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31.
广东省新发现一种危害水稻的入侵性瘿螨   总被引:1,自引:0,他引:1  
最近两年一种新的入侵性瘿螨在中国广东省韶关市危害水稻。这种螨曾经在泰国北部被报道过,推测后来传入中国,目前在韶关严重危害水稻。这种螨被鉴定为具沟掌瘿螨Cheiracus sulcatus Keifer,并进行了重新描述和绘图,对危害症状进行了拍照和描述。文章还分析了其扩散风险性,并提出了控制传播的建议。  相似文献   
32.
退化红壤植被恢复对土壤螨类群落结构的影响   总被引:6,自引:0,他引:6  
对退化红壤地区的旱生性草坡、稀疏针叶林、针叶林、针阔混交林等4种植被恢复类型及裸地、顶级常绿阔叶林等2个对照样地的土壤螨类群落进行四季调查,共捕获4亚目53科,其中隐气门亚目27科(Cryptostigmata),前气门亚目(Prostigmata)17科,中气门亚目(Mesostigmata)8科,无气门亚目(Astigmata)1科,优势类群为矮汉甲螨科(Nanhermanniidae)和单翼甲螨科(Haplozetidae),常见类群包括若甲螨科(Oribatulidae)、盖头甲螨科(Tectocepheidae)等16科。应用个体密度、类群数、香农多样性、密度.类群DG指数、丰富度和均匀度、甲螨群落的MGP分析和捕食性螨类MI指数,研究其中螨类的群落结构特征。研究结果表明:不同植被类型土壤螨类群落差异显著,各项指标均以常绿阔叶林为最高,其次为稀疏针叶林,显著高于其它样地(P〈0.05),针叶林和裸地处于最低水平。甲螨群落类群结构中,各植被类型中的甲螨群落均属于M型;甲螨个体密度结构类型中,裸地属于MP型,旱生性草坡属P型,常绿阔叶林属于O型,其它均属于M型。中气门螨类的MI指数在各植被类型没有明显的变化。DCA分析将6类型分为3类:裸地、常绿阔叶林各为一类,其余各类型归为一类,这显示了土壤螨类群落对植被恢复不同类型的响应。  相似文献   
33.
HLA-A, -B and -DRB1 allele frequencies and their haplotype frequencies in 21,918 Chinese residents living in Liaoning Province, who were registered as volunteer donors of China Marrow Donor Registry, were investigated. They are composed of 93.37% Han Chinese, 5.1% Manchus, 0.57% Mongols, 0.46% Hui persons, 0.29% Koreans and 0.14% Xibe ethnic group. In total eighteen different HLA-A alleles, forty-eight different HLA-B alleles and fourteen different HLA-DRB1 alleles have been identified. Their frequencies are in agreement with the Hardy-Weinberg equilibrium. For Han Chinese in Liaoning, 1,534 different HLA-A-B-DRB1 haplotypes were identified, with a frequency of higher than 0.01%. A*30-B*13-DRB1*07, A*02-B*46-DRB1*09 and A*02-B*13-DRB1*12 are the most frequent haplotypes among Liaoning Han. While Liaoning Han, Liaoning Manchu, Liaoning Mongol, Liaoning Hui and Liaoning Korean share the northern Han characteristic haplotypes, all minority ethnic groups with the exception of Liaoning Manchu have developed their own unique HLA profiles. This dataset characterizes the HLA allele and haplotype frequencies in the Liaoning area and suggests that it is different from those in other parts of China and ethnic groups, which implicates transplant donor searching strategies and studies on population genetics.  相似文献   
34.
35.
MYB 转录因子在植物抗逆胁迫中的作用及其分子机理   总被引:26,自引:0,他引:26  
刘蕾  杜海  唐晓凤  吴燕民  黄玉碧  唐益雄 《遗传》2008,30(10):1265-1271
摘要: 在植物抗逆反应体系中, 通过转录因子调控功能基因的表达, 是植物逆境应答反应的关键环节。作为植物体内最大的转录因子家族之一, MYB(v-myb avian myeloblastosis viral oncogene homolog)类转录因子在植物抗逆胁迫过程中起着重要的作用。文章论述了MYB转录因子的结构特征、功能特性及其分子机理, 并结合研究进展着重讨论了它们在植物抗逆胁迫中的作用。  相似文献   
36.
