New Materials of Eriocaulon L. from China

This paper consists of a part of pertinent data obtained through a critical study of Eriocaulaceae from China. Included in it are three new series: Leiantha, Robustiora and Mangshanensia; seven new species: Eriocaulon acutibracteatum, E. angustulum, E. bilobatum, E. leianthum, E. sclerophyllum, E. glabri-petalum and E. mangshanense; five new varieties: E. rockianum var. latifolium, E. merrillii var. longibracteatum, E. sikokianum var. Linanense, E. alpestre var. sichanense and E. nantoense var. micropetalum; two new combinations: E. yaoshanense var. brevicalyx; E. nantoense var. parviceps; three new records in China: E. brownianum, E.brownianum var.nilagirense, E. zollingerianum; five: E. henryanum, E.pullum, E. yaoshanense, E. taishanense and E.faberi. In addition, fifteen taxon names are newly reduced to synonyms: E. yunnanense=E. brownianum; E. longifolium, E. sexangulare var. longifolium, E. sinii, E. kwangtungense and E. willdinovianum = E. sexangulare; E. setaceum var. capillus-naiadis= E. setaceum; E. filifolium = E. yaoshanense; E. suishaense, E. merrillii var. suishaense=E.merrillii; E. kengii=E.sikokianum; E. whangii=E.buergerianum; E. nipponicum, E. decemflorum var. nipponicum= E. decemflorum and E. nantoense var.trisectum = E. nantoense var.parviceps.     

New species of Elaphoglossum (Elaphoglossaceae) from northern South America

The fern genusElaphoglossum is well-represented in the Venezuelan pteridoflora with 98 species. Careful observation of the indument of rhizome and blade is necessary to distinguish the taxa. Thirty-three species and one variety are here describe as new:E. anceps, E. appressum, E. atrorubens, E. atrosquamatum, E. chrysopogon, E. crispatum var.crispatum, E. crispatum var.beitelii, E. delicatulum, E. dolichopus, E. drewianum, E. eriopus, E. floccosum, E. grallator, E. hieracioides, E. incubus, E. luteynii, E. maguirei, E. nigrocostatum, E. obovatum, E. ornithoglossum, E. ortegae, E. pilosius, E. praetermissum, E. stenoglossum, E. stergiossi, E. steyermarkii, E. styriacum, E. succubus, E. tachirense, E. tantalinum, E. urophyllum, E. vanderwerffii, E. vareschianum, andE. variolatum.     

Nineteen new species of Elaphoglossum (Elaphoglossaceae, Pteridophyta) from Bolivia

We describe and illustrate 19 new species ofElaphoglossum from Bolivia:E. ayopayaense, E. carrascoense, E. choquetangae, E. cotapatense, E. crispipalea, E. cruzense, E. elkeae, E. ellenbergianum, E. gonzalesiae, E. inquisitivum, E. madidiense, E. murinum, E. neei, E. palmarum, E. pannosum, E. paucinervium, E. puberulentum, E. pulchrum, andE. sunduei.     

Apolipoprotein E polymorphism in Saudis

Apolipoprotein E (apoE) genotypes were determined in 165 Saudis. The prevalence of genotype, E3/E3, E3/E4 and E4/E4 was found to be 71, 27 and 2% respectively. The E3/E3 was the most prevalent genotype among the Saudis followed by E3/E4. However, other genotypes E2/E2, E2/E3 and E2/E4 were absent showing the absence of E2 allele in the test population. The high frequencies of the E3 allele (0.845) and E3/E3 genotype (0.71) and absence of E2 allele in Saudis under study are similar to those reported earlier for Native Americans, Mexican-Americans, Mayans, Cayapa, Mazatecan Indians and Mexican Mestizos populations.     

Apolipoprotein E polymorphism in Saudis

Apolipoprotein E (apoE) genotypes were determined in 165 Saudis. The prevalence of genotype, E3/E3, E3/E4 and E4/E4 was found to be 71, 27 and 2% respectively. The E3/E3 was the most prevalent genotype among the Saudis followed by E3/E4. However, other genotypes E2/E2, E2/E3 and E2/E4 were absent showing the absence of E2 allele in the test population. The high frequencies of the E3 allele (0.845) and E3/E3 genotype (0.71) and absence of E2 allele in Saudis under study are similar to those reported earlier for Native Americans, Mexican-Americans, Mayans, Cayapa, Mazatecan Indians and Mexican Mestizos populations.     

