金钱槭属植物的遗传多样性与保护策略

金钱槭属包括2个种:金钱槭(Dipteronia sinensis Oliv.)和云南金钱槭(Dipteronia dyeriana Henry),均为珍稀濒危植物,主要分布于中国的中部和南部。该研究应用18种随机扩增多态性DNA(RAPD)引物、8对扩增片段长度多态性(AFLP)引物和10种多态性叶绿体微卫星基因(cpSSR)引物,获得金钱槭和云南金钱槭的遗传多样性与种群结构的相关信息。结果表明,在物种水平上,由RAPD(金钱槭:H=0.386 4,Hsh=0.556 3;云南金钱槭:H=0.304 7,Hsh=0.445 0)和AFLP(金钱槭:H=0.331 9,Hsh=0.488 0;云南金钱槭:H=0.304 7,Hsh=0.4450)2个核标记的遗传多样性具有可比性,而cpSSR标记(金钱槭He=0.603 2,云南金钱槭He=0.671 1)的遗传多样性高于AFLP和RAPD标记的遗传多样性,遗传分化系数(GST)也显示出相似的结果,由此揭示2个种均拥有相对较高的遗传多样性和遗传分化。研究认为,人类活动破坏植物栖息地是造成2种物种处于濒危状态的主要原因;从长远来看,保护2种金钱槭属植物的主要策略是保护植物栖息地,同时应加强扩大种群规模以维持现有遗传变异水平。     

金钱槭和云南金钱槭遗传多样性比较研究

金钱槭属(Dipteronia)是我国特有少种属,属下仅金钱槭(D. sinensis)和云南金钱槭(D. dyeriana)两种。该文用RAPD标记揭示了金钱槭的遗传多样性和遗传结构,并与云南金钱槭的RAPD研究结果进行了比较。同时,对两物种遗传距离与地理距离的相关性进行了分析,结果有助于阐释该属植物遗传变异的产生机制。研究显示,18条随机引物在17个金钱槭居群(226个个体)中检测到128个扩增位点,物种水平的多态位点比率为92.97%,在4个云南金钱槭居群(45个个体)中则检测到103个扩增位点,物种水平的多态位点比率为81.55%,金钱槭的多态位点比率高于云南金钱槭。相似性系数值、Shannon多样性指数和Nei基因多样性指数分析反映了与多态位点比率相一致的结果。AMOVA(Analysis of molecular variance)分析结果显示,金钱槭居群内、居群间的遗传变异分别占总变异量的56.89%和43.11%。云南金钱槭居群内、居群间的遗传变异分别占总变异量的57.86 %和42.14%。Shannon多样性指数、Nei基因多样性指数的分析结果与AMOVA分析结果趋势相同。上述特征值揭示,金钱槭和云南金钱槭居群间的遗传分化均已达到较高水平,推测居群间低水平的基因流可能是导致上述现象产生的原因之一。遗传距离与地理距离的相关分析结果显示,金钱槭居群间的遗传距离与经度差异存在极显著水平的相关性(p<0.01),云南金钱槭居群间的遗传距离与地理隔离则无显著相关关系。说明在大尺度上遗传距离与地理距离相关而在小范围内则无上述关系,该结果可能与位于不同分布区内的物种所承受的生境选择压力不同有关。建议在对该属植物进行就地保护时,应设立多个保护点,保护自然居群及其周围生境;在迁地保护时,应通过加大居群间种子和幼苗的交换,人为创造基因交流和重组的条件,保存该属植物的遗传多样性。     

槭树科植物广义形态学性状分支分析

通过45个广义的形态学性状对槭树科(Aceraceae)尤其是槭属(Acer L.)的主要类群做了分支分析,结果显示：1)槭属内由于各类群分布着较多的同塑性状状态,而难以为属下组间关系的解决提供更多有价值的信息;通过对具体的性状状态分布分析显示,对于象槭属这样在形态上分化较大的类群,由于多数分类性状在不同类群间经历了平行和逆转演化,因而在较低分类阶元水平很难选择合适的性状来通过分支分析构建其系统发育;2)鸡爪槭组(section Palmata)作为整个槭属的基部类群,虽然支持率较低,但与其它类群相比在槭属内维持了较多的原始性状;3)金钱槭属(Dipteronia Oliv.)的两个种作为单系得到了100％的靴带支持,且和槭属作为姐妹群也得到了较好的支持。     

