宁强矮马线粒体DNA D-loop区的遗传多样性

【目的】研究宁强矮马线粒体DNA（mitochondrial DNA,mtDNA）D-loop区的遗传多样性及其母系起源进化,为其遗传资源保护提供理论数据。【方法】采用PCR和测序技术分析12匹宁强矮马mtDNA D-loop区的600 bp核酸序列,并基于mtDNA D-loop区序列将宁强矮马和NCBI公布的其它马种进行系统树构建。【结果】宁强矮马群体存在9种单倍型,检测到34处SNP位点,占所分析位点总数的5.67%,各单倍型间的遗传距离为0.002—0.035,单倍型多样性为0.978±0.054,核苷酸多性为0.01988±0.00818。聚类分析表明宁强矮马分布在4个支系中,与胡克尔马、设特兰马、德保马、蒙古马和车巨马亲缘关系较近,与纯血马、云南马和韩国济州岛本土马的亲缘关系较远。【结论】宁强矮马具有比较丰富的遗传多样性,在进化的历史过程中受到其它马种的影响较大。     

Rickettsia-like Bacterium Associated with Pierce's Disease of Grapes

A pleomorphic bacterium was observed by electron microscopy in grape plants infected with Pierce's disease. The organism was located in xylem tissue, and its occurrence was closely associated with symptoms of Pierce's disease. The bacterium resembled a rickettsia in morphology, in its failure to grow on cell-free media, and in its sensitivity to tetracycline antibiotics.     

贵州矮马与伊犁马生长激素基因5’侧翼区的结构特征

为了摸索贵州矮马生长发育的调控机制,探明贵州矮马与伊犁马生长激素基因5’侧翼区的结构特征,以4～5龄的贵州矮马和7～8龄的新疆伊犁马为研究对象,采用直接测序法从两种马基因组中克隆了生长激素(GH)基因5’侧翼区的DNA序列,并进行生物信息学分析。结果表明:1)从基因组中克隆的711bp片段为GH基因5’侧翼区序列;2)两个马品种的GH基因5’侧翼区中都存在TATA box、CAATbox、GC box和Octamer位点等真核生物启动子结构;3)从伊犁马GH基因5’侧翼区中检测到1个位于30bp处的突变位点发生了G→C颠换,由此新增了1个转录因子upstream stimulatory factor(USF)结合位点;4)从贵州矮马和伊犁马GH基因的5’侧翼区序列中发现了MZF1、CdxA、Nkx-2、AML-1a和c-Myc等19种共58个转录因子的结合位点。结论:克隆的711bp基因序列中存在大量的转录调控元件。     

两个西南马种GHR基因第10外显子SSCP分析

通过PCR-SSCP检测10匹宁强矮马和12匹贵州马GHR基因第10外显子的多态性分析,结果表明,宁强矮马和贵州马GHR基因外显子10的第2和第4区域的保守性较高,基因多样性相对较低,第1和第3区的遗传变异较大,基因多样性水平较高。分析比较发现宁强矮马GHR基因外显子10的多态性比贵州马稍高,首次表明宁强矮马在GHR10上存在较大的遗传多态性。     

贵州矮马、西南马和伊犁马刺豚鼠信号蛋白基因的多态性

为了探索贵州矮马、西南马、伊犁马刺豚鼠信号蛋白(Agouti signaling protein,ASIP)基因与马品种毛色之间的关系,采用缺口PCR技术分析了141份贵州矮马、西南马、伊犁马的ASIP基因型,并进行克隆测序。结果表明,扩增出的793 bp和385 bp 2个片段为ASIP基因,793 bp片段中缺失一段11 bp的核苷酸,定义为a基因型,385 bp片段结构完整,定义为A基因型;3个马群体中A等位基因在骝毛中占优势;但aa基因型对应的毛色只有小部分为黑毛,绝大部分为栗毛、骝毛和复色毛,与已知的aa基因型决定黑毛的规律不相符,说明aa基因型可能不是中国马品种黑毛的决定基因型。     

宁强矮马生长激素基因（GH）的遗传变异分析

 【目的】通过分析不同动物和中国几个地方马种生长激素基因序列,为宁强矮马起源和矮化形成机制的研究提供分子水平的试验依据。【方法】通过PCR扩增宁强矮马生长激素基因并进行测序,用DNAMAN软件对不同动物的生长激素基因序列进行比对分析。【结果】马品种间29个位点发生遗传变异,编码区11个位点发现遗传多态现象。以蒙古马生长激素氨基酸序列为标准,宁强矮马仅在1 765位点的变异导致氨基酸发生改变。以生长激素的mRNA序列为基本数据进行聚类分析,宁强矮马和德保马67的同源性为100%,与百色马的同源性为99.8%,与蒙古马的同源性为99.7%。【结论】马属动物生长基因序列与猪和狗的同源性较高,宁强矮马1 765位的G→A可能影响到宁强矮马的生长发育。     

