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1.
2013年在中国台湾地区发现了第一例人感染H6N1禽流感,研究该地区H6N1病毒血凝素基因(HA)的适应性进化特征和种群动力学,将为人感染H6N1病毒的来源、进化及致病机制的理解提供更多信息,为进一步的研究和防治提供一定帮助。本研究从Flu和GISAID两大数据库中获得中国台湾地区所有已释放的H6N1病毒的HA序列,构建系统发育树和进化动力曲线,并推测其进化速率,分析其适应性进化特征。结果表明中国台湾地区H6N1病毒的HA有五种类型,其中人感染H6N1病毒的HA所属类型为目前当地优势类型;该病毒种群于1971年底第一次扩张,2008年迅速减少,而后又略有增加。同时在长期的进化过程中,3个位点受到正选择作用的影响,增加了病毒的适应能力;89个位点受负选择作用的影响,它们在病毒的复制、流行中可能具有重要的功能;其中剪切位点附近的329位所受负选择作用强烈(PSLAC0.001、PFEL0.000、BFREL137),此位点可能与病毒毒力有关。中国台湾地区H6N1病毒的HA已发生了明显的适应性进化,具有发生疫情的可能性,人们应高度重视,并能及时给与监测和防治。  相似文献   

2.
细小病毒主要以犬类为自然宿主,可引起犬类严重全身性反应,患病率仅次于犬瘟热。由于该病毒容易发生抗原漂移,造成防控上存在较大的难度。本研究对国内细小病毒的流行特点及防治研究进展作一综述。  相似文献   

3.
付银  常惠芸  刘静  陈慧勇 《生命科学》2013,(11):1065-1070
口蹄疫病毒(FMDV)导致了偶蹄动物口蹄疫的发生,它是一类有着自身特点的RNA病毒。首先,FMDV衣壳蛋白VP1识别结合宿主细胞膜上的整联蛋白等受体,以内吞的方式进入细胞,利用宿主细胞成分完成病毒蛋白的合成。这些新合成的L^pro、2C和3C^pro等病毒致病因子进一步抑制宿主基因的转录和翻译,诱导细胞凋亡和白噬,并抑制干扰素介导的一系列先天性和获得性免疫反应。宿主则在病毒侵染细胞的初期,利用病毒识别受体等来识别病毒并诱导合成干扰素等细胞因子,介导多种免疫反应以清除病毒。病毒和宿主两者在持续的利用和较量中完成疾病的发生和痊愈等。其次,不断发现的病毒受体、结合基序、致病因子及宿主细胞的多种免疫调节因子将成为相关领域新的研究内容。综上,开发高效安全疫苗、增强自身免疫力及利用RNAi直接抑制病毒RNA等便成为现代FMDV防治的主要内容。  相似文献   

4.
禽流感与禽流感病毒研究进展   总被引:7,自引:1,他引:6  
对禽流感的症状、传播、感染、流行规律、疾病发生历史、流行监测、诊断、防治以及禽流感病毒的分类地位、命名、病毒粒子形态结构、病毒基因组结构、病毒复制、病毒变异的研究进展作了综合评述,并对该领域的研究热点和方向作了探讨。  相似文献   

5.
松毛虫质型多角体病毒的宿主域与交叉感染   总被引:2,自引:0,他引:2  
自1956年从赤松毛虫Dendrolimus spectabilis上首次发现赤松毛虫质型多角体病毒1型(D. spectabilis cytovirus 1,DsCPV-1)以来,先后从马尾松毛虫D. punctatus、油松毛虫D. tabulaeformis、赤松毛虫、德昌松毛虫D. p. tehchangensis、文山松毛虫D. p. Wenshangensis和落叶松毛虫D. superans上发现了质型多角体病毒(cytoplasmic polyhedrosis virus,CPV)。病毒基因组dsRNA电泳图谱分析表明,这些松毛虫CPV的不同分离株均属于质型多角体病毒1型(cytovirus 1)。这些松毛虫CPV病毒可以感染鳞翅目10科35种昆虫,其中对多种昆虫具有很高的感染力和良好的杀虫效果,可以从中筛选替代宿主生产松毛虫CPV杀虫剂,用于害虫生物防治。松毛虫CPV接种某些昆虫后病毒的基因组dsRNA电泳图谱发生了改变,可能是异源病毒诱发了宿主自身潜伏型病毒的感染复制。  相似文献   

