Genetic Relationship between a Natural Hybrid Meconopsis× cookei (Papaveraceae) and Its Parents Based on cpDNA trnL- trnF Region Sequence

The Chloroplast DNA trnL- trnF region sequences from a natural hybrid species Meconopsis× cookei and its parents M. punicea and M. quintuplinervia were obtained by using direct sequencing method. The sequence length of trnL- trnF region is 960 bp for M. × cookei, 961 bp for M. punicea, and 957 bp for M. quintuplinervia. The sequences were aligned by the software Clustal X, and then the bases per locus were compared by using the software with manual method. The aligned sequence length is 964 bp, of which trnL intron is 512 bp, the 3′exon of trnL is 50 bp, trnL- trnF intergenic spacer ( IGS) is 361 bp, and the 5′end segment of trnF is 41 bp. Total 25 variable loci were detected from the aligned sequence, of which 21 (84% ) sites are same between M. × cookei and M. punicea, and only one (4%) is same between M. × cookei and M. quintuplinervia , the remaining three loci (12% ) are different among M. × cookei, M. punicea, and M. quintuplinervia. The results show that the cpDNA trnL- trnF region of the natural hybrid species M. ×cookei was inherited from its parent M. punicea. Therefore, according to the plastid inheritance law, our molecular evidences indicate that M. punicea is the mother of hybrid species M. × cookei and M. quintuplinervia is its father.     

The unique solution structure and immunochemistry of the Candida albicans beta -1,2-mannopyranan cell wall antigens.

Synthetic oligomers of the antigenic Candida albicans (1-->2)-beta-mannopyranans adopt a compact solution conformation that leads to numerous inter-residue nuclear Overhauser effects, including unprecedented nuclear Overhauser effects between n and n + 3 residues. In excellent agreement with experimentally determined distances, unrestrained molecular dynamics point to a single family of conformations that approximate a compact helical motif with a three-residue repeat for this unique homopolymer. When the synthetic di- to hexasaccharides were employed as inhibitors of monoclonal antibodies, which protect mice against a lethal dose of the yeast pathogen, a novel pattern of inhibitor activity was observed. Instead of the paradigm first reported by Kabat (Kabat, E. A. (1962) Fed. Proc. 21, 694-701; Kabat, E. A. (1966) J. Immunol. 97, 1-11), wherein homo-oligosaccharides exhibit increasing inhibitory activity with increasing size, here the maximum activity is reached for di- and trisaccharides and diminishes significantly for tetra-, penta-, and hexasaccharides. These immunochemical data correlate with the ordered conformation of the beta-1,2-linked mannopyranan and imply that a uniquely small antigenic determinant has potential as a component of synthetic conjugate vaccines against Candida albicans.     

A cross-neutralizing antibody between HIV-1 and influenza virus

Incessant antigenic evolution enables the persistence and spread of influenza virus in the human population. As the principal target of the immune response, the hemagglutinin (HA) surface antigen on influenza viruses continuously acquires and replaces N-linked glycosylation sites to shield immunogenic protein epitopes using host-derived glycans. Anti-glycan antibodies, such as 2G12, target the HIV-1 envelope protein (Env), which is even more extensively glycosylated and contains under-processed oligomannose-type clusters on its dense glycan shield. Here, we illustrate that 2G12 can also neutralize human seasonal influenza A H3N2 viruses that have evolved to present similar oligomannose-type clusters on their HAs from around 20 years after the 1968 pandemic. Using structural biology and mass spectrometric approaches, we find that two N-glycosylation sites close to the receptor binding site (RBS) on influenza hemagglutinin represent the oligomannose cluster recognized by 2G12. One of these glycan sites is highly conserved in all human H3N2 strains and the other emerged during virus evolution. These two N-glycosylation sites have also become crucial for fitness of recent H3N2 strains. These findings shed light on the evolution of the glycan shield on influenza virus and suggest 2G12-like antibodies can potentially act as broad neutralizers to target human enveloped viruses.     

大豆田中大豆蚜天敌昆虫群落结构分析

为了明确大豆田中大豆蚜Aphis glycines Matsumura天敌昆虫的群落结构特点,采用系统调查法对大豆蚜天敌的种类及数量进行调查。结果表明,大豆蚜天敌昆虫主要有5目11科19种,另外还有一些捕食性蜘蛛。主要优势种为小花蝽Orius minutus、龟纹瓢虫Propylaea japonica、中华草蛉Chrysopa sinica以及蚜小蜂Aphelinus sp.和异色瓢虫Leis axyridis,捕食性蜘蛛其中小花蝽的相对丰盛度达到0.26以上。小花蝽和龟纹瓢虫发生较早,是大豆蚜发生初期的主要控制因素。物种多样性、均匀度、丰富度、物种数和个体数整体趋势表现为先增加后降低,在7、8月达最大;而优势集中性和优势度则表现为先降低后增加的趋势,群落较稳定。     

Use of proteomic differential displays to assess functional discrepancies and adjustments of human bone marrow- and Wharton jelly-derived mesenchymal stem cells

