Evidence for association of D1S249 locus on human chromosome 1 with the susceptibility to essential hypertension in Han Chinese

Essential hypertension (EH) is thought to result from theinteraction of environmental and genetic factors. The molecular genetics of EH has witnessed considerable progress during the past few years. However, the number of genes involved, their chromosomal location and the magnitude of their effect on EH susceptibility are unknown. We conducted the present study to screen susceptibility genes to essential hypertension using a genome-wide scanning method in a group of Han people from Fangshan district located in the southwest of Beijing. A case-control study and affected sibpair were performed. Genotyping was carried out using a fluorescence-based semiautomated technique on automated DNA sequencer (ABI 377, PE). The basis for the genome-screen was the ABI prism linkage mapping sets of 400 microsatellite markers (version 2, PE, Co.). PCR for amplification of markers was carried out as multiplex reactions with Ampli Taq gold (PE, Co.) following protocols developed in our laboratory. Data were exported as a text file from genotyper for subsequent two-point affected sibpair linkage analysis. The data from case-control association study showed a linkage disequilibrium between EH and marker D1S249 locus (X2 = 14.6, P = 0.002). There are 12 alleles in the D1S249 locus. The frequency of A9 allele in hypertension was higher than in normotensives, (13.6% v.s. 2.7%, X2 = 6.30, p = 0.01, OR = 4.57, 95%CI = 1.24-25.4). The data from two-point affected sibpair linkage analysis demonstrated a linkage between EH and A9 allele, P＜0.05. It suggested that microsatellite marker D1S249 locus might be associated with the genetic susceptibility to essential hypertension in Han Chinese.     

水蜡蛾一新属一新种：（鳞翅目：水蜡蛾科）

Brahmaea属是Walker(1855)以Bombyx certhia Fabricius为模式种成立的。Mell(1929)根据成虫形态特征、后翅翅脉的差异(有无连接Sc+R_1和Rs脉的横脉),将亚洲的水蜡蛾分为二群,建立一个新亚属 Brahmophthalma Mell并绘有Brahmaea Walker属与新亚属内每个种的翅脉简图以示区别;Bryk(1949)将Brahmophthalma提升为属。我们在整理和研究水蜡蛾的标本中,发现Brahmaea Walker属中实际存在着成虫形态和外生殖器差别很大的两个类群,作者认为有必要将其分为两个属,建立一个新属,并记述一新种。     

锐孔菌属一新种

本文报道了多孔菌科(Polyporaceae)锐孔菌属(Oxyporus)一新种:长白锐孔菌(Oxyporus changbaiensis Y.P.Bai et X.L.Zeng)。本种在形态特征上与黄白锐孔菌[Oxy-porus cervino-gilvus(Jungh.)Ryv.]相近,但菌丝具有大量横隔膜,且孢子较宽;亦与宽边锐孔菌[Oxyporus latemaginatus(Dur.et Mont.)Donk]相似,但孢子较大,有时有菌盖,囊状体上部被以结晶。文中有拉丁文及中文描述。     

尖萼耧斗菜幼苗初生维管系统的解剖学研究

尖萼耧斗莱(Aquilegia oxysepala Trautv.et Mey.)属毛莨科(Ranunculaceae)耧斗菜属(Aquilegia)植物。其幼苗初生维管系统的解剖学研究表明,它与毛莨科的其它属同样,存在一个以子叶节区为中心的两个过渡区。幼苗的初生维管系统可分为上胚轴苗区、子叶节区和下胚轴根区等三个区。解剖研究进一步验证了谷安根等(1990)提出的关于子叶节区理论是客观存在的,同时也为揭示毛莨科植物的起源和演化积累一份新资料。     

Identification of mitogen-activated protein kinase signaling pathways that confer resistance to endoplasmic reticulum stress in Saccharomyces cerevisiae