6.
近几年来,山东省一些林场的赤松毛虫自然发生流行性病毒病,当地进行人工喷洒病毒防治松毛虫大面积试验获得良好效果。继后我们又发现山东省其它一些林果业害虫也有类似的自然死亡现象,现将采集到的几种昆虫病毒进行研究鉴定,简报如下。 1.赤松毛虫(Dendrolimus spectabilis Butler)细胞质型多角体病毒(CPV)及颗粒体病毒(GV) 1973年以来,山东省沂南县东风林场的赤松毛虫经常发生流行病而大量死亡;经调查此病分为萎  相似文献   

7.
人类T细胞白血病1型病毒(Human T-cell leukemia virus type 1,HTLV-1)是与人类疾病发生密切相关的逆转录病毒。该病毒的感染可引起成人T细胞白血病(Adult T-cell leukemia,ATL)等多种疾病的发生。Tax和HBZ(HTLV-1 basic zipper protein)是由HTLV-1前病毒编码的两个关键病毒蛋白,它们被认为在HTLV-1病毒的复制、生存和致癌过程中发挥了至关重要的作用。本文就Tax和HBZ的蛋白结构以及它们在调控病毒转录、细胞生长和凋亡、病毒潜伏期,最终协同促进成人T细胞白血病发生过程中发挥的作用作一综述。  相似文献   

8.
玉米矮花叶病研究进展   总被引:4,自引:0,他引:4  
玉米矮花叶病(maize dwarf mosaic virus,MDMv)是世界上玉米产区普遍发生的病毒病害之一.自20世纪90年代以来,我国玉米矮花叶病发生严重,山西、甘肃、山东、河北以及北京等省市先后大流行,造成了巨大的农业经济损失.在我国玉米产区造成危害的主要是该病毒的B株系,主要借蚜虫传播和种子传播;在玉米矮花叶病的防治中,种植抗病品种,并辅以合理的栽培管理,可有效防止MDMV.本文主要综述玉米矮花叶病病毒的理化特性、玉米矮花叶病的发生危害、病原及其传播方式、发病条件、流行与防治、品种(自交系)抗性、抗性鉴定、抗性遗传及其抗病基因工程研究等方面的研究进展,以期为以后玉米矮花叶病的有效防治提供一定的参考.  相似文献   

9.
【背景】病毒可以随同草莓无性繁殖材料传播扩散,导致产量和品质下降。选育无病毒种苗是草莓病毒病防治的主要措施,高效、灵敏的检测技术可为草莓病毒病防治提供技术保障。【目的】为明确8种能够侵染草莓的病毒在北京地区设施草莓上的发生情况,应用酶联免疫吸附测定(Enzyme-LinkedImmunosorbentAssay,ELISA)进行检测。【方法】将待检病毒的阳性对照样品分别进行间接法和双抗夹心法(Double-Antibody Sandwich,DAS) ELISA检测,以空白对照和阴性对照作参照比较,确定应用DAS-ELISA检测体系结合田间症状对北京地区采集的草莓样品进行病毒检测,并利用逆转录-聚合酶链式反应和序列测定方法对阳性样品进一步验证,确定检测结果的可靠性。【结果】侵染北京地区设施草莓的病毒为草莓轻型黄边病毒(StrawberryMildYellowEdgeVirus,SMYEV)。‘红颜’品种的病毒检出率为8.1%,‘天香’品种的检出率为2.7%,其他品种均未检出病毒。【结论】研究结果为北京地区设施草莓病毒的检测以及草莓病毒病的科学防治提供理论依据。  相似文献   

10.
木毒蛾复合病毒制剂研究   总被引:1,自引:0,他引:1  
通过木毒蛾质型多角体病毒、核型多角体病毒和颗粒体病毒,对木毒蛾幼虫的复合感染试验,以及三种病毒最佳配比的筛选试验,发现木毒蛾质型多角体病毒、核多角体病毒和颗粒体病毒,按6:3:1混合后防治木毒蛾效果最佳。同时通过添加适量936乳油和人工大田繁殖木毒蛾病毒,较好地解决了病毒制剂的室温保存问题和毒源生产问题。复合病毒制剂的林间大面积防治试验结果表明,该制剂防治效果好,配制容易,成本低廉,不污染环境,是一种优良的生物制剂。  相似文献   