云南金钱槭形态变异与遗传变异的相关性研究

对我国特有珍稀濒危保护植物云南金钱槭的形态变异水平、遗传变异模式以及两者之间的相关性进行了研究。形态学性状分析结果表明 :各居群形态性状变异系数的平均值从大到小排列为 :文山居群 (WSh)、屏边居群 (PB)、黑龙潭居群 (HL T)、蒙自居群 (MZ) ;文山居群与屏边、黑龙潭、蒙自居群间已产生显著或极显著水平的形态差异 ,而后三者间的差异未达显著水平。RAPD分析检测到 10 3个位点 ,其中多态位点 84个 ,云南金钱槭物种水平的多态位点比率为 81.5 5 % ,与其它珍稀濒危植物相比该种的遗传多样性水平不低。 AMOVA和 N ei基因多样性指数分析显示 ,尽管大部分遗传变异仍存在于居群内 (分别为5 7.86 %、5 7.33% ) ,但居群间的遗传变异已达较高水平 (分别为 4 2 .14 %、4 2 .6 7% )。相关分析结果显示 ,云南金钱槭的形态变异与海拔、土壤有机质等生态因子有着显著或极显著水平的相关性 ,但与遗传变异的相关性未达显著水平 ,说明云南金钱槭的形态变异虽然具有一定的遗传基础 ,但可塑性及环境压力对形态变异的产生作用更大一些。基于形态性状和 RAPD数据的聚类分析则进一步说明 ,云南金钱槭的形态变异受到环境因子的强烈影响而与遗传背景的关系不显著     

封面植物简介——金钱槭

金钱槭(Dipteronia sinensis Oliv．)隶属于槭树科金钱槭属,为中国特有的寡种属植物之一。金钱槭为落叶乔木,高可达10m,具裸露的冬芽。奇数羽状复叶对生,通常具7～11枚小叶。花白色,杂性,     

封面植物简介——金钱槭

金钱槭(Dipteronia sinensis Oliv．)隶属于槭树科金钱槭属,为中国特有的寡种属植物之一。金钱槭为落叶乔木,高可达10m,具裸露的冬芽。奇数羽状复叶对生．通常具7～11枚小叶。花白色,杂性,雄花与两性花同株,形成网锥花序。翅果周围环绕着圆形的翅．嫩时粉红色．成熟时棕黄色,状如占钱。金钱槭分布于陕西、     

云南金钱槭果实、种子形态分化研究

对5个云南金钱槭(Dipteronia dyeriana Henry)天然居群的果实、种子形态进行研究.测量了果实和种子的长度、宽度、重量等12个表型性状指标.数据统计结果显示5个云南金钱槭居群按果实、种子大小进行排序为蒙自(MZ)>屏边(PB)>文山1(WSh1)>文山3(WSh3)>文山2(WSh2).表型性状在居群内和居群间均存在着一定程度的变异,其中居群间变异系数的平均值从0.064(果实整体形态,PL/PB)到0.197(种子重量,SW),相比之下果实整体形态最为稳定.居群间形态总体差异显著性配对t检验结果说明,多数居群间已产生较明显的形态分化.Ward聚类和相关分析结果都表明表型性状与生态因子、海拔高度之间存在着一定程度的相关性,多种生态因子的共同作用是导致果实、种子形态特征产生差异的主要原因.     

基于ITS与 trn L-F序列探讨槭树科的系统发育

报道了槭树科41种(其中槭属39种)植物的 trn L-F和ITS序列(其中部分种的ITS序列为重新测定),以期通过分子手段对槭树科内部尤其是复杂的槭属的系统发育关系进行重建.以无患子科和七叶树科为外类群,基于对57个种单独的ITS序列(包括从GenBank下载的16种的序列)、41种 trn L-F序列及41种两者序列的联合数据,分别采用最大简约法(Maximum Parsimony Method)和邻接法(Neighbor-Joining Method)对槭树科的系统发育进行了分析.结果显示,整个槭树科为一单系类群;金钱槭位于槭树科的基部;但由于云南金钱槭( Dipteronia dyerana )聚在了槭属内部,认为金钱槭属和槭属均可能是非单系类群;槭属内组间关系的支持率普遍较低,但多数组的组内关系得到了较好的支持.将两个片段结合比单独的ITS或 trn L-F分析能更好地解决槭属内部的系统关系,其中sect.Palmata 和sect.Microcarpa ,sect.Platanoidea 、sect.Lithocarpa 和sect.Macrophylla ,sect.Integrifolia 、sect.Trifoliata 和sect.Pentaphylla ,以及sect.Acer 、sect.Goniocarpa 和sect.Saccharina (sensu Ogata)的组间亲缘关系得到了一定的支持,但对其中部分组的划分可能应做进一步调整.重新评价了徐廷志系统中对sect.Rubra 和sect.Saccharodendron 的处理.     

