Geographic variation in parasitism rates of two sympatric cuckoo hosts in China

Rates of brood parasitism vary extensively among host species and populations of a single host species. In this study, we documented and compared parasitism rates of two sympatric hosts, the Oriental Reed Warbler (Acrocephalus orientalis) and the Reed Parrotbill (Paradoxornis heudei), in three populations in China. We found that the Common Cuckoo (Cuculus canorus) is the only parasite using both the Oriental Reed Warbler and Reed Parrotbill as hosts, with a parasitism rate of 22.4%-34.3% and 0%-4.6%, respectively. The multiple parasitism rates were positively correlated with local parasitism rates across three geographic populations of Oriental Reed Warbler, which implies that higher pressure of parasitism lead to higher multiple parasitism rate. Furthermore, only one phenotype of cuckoo eggs was found in the nests of these two host species. Our results lead to two conclusions: (1) The Oriental Reed Warbler should be considered the major host of Common Cuckoo in our study sites; and (2) obligate parasitism on Oriental Reed Warbler by Common Cuckoo is specialized but flexible to some extent, i.e., using Reed Parrotbill as a secondary host. Further studies focusing on egg recognition and rejection behaviour of these two host species should be conducted to test our predictions.     

Three New Flavone Glycosides from Drymaria diandra B1.

In order to find new structural and biologically active compounds, the constituents from the whole plant of Drymaria diandra B1. （Caryophyllaceae） were investigated and three new flavone glycosides, named drymariatins B （1）, C （2）, and D （3）, were isolated by solvent partition, Si gel, sephadex LH-20, and Rp- 18 column chromatography. Using spectroscopic methods, including two-dimensional nuclear magnetic resonance analysis, the structures of these compounds were elucidated as 6-C-（2-deoxy-β-D-fucopyranosyl）- 5,7,4＇-trihydroxyl-flavone, 6-C-（2-deoxy-β-D-fucopyranosyl）-7-O-（β-D-glucopyranosyl）-5,4＇-dibydroxyl- flavone, and 6-C-（3-keto-β-digitoxopyranosyl）-7-O-（β-D-glucopyranosyl）-5,4＇-dihydroxyl-flavone.     

Chemical Constituents of the Roots of Anemone altaica Fisch. ex C. A. Mey.

The roots of Anemone altaica Fisch. ex C. A. Mey. have been used in the treatment of epilepsia, neurasthenia, and arthritis in Chinese folk medicine for a long time. In order to find new and bioactive compounds, the chemical constituents of the roots of A. altaica were investigated and nine compounds were isolated from the EtOH extract of this plant. On the basis of spectroscopic methods, the structures of these compounds were elucidated as 4-（9H-β-carbolin- 1-yl）-4-oxo-butyric acid （1）, carboxymethyl isoferulate （2）, isoferulic acid （3）, cirsiumaldehyde （4）, 5-hydroxy-4-oxo-pentanoic acid （5）, triacontane （6）, palmic acid （7）, β-sitosterol （8）, and daucosterol （9）. Among them, 1 and 2 were new compounds, and 3 and 4 were obtained from this genus for the first time.     

Root Morphology and Zn^2＋ Uptake Kinetics of the Zn Hyperaccumulator of Sedum alfredii Hance

Root morphology and Zn^2＋ uptake kinetics of the hyperaccumulating ecotype （HE） and nonhyperaccumulating ecotype （NHE） of Sedum alfredii Hance were investigated using hydroponic methods and the radiotracer flux technique. The results indicate that root length, root surface area, and root volume of NHE decreased significantly with increasing Zn^2＋ concentration in growth media, whereas the root growth of HE was not adversely affected, and was even promoted, by 500μmol/L Zn^2＋. The concentrations of Zn^2＋ in both ecotypes of S. alfredii were positively correlated with root length, root surface area and root volumes, but no such correlation was found for root diameter. The uptake kinetics for ^65Zn^2＋ in roots of both ecotypes of S. alfredii were characterized by a rapid linear phase during the first 6 h and a slower linear phase during the subsequent period of investigation. The concentration-dependent uptake kinetics of the two ecotypes of S. alfredii could be characterized by the Michaelis-Menten equation, with the Vmax for ^65Zn^2＋ influx being threefold greater in HE compared with NHE, indicating that enhanced absorption into the root was one of the mechanisms involved in Zn hyperaccumulation. A significantly larger Vmax value suggested that there was a higher density of Zn transporters per unit membrane area in HE roots.     