Hypoxia activates all components of the unfolded protein response (UPR), a stress response initiated by the accumulation of unfolded proteins within the endoplasmic reticulum (ER). Our group and others have shown previously that the UPR, a hypoxia-inducible factor-independent signaling pathway, mediates cell survival during hypoxia and is required for tumor growth. Identifying new genes and pathways that are important for survival during ER stress may lead to the discovery of new targets in cancer therapy. Using the set of 4,728 homozygous diploid deletion mutants in budding yeast, Saccharomyces cerevisiae, we did a functional screen for genes that conferred resistance to ER stress-inducing agents. Deletion mutants in 56 genes showed increased sensitivity under ER stress conditions. Besides the classic UPR pathway and genes related to calcium homeostasis, we report that two additional pathways, including the SLT2 mitogen-activated protein kinase (MAPK) pathway and the osmosensing MAPK pathway, were also required for survival during ER stress. We further show that the SLT2 MAPK pathway was activated during ER stress, was responsible for increased resistance to ER stress, and functioned independently of the classic IRE1/HAC1 pathway. We propose that the SLT2 MAPK pathway is an important cell survival signaling pathway during ER stress. This study shows the feasibility of using the yeast deletion pool to identify relevant mammalian orthologues of the UPR.     

Multiple endonucleases function to repair covalent topoisomerase I complexes in Saccharomyces cerevisiae

Topoisomerase I plays a vital role in relieving tension on DNA strands generated during replication. However if trapped by camptothecin or other DNA damage, topoisomerase protein complexes may stall replication forks producing DNA double-strand breaks (DSBs). Previous work has demonstrated that two structure-specific nucleases, Rad1 and Mus81, protect cells from camptothecin toxicity. In this study, we used a yeast deletion pool to identify genes that are important for growth in the presence of camptothecin. In addition to genes involved in DSB repair and recombination, we identified four genes with known or implicated nuclease activity, SLX1, SLX4, SAE2, and RAD27, that were also important for protection against camptothecin. Genetic analysis revealed that the flap endonucleases Slx4 and Sae2 represent new pathways parallel to Tdp1, Rad1, and Mus81 that protect cells from camptothecin toxicity. We show further that the function of Sae2 is likely due to its interaction with the endonuclease Mre11 and that the latter acts on an independent branch to repair camptothecin-induced damage. These results suggest that Mre11 (with Sae2) and Slx4 represent two new structure-specific endonucleases that protect cells from trapped topoisomerase by removing topoisomerase-DNA adducts.     

Methylation differences of the neuronatin gene promoter region in liver between normal and cloned pigs

Abnormal phenotypes in cloned pigs can be partly due to changes in epigenetic modifications such as methylation levels of promoter CpG islands. Neuronatin is an imprinted gene, conserved in human, pig, cattle and mouse, which is expressed exclusively from the paternal allele. Three CpG islands located in the promoter region of the porcine neuronatin gene have the potential to regulate the gene expression by cytosine methylation. To illustrate whether neuronatin was differentially expressed among nuclear transfer macroglossia–positive and nuclear transfer macroglossia–negative pigs and in vitro‐fertilized pigs, we detected its expression level by qRT‐PCR and further quantified methylation levels by pyrosequencing DNA from the liver. The results showed that neuronatin was expressed at a significantly higher level in livers of nuclear transfer macroglossia‐positive pigs compared with normal cloned and in vitro‐fertilized pigs. Livers of nuclear transfer macroglossia‐positive pigs also had a significantly lower methylation level at CpG island 2 and CpG island 3 in the promoter region.     

hCD2-iCre and Vav-iCre Mediated Gene Recombination Patterns in Murine Hematopoietic Cells

