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991.
福建马铃薯S病毒的分子鉴定及发生情况   总被引:2,自引:0,他引:2       下载免费PDF全文
为明确福建省马铃薯S病毒(PVS)的发生与分布情况,对福建省马铃薯主要种植区的PVS进行了鉴定和普查.在利用电镜技术和传统生物学方法鉴定的基础上,克隆了PVS外壳蛋白(cp)基因,依据PVS外壳蛋白氨基酸序列建立了PVS不同分离物的系统进化树.研究表明,利用PVS 外壳蛋白氨基酸序列分析可准确鉴定PVS,同时可分析不同分离物间的分子差异.利用病毒特异性引物和DIG标记的PVS cp基因为探针,分别利用RT-PCR技术和核酸斑点杂交技术(NASH)对PVS进行了检测,并对检测技术进行了改进.调查结果表明,PVS在福建省广泛分布,发病率最高可达80%以上,当地农家自留种可能是田间PVS的主要来源.  相似文献   
992.
AIM: To evaluate the effects of lactacystin (LAC) and β-lactacystin (β-LAC), proteasome inhibitor, on the proliferation and activation of T lymphocytes. METHODS: Flow cytometry was used to analyse the proliferation and the expression of CD69, CD25 and CD3 in PHA activated T-lymphocytes. Furthermore, the expression of PA28 and IL-2 mRNA were assayed by competitive RT-PCR. RESULTS: (1) LAC and β-LAC significantly decreased the incorporation in PHA activated T-lymphocytes. (2) Although LAC and β-LAC did not affect the expression of CD69 at any time, they significantly inhibited the expression of CD25 (48 h, 72 h, P<0.05). (3) In comparison with control, LAC and β-LAC significantly down-regulated the expression of PA28 and IL-2 mRNA (48 h, 72 h, P<0.05).CONCLUSIONS: LAC and β-LAC significantly inhibit the proliferation and activation of T lymphocytes. Mechanisms involved are inhibition of CD25 and down-regulation of PA28 and IL-2 mRNA expression.  相似文献   
993.
AIM: To investigate the effect and mechanism of fluvastatin on the migration induced by platelet derived growth factor-BB (PDGF-BB) and endothelin-1 (ET-1) in cultured vascular smooth muscle cells (VSMCs). METHODS: Cultured VSMCs derived from spontaneously hypertensive rats (SHR) were used. Cell migration was determined by modified Boyden chamber assays. Intracellular free calcium ([Ca2+]i) was measured with fluorescent Ca2+ indicator Fura-2/AM. RESULTS: PDGF-BB and ET-1 significantly induced VSMCs migration, which was inhibited by pretreatment of VSMCs with fluvastatin (10-9-10-5 mol/L) in a dose-dependent manner, and the peak inhibition rate of migration induced by PDGF-BB and ET-1 was over 86.67%. Fluvastatin also attenuated the increase in [Ca2+]i induced by PDGF-BB and ET-1, with a peak inhibition rate of 86.76% and 65.32%, respectively. CONCLUSION: PDGF-BB and ET-1 promote migration of VSMCs from SHR.Fluvastatin may have direct inhibitory effects on cell migration induced by PDGF-BB and ET-1. The increase in [Ca2+]i may acts as intracellular signaling in the migration in response to PDGF-BB and ET-1 in VSMCs.  相似文献   
994.
AIM: To investigate the relation between the time- spatiotemporal expression of caspase-9 and photoreceptor apoptosis as well as electroretinography (ERG) in Royal College of Surgeons (RCS) rats. METHODS: Twelve non-pigmented degenerative RCS rats at age of 15, 20, 25, 30 days were sacrificed after ERG examination. The caspase-9 expression was analyzed with immunohistochemical staining, fluoro-metric activity assay and Western blotting. Apoptotic retinal neurons were detected by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) technique. RESULTS: The latency and amplitude of b-wave were (58.60±3.42) ms and (109.07±14.50) mV, (56.45±1.08) ms and (109.00±7.35) mV, respectively, in 15 and 20 days old degenerative RCS rats. The ERG resembled flat form in the degenerative RCS rats at age of 25 and 30 days. TUNEL-positive cells were located only in the outer nuclear layer, mostly prevailed in 25-day-old group. Caspase-9 protein expressed in the rat retina started to be found immunohistochemically in 25-day-old and was most predominant in the inner segment. Fluorometric activity assay showed that caspase-9 activity reached its peak, (10.98±0.13) nmol·g-1·min-1 at 20th day. Western blot assay revealed the small cleavage fragmentation at 20th day. No cleavage fragmentation was revealed in the 15-day-old degenerative RCS rats and all other control rats. CONCLUSION: The activation and time-spatiotemporal expression of caspase-9 are coincidence with photoreceptor apoptosis as well as the loss of vision function in RCS degenerative rats, which implicates the important role of caspase-9 in photoreceptor apoptosis.  相似文献   
995.
