刺果番荔枝中的番荔枝内酯

从刺果番荔枝（Ａｎｎｏｎａ ｍ ｕｒｉｃａｔａ Ｌ．）的种子中分离到３ 个单四氢呋喃型番荔枝内酯类化合物,用波谱方法鉴定为海南哥纳香甲素（ｈｏｗ ｉｉｃｉｎ Ａ, Ｓ１３）、乙素（ｈｏｗ ｉｉｃｉｎ Ｂ, Ｓ５）和新化合物４－去氧海南哥纳香乙素（４－ｄｅｓｏｘｙｈｏｗ ｉｉｃｉｎ Ｂ, Ｓ２）。     

A comparative analysis of genetic polymorphism in wild and cultivated barley from Tibet using isozyme and ribosomal DNA markers.

This study was conducted to address some of the issues concerning the possible significance of Tibet in the origin and evolution of cultivated barley. A total of 1757 barley accessions from Tibet, including 1496 entries of Hordeum vulgare ssp. vulgare (HV), 229 entries of the six-rowed wild barley H. vulgare ssp. agriocrithon (HA), and 32 entries of the two-rowed wild barley H. vulgare ssp. spontaneum (HS), were assayed for allozymes at four esterase loci. A subsample of 491 accessions was surveyed for spacer-length polymorphism at two ribosomal DNA loci. Genetic variation is extensive in these barley groups, and the amount of genetic diversity in cultivated barley of this region is comparable with that of cultivated barley worldwide. The level of genetic variation of HA is significantly lower than the other two barley groups, and there is also substantial heterogeneity in the level of polymorphism among different agrigeographical subregions. However, little genetic differentiation was detected among the three barley groups (HV, HA, and HS), as well as among different agrigeographical subregions. Comparison of the results from this and previous studies indicated a strong differentiation between Oriental and Occidental barley, thus favoring the hypothesis of a diphyletic origin of cultivated barley.     

Definition of an HLA-DPw2-restricted epitope on NS3, recognized by a dengue virus serotype-cross-reactive human CD4+ CD8- cytotoxic T-cell clone.

We previously reported that the clone JK34 was cross-reactive for dengue virus types 1, 2, 3, and 4 and recognized NS3 (I. Kurane, M. A. Brinton, A. L. Samson, and F. A. Ennis, J. Virol. 65:1823-1828, 1991). In the present experiments, we defined the epitope at the amino acid level, with 93 15-mer overlapping peptides which cover the entire NS3. A peptide 4 which contains amino acids 251 to 265 of NS3 sensitized the autologous B lymphoblastoid cell line (LCL) to the lysis by JK34. The smallest peptide recognized by JK34 was a 10-mer peptide which contains amino acids 255 to 264 (EIVDLMCHAT). A monoclonal antibody to HLA-DP inhibited the lysis of epitope peptide-pulsed autologous LCL by JK34. Genotypic typing revealed that the HLA-DP of this donor is DPA1*01, DPB1*0201, which is serologically defined as HLA-DPw2. JK34 lysed peptide 4-pulsed allogeneic LCL which carried HLA-DPw2. These results indicate that HLA-DPw2 is the restriction allele for recognition of this epitope by JK34.     

Bisphenol S induces oxidative stress-mediated impairment of testosterone synthesis by inhibiting the Nrf2/HO-1 signaling pathway

Bisphenol S (BPS) is an environmental endocrine disruptor widely used in industrial production. BPS induces oxidative stress and exhibits male reproductive toxicity in mice, but the mechanisms by which BPS impairs steroid hormone synthesis are not fully understood. Nuclear factor erythroid 2-related factor 2(Nrf2)/HO-1 signaling is a key pathway in improving cellular antioxidant defense capacities. Therefore, this study explored the effects of exposure to BPS on testosterone synthesis in adult male mice and its mechanisms with regard to the Nrf2/HO-1 signaling pathway. Adult male C57BL/6 mice were orally exposed to BPS (2, 20, and 200 mg/kg BW) with sesame oil as a vehicle (0.1 ml/10 g BW) per day for 28 consecutive days. The results showed that compared with the control group, serum testosterone levels were substantially reduced in the 20 and 200 mg/kg BPS treatment groups, and testicular testosterone levels were reduced in all BPS treatment groups. These changes were accompanied by a prominent decrease in the expression levels of testosterone synthesis-related enzymes (STAR, CYP11A1, CYP17A1, HSD3B1, and HSD17B3) in the mouse testis. In addition, BPS induced oxidative stress in the testis by upregulating the messenger RNA and protein levels of Keap1 and downregulating the levels of Nrf2, HO-1, and downstream antioxidant enzymes (CAT, SOD1, and Gpx4). In summary, our results indicate that exposure of adult male mice to BPS can inhibit Nrf2/HO-1 signaling and antioxidant enzyme activity, which induces oxidative stress and thereby may impair testosterone synthesis in testicular tissues, leading to reproductive damage.     

