Amblyomma sculptum: genetic diversity and rickettsias in the Brazilian Cerrado biome

Amblyomma sculptum (Ixodida: Ixodidae) Berlese, 1888 is the most important tick vector in Brazil, transmitting the bioagent of the most severe form of spotted fever (SF) in part of the Cerrado (in the states of Minas Gerais and São Paulo). In another part of the Cerrado (Central‐West region of Brazil), a milder form of SF has been recorded. However, neither the rickettsia nor the vector involved have been characterized. The aim of the current study was to analyse genetic variation and the presence of rickettsia in A. sculptum in Cerrado, from silent areas and with the milder form of SF. Samples were subjected to DNA extraction, amplification and sequencing of 12S rDNA, cytochrome oxidase subunit II and D‐loop mitochondrial genes (for tick population analyses), and gltA, htrA, ompA and gene D (sca4) genes for rickettsia researches. Exclusive haplotypes with low frequencies, high haplotype diversity and low nucleotide diversity, star‐shaped networks and significant results in neutrality tests indicate A. sculptum population expansions in some areas. Rickettsia amblyommatis, Candidatus Rickettsia andeanae and Rickettsia felis were detected. The A. sculptum diversity is not geographically, or biome delimited, pointing to a different potential in vector capacity, possibly associated with differing tick genetic profiles.     

Acetazolamide inhibits osmotic water permeability by interaction with aquaporin-1

Water channel proteins, known as aquaporins, are transmembrane proteins that mediate osmotic water permeability. In a previous study, we found that acetazolamide could inhibit osmotic water transportation across Xenopus oocytes by blocking the function of aquaporin-1 (AQP1). The purpose of the current study was to confirm the effect of acetazolamide on water osmotic permeability using the human embryonic kidney 293 (HEK293) cells transfected with pEGFP/AQP1 and to investigate the interaction between acetazolamide and AQP1. The fluorescence intensity of HEK293 cells transfected with pEGFP/AQP1, which corresponds to the cell volume when the cells swell in a hyposmotic solution, was recorded under confocal laser fluorescence microscopy. The osmotic water permeability was assessed by the change in the ratio of cell fluorescence to certain cell area. Acetazolamide, at concentrations of 1 and 10muM, inhibited the osmotic water permeability in HEK293 cells transfected with pEGFP/AQP1. The direct binding between acetazolamide and AQP1 was detected by surface plasmon resonance. AQP1 was prepared from rat red blood cells and immobilized on a CM5 chip. The binding assay showed that acetazolamide could directly interact with AQP1. This study demonstrated that acetazolamide inhibited osmotic water permeability through interaction with AQP1.     

苜蓿切叶蜂滞育的诱导因素研究

苜蓿切叶蜂Megachile rotundata(F.)预蛹的滞育主要受光周期和温度的影响。雌蜂感受光周期的变化是决定子代预蛹是否进入滞育的一个主要因素;当代的幼期,特别是高龄幼虫(约3龄)到预蛹这一阶段所感受的温度变化,对预蛹滞育有很大的影响,此期如果环境温度低于(21.59±1.03)℃,可有超过50%的个体进入滞育。此外,放蜂地区的纬度及蜂的代次对预蛹的滞育亦有重要的影响。     

In Vivo Generation of Post-infarct Human Cardiac Muscle by Laminin-Promoted Cardiovascular Progenitors

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农田防护林木材材质物理特性研究

对早柳和小青杨的年轮宽度、年轮密度、木材纤维长度和干缩率及其径向变异进行了研究．结果表明,木材物理特性受年轮年龄的影响显著,而纤维长度不受年轮宽度影响．综合材质物理特性的径向变异规律,可将旱柳和小青杨整个生长期划分为４个时期：幼林期、速生期、成熟期和更新期,确定了各生长期的年龄值．     

浙江天童20ha常绿阔叶林动态监测样地的群落特征

常绿阔叶林是我国东部低海拔地区的典型植被,基于大型动态监测样地的群落特征分析是揭示其生物多样性维持机制的基础.作者在天章国家森林公园建立了20 ha的样地,并完成了第一次群落学特征调查和分析.结果显示,样地内共有胸径≥1 cm的木本植物152种94,603株,隶属51科94属.重要值最大的前3个科依次是山茶科、樟科和壳斗科.属水平上热带区系成分占总属数的52.1%,温带区系成分占42.6%.常绿物种在样地内占绝对优势,占总重要值的80.3%.重要值最大的3个种依次是细枝柃(Eurya loquaiana)、黄丹木姜子(Litsea elongata)和南酸枣(Choerospondias axiliaris);稀有种共计55种,占总物种数的36.2%.木本植物整体径级结构呈逆"J"字型.萌枝分枝 情况表明,常绿物种的萌、分枝能力强于落叶物种.此结果表明天童常绿阔叶林物种组成丰富,群落成熟稳定,更新良好,反映了亚热带东部常绿阔叶林的典型特征.     