Experimental hybridizations of Eriophyllum annuals (Asteraceae, Helenieae)

Seven of the eight annual species of Eriophyllum, a western North American genus, were studied in greenhouse and garden. Eriophyllum congdonii and E. nubigenum proved to be self-compatible; E. ambiguum, E. multicaule, E. pringlei, and E. wallacei were self-incompatible; E. lanosum was not studied. All combinations of artificial hybridizations were attempted except E. congdonii × E. lanosum. Among the species with n = 7, fertile hybrids came from E. congdonii × E. nubigenum and sterile hybrids from E. ambiguum var. ambiguum × E. pringlei, E. ambiguum var. paleaceum × E. congdonii, E. multicaule, E. nubigenum, and E. pringlei, as well as E. multicaule × E. congdonii and E. multicaule × E. pringlei. The other homoploid combinations failed, as did heteroploid combinations involving the annual species with n = 7 and either E. wallacei (n = 5) or E. lanosum (n = 4). Sterile hybrids were generated in crosses of E. congdonii to the perennial E. lanatum (x = 8).     

Hybrid pyruvate dehydrogenase complexes reconstituted from components of the complexes from Escherichia coli and Azotobacter vinelandii

The pyruvate dehydrogenase complex of Escherichia coli was isolated in a simple three-step procedure. Its chain stoichiometry, determined by trinitrobenzoate modification was found to be 1.4 E1:1 E2:0.6 E3. It was reproducible within 10% from preparation to preparation. The E. coli complex was resolved by chromatography on activated thiol Sepharose. Reconstitution of activity yielded a stoichiometry of 1.0 E1:1 E2:0.5 E3. The optimum binding stoichiometry of E1E2 and E2E3 subcomplexes was determined by sedimentation experiments and found to be 2.0 E1:1 E2 and 2.5 E3:1 E2, respectively. Competition between E1 and E3 was observed in the binding experiments, but not in the kinetic experiments. Hybrid active complexes could be reconstituted from either an E1E2 subcomplex from Azotobacter vinelandii and the E3 component from E. coli or from E2E3 subcomplex from E. coli and the E1 component from A. vinelandii. Low activity and weak binding was observed when E1 from E. coli was recombined with an E2E3 subcomplex from A. vinelandii or when E3 from A. vinelandii was recombined with an E1E2 subcomplex from E. coli. The association behaviour and stoichiometry of the reconstituted complexes is determined by the nature of the E2 component. The formation of hybrid complexes indicates a considerable structural similarity between the complexes from both sources, despite the differences in size and stoichiometry.     

Structural bases for the specific interactions between the E2 and E3 components of the Thermus thermophilus 2-oxo acid dehydrogenase complexes

Pyruvate dehydrogenase (PDH), branched-chain 2-oxo acid dehydrogenase (BCDH) and 2-oxoglutarate dehydrogenase (OGDH) are multienzyme complexes that play crucial roles in several common metabolic pathways. These enzymes belong to a family of 2-oxo acid dehydrogenase complexes that contain multiple copies of three different components (E1, E2 and E3). For the Thermus thermophilus enzymes, depending on its substrate specificity (pyruvate, branched-chain 2-oxo acid or 2-oxoglutarate), each complex has distinctive E1 (E1p, E1b or E1o) and E2 (E2p, E2b or E2o) components and one of the two possible E3 components (E3b and E3o). (The suffixes, p, b and o identify their respective enzymes, PDH, BCDH and OGDH.) Our biochemical characterization demonstrates that only three specific E3*E2 complexes can form (E3b*E2p, E3b*E2b and E3o*E2o). X-ray analyses of complexes formed between the E3 components and the peripheral subunit-binding domains (PSBDs), derived from the corresponding E2-binding partners, reveal that E3b interacts with E2p and E2b in essentially the same manner as observed for Geobacillus stearothermophilus E3*E2p, whereas E3o interacts with E2o in a novel fashion. The buried intermolecular surfaces of the E3b*PSBDp/b and E3o*PSBDo complexes differ in size, shape and charge distribution and thus, these differences presumably confer the binding specificities for the complexes.     