馬瘟的血液学变化

本项研究工作对马瘟病畜进行了血液学检查。在病程的高热期和症状明显期时,马瘟病畜的红细胞沉降率明显加快,高热期时病畜血液的嗜酸粒细胞数量减少,其数量于降热后稍有回升,但仍少于接种前的数值。马瘟时血液内未见有担铁细胞出现。病畜血液的红细胞数量及血红蛋白含量未见变化,但血液中的嗜中性粒细胞呈现左移。病畜血清胆红质试验时,间接反应增强并出现直接迟缓反应。病畜在高热期时红细胞脆性轻度增高。     

Evolutionary Patterns of the Proviral gp90 V3 to V5 Regions of Equine Infectious Anemia Virus Associated with Immune Selection in Progressors and Nonprogressors

The aim of this study was to determine the genomic evolutionary pattern of virulent equine infectious anemia virus (EIAV)during persistent infection.The evolutionary dynamics of proviral genomes were examined by challenging an EIAV seronegative equine (pony 1) and three EIAV vaccinated equines (ponies 4,7,and 8) with the Chinese virulent strain EIAVL.Ponies I and 7 succumbed to disease and were called progressors,while ponies 4 and 8 lacked clinical symptoms and were considered nonprogressors.Sequences spanning the V3,V4,and V5 hyper-variable regions of the EIAV-L envelope gp90 gene were sequenced from each pony as evolutionary markers of the provirus.The proviral genome of the EIAV-Linoculum evolved during persistent infection and displayed different patterns between EIA progressors and nonprogressors.Inoculum-like variants were isolated from nonprogressors during persistent infection,but only from progressors during acute infection.Variant mutations from nonprogressors were dispersed throughout the sequenced region,while those from progressors were predominantly localized to V3.Humoral immunity and virus variant population selection analyses indicated that immune selection was positive in chronically infected progressors and weak in nonprogressors.In-frame stop codons were frequently localized to a defect "hot spot".The high number of defective variants in nonprogressors may promote disease survival.     

紫云县贵州矮马资源评价

对贵州省紫云县境内现存的贵州矮马数量及分布进行了调查。全县12个乡镇中,贵州矮马存栏1 421匹,其中公马611匹,母马810匹;其毛色以骝毛和栗毛为主。雌雄矮马的体高、体长、胸围、头长和颈长没有明显差异,但雄性个体的管围明显较粗。雄性矮马的红细胞数量较多但体积较小,血小板和中间细胞数量较高,血清总胆固醇和高密度脂蛋白胆固醇水平较雌性的低;雌性矮马妊娠时血小板数量和低密度脂蛋白水平代偿性下降,但中性粒细胞数量和CO2结合能力升高。雄性矮马与雌性矮马的使役能力没有明显差别。目前贵州矮马混养、无序买卖及疾病预防不足是其死亡率高、体高上升的重要原因。     

Viruses associated with epidemic hemorrhagic fevers of the Philippines and Thailand

Epidemiologic, clinical, and etiologic studies were carried out on a newly recognized, frequently fatal, pediatric disease syndrome which occurred in urban areas infested with Aedes aegypti mosquitoes. Four types of dengue virus (two of which are new), chikungunya virus, and another virus yet to be identified were isolated from the blood of patients. Dengue viruses, types 2 and 3, were isolated from the mosquitoes. Ample serologic confirmation was obtained of concurrent hemorrhagic fever and infection with one or more of these viruses. Thus, it was discovered that viruses of previously recognized types and of closely related new types apparently have etiologic roles in a new and highly dangerous epidemic disease syndrome.     

Plant mycoplasmas: a cultivable spiroplasma causes corn stunt disease

A spiroplasma can be isolated and grown continuously in cell-free medium from stunted corn or from Drosophila injected with sap expressed from diseased corn. The organism is serologically related to, but not identical with, Spiroplasma citri, the causative agent of citrus stubborn disease. Leafhopers injected with cultured organisms induced typical symptoms of the corn stunt disease when placed on previously healthy corn plants.     

宁强矮马考察报告

宁强矮马,产于陕西宁强县嘉陵江的西北部,秦岭南坡区的深山峡谷之中。它占当地马匹总数不到10％,体高106cm以下,属乘(驮)用型马种。     

Corn stunt spiroplasma: isolation, cultivation, and proof of pathogenicity

A spiroplasma isolated from corn infected with corn stunt disease has been successfully cultivated in vitro. Acid formation was associated with its growth in liquid medium, and fried egg-shaped or granulated colonies developed on solid agar medium. Healthy leafhopper vectors injected with or allowed to feed on isolates from various serial passages through liquid medium were able to transmit the corn stunt agent to healthy corn plants, inducing typical corn stunt disease in the plants. The spiroplasma was reisolated and cultivated from such diseased plants and was indistinguishable morphologically from the original isolates. These results provide the first definite proof that the corn stunt disease is caused by the corn stunt spiroplasma.     

