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A region of the Herpesvirus saimiri genome required for oncogenicity   总被引:26,自引:0,他引:26  
Herpesvirus saimiri naturally infects squirrel monkeys (Saimiri sciureus) without producing signs of disease; infection of other New World primates, however, results in a rapidly progressing, malignant, T-cell lymphoma. Results described in this report identify a region of the viral genome that is required for oncogenicity in owl monkeys (Aotus trivirgatus); this region is not required for replication of the virus. This is believed to be the first such genomic region identified in a herpesvirus system.  相似文献   

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Desipramine and several other tricyclic antidepressant drugs reverse chloroquine resistance in Plasmodium falciparum in vitro at concentrations observed in the plasma of human patients treated for depression. Reversal of resistance is associated with increased chloroquine accumulation in the parasite, probably because of inhibition of a putative chloroquine efflux pump. When owl monkeys (Aotus lemurinus lemurinus) infected with chloroquine-resistant Plasmodium falciparum were treated with chloroquine plus desipramine, their parasitemias were rapidly suppressed. Desipramine was found to be one of the most effective compounds yet described for the reversal of chloroquine resistance both in vitro and in vivo.  相似文献   

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Plasmodium falciparum chloroquine resistance is a major cause of worldwide increases in malaria mortality and morbidity. Recent laboratory and clinical studies have associated chloroquine resistance with point mutations in the gene pfcrt. However, direct proof of a causal relationship has remained elusive and most models have posited a multigenic basis of resistance. Here, we provide conclusive evidence that mutant haplotypes of the pfcrt gene product of Asian, African, or South American origin confer chloroquine resistance with characteristic verapamil reversibility and reduced chloroquine accumulation. pfcrt mutations increased susceptibility to artemisinin and quinine and minimally affected amodiaquine activity; hence, these antimalarials warrant further investigation as agents to control chloroquine-resistant falciparum malaria.  相似文献   

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小麦抗旱生态分类中的主要农艺性状   总被引:4,自引:0,他引:4  
选用15个冬小麦品种(系)、在大田自然干旱条件下种植。对专家经验分类和两种较理想的数学分类结果(对应分析法和模糊聚类法)分别进行了逐步判别分析,从21个农艺性状中筛选出5个在小麦抗旱生态分类鉴定中应用价值较大的性状。它们是:株高、茎粗、旗叶弯曲度、千粒重、顶部三叶面积。其中以株高、茎粗、旗叶弯曲度最为重要。  相似文献   

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丽水地区茶园主要害虫及其天敌种类调查   总被引:2,自引:0,他引:2       下载免费PDF全文
近年对浙江省丽水茶区的莲都区、龙泉市、松阳县、遂昌县、景宁县、缙云县、庆元县、云和县和青田县茶园主要害虫和种类进行了考察。本文记载了害虫100种,各类天敌168种,其中天敌昆虫91种、蜘蛛33种、虫生真菌36种、昆虫病毒7种、昆虫病原细菌1种,还有中性昆虫22种。拟为茶园病虫资源的调查与利用提供参考。  相似文献   

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平顶山市主要农作物的比较优势分析   总被引:9,自引:1,他引:9  
对平顶山市主要农作物的单产比较优势指数、规模比较优势指数以及综合比较优势指数进行了计算和分析,结果表明:与河南省的平均水平相比,玉米、薯类、烟叶具有明显的比较优势;与全国平均水平相比,小麦、玉米、薯类、花生、芝麻、烟叶具有明显的比较优势。在对主要农作物比较优势分析的基础上提出了平顶山市农作物结构调整的建议。  相似文献   

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We surveyed an Anopheles gambiae population in a West African malaria transmission zone for naturally occurring genetic loci that control mosquito infection with the human malaria parasite, Plasmodium falciparum. The strongest Plasmodium resistance loci cluster in a small region of chromosome 2L and each locus explains at least 89% of parasite-free mosquitoes in independent pedigrees. Together, the clustered loci form a genomic Plasmodium-resistance island that explains most of the genetic variation for malaria parasite infection of mosquitoes in nature. Among the candidate genes in this chromosome region, RNA interference knockdown assays confirm a role in Plasmodium resistance for Anopheles Plasmodium-responsive leucine-rich repeat 1 (APL1), encoding a leucine-rich repeat protein that is similar to molecules involved in natural pathogen resistance mechanisms in plants and mammals.  相似文献   