11.
Aquaporins: water channel proteins of the cell membrane   总被引:37,自引:0,他引:37  
Aquaporins (AQP) are integral membrane proteins that serve as channels in the transfer of water, and in some cases, small solutes across the membrane. They are conserved in bacteria, plants, and animals. Structural analyses of the molecules have revealed the presence of a pore in the center of each aquaporin molecule. In mammalian cells, more than 10 isoforms (AQP0-AQP10) have been identified so far. They are differentially expressed in many types of cells and tissues in the body. AQP0 is abundant in the lens. AQP1 is found in the blood vessels, kidney proximal tubules, eye, and ear. AQP2 is expressed in the kidney collecting ducts, where it shuttles between the intracellular storage sites and the plasma membrane under the control of antidiuretic hormone (ADH). Mutations of AQP2 result in diabetes insipidus. AQP3 is present in the kidney collecting ducts, epidermis, urinary, respiratory, and digestive tracts. AQP3 in organs other than the kidney may be involved in the supply of water to them. AQP4 is present in the brain astrocytes, eye, ear, skeletal muscle, stomach parietal cells, and kidney collecting ducts. AQP5 is in the secretory cells such as salivary, lacrimal, and sweat glands. AQP5 is also expressed in the ear and eye. AQP6 is localized intracellular vesicles in the kidney collecting duct cells. AQP7 is expressed in the adipocytes, testis, and kidney. AQP8 is expressed in the kidney, testis, and liver. AQP9 is present in the liver and leukocytes. AQP10 is expressed in the intestine. The diverse and characteristic distribution of aquaporins in the body suggests their important and specific roles in each organ.  相似文献   

12.
S. Xie  Y. Cui    T. Zhang  Z. Li 《Journal of fish biology》2000,57(4):867-880
Feeding ecology of three small fish species, Hypseleotris swinhonis, Ctenogobius giurinus and Pseudorasbora parva was studied seasonally in the Biandantang Lake, a small, shallow lake in central China. Gut length, adjusted for total body length, was significantly higher in spring than in other seasons for all the three species. Seasonal changes in gut length were not associated with changes in food quality. Weight of fore-gut contents, adjusted for body weight, was significantly higher in winter and spring than in summer and autumn in H. swinhonis and C. giurinus , and significantly higher in autumn than in spring and summer for P. parva. Percentage of empty fore-guts was highest in summer and lowest in spring for H. swinhonis and C. giurinus , and highest in winter and lowest in autumn for P. parva. Diet of the three small fishes showed apparent seasonal changes, and these changes reflected partly the seasonal fluctuations of food resources in environment. Diet breadth was high in winter and low in autumn for H. swinhonis , high in winter and low in spring and summer for C. giurinus , and high in autumn and low in spring for P. parva. Diet overlaps between pairs of species were biologically significant in most cases, except between H. swinhonis and P. parva in summer and autumn and between C. giurinus and P. parva in autumn.  相似文献   

13.
啮齿动物作用下退耕地山杏种子扩散与贮藏的季节变化   总被引:2,自引:0,他引:2  
啮齿动物对植物种子的取食和扩散影响种子的时空分布,继而影响种子的萌发和幼苗建成,因而在森林更新中起着重要作用.在国有济源市愚公林场,选择退耕地生境,于春季、夏季、秋季分别释放人工标记的山杏种子,观察啮齿动物扩散与埋藏山杏种子的季节性差异.结果表明:1)退耕地中的啮齿动物主要包括大林姬鼠、社鼠、黑线姬鼠;2)山杏种子扩散速率在春季显著慢于夏季,夏季显著慢于秋季;3)种子搬运量受季节和种子状态交互作用影响,春季显著少于夏季,夏季显著少于秋季;4)不同季节种子平均搬运距离不同,秋季不同状态种子的搬运距离均大于春季和夏季;5)啮齿动物对山杏种子的贮藏点大小多为1粒种子,少量为2、3粒种子,且贮藏点大小与季节间存在显著的交互作用,春季单粒种子的贮藏点数量显著少于夏季和秋季,而夏季与秋季的贮藏点则倾向于多粒种子;6)在夏季和秋季各有5枚(共释放1800枚)被啮齿动物分散贮藏的山杏种子建成幼苗.  相似文献   

