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1.
王长云  刘海燕  邵长伦  王亚楠    李 亮  管华诗 《生态学报》2008,28(5):2320-2320~2328
软珊瑚(Sinularia flexibilis)和柳珊瑚(Plexaura homomalla)属于海洋低等无脊椎动物,虽然这些动物自身缺乏有效的物理防御手段,却能在竞争激烈的海洋环境中生存与繁衍,这主要是依靠其次级代谢产物的化学防御作用.这些次级代谢产物聚积在体内或释放到环境中,作用主要体现在抵御捕食者、抗病原微生物、克生与防附着等方面.珊瑚化学防御物质的研究有助于探讨珊瑚与其环境中其它生物的化学生态关系,属于海洋化学生态学研究的重要内容之一,其研究方法和思路对海洋活性天然产物乃至海洋新药先导化合物的发现,具有重要的启迪作用.综述了软珊瑚和柳珊瑚化学防御物质的研究进展,并阐释了软珊瑚和柳珊瑚中具有拒捕食、克生、防生物附着等生物活性的次级代谢产物的结构及其化学防御作用.  相似文献   

2.
采用高精度计算机断层扫描和三维重建技术,获取了大量来自云南下泥盆统洛霍考夫阶西屯组和西山村组下部花鳞鱼鳞片的三维重建模型。描述了花鳞鱼类的一个已知属——副花鳞鱼属(Parathelodus)的共7个种,三裂副花鳞鱼(P. trilobatus)、亚洲副花鳞鱼(P. asiaticus)、角状副花鳞鱼(P. cornuformis)、雅致副花鳞鱼(P. scitulus)、西屯副花鳞鱼(新种)(P. xitunensis sp. nov.)、王氏副花鳞鱼(新种)(P. wangi sp. nov.)和寥廓副花鳞鱼(新种)(P.liaokuoensis sp. nov.)。新材料的发现将副花鳞鱼的地层分布从洛霍考夫阶西屯组至西山村组上部延伸到西山村组下部,最低层位已非常靠近志留系与泥盆系的界线。西屯副花鳞鱼、王氏副花鳞鱼和廖廓副花鳞鱼3个新种的发现提高了我们对中国早泥盆世花鳞鱼类多样性的认识。  相似文献   

3.
为探讨细胞基质Ⅰ型胶原(Col-Ⅰ)对头颈鳞癌细胞转移和增殖能力的影响,以头颈鳞癌细胞株为对象,运用transwell小室检查细胞的体外迁移能力,用倒置显微镜成像系统检测细胞的运动速度和扩散能力,Western blotting或/和免疫细胞荧光染色检测细胞表面黏附分子E-cadherin的表达和β-catenin的细胞定位,采用MTT以及PCNA的表达水平评价细胞增殖.结果显示,Col-Ⅰ能够促进头颈鳞癌细胞迁移、提高细胞运动速度、加快细胞扩散,其可能机制是通过上调β-连环蛋白磷酸化,从而下调黏附蛋白E-cadherin的表达.Col-Ⅰ还能促进头颈鳞癌细胞的增殖,其可能机制是增加β-catenin的核移位,提高细胞周期蛋白D1(cyclin D1)表达.研究结果表明,Col-Ⅰ通过上调β-catenin磷酸化水平,以及促进β-catenin核移位,从而增强头颈鳞癌细胞的转移和增殖能力.  相似文献   

4.
软珊瑚二萜葡萄糖甙的抗炎作用   总被引:3,自引:0,他引:3  
软珊瑚二萜葡萄糖甙(SCDG)系一个新的海洋化学合成物,实验表明:SCDG对多种急性炎症及慢性炎症模型均显示了良好的抗炎效果,提示SCDG有一定的抗炎作用。  相似文献   

5.
【目的】开发一种高效地从造礁石珊瑚中分离、培养共生虫黄藻的技术方法,为珊瑚共生虫黄藻藻种资源储备和生理功能研究积累基础。【方法】首先采用微孔滤网过滤法和密度梯度离心法从造礁石珊瑚组织中直接分离或富集共生虫黄藻细胞,然后用改良的L1培养基在96孔板上对所得细胞进行离体培养,最后进行单细胞分离、培养和(或)平板划线培养获得单克隆虫黄藻细胞系。对所得虫黄藻单克隆藻株进行聚合酶链式反应-限制性内切酶片段长度多态性(polymerase chainreaction-restrictionfragmentlengthpolymorphism,PCR-RFLP)分析,结合内转录间隔区2(internal transcribed spacer2,ITS2)和大亚基(large subunit,LSU)测序进行物种鉴定及系统发育分析。【结果】采用上述方法从涠洲岛的霜鹿角珊瑚(Acropora pruinose)和西沙群岛的丛生盔形珊瑚(Galaxea fascicularis)及柔枝鹿角珊瑚(Acropora tenuis)中分离、培养得到3个虫黄藻株系,编号分别为AP21C1、GF21D1和AT21A...  相似文献   