封面植物简介——金钱槭

金钱槭(Dipteronia sinensis Oliv．)隶属于槭树科金钱槭属,为中国特有的寡种属植物之一。金钱槭为落叶乔木,高可达10m,具裸露的冬芽。奇数羽状复叶对生,通常具7～11枚小叶。花白色,杂性,雄花与两性花同株,形成圆锥花序。翅果周围环绕着圆形的翅,嫩时粉红色,成熟时棕黄色,状如古钱。金钱槭分布于陕西、     

封面植物简介——金钱槭

金钱槭（Dipteronia sinensis Oliv．）隶属于槭树科金钱槭属,为中国特有的寡种属植物之一。金钱槭为落叶乔木,高可达10m,具裸露的冬芽。奇数羽状复叶对生,通常具7～11枚小叶。花白色,杂性,雄花与两性花同株,形成圆锥花序。翅果周围环绕着圆形的翅,嫩时粉红色,成熟时棕黄色,状如古钱。金钱槭分布于陕西、     

Foreign exploration for Scirtothrips perseae Nakahara (Thysanoptera: Thripidae) and associated natural enemies on avocado (Persea americana Miller)

Scirtothrips perseae Nakahara was discovered attacking avocados in California, USA, in 1996. Host plant surveys in California indicated that S. perseae has a highly restricted host range with larvae being found only on avocados, while adults were collected from 11 different plant species. As part of a management program for this pest, a “classical” biological control program was initiated and foreign exploration was conducted to delineate the home range of S. perseae, to survey for associated natural enemies and inventory other species of phytophagous thrips on avocados grown in Mexico, Guatemala, Costa Rica, the Dominican Republic, Trinidad, and Brazil. Foreign exploration efforts indicate that S. perseae occurs on avocados grown at high altitudes (>1500 m) from Uruapan in Mexico south to areas around Guatemala City in Guatemala. In Costa Rica, S. perseae is replaced by an undescribed congener as the dominant phytophagous thrips on avocados grown at high altitudes (>1300 m). No species of Scirtothrips were found on avocados in the Dominican Republic, Trinidad, or Brazil. In total, 2136 phytophagous thrips were collected and identified, representing over 47 identified species from at least 19 genera. The significance of these species records is discussed. Of collected material 4% were potential thrips biological control agents. Natural enemies were dominated by six genera of predatory thrips (Aeolothrips, Aleurodothrips, Franklinothrips, Leptothrips, Scolothrips, and Karnyothrips). One genus each of parasitoid (Ceranisus) and predatory mite (Balaustium) were found. Based on the results of our sampling techniques, prospects for the importation of thrips natural enemies for use in a “classical” biological control program in California against S. perseae are not promising.     

Structural Peculiarities of Na+,K+-ATPase Isozymes from the Calf Brain

Functionally active preparations of Na⁺,K⁺-ATPase isozymes from calf brain that contain catalytic subunits of three types (1, 2, and 3) were obtained using two approaches: a selective removal of contaminating proteins by the Jorgensen method and a selective solubilization of the enzyme with subsequent reconstitution of their membrane structure by the Esmann method. The ouabain inhibition constants were determined for the isozymes. The real isozyme composition of the Na⁺ pump from the grey matter containing glial cells and the brain stem containing neurons was determined. The plasma membranes of glial cells were shown to contain mainly Na⁺,K⁺-ATPase of the 11 type and minor amounts of isozymes of the 22(1) and the 31(2) type. The axolemma contains 21 and 31 isozymes. A carbohydrate analysis indicated that 11 enzyme preparations from the brain grey matter substantially differ from the renal enzymes of the same composition in the glycosylation of the 1 isoform. An enhanced sensitivity of the 3 catalytic subunit of Na⁺,K⁺-ATPase from neurons to endogenous proteolysis was found. A point of specific proteolysis in the amino acid sequence PNDNR⁴⁹² Y⁴⁹³ was localized (residue numbering is that of the human 3 subunit). This sequence corresponds to one of the regions of the greatest variability in 1-, 2-, 3-, and 4-subunits, but at the same time, it is characteristic of the 3 isoforms of various species. The presence of the 3 isoform of tubulin (cytoskeletal protein) was found for the first time in the high-molecular-mass Na⁺,K⁺-ATPase 31 isozyme complex isolated from the axolemma of brain stem neurons, and its binding to the 3 catalytic subunit was shown.     