Legionnaires' disease: structural characteristics of the organism

The Legionnaires' disease organism was isolated from lung tissue taken from two fatalities of the Legionnaires' disease epidemic that occurred in Philadelphia during 1976. In yolk sac tissue the agent grew as a small coccobacillary microorgansim, which was Gram variable and Giménez positive. Intracellular coccoid and bacillary forms, detected by electron microscopy, within and without vacuoles, underwent multiplication by septate binary fission. Some of the intracellular forms resembled obligate intracellular pathogens. On defined bacteriologic media, the organisms were predominantly bacillary. The organism conforms to the morphologic criteria of a prokaryocyte.     

Pathogenesis of dengue: challenges to molecular biology

Dengue viruses occur as four antigenically related but distinct serotypes transmitted to humans by Aedes aegypti mosquitoes. These viruses generally cause a benign syndrome, dengue fever, in the American and African tropics, and a severe syndrome, dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS), in Southeast Asian children. This severe syndrome, which recently has also been identified in children infected with the virus in Puerto Rico, is characterized by increased vascular permeability and abnormal hemostasis. It occurs in infants less than 1 year of age born to dengue-immune mothers and in children 1 year and older who are immune to one serotype of dengue virus and are experiencing infection with a second serotype. Dengue viruses replicate in cells of mononuclear phagocyte lineage, and subneutralizing concentrations of dengue antibody enhance dengue virus infection in these cells. This antibody-dependent enhancement of infection regulates dengue disease in human beings, although disease severity may also be controlled genetically, possibly by permitting and restricting the growth of virus in monocytes. Monoclonal antibodies show heterogeneous distribution of antigenic epitopes on dengue viruses. These epitopes serve to regulate disease: when antibodies to shared antigens partially neutralize heterotypic virus, infection and disease are dampened; enhancing antibodies alone result in heightened disease response. Further knowledge of the structure of dengue genomes should permit rapid advances in understanding the pathogenetic mechanisms of dengue.     

PATHOGENIC PLEUROPNEUMONIA-LIKE MICROORGANISMS FROM ACUTE RHEUMATIC EXUDATES AND TISSUES

In suitable cell-free media it has been possible to cultivate pleuropneumonia-like microorganisms from the following materials, first, from chorioallantoic membranes in which lesions were apparently induced by exudates from patients with rheumatic fever; second, from pneumonic lungs of mice inoculated with similar exudates or with suspensions of the abovementioned abnormal membranes; and third, directly from the arthritic exudate of a patient with rheumatic fever, and also from an erythema nodosum nodule excised from a patient with this same disease. With three different subcultures from joint fluid, iritis has been induced in rabbits; and following intranasal inoculation with the same cultures there has developed in mice a pneumonia similar to that found in mice inoculated with rheumatic exudates and with suspensions of chorioallantoic membranes infected with rheumatic exudates. Therefore it seems probable that in all instances the pathogenic agent was derived from similar sources, viz., patients with rheumatic fever. Further work will be required to demonstrate the etiologic significance of these pathogenic agents in rheumatic fever.     

Korean hemorrhagic fever: propagation of the etiologic agent in a cell line of human origin

The etiologic agent of Korean hemorrhagic fever has been propagated in a human cultured cell line derived from a carcinoma of the lung. The cells, described as type II, alveolar epithelial, support replication of the agent and successive passages. Antigen of the Korean hemorrhagic fever agent is readily detected in infected cells by means of direct or indirect fluorescent antibody techniques. Previous attempts to propagate this agent in vitro had been unsuccessful.     

New method for manipulation,maintenance, and cloning of single mammalian cells in vitro

Individual mammalian cells can be isolated with the aid of easily handled glass beads to which the cells have become attached. Procedures for the preparation of cell cultures on beads, and for the recognition and manipulation of beads carrying single monocytes, HeLa cells, and Detroit-98 cells are described. Data obtained with Brucella infected monocytes, illustrating the efficiency of the method, are presented.     

应用血清LDH同工酶对宁强矮马亲缘关系的分析

检测宁强矮马和中型马血清,用聚丙烯酰胺凝胶电泳,一般可获5条LDH同工酶酶带。薄层自动扫描仪扫描、计算酶谱曲线活力区带的百分含量,经t检验差异均不显著(P>0.05)。将5个马种血清LDH同工酶活力区带百分含量,采用标准化欧氏平方距离的最小非类似值,以最短距离法聚类,西南马系统的4个马种在4.0197值时聚为一类(宁强矮马和中型马为0.2296,建昌马和安宁果下马为3.2315),而伊吾马在13.659值时才与西南马聚为一类。     

鸡波德特氏菌病的研究

１９９５年９月在陕西咸阳首次发现鸡的波德特氏菌病。病鸡以流浆液性鼻液、眼睑肿胀、眼睛流泪及呼吸困难为特征。不同年龄的鸡均可感染，幼龄鸡的发病率和死亡率明显高于成年鸡。分离菌的２４ｈ肉汤培养物（０．２ｍＬ）感染小鼠及豚鼠可于２４ｈ内引起死亡；经鼻感染６０日龄鸡复制出了与自然病例相同的临床表现，病死率６０％，并回收到了接种菌。本文对分离的波德特氏菌的培养特性、形态特征、致病性、抗生素的敏感性、灭活苗的研制及免疫防制进行了深入研究。