6.
为了解珊瑚菜(Glehnia littoralis)夏季生长停滞的原因,以其伴生种滨旋花(Calystegia soldanella)为参考,对他们的叶片代谢系统的耐热性进行了研究。结果表明,珊瑚菜叶片光合作用的失活温度和膜透性的半致死温度均比滨旋花低大约5℃。珊瑚菜和滨旋花在温度为50℃时仍然保持很高的的呼吸速率(仅分别下降10%和24%),明显高于各自的光合系统和质膜系统的耐热温度。高斯回归分析表明,珊瑚菜的光合速率与呼吸速率比明显低于滨旋花。因此,高温下的光合产物昼夜过度消耗可能是珊瑚菜夏天生长停滞的原因,也可能与其整体较低的耐热性有关。  相似文献   

7.
一个新的化合物Nephoxaloid(1)具有独特的三环骨架结构和一个已知的化合物蕨藻素Caulerpin(2)从中国国西沙群岛的软珊瑚Nephthea sp.中分离得到。通过NMR和MS对它们的平面结构进行分析,化合物(1)和(2)对少数癌细胞株具有细胞毒性作用也有报道。  相似文献   

8.
【目的】南海珊瑚共附生真菌Aspergillus sp. SCSIO 40435次级代谢产物分离鉴定及抑菌活性筛选。【方法】利用稀释涂布平板法分离珊瑚共附生真菌。采用单菌多代谢产物方法(one strain many compounds,OSMAC)对分离菌株进行化学多样性筛选,并采用滤纸片扩散法对真菌发酵产物进行抑菌活性分析。通过ITS测序鉴定活性菌株SCSIO 40435的分类地位,运用多种色谱手段从其粗提物中分离纯化单体化合物,并利用各种波谱手段(HRESIMS、1D和2D NMR、单晶X-ray衍射法等)确定化合物的结构。最后,采用微量肉汤稀释法对单体化合物的抑菌活性进行评估。【结果】从南海珊瑚样品中分离得到19株共附生真菌,结合化学多样性和抑菌活性分析,筛选出1株产物丰富且具有多种抑菌活性的菌株SCSIO40435。利用ITS测序分析将其鉴定为曲霉属真菌(Aspergillus sp.),进一步从其发酵产物中分离鉴定了4个对三联苯类化合物:dicandidusin A(1)、candidusin A(2)、terphenyllin(3)和4″-deoxyterphenylli...  相似文献   

9.
MOC-31和CD44v6在良恶性腹水鉴别诊断中的应用   总被引:1,自引:0,他引:1  
目的探讨检测肿瘤标志物MOC-31和CD44v6对鉴别良恶性腹水的诊断价值。方法利用液基薄层细胞学自动涂片技术方法筛查出查到肿瘤细胞的恶性腹水标本390例以及良性腹水标本100例,分别采用酶联免疫吸附法(ELISA)和免疫细胞化学染色检测MOC-31和CD44v6的含量和表达情况。结果 ELISA结果显示MOC-31和CD44v6在良性腹水中的含量分别为21±4ng/ml和291±32ng/ml,在恶性腹水中的含量分别为98.1±19.3ng/ml和891±116ng/ml,差异均具有显著性(P<0.05);免疫细胞化学染色显示MOC-31在恶性腹水细胞中阳性表达250例,良性腹水细胞中阳性表达5例;CD44v6在恶性腹水细胞中阳性表达266例,良性腹水细胞中阳性表达3例,差异均具有显著性(P<0.05)。结论 MOC-31和CD44v6可以做为良恶性腹水鉴别诊断的重要指标,值得在临床病理工作中推广应用。  相似文献   

10.
用经草鱼生长激素(gcGH)免疫的BALB/c小鼠脾细胞与小鼠骨髓瘤细胞(Sp2/O-Ag14)融合,经3次克隆化培养和ELISA筛选,得到7株阳性杂交瘤细胞株,其中2株为强阳性。交叉试验表明,这些杂交瘤细胞株所分泌的单克隆抗体(McAb)同大鳞大马哈鱼生长激素(sGH)、大鳞大马哈鱼促性腺激素(sGTH)及牛生长激素(bGH)均不起反应。小鼠腹水McAbs滴度高达1:1280000。受体-gcGH-McAb夹心试验表明,McAb确与有活性的gcGH有特异反应。用间接ELISA方法可检测到浓度为0.125#g/ml的gcGH。  相似文献   