Characterization of SSEA-1 glycolipids from the brain of a patient with fucosidosis

Neutral glycolipids from the brain of a patient with Fucosidosis were analyzed and two complex glycolipids containing five and eight sugars were isolated from the cortical grey matter. These two glycolipids reacted with antibodies recognizing the SSEA-1 [Le^x(X)] carbohydrate determinant. SSEA-1 glycolipids are normally expressed in human embryonic brain but are found in only small amounts in postnatal human brain. The accumulation of the two SSEA-1 glycolipids in Fucosidosis brain thus represents a defect which affects the normal developmentally regulated decrease in postnatal, expression of these glycolipids, and may be a contributing factor in the abnormal brain development associated with the disease. Chemical characterization of the two isolated glycolipids by gas chromatographic and mass spectrometric analyses has identified the two glycolipids as lacto-N-fucopentaosylceramide (III) and difucosyl-neolactonorhexaosylceramide.Abbreviations DCl direct chemical ionization - FAB tastatiom bombardment - GC gas chromatography - GSLs glycosphingolipids - MS mass spectrometry - SSEA-1 stage specific embryonic antigen-1 - TLC thin layer chromatographys     

1H and13C-NMR analysis of four pentasaccharides from urine of blood-group A and B,Leb adults. Confirmation of the structure of two new oligosaccharides: Fuc(α1–2)[GalNAc(α1–3)]Gal(β1–3)[Fuc(α1–4)]Glc and Fuc(α1–2)[Gal(α1–3)]Gal(β1–3)[Fuc(α1–4)]Glc

The major pentasaccharides Fuc(1-2)[GalNAc(1-3)]Gal(1-4)[Fuc(1-3)]Glc and Fuc(1-2) [Gal(1-3)]Gal(1-4)[Fuc(1-3)]Glc, which are normally present in the urine of bloodgroup A Le^b and B Le^b healthy subjects, were each found to be contaminated by a minor component when analysed by¹H-NMR. The determination of these structures, Fuc(1-2) [GalNAc(1-3)]Gal(1-3)[Fuc(1-4)]Glc and Fuc(1-2) [Gal(1-3)]Gal(1-3)[Fuc(1-4)]Glc, was based on the results of methylation analysis and¹H/¹³C-NMR spectroscopy.Abbreviations HPLC high performance liquid chromatography - GLC gas liquid chromatography - NMR nuclear magnetic resonance - COSY correlation spectroscopy - Gal d-galactopyranose - GalNAc 2-acetamido-2-deoxy-d-galactopyranose - Glc d-glucopyranose - Fuc l-fucopyranose - LNDFH I lacto-N-difucohexaose I (Le^b determinant     

Phylogeny of cardinalfishes (Teleostei: Gobiiformes: Apogonidae) and the evolution of visceral bioluminescence

The cardinalfishes (Apogonidae) are a diverse clade of small, mostly reef-dwelling fishes, for which a variety of morphological data have not yielded a consistent phylogeny. We use DNA sequence to hypothesize phylogenetic relationships within Apogonidae and among apogonids and other acanthomorph families, to examine patterns of evolution including the distribution of a visceral bioluminescence system. In conformance with previous studies, Apogonidae is placed in a clade with Pempheridae, Kurtidae, Leiognathidae, and Gobioidei. The apogonid genus Pseudamia is recovered outside the remainder of the family, not as sister to the superficially similar genus Gymnapogon. Species sampled from the Caribbean and Western Atlantic (Phaeoptyx, Astrapogon, and some Apogon species) form a clade, as do the larger-bodied Glossamia and Cheilodipterus. Incidence of visceral bioluminescence is found scattered throughout the phylogeny, independently for each group in which it is present. Examination of the fine structure of the visceral bioluminescence system through histology shows that light organs exhibit a range of morphologies, with some composed of complex masses of tubules (Siphamia, Pempheris, Parapriacanthus) and others lacking tubules but containing chambers formed by folds of the visceral epithelium (Acropoma, Archamia, Jaydia, and Rhabdamia). Light organs in Siphamia, Acropoma, Pempheris and Parapriacanthus are distinct from but connected to the gut; those in Archamia, Jaydia, and Rhabdamia are simply portions of the intestinal tract, and are little differentiated from the surrounding tissues. The presence or absence of symbiotic luminescent bacteria does not correlate with light organ structure; the tubular light organs of Siphamia and chambered tubes of Acropoma house bacteria, those in Pempheridae and the other Apogonidae do not.     