14.
Palynology of South Indian Zingiberaceae   总被引:1,自引:0,他引:1  
MANGALY, J. K. & NAYAR, J. 1990. Palynology of South Indian Zingiberaceae. Light microscope studies on pollen morphology of 21 Old World, tropical taxa of Zingiberaceae reveal that an exine is absent only in Kaempferia . A discontinuous exine layer consisting of circular plates joined together at margins occurs in Alpinia galanga and Amomum hypoleucum while all other taxa possess an uninterrupted exine layer which is commonly 0.7 μm to less than 2.0 μrn thick (3.2 μm in Zingiber zerumbet , 2.5 μm in Amomum hypoleucum ). Exine is spinose in Alpinia (smooth in Alpinia sanderae ), Amomum and Boesenbergia , verrucose in Eleltaria , tuberculate to areolate or striate in Zingiber , papillose in Globba and smooth or nearly so in Curcuma, Costus and Hedychiurn . Pollen grains are spheroidal, 50–90 μm in size (35 μm in Globba ophioglossa ), and inaparturate (foraminate in Costus ), except in Curcuma and Zingiber where they are ovoid to ellipsoidal, 70–135 times 60–80 μm in size and sulcate. A lamellated intine, much thicker than the exine, occurs in all, and it is thinner at the apertural region in Curcuma, Costus and Zingiber; in Elettaria and Hedychiurn it is thinner in one or few large scattered circular areas, and in Boesenbergia and Alpinia zerumbet on one side of the grains. Palynologirally Alpinia, Amomum, Boesenbergia, Kaempferia and Zingiber constitute one group while Elettaria, Hedychiurn and Costus constitute another.  相似文献   

15.
The spined soldier bug, Podisus maculiventris, is a generalist predator of insects and has been used in biological control. However, information on the digestion of food in this insect is lacking. Therefore, we have studied the digestive system in P. maculiventris, and further characterized carbohydrases in the digestive tract. The midgut of all developmental stages was composed of anterior, median, and posterior regions. The volumes of the anterior midgut decreased and the median midgut increased in older instars and adults, suggesting a more important role of the median midgut in food digestion. However, carbohydrase activities were predominant in the anterior midgut. In comparing the specific activity of carbohydrases, α‐amylase activity was more in the salivary glands (with two distinct activity bands in zymograms), and glucosidase and galactosidase activities were more in the midgut. Salivary α‐amylases were detected in the prey hemolymph, demonstrating the role of these enzymes in extra‐oral digestion. However, the catalytic efficiency of midgut α‐amylase activity was approximately twofold more than that of the salivary gland enzymes, and was more efficient in digesting soluble starch than glycogen. Midgut α‐amylases were developmentally regulated, as one isoform was found in first instar compared to three isoforms in fifth instar nymphs. Starvation significantly affected carbohydrase activities in the midgut, and acarbose inhibited α‐amylases from both the salivary glands and midgut in vitro and in vivo. The structural diversity and developmental regulation of carbohydrases in the digestive system of P. maculiventris demonstrate the importance of these enzymes in extra‐oral and intra‐tract digestion, and may explain the capability of the hemipteran to utilize diverse food sources.  相似文献   

16.
We present an updated worldwide phylogenetic classification of Poaceae with 11 783 species in 12 subfamilies, 7 supertribes, 54 tribes, 5 super subtribes, 109 subtribes, and 789 accepted genera. The subfamilies (in descending order based on the number of species) are Pooideae with 4126 species in 219 genera, 15 tribes, and 34 subtribes; Panicoideae with 3325 species in 242 genera, 14 tribes, and 24 subtribes; Bambusoideae with 1698 species in 136 genera, 3 tribes, and 19 subtribes; Chloridoideae with 1603 species in 121 genera, 5 tribes, and 30 subtribes; Aristidoideae with 367 species in three generaand one tribe; Danthonioideae with 292 species in 19 generaand 1 tribe; Micrairoideae with 192 species in nine generaand three tribes; Oryzoideae with 117 species in 19 genera, 4 tribes, and 2 subtribes; Arundinoideae with 36 species in 14 genera and 3 tribes; Pharoideae with 12 species in three generaand one tribe; Puelioideae with 11 species in two generaand two tribes; and the Anomochlooideae with four species in two generaand two tribes. Two new tribes and 22 new or resurrected subtribes are recognized. Forty-five new (28) and resurrected (17) genera are accepted, and 24 previously accepted genera are placed in synonymy. We also provide an updated list of all accepted genera including common synonyms, genus authors, number of species in each accepted genus, and subfamily affiliation. We propose Locajonoa, a new name and rank with a new combination, L. coerulescens. The following seven new combinations are made in Lorenzochloa: L. bomanii, L. henrardiana, L. mucronata, L. obtusa, L. orurensis, L. rigidiseta, and L. venusta.  相似文献   