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海南中西部橡胶主栽品种寒害适应性调查   总被引:1,自引:0,他引:1  
2008年4月针对橡胶品种、树龄及立地环境等因素,对海南巾西部植胶区的儋州、临高、白沙等地主要橡胶品种的寒害情况进行了调查,结果表明:临高植胶区受寒害影响最严重,儋州、白沙植胶区的寒害相对较轻;橡胶品种热研7-33-97表现出较好的寒害适应性(寒害级别和指数分别为1.07级和17.91),RRIM600和热研8-79的寒害适应性次之,而PR107的寒害适应性最差、受害最严重(寒害级别和寒害指数分别达到2.42级和40.27);此外,开割树比幼龄树较抗寒,但与近开割树的寒害差异不明显.  相似文献   

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广东省主要番茄品种对青枯病的抗性研究初报   总被引:2,自引:1,他引:2  
选取不同致病力的番茄青枯菌菌株,就广东生产上栽培的主要番茄品种对青枯病的抗性进行测定,结果表明:对于致病型Ⅰ的代表菌株(ZC-1),除年丰、穗丰和益丰3个品种表现为耐病外,其余6个品种均表现为感病;而对于致病型Ⅳ的代表菌株(SS-6),丰顺、大丰顺、新星101、年丰、益丰和穗丰均表现为高抗,金丰1号表现为中抗,红宝石和益农101表现为感病。  相似文献   

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白斑综合征病毒广西株缺失区基因的比较分析   总被引:1,自引:0,他引:1  
为了解广西养殖凡纳滨对虾中白斑综合征病毒(white spot syndrome virus,WSSV)的感染流行情况,并探讨WSSV广西株缺失区ORF23/24基因的遗传进化差异及其与各地WSSV毒株间的遗传进化关系,2010年5月至2013年9月在广西凡纳滨对虾主产区北海、钦州和防城港共采集306份患病虾样品,应用世界动物卫生组织(OIE)推荐的套式聚合酶链式反应(nested-PCR)方法进行WSSV检测;选取第一轮PCR为阳性的53份样品进行缺失区ORF23/24基因的PCR扩增,并将12份阳性PCR产物进行克隆、序列测定与比较分析。结果显示:306份患病虾样品中有82份为WSSV感染阳性,阳性率为26.8%;12株WSSV广西株缺失区ORF23/24基因大小均为2 096 bp,相对于此区域最为完整的WSSV-TW株,广西株均在中间缺失了10 970 bp;12株WSSV广西株的缺失区ORF23/24基因差异小,核苷酸同源性均在99.6%以上,仅存在少数碱基的替换,没有缺失和插入,其中BH-3、QZ-1、FCG-1和FCG-2的核苷酸序列完全一致;基于缺失区构建的系统发育进化树显示,WSSV广西地方株在遗传上相距较近,全部与印度株IN-05-Ⅰ聚在一个大的分支,而与台湾株、中国株及韩国株在遗传上相距较远。研究表明,WSSV感染在广西凡纳滨对虾主要养殖地区存在一定程度的流行;广西WSSV毒株缺失区ORF23/24基因的变异类型为中间大片段缺失,各毒株间无明显的地域和时间差异;WSSV广西株与印度株IN-05-Ⅰ的遗传进化关系最近。  相似文献   

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贵州省辣椒主栽品种抗疫病性鉴定   总被引:6,自引:0,他引:6  
采用灌根法对21个辣椒主栽品种进行了苗期人工接种鉴定.结果表明,对辣椒疫病表现高抗的品种有毕节线椒、雷山朝天椒和遵义朝天椒,表现抗的品种有7个,中抗品种6个,感病品种5个,分别占鉴定总数的14.3 %、33.3 %、28.6 %和23.8 %.7个辣椒品种进行田间自然抗性鉴定结果显示,当地普遍种植的湘研系列大辣椒品种高度感病,地方品种的抗病性相对较好,尤其是遵义朝d椒和绥阳辣椒等干椒品种.  相似文献   

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