江淮稻区稻象虫生物学、生态学的研究

在扬州地区,稻象虫一年发生1代。以老熟幼虫越冬,其越冬存活率免耕田>少耕田>常规耕田,肾发育的高低温临界点为38．16℃和9．84℃,最适发育温度26.52℃,有效积温117.8日度,每头稻虫产卵卵3-29粒,平均18．8粒;成虫羽化后17-31天为产卵盛期;产卵孔平均高度为4.1±1.5cm,水象下卵孔占28．6％：产卵孔与取食孔特征不同．卵期7±1．8天．成,幼虫的各群空间格局基本属密集颁布（仅x^-≤3时的成虫种群为随机分布)．单季稻的为害重于双季稻;沙质土壤的发生量多于粘壤土,稻—麦（油菜）两熟制田的为害显重于稻-稻麦(油菜）三熟制田。     

Changes in composition and structure of Vitex shrubland in northern China in relation to human disturbance

Vegetation and biomass in six plots, each with five quadrats, in Vitex shrubland in northern China were related to type and degree of human disturbance. Canonical correspondence analysis of the vegetation and environmental data showed two lines of variation, the first one highly correlated with the degree of disturbance, but the second one appearing within the disturbed plots cannot yet be fully explained. Changes in life-form spectrum were small, but the geographical spectrum changed under heavy disturbance towards a higher proportion of tropical, subtropical and cosmopolitan species. The number of shrub species also decreased noticeably. The above-ground biomass of both Vitex and the accompanying species and the total above-ground biomass of the shrubland was negatively correlated with the intensity of disturbance. The root/stem biomass ratio in Vitex reaches values of over 5 in disturbed plots, but only between 1 and 2 in the protected plots.     

异育银鲫及其人工杂合种外源遗传物质的检测分析

采用 DNA 杂交的方法,对异育银鲫及其人工杂合种进行了外源 DNA 的检测分析,发现两个雌核发育系的异育银鲫及其人工杂合种的 DNA 与红鲤 DNA 片段间的分子杂交均有阳性斑点出现,这表明,在异育银鲫及其人工杂合种产生过程中,父本(红鲤)的 DNA 片段的确可以随机地掺入到母本细胞的 DNA 中,从而产生了异精效应,使其子代生长加快,并出现父本性状。     

湿地松木质部和针叶松脂合成基因分析

为挖掘湿地松(Pinus elliottii)松脂合成相关的基因,对不同采脂期的木质部和针叶进行高通量转录组测序,与火炬松(Pinus taeda)参考基因组进行比对,共获得了68 211条unigenes,546 356 450条clean reads,平均比对率达90.21%。将不同时期木质部、木质部与针叶间进行两两对比,以P＜0.05,|log₂FoldChange|＞1.0为标准来筛选差异基因,并进行GO和KEGG富集分析。结果表明,参与萜类物质合成的差异基因有133个,其中大部分富集在MEP途径,从差异基因中挑选8个产脂相关的候选基因进行RT-qPCR验证,确定HMGR、DXS、TPS、ABC转运蛋白基因与产脂存在关联性。通过转录组测序与分析,挖掘出133个参与松脂萜类物质合成相关的差异基因,其中萜烯合酶基因(TPS)和ABC转运基因在正调控萜类物质合成中发挥关键作用。     

First chemical synthesis of a scorpion alpha-toxin affecting sodium channels: the Aah I toxin of Androctonus australis hector.

Aah I is a 63-residue alpha-toxin isolated from the venom of the Buthidae scorpion Androctonus australis hector, which is considered to be the most dangerous species. We report here the first chemical synthesis of Aah I by the solid-phase method, using a Fmoc strategy. The synthetic toxin I (sAah I) was renatured in DMSO-Tris buffer, purified and subjected to thorough analysis and comparison with the natural toxin. The sAah I showed physico-chemical (CD spectrum, molecular mass, HPLC elution), biochemical (amino-acid composition, sequence), immunochemical and pharmacological properties similar to those of the natural toxin. The synthetic toxin was recognized by a conformation-dependent monoclonal anti-Aah I antibody, with an IC50 value close to that for the natural toxin. Following intracerebroventricular injection, the synthetic and the natural toxins were similarly lethal to mice. In voltage-clamp experiments, Na(v) 1.2 sodium channel inactivation was inhibited by the application of sAah I or of the natural toxin in a similar way. This work describes a simple protocol for the chemical synthesis of a scorpion alpha-toxin, making it possible to produce structural analogues in time.