亚热带常绿阔叶林林窗物种丰富度的影响因素

林窗是森林群落物种多样性维持中十分重要的结构,但其本身物种多样性的维持机制尚不清楚,可能与相邻群落的物种丰富度、林窗面积以及土壤和地形因子等有关。本文选取浙江天童20 ha森林动态监测样地内的84个冠林窗作为研究对象,分析了林窗内部以及不同距离邻域内的物种组成,选取包含大部分林窗内物种(≥75%),并且对林窗内物种丰富度影响最大的邻域作为相关邻域(林窗周围成熟植株通过种子传播影响林窗物种丰富度,把距离冠林窗边缘5 m范围内的区域作为种源效应邻域;由于距离林窗较近,物种组成与林窗形成时仍存活个体的物种组成相似,故把距离冠林窗边缘4 m范围内的区域作为距离效应邻域),然后计算种源效应邻域内成熟植株的物种丰富度、距离效应邻域内所有植株的物种丰富度、冠林窗的面积、地形因子(海拔、坡度、坡向、凸度)和土壤因子(p H值、全氮、全碳、全磷),最后对11个潜在的影响因素进行随机组合,构建广义线性回归模型,筛选最优模型(AICc最小)进行分析。结果显示:种源效应邻域内成熟植株的物种丰富度和冠林窗面积显著影响林窗内物种丰富度,其他因素并未对冠林窗内物种丰富度产生显著影响。上述结果说明,冠林窗面积的大小以及外部种源的丰富程度是决定冠林窗内物种丰富度的主要因素,其他因素可能只产生间接影响。     

Characterization of the Ubiquitin-Conjugating Enzyme Gene Family in Rice and Evaluation of Expression Profiles under Abiotic Stresses and Hormone Treatments

Ubiquitin-conjugating enzyme E2s (UBCs), which catalyze the transfer of ubiquitin to substrate or E3 ligases, are key enzymes in ubiquitination modifications of target proteins. However, little is known about the knowledge of UBC gene family in rice. In this study, a total of 39 UBC encoding genes, which all contained an UBC domain with a cysteine active site, were identified in the rice genome. These were classified into fifteen distinct subfamilies based upon their sequence similarity and phylogenetic relationships. A subset of 19 OsUBC genes exhibited chromosomal duplication; 4 and 15 OsUBC genes were tandemly and segmentally duplicated, respectively. Comprehensive analyses were performed to investigate the expression profiles of OsUBC genes in various stages of vegetative and reproductive development using data from EST, Microarrays, MPSS, and real-time PCR. Many OsUBC genes exhibited abundant and tissue-specific expression patterns. Moreover, 14 OsUBCs were found to be differentially expressed under treatments with drought, or salt stresses. The expression analysis after treatments with IAA, 6-BA, GA and ABA indicated that almost all OsUBC genes were responsive to at least two of the four hormones. Several genes were significantly down-regulated under all of the hormone treatments, and most of the genes reduced by 6-BA were also reduced by GA. This study will facilitate further studies of the OsUBC gene family and provide useful clues for functional validation of OsUBCs in rice.     

铅锌镉联合染毒及营养干预对大鼠血液系统的影响研究

目的：了解铅锌镉联合染毒对大鼠血液系统的影响及营养干预对其损伤的修复作用。方法：选择SPF级初断乳Wistar大鼠72只,随机分为对照组、染毒组和干预组,分别采用生理盐水、铅锌镉联合染毒液及染毒后以营养干预液灌胃28天和56天之后,检测其血液系统中五元素和血细胞的指标。结果：染毒组较对照组大鼠血铜、血锌含量高,血钙含量低于对照组,差异均有统计学意义（P〈0．05）;染毒组血铜含量高于干预组,血钙含量低于干预组,差异均有统计学意义（P〈0．05）;干预组红细胞（RBC）计数、血红蛋白（Hb）、血细胞比容（HCT）均高于染毒组,差异均有统计学意义（P〈0．05）;对照组白细胞（WBC）计数高于染毒组、干预组,差异均有统计学意义（P〈0．05）。结论：铅镉对大鼠血铜、血钙、血锌水平有影响;综合营养干预对重金属元素造成的血液系统损伤有明显的拮抗作用,对血液系统有一定的保护及修复作用。