Cre-recombinase mediated conditional deletion of Lox-P site flanked ("floxed") genes is widely used for functional gene annotation in mice. Many different Cre-transgenic mouse lines have been developed for cell-type specific gene disruption. But often, the precise tissue-patterns of Cre activity remain incompletely characterized. Two widely used transgenes for conditional gene recombination in hematopoietic cells are Vav-iCre driven from the murine Vav1 promotor, and hCD2-iCre driven from the human CD2 promotor. Vav-iCre expresses active Cre in fetal and adult hematopoietic stem cells and all descendants, hCD2-iCre in immature and mature B and T lymphocytes. To better characterize which hematopoietic cells contain hCD2-iCre activity, we compared EYFP fluorescence in hCD2-iCre^+/- R26-stop-EYFP^+/- and Vav-iCre^+/- R26-stop-EYFP^+/-mice. R26-stop-EYFP ubiquitously encodes EYFP preceded by a floxed stop cassette. By removing it, Cre activity induces measurable EYFP expression. Our results confirm the known activity patterns for both Cre transgenes and unveil additional hCD2-iCre mediated reporter gene recombination in common lymphoid progenitors, in natural killer cells and their progenitors, and in plasmacytoid and conventional dendritic cells. This supports previously proposed common lymphoid origins for natural killer cells and subsets of dendritic cells, and indicates the need to consider pleiotropic effects when studying hCD2-iCre mediated conditional knockout mice. Vav-iCre^+/- R26-stop-EYFP^+/-mice did not show the non-hematopoietic recombination in vascular endothelial cells seen in other Vav-Cre mouse lines, but displayed an unexpected Vav-iCre mediated recombination in a bone cell subset lacking hematopoietic markers. This pinpoints the need to consider stromal cell contributions to phenotypes of Vav-iCre mediated conditional knockout mice. Altogether, our data provide the first detailed assessment of hCD2-iCre and Vav-iCre mediated deletion of floxed genes during lymphocyte development from hematopoietic stem cells and open up novel applications for either Cre-transgenic mouse line.     

Quasi-Static and Dynamic Nanoindentation of Some Selected Biomaterials

This study details an investigation of the viscoelastic behavior of some biomaterials （nacre, cattle horn and beetle cuticle） at lamellar length scales using quasi-static and dynamic nanoindentation techniques in the materials＇ Transverse Direction （TD） and Longitudinal Direction （LD）. Our results show that nacre exhibits high fracture toughness moving towards a larger cam- paniForm as the stress frequency varies from 10 Hz to 200 Hz. Elytra cuticle exhibits the least fracture toughness presenting little energy dissipation in TD. It was initially speculated that the fracture toughness of the subject materials would be directly related to energy-dissipating mechanisms （mechanical hysteresis）, but not the maximum value of the loss tangent tan＆ However, it was found that the materials＇ elastic modulus and hardness are similar in both the TD and LD when assessed using the quasi-static nanoindentation method, but not dynamic nanoindentation. It is believed that the reported results can be useful in the design of new crack arrest and damping materials based on biological counterparts.     

Small brown planthopper resistance loci in wild rice (Oryza officinalis)

Host-plant resistance is the most practical and economical approach to control the rice planthoppers. However, up to date, few rice germplasm accessions that are resistant to the all three kinds of planthoppers (1) brown planthopper (BPH; Nilaparvata lugens Stål), (2) the small brown planthopper (SBPH; Laodelphax striatellus Fallen), and (3) the whitebacked planthopper (WBPH, Sogatella furcifera Horvath) have been identified; consequently, the genetic basis for host-plant broad spectrum resistance to rice planthoppers in a single variety has been seldom studied. Here, one wild species, Oryza officinalis (Acc. HY018, 2n = 24, CC), was detected showing resistance to the all three kinds of planthoppers. Because resistance to WBPH and BPH in O. officinalis has previously been reported, the study mainly focused on its SBPH resistance. The SBPH resistance gene(s) was (were) introduced into cultivated rice via asymmetric somatic hybridization. Three QTLs for SBPH resistance detected by the SSST method were mapped and confirmed on chromosomes 3, 7, and 12, respectively. The allelic/non-allelic relationship and relative map positions of the three kinds of planthopper resistance genes in O. officinalis show that the SBPH, WBPH, and BPH resistance genes in O. officinalis were governed by multiple genes, but not by any major gene. The data on the genetics of host-plant broad spectrum resistance to planthoppers in a single accession suggested that the most ideally practical and economical approach for rice breeders is to screen the sources of broad spectrum resistance to planthoppers, but not to employ broad spectrum resistance gene for the management of planthoppers. Pyramiding these genes in a variety can be an effective way for the management of planthoppers.