Organization of the cores of the mammalian pyruvate dehydrogenase complex formed by E2 and E2 plus the E3-binding protein and their capacities to bind the E1 and E3 components

The subunits of the dihydrolipoyl acetyltransferase (E2) component of mammalian pyruvate dehydrogenase complex can form a 60-mer via association of the C-terminal I domain of E2 at the vertices of a dodecahedron. Exterior to this inner core structure, E2 has a pyruvate dehydrogenase component (E1)-binding domain followed by two lipoyl domains, all connected by mobile linker regions. The assembled core structure of mammalian pyruvate dehydrogenase complex also includes the dihydrolipoyl dehydrogenase (E3)-binding protein (E3BP) that binds the I domain of E2 by its C-terminal I' domain. E3BP similarly has linker regions connecting an E3-binding domain and a lipoyl domain. The composition of E2.E3BP was thought to be 60 E2 plus approximately 12 E3BP. We have prepared homogenous human components. E2 and E2.E3BP have s(20,w) values of 36 S and 31.8 S, respectively. Equilibrium sedimentation and small angle x-ray scattering studies indicate that E2.E3BP has lower total mass than E2, and small angle x-ray scattering showed that E3 binds to E2.E3BP outside the central dodecahedron. In the presence of saturating levels of E1, E2 bound approximately 60 E1 and maximally sedimented 64.4 +/- 1.5 S faster than E2, whereas E1-saturated E2.E3BP maximally sedimented 49.5 +/- 1.4 S faster than E2.E3BP. Based on the impact on sedimentation rates by bound E1, we estimate fewer E1 (approximately 12) were bound by E2.E3BP than by E2. The findings of a smaller E2.E3BP mass and a lower capacity to bind E1 support the smaller E3BP substituting for E2 subunits rather than adding to the 60-mer. We describe a substitution model in which 12 I' domains of E3BP replace 12 I domains of E2 by forming 6 dimer edges that are symmetrically located in the dodecahedron structure. Twelve E3 dimers were bound per E248.E3BP12 mass, which is consistent with this model.     

中国人群(京津地区)载脂蛋白E基因多态性和表型分布的研究

本文利用作者建立的密度梯度超速离心分离VLDL的新方法和分析等电聚焦电泳,测定了95例中国人Apo-E基因多态性和其表型分布以及血脂水平。所得表型分布趋势与国外报告一致:E_3/E_3频率最高,E_3/E_2和E_3/E_4次之,E_4/E_4,E_4/E_2和E_2/E_2最低。同对发现中国人群的E_3/E_3表型百分分布明显高于西方人群,但未发现有E_2/E_2表型。我国人群Apo-E表型分布的这种特征可能与中国人群冠心病的患病率较西方人群为低有关。血清脂质测定和分析表明,具有不同表型人群的血脂水平无显著的统计学差异。     

Purification and application of bacterially expressed chimeric protein E1E2 of hepatitis C virus

E1 and E2 glycoproteins are structural components of hepatitis C virus (HCV) virion. They are involved in cellular receptors interaction, neutralising antibodies elicitation, and viral morphogenesis. They are considered as major candidates for anti-HCV vaccine. In this report, we first expressed tandem E1E2 as well as C-terminally truncated E1 fragment and C-terminally truncated E2 fragment, respectively, in Escherichia coli cells and the proteins were purified to homogenesis. All the purified proteins can react specifically with patient sera. Both purified chimeric protein E1E2 and protein E2 can interact with a putative cellular receptor CD81, while purified protein E1 cannot interact with CD81. The sera of rabbit immunized with the E1E2 inhibited the binding of E2 protein to the major extracellular loop of human CD81 and reacted with both proteins E1 and E2, respectively. Anti-E1 and E2 antibodies can be generated simultaneously in the rabbit immunized with the E1E2, and the titers of antibodies were 63 or 56% higher than the titers induced by E1 or E2 alone, respectively. The results suggest that E1 and E2 can enhance their immunogenicity each other in chimeric protein E1E2 and the E. coli-derived chimeric protein E1E2 and corresponding antisera can be used as an useful tools in anti-HCV vaccine research.     