11.
Cloning and characterization of a family of proteins associated with Mpl.   总被引:4,自引:0,他引:4  
Thrombopoietin (TPO) controls the formation of megakaryocytes and platelets from hematopoietic stem cells via activation of the c-Mpl receptor and multiple downstream signal transduction pathways. We used two-hybrid screening to identify new proteins that interacted with the cytoplasmic domain of Mpl, and we found a new family of proteins designated A2D (for Ataxin-2 Domain protein). The A2D are 130-kDa proteins that have three regions similar to those of Ataxin-2, the gene product causing familial type 2 spinocerebellar ataxia. A2D has several isoforms with different C-terminal domains, all produced from a single gene by alternative splicing. Northern blotting indicated that the A2D gene is widely expressed in immortalized cell lines and hematopoietic and fetal tissues. A2D proteins were constitutively associated with Mpl in vivo in human hematopoietic UT7 cells. TPO also caused the release of A2D from the activated receptor, and the phosphorylation of A2D on tyrosines residues was dependent on the Mpl C-terminal domain. Finally, A2D bound to the unstimulated erythropoietin receptor, whereas erythropoietin caused dissociation from the erythropoietin receptor, suggesting that A2D proteins are new components of the cytokine signaling system.  相似文献   

12.
A series of D–A-type copolymers was designed and studied systematically for the purpose of gaining a deeper understanding of how the D/A ratio may influence the geometric and electronic properties when it varies from 2:1 to 6:1 by using DFT method. The results show that it has a significant effect on the bond length alternation, band gap, bandwidth and effective mass of carriers of the designed D–A-type copolymers. But its influence on the geometric and electronic properties shows something very different in degree when it increases from 2:1 to 4:1 and then increases further from 4:1 to 6:1. It is found that the effects of increasing D/A ratio on geometric and electronic properties are much stronger when the D/A ratio increases from 2:1 to 4:1 than when it further increases from 4:1 to 6:1. The theoretical results show that the polymers with a D/A ratio of 2:1 have much smaller effective mass of carriers and much wider bandwidth compared to those polymers with the D/A ratio of 4:1 and 6:1. Therefore, the designed D–A-type copolymers with a D/A ratio of 2:1 may actually be the better candidates for intrinsic conduction materials.  相似文献   

13.
In the study of aggrecan fragmentation several methods to extract and purify aggrecan from cartilage and synovial fluid (SF) are used. This work compares and evaluates the effectiveness for purification of aggrecan of the most commonly used methods by the ratio of sulfated glycosaminoglycan (sGAG) to protein and by fragment analysis by Western blot. A novel method for purification of aggrecan fragments from SF by boiling (Boiled SF) is also presented.Of the sGAG extracted from cartilage by guanidinium, 66% was recovered by associative–dissociative cesium chloride density gradient centrifugation (A1D1–D3) with a 9 times higher ratio of sGAG to protein in the A1D1 fraction. Although less enriched in aggrecan, the Western blot aggrecan pattern of the guanidinium extracted sample resembled that of the combined patterns of the A1D1, A1D2 and A1D3 fractions.The recoveries of sGAG from SF purified by anion chromatography and Alcian blue precipitation were around 50%, while the recoveries were over 80% in the associative or dissociative density gradient fractions (A1 and D1) and Boiled SF. The purification compared to neat SF ranged from 9 times in boiled SF to 1800–1900 times in Alcian blue and D1 samples. To obtain reliable results when analyzing synovial fluid aggrecan fragments by Western blot, purification was necessary. The immuno-pattern of anion chromatography purified SF resembled the patterns of A1 and D1, while the pattern of Boiled SF resembled the D1 sample.This work suggests that aggrecan fragments extracted from cartilage by guanidinium need no further purification to be analyzed by Western blot, whereas aggrecan fragments in SF are best analyzed in the A1 and D1 fractions or in the Boiled SF sample.  相似文献   

14.
Sequences of both internal and external transcribed spacers of nuclear ribosomal DNA were sequenced for four species belonging to the Dactylorhiza maculata group or "spotted marsh-Orchids". These four species are D. fuchsii, D. saccifera, D. foliosa, and D. maculata. Extensive nuclear ribosomal DNA polymorphism was uncovered within the diploid D. fuchsii and the putative autotetraploid D. maculata. Within the phylogenetic trees reconstructed using parsimony and Bayesian analyses, four main lineages (A, B, C, and D) were well supported. While D. saccifera, D. maculata, and D. foliosa were confined to clades B, C, and D, respectively, D. fuchsii accessions were spread over three clades (A, B, and C). Lineage C, which included accessions of the diploid D. fuchsii and the tetraploid D. maculata, was closely related to the lineage of D. foliosa (lineage D), an endemic diploid species from Madeira. Moreover, intra-individual polymorphism was found within accessions of D. maculata, D. fuchsii, and D. saccifera. It is shown that in some instances two lineages, contributed to the observed intra-individual polymorphism (C and A in D. maculata, A and B in D. fuchsii and D. saccifera). Evolutionary scenarios leading to this extensive nuclear ribosomal DNA polymorphism are discussed in the light of results from maternally inherited chloroplast DNA markers and an autopolyploid origin of D. maculata from a D. foliosa-like ancestor is postulated.  相似文献   