Cyclin-dependent kinase (CDK) inhibitor p27Kip1 binds to the cyclin E.CDK2 complex and plays a major role in controlling cell cycle and cell growth. Our group and others have reported that anti-HER2 monoclonal antibodies exert inhibitory effects on HER2-overexpressing breast cancers through G1 cell cycle arrest associated with induction of p27Kip1 and reduction of CDK2. The role of p27Kip1 in anti-HER2 antibody-induced cell cycle arrest and growth inhibition is, however, still uncertain. Here we have provided several lines of evidence supporting a critical role for p27Kip1 in the anti-HER2 antibody-induced G1 cell cycle arrest and tumor growth inhibition. Induction of p27Kip1 and G1 growth arrest by anti-HER2 antibody, murine 4D5, or humanized trastuzumab (Herceptin) are concentration-dependent, time-dependent, irreversible, and long-lasting. The magnitude of G1 cell cycle arrest induced by trastuzumab or 4D5 is well correlated with the level of p27Kip1 protein induced. Up-regulation of p27Kip1 and G1 growth arrest could no longer be removed with as little as 14 h of treatment with trastuzumab. Anti-HER2 antibody-induced p27Kip1 protein, G1 arrest, and growth inhibition persist at least 5 days after a single treatment. The magnitude of growth inhibition of breast cancer cells induced by anti-HER2 antibody closely parallels the level of p27Kip1 induced. Induced expression of exogenous p27Kip1 results in a p27Kip1 level-dependent G1 cell cycle arrest and growth inhibition similar to that obtained with anti-HER2 antibodies. Reducing p27Kip1 expression using p27Kip1 small interfering RNA blocks anti-HER2 antibody-induced p27Kip1 up-regulation and G1 arrest. Treatment with anti-HER2 antibody significantly increases the half-life of p27Kip1 protein. Inhibition of ubiquitin-proteasome pathway, but not inhibition of calpain and caspase activities, up-regulates p27Kip1 protein to a degree comparable with that obtained with anti-HER2 antibodies. We have further demonstrated that anti-HER2 antibody significantly decreases threonine phosphorylation of p27Kip1 protein at position 187 (Thr-187) and increases serine phosphorylation of p27Kip1 protein at position 10 (Ser-10). Expression of S10A and T187A mutant p27Kip1 protein increases the fraction of cells in G1 and reduces a further antibody-induced G1 arrest. Consequently, p27Kip1 plays an important role in the anti-HER2 antibody-induced G1 cell cycle arrest and tumor growth inhibition through post-translational regulation. Regulation of the phosphorylation of p27Kip1 protein is one of the post-translational mechanisms by which anti-HER2 antibody upregulates the protein.  相似文献   
37.
HW Gao  LP Wang  S Liang  YX Liu  SL Tong  JJ Wang  YP Li  XF Wang  H Yang  JQ Ma  LQ Fang  WC Cao 《PloS one》2012,7(8):e43686
Malaria is re-emerging in Anhui Province, China after a decade long’ low level of endemicity. The number of human cases has increased rapidly since 2000 and reached its peak in 2006. That year, the malaria cases accounted for 54.5% of total cases in mainland China. However, the spatial and temporal patterns of human cases and factors underlying the re-emergence remain unclear. We established a database containing 20 years’ (1990–2009) records of monthly reported malaria cases and meteorological parameters. Spearman correlations were used to assess the crude association between malaria incidence and meteorological variables, and a polynomial distributed lag (PDL) time-series regression was performed to examine contribution of meteorological factors to malaria transmission in three geographic regions (northern, mid and southern Anhui Province), respectively. Then, a two-year (2008–2009) prediction was performed to validate the PDL model that was created by using the data collected from 1990 to 2007. We found that malaria incidence decreased in Anhui Province in 1990s. However, the incidence has dramatically increased in the north since 2000, while the transmission has remained at a relatively low level in the mid and south. Spearman correlation analyses showed that the monthly incidences of malaria were significantly associated with temperature, rainfall, relative humidity, and the multivariate El Niño/Southern Oscillation index with lags of 0–2 months in all three regions. The PDL model revealed that only rainfall with a 1–2 month lag was significantly associated with malaria incidence in all three regions. The model validation showed a high accuracy for the prediction of monthly incidence over a 2-year predictive period. Malaria epidemics showed a high spatial heterogeneity in Anhui Province during the 1990–2009 study periods. The change in rainfall drives the reemergence of malaria in the northern Anhui Province.  相似文献   
38.