Mesenchymal stem cells (MSCs) from bone marrow are suitable for the reconstruction of connective tissues and even brain tissue but have limitations in terms of cell expansion and fully specific differentiation. In our current study, we have attempted to adjust and improve the cell expansion and differentiation properties of human MSCs from different tissues. MSCs from normal bone marrow and Wharton jelly were subjected to proteomic differential displays, followed by functional adjustments based on these displays. Bone marrow MSCs expressed more transgelin-2 and differentiated more rapidly into bone nodules but showed a slower growth rate. A knockdown of transgelin-2 expression by specific small interfering RNA (siRNA) significantly increased the growth rate of these cells, the G1/S phase cell cycle transition, and the interaction of cyclin D1 with cdk2. Wharton jelly MSCs expressed the chaperone protein HSP90β at higher levels and differentiated slowly toward an osteogenic lineage. However, the knockdown of HSP90β expression significantly increased bone nodule formation, inhibited cell growth, decreased the number of cells in the G1/S phase of the cell cycle, and decreased the interaction of cyclin D1 with cdk2 and of cyclin E with cdk2. These results were validated by the in vivo repair of segmental bone defects in a mouse model with severe combined immunodeficiency. We thus demonstrate an improvement in the cell expansion and tissue regeneration properties of human MSCs through specific adjustments.     

绿绒蒿自然杂交种及其亲本cpDNA trnL- trnF 基因的遗传学分析

对自然杂交种Meconopsis× cookei 及其亲本红花绿绒蒿M. punicea 和五脉绿绒蒿M. quintuplinervia 的叶绿体DNA trnL- trnF 区进行了序列测定, 所得序列的长度为957～961 bp , 其中M. × cookei 的序列长度为960bp , 红花绿绒蒿为961 bp , 五脉绿绒蒿为957 bp。利用软件Clustal X 对所得序列进行排序和碱基比较, 排序后的序列长度为964 bp , 其中trnL intron 为512 bp , trnL 3′exon 为50 bp , trnL- trnF intergenic spacer ( IGS) 为361 bp , 还包括41 bp 的trnF 5′端片段。整个trnL- trnF 区序列共有25 个变异位点, 其中杂交种M. × cookei与红花绿绒蒿具有相同碱基的位点有21 个( 占84% ) , M. × cookei 与五脉绿绒蒿具有相同碱基的位点仅有1 个(占4% ) , 余下3 个位点( 占12%) 中, M. × cookei 的碱基与两个亲本均不相同。分析结果表明, 杂交种M. × cookei 的叶绿体基因trnL- trnF 来自红花绿绒蒿, 根据质体细胞质遗传的规律, 从而推测红花绿绒蒿为该杂交种的母本, 五脉绿绒蒿为其父本。     

应用微卫星标记分析野生红光熊蜂蜂王的一妻多夫水平

为了摸清自然条件下红光熊蜂Bombus ignitus Smith的一妻多夫水平,本实验采用B118、B11、B96、B124和B126微卫星位点,对来自5群野生红光熊蜂(A、B、C、D和E)的工蜂和雄蜂样本进行了分析。结果推导出:在A、B、C、D和E群体的工蜂基因型中,来自父本的基因型分别有3、2、3、4和3种,即与母本蜂王交配的雄蜂数量分别是3、2、3、4和3只。表明在自然条件下,红光熊蜂同其他蜜蜂科的蜂种一样,也存在一妻多夫现象,且与蜂王交配的雄蜂数量平均为3只。     

The bound states of amphipathic drugs in lipid bilayers: study of curcumin

Drug-membrane interactions are well known but poorly understood. Here we describe dual measurements of membrane thickness change and membrane area change due to the binding of the amphipathic drug curcumin. The combined results allowed us to analyze the binding states of a drug to lipid bilayers, one on the water-membrane interface and another in the hydrocarbon region of the bilayer. The transition between the two states is strongly affected by the elastic energy of membrane thinning (or, equivalently, area stretching) caused by interfacial binding. The data are well described by a two-state model including this elastic energy. The binding of curcumin follows a common pattern of amphipathic peptides binding to membranes, suggesting that the binding states of curcumin are typical for amphipathic drugs.     

Response of leaf, sheath and stem nutrient resorption to 7 years of N addition in freshwater wetland of Northeast China

Background and Aims

Increased N availability induced by agricultural fertilization applications and atmospheric N deposition may affect plant nutrient resorption in temperate wetlands. However, the relationship between nutrient resorption and N availability is still unclear, and most studies have focused on leaf nutrient resorption only. The aim of our study was to examine the response of leaf and non-leaf organ nutrient resorption to N enrichment in a temperate freshwater wetland.

Methods

We conducted a 7-year N addition experiment to investigate the effects of increased N loading on leaf, sheath and stem nutrient (N and P) resorption of two dominant species (Deyeuxia angustifolia and Glyceria spiculosa) in a freshwater marsh in the Sanjiang Plain, Northeast China.

Results

Our results showed that, for both leaf and non-leaf organs (sheath and stem), N addition decreased N resorption proficiency and hence increased litter N concentration. Moreover, the magnitude of N addition effect on N resorption proficiency varied with fertilization rates for D. angustifolia sheaths and stems, and G. spiculosa leaves. However, increased N loading produced inconsistent impacts on N and P resorption efficiencies and P resorption proficiency, and the effects only varied with species and plant organs. In addition, N enrichment increased litter mass and altered litter allocation among leaf, sheath and stem.

Conclusions

Our results highlight that leaf and non-leaf organs respond differentially to N addition regarding N and P resorption efficiencies and P resorption proficiency, and also suggest that N enrichment in temperate freshwater wetlands would alter plant internal nutrient cycles and increase litter quality and quantity, and thus substantially influence ecosystem carbon and nutrient cycles.