Biological control of three floating water weeds,<Emphasis Type="Italic">Eichhornia crassipes,Pistia stratiotes</Emphasis>, and <Emphasis Type="Italic">Salviniamolesta</Emphasis> in the Republic of Congo

Since 1999, four specific weevils (Coleoptera, Curculionidae) were released in the Republic of Congo against three exotic floating water weeds: Neochetina eichhorniae Warner and N. bruchi Hustache against water hyacinth, Neohydronomus affinis Hustache against water lettuce, and Cyrtobagous salviniae Calder and Sands against water fern. Recoveries of exotic weevils were made from all 24 release sites except one, and all four species have established and spread (up to 800 km for water hyacinth weevils). Within a few years of releases, control of water fern and water lettuce was such that fishing and navigation could be resumed, while reductions of water hyacinth populations were only beginning.     

N-andO-glycosylation of glycoprotein C synthesized by Herpes simplex virus type 1-infected ricin resistant cells

The progeny of Herpes simplex virus type 1 (HSV-1) grown in ricin-resistant 14 cells (Ric^R14) lackingN-acetylglucosaminyltransferase I was released in the extracellular medium at a very low rate. By using a monoclonal antibody immobilized on Sepharose we purified from HSV-1-infected Ric^R14 cells a viral glycoprotein (gC), which carries bothN-andO-linked oligosaccharides. Glycopeptides obtained from [³H]mannoselabeled gC by Pronase digestion were entirely susceptible to endo--N-acetylglucosaminidase H, and the major oligosaccharide released was Man₄GlcNAc. The accumulation of this high-mannose species was related to the enzymic defect of the host cells and to the long retention of the viral glycoprotein within the cells. The extent ofO-glycosylation evaluated in [¹⁴C]glucosamine-labeled gC from Ric^R14 cells as compared to that of gC from wild type cells did not appear to be significantly modified.Abbreviations Con A concanavalin A - BHK cells baby hamster kidney cells - HSV Herpes simplex virus     

Elucidation of Structure of Lipid A from the Marine Gram-Negative Bacterium Pseudoalteromonas haloplanktis ATCC 14393T

The chemical structure of lipid A, from the marine -proteobacterium Pseudoalteromonas haloplanktis 14393, a main product of lipopolysaccharide hydrolysis (1% AcOH), was determined using chemical methods and NMR spectroscopy. The lipid A was shown to be -1,6-glucosaminobiose 1,4-diphosphate acylated with two (R)-3-hydroxyalkanoic acid residues at C3 and C3 and amidated with one (R)-3-hydroxydodecanoyl and one (R)-3-dodecanoyloxydodecanoyl residue at N2 and N2, respectively.     

A molecular phylogeny of Hebeloma species from Europe

In order to widen the scope of existing phylogenies of the ectomycorrhizal agaric genus Hebeloma a total of 53 new rDNA ITS sequences from that genus was generated, augmented by sequences retrieved from GenBank, and analysed using Bayesian, strict consensus and neighbour joining methods. The lignicolous Hebelomina neerlandica, Gymnopilus penetrans, and two species of Galerina served as outgroup taxa. Anamika indica, as well as representatives of the genera Hymenogaster and Naucoria, were included to test the monophyly of Hebeloma, which is confirmed by the results. Hebeloma, Naucoria, Hymenogaster and Anamika indica cluster in a strongly supported monophyletic hebelomatoid clade. All trees largely reflect the current infrageneric classification within Hebeloma, and divide the genus into mostly well-supported monophyletic groups surrounding H. crustuliniforme, H. velutipes, H. sacchariolens, H. sinapizans, and H. radicosum, with H. sarcophyllum being shown at an independent position; however this is not well supported. The section Indusiata divides with strong support into three groups, the position of the pleurocystidiate Hebeloma cistophilum suggests the possible existence of a third subsection within sect. Indusiata. Subsection Sacchariolentia is raised to the rank of section.