柑桔裂皮病是一种危险性病害,笔者对其症状、发生危害情况进行了调查与观察,该病具有以品种带病传入和苗木传播为主、快速影响树势、产量和潜伏期长的特点,在防控对策上,应重点加强检疫严禁乱调种苗、建立无病毒苗木繁育体系及时清除病树、防止人为传播和加强培训提高防控意识。  相似文献   
996.
AIM: To down-regulate expression of c-myc through antisense therapy and to investigate its effect on the sensitivity of osteosarcoma MG-63 cells to cisplatin-induced apoptosis. METHODS: The recombinant adenovirus (Ad-Asc-myc) encoding antisense c-myc fragment was constructed and transfected into osteosarcoma MG-63 cells in vitro in order to down-regulate the expression of c-myc, and the change in the sensitivity to cisplatin-induced apoptosis was observed. MTT, Western blot, RT-PCR, flow cytometry (FCM) and electron microscope were used to evaluate tumor cell proliferation in vitro, genes expression related to apoptosis regulation and effects on the sensitivity of osteosarcoma MG-63 cells to cisplatin-induced apoptosis. RESULTS: Ad-Asc-myc down-regulated the expression of c-myc protein after transfected MG-63 cells for 48 h, combined with the treatment of 2.0 mg/L cisplatin for 2 h inhibited tumor cell proliferation in vitro by 38.0%. RT-PCR revealed that Ad-Asc-myc down-regulated the expression of Bcl-2 and up-regulated the expression of Bax. No appreciable change was observed in the expression of E2F-1. FCM showed that Ad-Asc-myc induced apoptosis in intransfected cells, and rendered it more sensitive to cisplatin. CONCLUSION: Antisense c-myc is able per se to induce apoptosis and sensitize osteosarcoma cells to cisplatin-induced apoptosis.  相似文献   
997.
阿拉善荒漠特有珍稀濒危植物绵刺克隆生长构型研究   总被引:13,自引:1,他引:13  
绵刺是阿拉善荒漠特有珍稀濒危植物 ,其具有独特的克隆生长构型 :由枝条下垂形成长间隔物的典型的游击型克隆生长构型和由根茎处形成的典型的密集型克隆生长构型。本文以环境塑造与克隆生长构型的可塑性关系研究绵刺的克隆生长构型 ,揭示其对环境表现出生态对策的高度适应性和可塑性  相似文献   
998.
Japanese leaf beet Beta vulgaris var. cicla cv. Fudanso plants were found to contain four double-stranded RNA (dsRNA) components in apparently healthy beet plants. Two were identified as from beet cryptic virus 1 (BCV1), but the other two showed different mobilities on gel electrophoresis and were transcribed into complementary DNA (cDNA) and cloned. Hybridization analysis showed no significant sequence homology between these two dsRNAs and the dsRNA components of BCV1 or the other known cryptic virus of beet, BCV2. Slot- and dot-blot hybridization were used with cDNA clones as probes to identify plants containing these two dsRNA components. Virus particles were purified from these plants and were shown to contain the two new dsRNA components, thus demonstrating the existence of a new beet cryptic virus, which we have called BCV3.  相似文献   
999.
豫西旱作烤烟优质稳产的优化水分管理模式研究   总被引:5,自引:0,他引:5  
豫西烟区年降雨量少,时空分布不均,土壤供水与烟叶生产需水出现矛盾,影响该区烟叶产量和质量。研究结果揭示,深耕可有效增加土壤蓄水,冬前起垄比春季起垄提高了土壤的含水量。增加有机肥,不仅增加土壤蓄水力,而且还有效提高烟叶的产量和质量。推迟移栽,地覆盖可提高水分利用率。通过以上技术措施,达到旱区烤烟优质的稳产的目的。  相似文献   
1000.
OPAY02型2条多态性条带经克隆、测序和引物设计后,转换成SCAR标记,并对86个新扬州鸡随机交配后代基因组DNA进行了PCR扩增.2条带DNA序列与红色原鸡基因组序列比对结果表明,大分子量条带与位于红色原鸡第3号染色体上序列有98%的同源性,共检测到8个SNPS,其中195位的碱基T→G,316位的A→T,538位的G→A,731位的T→A,1 147位的G→A,1 329位的T→C,1 927位的C→T,2 081位的C→T,小分子量条带与红色原鸡没有同源序列,推测新扬州鸡野祖除红色原鸡外,还有其它来源.SCAR标记分析表明,经条件优化随机扩增的OPAY02型标记稳定、可靠,可用于遗传分析.2条带所在座位群体基因型平衡性测验结果表明,所测新扬州鸡群体处于平衡状态,选择可以打破平衡,有利于动物育种.  相似文献   
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