【背景】乳链菌肽主要是由乳酸乳球菌生产的一类多肽,对革兰氏阳性菌有抑菌作用,是目前联合国粮食及农业组织/世界卫生组织唯一批准使用的天然食品防腐剂。但是其产量低、缺乏简便高效的检测方法,限制了其研究和应用。【目的】构建一种可输出肉眼可见红色荧光的细胞分子传感器,以期能简单方便地检测样品中的乳链菌肽,同时应用该传感器筛选乳链菌肽生产菌株。【方法】用Golden-Gate克隆方法构建含乳链菌肽诱导启动子和下游红色荧光蛋白基因(两种)的载体,转入Lactococcus lactis中。用细胞传感器筛选可能的乳链菌肽生产菌株。【结果】构建的两种乳链菌肽细胞分子传感器都能对2-200 ng/mL乳链菌肽有灵敏的响应,可用于定量测定。两种传感器的最大荧光强度和表型也有所不同。利用细胞传感器确定了Lactococcus lactis ATCC 11454乳链菌肽的产生,同时排除了一个能产其他抗菌化合物的菌株。【结论】构建的细胞分子传感器能特异性地响应乳链菌肽,并能简单快速地筛选乳链菌肽菌株。  相似文献   
39.
利用流式细胞仪研究拟南芥叶发育过程中细胞周期的调控   总被引:1,自引:0,他引:1  
叶的形态建成依赖于细胞不断地分裂增殖和不同类型细胞的特化。在叶发育早期,叶细胞主要通过旺盛的有丝分裂来增加原基中细胞的数目。随着叶片的生长,叶细胞自顶部向基部逐渐退出有丝分裂进入内复制来增加细胞的倍性,同时伴随细胞的扩展和分化。本文介绍利用流式细胞仪研究双子叶模式植物拟南芥叶发育过程中细胞周期调控的方法和具体研究实例。我们发现至少存在3种类型的细胞周期异常的拟南芥叶发育突变体。此外,我们还介绍利用流式细胞仪测定DNA复制效率的方法。  相似文献   
40.
野生动植物种群和生物多样性的垂直分布模式是生态学研究中的重要问题,而目前对于大型兽类的垂直分布模式却了解较少。本研究以秦岭南坡森林生态系统中的有蹄类动物为对象,使用相机陷阱调查技术(camera-trapping),系统的调查了研究区域内大中型兽类的分布情况。我们将研究区域按300 m垂直间隔划分为5个海拔段,分别计算各海拔段内目标物种的相对多度指数(Relative Abundance Index, RAI)和物种丰富度(species richness),研究有蹄类动物群落的组成和垂直分布特征。2008年3~12月,共调查123个有效位点,在4 307个有效相机工作日中共记录到7种森林有蹄类动物。其中,羚牛(Budorcas taxicolor)为秦岭南坡有蹄类动物群落中的优势物种(平均RAI = 110.66),种群数量最多;其次是野猪(RAI = 28.25)和斑羚(RAI = 25.10);林麝(Moschus berezovskii)则是群落中种群数量最少的物种(RAI = 1.33)。在本研究所涉及的海拔梯度内,各物种种群数量的垂直分布模式为:羚牛和林麝为单峰型,种群数量在中间海拔段存在一个峰值,两侧递减;斑羚(Naemorhedus goral)为单调递增型(R2 = 0.84),种群数量大体随着海拔梯度的升高而增加;小麂(Muntiacus reevesi)(R2 = 0.94)和鬣羚(Capricornis sumatraensis)(R2 = 0.79)为单调递减型,种群数量随着海拔梯度的升高而减少;野猪(Sus scrofa)和毛冠鹿(Elaphodus cephalophus)为复合型,分布模式较为复杂。整个有蹄类群落的物种丰富度的垂直分布表现为中峰模式,在1 700~2 300 m的中等海拔段最高,符合中域效应假说的预测。  相似文献   
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