was placed in a small closed room with a freely-moving tree shrew. For the first four trials, the tree shrew was not trapped when it entered the cage and ate the bait apple, but it was trapped and kept in the cage for 1 h on the fifth trial. Latency was defined as the time between release of the tree shrew and when it entered the captive cage. Latencies during the five trials indicated adaptation. A test trial 24 h later was used to measure whether the one-trial trapping during the fifth trial could form captive memory. Tree shrews showed much longer trapping latencies in the test trial than the adaptation trials. The N-methyl-d-aspartate (NMDA) receptor antagonist MK-801 (0.2 mg/kg, i.p.), known to prevent the formation of memory, did not affect latencies in the adaptation trails, but did block captive memory as it led to much shorter trapping latencies compared to saline treatment in the test trial. These results demonstrate a chronic social defeat model of depression and a novel one-trial captive conditioning model for learning and memory in tree shrews, which are important for mechanism studies of depression, learning,memory, and preclinical evaluation for new antidepressants.     

树鼩乳汁的主要成分检测及其意义

目的：探讨树鼩乳汁的基本成份,并和其它乳制品成份进行了比较分析。方法选取10只分娩后（1-21）d期间的哺乳期母树鼩,用人工被动母乳喂养方法让仔树鼩自由吮吸母乳,立即采用无菌操作的方法用注射器直接采取仔树鼩胃内的乳汁,1次／2 d,连续3-5次,每只母树鼩采取18 mL乳汁,按照国家标准的方法进行成分检测。结果树鼩乳汁总固形物为43.63％、脂肪为26.01％、蛋白质为10.41％、乳糖为0.45％、灰分为0.99％。树鼩乳的总固形物、灰分、蛋白质、脂肪、乳糖含量分别为牛乳的3.36、1.24、2.74、6.67、0.09倍;树鼩乳的总固形物、灰分、蛋白质、脂肪、乳糖含量分别为婴幼儿配方乳的1.44、0.20、0.58、1.53、0.06倍;与牛乳及婴幼儿配方乳矿物质成分含量相比,树鼩乳的矿物质成分钙、磷、钾、钠、镁、铁、锌含量均大于牛乳,分别为1.83、2.73、1.25、1.93、1.28、1.48倍,而均小于婴幼儿配方乳,分别为0.66、0.85、0.34、0.26、0.85、0.24、0.49倍。结论树鼩乳的主要营养成分呈现高脂高蛋白低糖的类型,可为树鼩人工育幼和饲养工作提供依据。     

Characterization of tree shrew telomeres and telomerase

The use of tree shrews as experimental animals for biomedical research is a new practice. Several recent studies suggest that tree shrews are suitable for studying cancers, including breast cancer, glioblastoma,lung cancer, and hepatocellular carcinoma. However, the telomeres and the telomerase of tree shrews have not been studied to date. Here, we characterize telomeres and telomerase in tree shrews. The telomere length of tree shrews is approximately 23 kb, which is longer than that of primates and shorter than that of mice, and it is extended in breast tumor tissues according to Southern blot and flow-fluorescence in situ hybridization(FISH) analyses. Tree shrew spleen, bone marrow, testis, ovary, and uterus show high telomerase activities, which are increased in breast tumor tissues by telomeric repeat amplification protocol assays. The telomere length becomes shorter, and telomerase activity decreases with age. The tree shrew TERT and TERC are more highly similar to primates than to rodents. These findings lay a solid foundation for using tree shrews to study aging and cancers.     

Mutations in the p53 tumor suppressor gene in tree shrew hepatocellular carcinoma associated with hepatitis B virus infection and intake of aflatoxin B1

Infection with hepadnaviruses and exposure to aflatoxin B1 (AFB1) are considered to be major risk factors in the development of hepatocellular carcinoma (HCC) in humans. A high rate of p53 mutations at codon 249 has been reported in these tumors. The tree shrew (Tupaia belangeri chinensis) is a useful animal model for the development of HCC after human hepatitis B virus (HBV) infection or AFB1 treatment. Therefore, it was of particular interest to determine whether the p53 gene in tree shrew HCCs associated with HBV infection and/or with exposure to AFB1 is affected in the same manner as in human HCCs. We determined the tree shrew p53 wild-type nucleotide sequences by RT-PCR and automatic DNA-sequencing. Tree shrew wild-type p53 sequence showed 91.7 and 93.4% homologies with human p53 nucleotide and amino acids sequences, respectively, while it showed 77.2 and 73.7% homologies in mice. One HCC and normal liver tissue from AFB1 treated and one HCC from AFB1- and HBV-treated tree shrew showed no change in p53 sequences, while three HCCs from AFB1- and HBV-treated tree shrews showed point mutations in p53 sequences. One HCC showed point mutations at codon 275, which is on the DNA-binding domain of p53 gene, which might be a cause of gain-of-function during the development of HCC. As a result, our finding indicates that tree shrews exposed to AFB1 and/or HBV had neither codon 249 mutations nor significant levels of other mutations in the p53 gene, as is the case with humans.     

滇西亚种树鼩体外寄生虫自然感染状况及分析

目的调查滇西亚种树鼩体外寄生虫的自然感染状况,为建立树鼩质量控制标准提供依据。方法对野生的滇西亚种树鼩和自繁F1代树鼩各60只分别用尸检法和活体法检测,随即采用拔毛或用透明胶带粘取腋下、耳根、腹股沟、肛门附近等处的毛发制片,置于体视镜和显微镜下观察虫体和虫卵。结果野生滇西亚种树鼩和自繁F1代树鼩体外寄生虫自然感染率分别为：虱子25%/6%、蚤5%/0、蜱1.6%/0、水蛭1.6%/0、虱子和蚤混合感染1.6%/0。结论野生树鼩体外寄生虫的自然感染多为虱子和蚤,其次还有蝉、水蛭,总感染率明显高于自繁F1代。使用灭虱灵对于驱除树鼩体外寄生虫具有较好的疗效。