Progress in studies on the induction and differentiation of embryonic stem cells

Embryonic stem cells (ESCs), which are isolated from the inner cell mass of the blastocysts, have the potential to give rise to an entire organism and to gen-erate every body cell type. During the last two years, much progress has been made in ESCs field, espe-cially in the induction and differentiation of ESCs. 1 ESCs differentiate into cells of different types 1.1 ESCs differentiate into germ cells In 2003, it was reported that mouse ESCs could differentiate into oocyte[1]. Oct-4 was …     

韩国豹猫与其它豹猫及西表猫之间的遗传分化:基于IRBP、12S rRNA 和Cyt b 序列的分析

利用韩国豹猫的IRBP、12S rRNA 和细胞色素b (Cyt b)序列,并将其与GenBank 中的豹猫及西表猫的上述基因进行比较,以此来重新分析韩国豹猫和其它豹猫及西表猫之间的遗传分化情况。首先,我们从18 只韩国豹猫的IRBP、12S rRNA 和Cyt b 序列分析中分别检测到6 个等位基因、1 个单倍型和3 个单倍型,推测曾经发生 在豹猫种群的瓶颈事件可能是本文发现的不同分子标记之间存在基因型丢失差异的原因。基于Cyt b 序列分析,证实东亚的豹猫形成一个单独的进化枝,本文得到的Cyt b 序列和之前发布结果支持一个分类理论,即认为东亚的豹猫就是东北森林猫。我们发现在IRBP、12S rRNA 基因上,韩国豹猫和西表猫存在相同的序列,支持将西表猫和豹猫视为同一物种。     

2007年夏季青岛石莼科(Ulvaceae)绿藻无机元素含量分析

2007年夏季对青岛沿海石莼科绿藻,包括定生石莼Ulva、定生浒苔Enteromorpha以及漂浮浒苔Enteromorpha进行了样本采集,针对其17种金属元素和3种非金属元素进行了含量分析与比较。结果表明,石莼科绿藻对铅、镉、铜、砷、锌等元素有较强的富集作用,可以作为海洋环境的藻类指示生物。另外,漂浮浒苔中多种元素含量明显少于定生种类,特别是铁、铝、磷等元素含量差别非常悬殊,最高可达100倍;相反的是,漂浮浒苔的钙元素含量接近于定生种类的两倍。上述结果可为石莼、浒苔等大型绿藻的加工利用提供参考。     

Fusion Protein of Interleukin 4 and Diphtherial Toxin with High Cytotoxicity to Cancer Cells

One means to improve the selectivity of cancer therapyis by directing foreign protein with activity againsttherapeutic targets that displays different expression levelon malignant cells from normal cells. There have hadsubstantial efforts to rationally de…     

中国鄂温克、鄂伦春、达斡尔族永生细胞系的建立与保存

本文采用EBV（Epstein?Barr Virus）上清液转化B淋巴细胞,并加入环胞霉素A（Cyclosporine A）抑制T淋巴细胞,成功地对中国东北地区鄂温克族、鄂伦春族及达斡尔族的部分个体建立了永生细胞系,其中鄂温克族49株,鄂伦春族40株,达斡尔族51株,总计140株。永久保存我国特有民族的基因组,为分析其遗传学差异奠定了基础。 Abstract：The immortal lymphoblastoid cell lines were established by EBV transformation of B cells and addition of cyclosporin A to inhabit the activity of T cells.In the present study ,140 immortal cell lines of the Ewenki,the Oroqen and the Daur ethnic groups in the Northeast China were established .This is an important part of the research of human genome diversity for the exploration of the origin and progression of different ethnic groups ,and also provide enough research materials for further studies.