15.
Ten new species of small dictyostelids, five belonging to Acytostelium (A. anastomosans, A. longisorophorum, A. magnisorum, A. serpentarium and A. singulare) and five to Dictyostelium (D. amphisporum, D. naviculare, D. oculare, D. potamoides and D. stellatum), were isolated from forest soils in the Great Smoky Mountains National Park. These species were recovered mostly from acidic soils and at higher elevations. They represent a large group of dictyostelids of small stature (<2 mm total height) on which we are beginning to accumulate more information.  相似文献   

16.
Antagonistic and reciprocal interactions are known to exist between adenosine and dopamine receptors in the striatum. In the present study, double immunofluorescence experiments with confocal laser microscopy showed a high degree of colocalization of adenosine A(2A) receptors (A(2A)R) and dopamine D(2) receptors (D(2)R) in cell membranes of SH-SY5Y human neuroblastoma cells stably transfected with human D(2)R and in cultured striatal cells. A(2A)R/D(2)R heteromeric complexes were demonstrated in coimmunoprecipitation experiments in membrane preparations from D(2)R-transfected SH-SY5Y cells and from mouse fibroblast Ltk(-) cells stably transfected with human D(2)R (long form) and transiently cotransfected with the A(2A)R double-tagged with hemagglutinin. Long term exposure to A(2A)R and D(2)R agonists in D(2)R-cotransfected SH-SY5Y cells resulted in coaggregation, cointernalization and codesensitization of A(2A)R and D(2)R. These results give a molecular basis for adenosine-dopamine antagonism at the membrane level and have implications for treatment of Parkinson's disease and schizophrenia, in which D(2)R are involved.  相似文献   

17.
18.
Combined somatic cell hybrid and linkage studies between D10S94 and five pericentromeric loci (FNRB, D10Z1, MEN2A, RBP3, and D10S15) have localized the new DNA sequence pcl1/A1S-6-c23 at D10S94 to 10q11.2. No recombinants were observed between D10S94 and D10Z1 or MEN2A. D10S94 maps in proximal 10q11.2 very near to MEN2A. There are three possible orders for the six loci that we investigated from the centromeric region of chromosome 10. At present the genetic data do not allow us to order MEN2A with respect to D10Z1 and D10S94. The three possible orders are FNRB-D10Z1-D10S94-MEN2A-RBP3-D10S15, FNRB-D10Z1-MEN2A-D10S94-RBP3-D10S15, and FNRB-MEN2A-D10Z1-D10S94-RBP3-D10S15. In view of the fact that no recombinants between D10S94 and MEN2A or between D10S94 and D10Z1 were observed, the combined haplotypes formed from RFLPs and D10Z1 and D10S94 will increase the informativeness and accuracy of genotype prediction for at-risk members of the families having the MEN 2A syndrome, particularly when the affected parent is female. The localization of D10S94 with respect to MEN2A will prove valuable in experiments directed toward cloning the MEN2A locus.  相似文献   

19.
We have previously demonstrated that adenosine controls the release of catecholamines (CA) from carotid body (CB) acting on A2B receptors. Here, we have tested the hypothesis that the control is exerted via an interaction between adenosine A2B and dopamine D2 receptors present in chemoreceptor cells. Experiments were performed in vitro in CB from 3 months rats. The effect of A2B adenosine and D2 dopamine agonists and antagonists applied alone or in combination were studied on basal (20%O2) and hypoxia (10%O2)-evoked release of CA and cAMP content of CB. We have found that adenosine A2 agonists and D2 antagonists dose-dependently increased basal and evoked release CA from the CB while A2 antagonists and D2 agonists had an inhibitory action. The existence of A2B-D2 receptor interaction was established because the inhibitory action of A2 antagonists was abolished by D2 antagonists, and the stimulatory action of A2 agonists was abolished by D2 agonists. Further, A2 agonists increased and D2 agonist decreased cAMP content in the CB; their co-application eliminated the response. The present results provide direct pharmacological evidence that an antagonistic interaction between A2B adenosine and D2 dopamine receptors exist in rat CB and would explain the dopamine-adenosine interactions on ventilation previously observed.  相似文献   

20.
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