17.
本文收集了19—38岁国人正常男性新鲜睾丸、附睾和输精管13例,进行了氧化还原酶组织化学染色、光镜定位及定性观察。结果表明:睾丸曲细精管和输出小管上皮的GDH,NADHD,NADPHD,SDH,GPDH,ICDH,MDH,LDH和G-6-PDH9种酶;睾丸间质细胞和附睾管上皮的NADHD,NADPHD,SDH,ICDH,MDH,GDH,LDH和G-6-PDH8种酶;输精管的NADHD,NADPHD,ICDH和GDH4种酶的酶活性呈强阳性或极强阳性。提示输出小管和头部附睾管含有的多种氧化还原酶对精子功能成熟有极重要作用。  相似文献   

18.
The ontogenetic trends in the expression of 25 isozymes in liver, gizzard, heart, and pectoralis muscle of White Leghorn chickens were examined using starch gel electrophoresis. Little change in expression during development was evident in liver S-AAT-A, GPI-A, S-ICDH-A, S-MDH-A and M-MDH-A, in gizzard S-ACON-A, ADH-A, GPI-A, HK-1, HK-3, ME-A PEP-1, and PGM-A, in heart ADH-A, HK-1, HK-3, ME-A, PEP-2, PGM-A, and LDH-A, in pectoralis M-ACON-A, S-ACON-A, ADH-A, HK-1, HK-3, ME-A, PEP-2, and PGM-A, and in liver, gizzard, and heart M-ACON-A, ALD-A, CK-A, G3PDH-A, HK-1, and PGDH-A. Increasing levels of activity were demonstrated in liver ADH-A, ME-A, and PEP-2, in heart M-MDH-A, S-ICDH-A, M-ICDH, and M-AAT-A, and in pectoralis LDH-A, LDH-B, G3PDH-3, ALD-A, CK-A, HK-2, and PGM-B. There was a decrease in the activity of HK-1 in liver and in PEP-1 and PGDH-A in pectoralis muscle throughout development. While CK-C is active in the embryonic pectoralis, CK-A is restricted to later developmental stages. Isozyme expressions in regions of the pectoralis containing fast and slow muscle fibers in 7-month-posthatch individuals were noted and found to be identical. The results underscore the need to use similar developmental stages and tissue samples in comparative electrophoretic studies of birds.This study was supported by Natural Sciences and Engineering Research Council of Canada Grant A9866 to J.P.B.  相似文献   

19.
Al adjuvants are used in vaccines to increase the immune response. NTPDase and AChE play a pivotal role and act in the regulation of the immune system. The effect of Al exposure in vitro and in vivo on NTPDase and AChE activities in the lymphocytes of rats was determined. In vitro, ATP hydrolysis was decreased by 20.4% and 17.3% and ADP hydrolysis was decreased by 36.5% and 34.8%, in groups D and E, respectively, when compared to the control. AChE activity was increased by 157.3%, 152.5%, 74.7% and 90.8% in groups B, C, D, and E, respectively, when compared to the control. In vivo, ATP hydrolysis was increased by 85% and 86% and ADP hydrolysis was increased by 104.2% and 74%, in Al plus citrate and Al groups, respectively, when compared to the control. AChE activity was increased by 50.7% in Al plus citrate and by 28.6% in Al groups, when compared to the control. Our results show that Al exposure both in vitro and in vivo altered NTPDase and AChE activities in lymphocytes. These results may demonstrate the ability of Al to elicit the immune system, where NTPDase and AChE activities can act as purinergic and cholinergic markers in lymphocytes.  相似文献   

20.
We investigated the effects of naringin on small intestine, liver, kidney and lung recovery after ischemia/reperfusion (I/R) injury of the gut. Rats were divided randomly into four groups of eight. Group A was the sham control; group B was ischemic for 2 h; group C was ischemic for 2 h and re-perfused for 2 h (I/R); group D was treated with 50 mg/kg naringin after ischemia, then re-perfused for 2 h. Endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) expressions were detected by immunolabeling. We also measured arginase activity, amounts of nitric oxide (NO) and total protein. iNOS was increased significantly in the small intestine, liver and kidney in group C. iNOS was decreased significantly only in small intestine and lung in group D. eNOS was increased significantly in the small intestine, liver and lung in group C. eNOS was decreased in small intestine, liver and lung in group D; however, eNOS was decreased in the kidney in group C and increased in the kidney in group D. The amount of NO was decreased significantly in all tissues in group D, but arginase activity was decreased in the small intestine and lung, increased in the kidney and remained unchanged in the liver in group D. The total protein increased in the small intestine and liver in group D, but decreased significantly in the kidney and lung in group D. Naringin had significant, salutary effects on the biochemical parameters of I/R by decreasing the NO level, equilibrating iNOS and eNOS expressions, and decreasing arginase activity.  相似文献   

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