IFN-γ、IL-1α、NGF-β和TNF-α在皖西白鹅小脑皮质发育中的表达

用免疫组织化学strept actividin-biotin complex(SABC)法,以干扰素-γ(IFN-γ)、白介素-1α(IL-1α)、神经生长因子-β(NGF-β)和肿瘤坏死因子-α(TNF-α)对胚龄13d、19d、24d、28d(E13、E19、E24、E28)和日龄7d、15d(P7、15)的皖西白鹅(WesternAnhuiwhitegoose)小脑皮质中的阳性细胞进行定位和半定量检测,探讨IFN-γ、IL-1α、NGF-β和TNF-α在小脑皮质发育中的作用。研究表明,外颗粒层细胞在E13、E19、E24、E28、P7有IFN-γ和TNF-α阳性表达;在E13、E19、E24、E28有IL-1α阳性表达;在E13、E19、E24有NGF-β阳性表达;且在所检测的6个时期中,4种细胞因子均在E19表达最强。Purkinje细胞层在E13、E19、E24、E28、P7、P15均有IFN-γ、IL-1α、TNF-α阳性表达;在E13、E19、E24、E28、P7有NGF-β阳性表达;内颗粒层细胞在E13、E19、E24、E28、P7、P15有IFN-γ阳性表达;在E13、E19、E24、E28、P7有IL-1α、TNF-α阳性表达;在E13、E19、E24、E28有NGF-β阳性表达。结果表明,E19可能为小脑皮质发育的"关键期";IFN-γ、IL-1α和TNF-α可能由小脑皮质自身合成;NGF-β可能由投射到Purkinje细胞的区域转运而来,且可能在Purkinje细胞生长发育过程中起营养作用;IFN-γ可能在颗粒细胞迁移过程中起干扰作用。     

Identification of enterococci at the species level by sequencing of the genes for D-alanine:D-alanine ligases

A PCR assay based on the use of degenerate oligodeoxyribonucleotides allowed characterization of a fragment internal to the ddl genes encoding D-alanine:D-alanine ligases in Enterococcus columbae, E. durans, E. malodoratus, E. mundtii, E. raffinosus, E. seriolicida, E. solitarius, and E. sulfureus. Phylogenetic analysis of the sequence of the amplification products and of those already obtained from E. aviuni, E. casseliflavus, E. cecorum, E. dispar, E. faecalis, E. faecium, E. flavescens, E. gallinarurm, E. hirae, E. pseudoavium, and E. saccharolvticus yielded an evolutionary tree with a topology similar to that based on 16S rRNA sequences. Partial sequencing of the ddl gene can therefore be used for genotypic identification of Enterococcus spp.     

Isozyme variations inAegilops andTriticum. III. Chromosomal basis of the esterase isozyme production in different organs of Chinese spring wheat

Developmental changes of esterase isozymes from the germination to the heading stage of normal and aneuploid lines of common wheat,Triticum aestivum cv. Chinese Spring were studied. A total of twenty major isozymes (Bands 1E to 20E) were observed, some of which were further separated to two to three closely located bands. Among these bands, 1E, 2E, 3E, 5E, 7E, 11E, 14E and 16E were found to be leaf-specific isozymes and 9E, 10E, 13E, 15E, 17E and 18E were seed-specific. Leaf-specific isozyme bands 1E, 2E and 5E are controlled by genes on three homoeologous chromosomes group 6, leaf-specific bands 7E, 11E, 14E and 16E and seed-specific bands 9E, 10E, 13E, 15E, 17E and 18E are under control of genes on homoeologous chromosomes of group 3. On the other hand, two bands, 19′E and 19″E are controlled by genes on chromosomes of homoeologous group 2 in roots of seedlings 10 days old. The present investigation showed that the genes for esterase production located on chromosome 6B had large effects in mature leaves, but chromosomes 6A and 6D had little effect on the esterase isozymes in homoeologous group 6. Genes located on chromosomes 3A, 3B and 3D have a large function in germinating seed; however, chromosomes 3B had little effect on the esterase isozymes in the mature leaf. Present findings confirmed that the chromosomes of the A, B and D genomes have different functions in the production of proteins or enzymes. Contribution from the Laboratory of Genetics, Faculty of Agriculture, Kyoto University, Japan, No. 401.     

DNA-damage response control of E2F7 and E2F8

Here, we report that the two recently identified E2F subunits, E2F7 and E2F8, are induced in cells treated with DNA-damaging agents where they have an important role in dictating the outcome of the DNA-damage response. The DNA-damage-dependent induction coincides with the binding of E2F7 and E2F8 to the promoters of certain E2F-responsive genes, most notably that of the E2F1 gene, in which E2F7 and E2F8 coexist in a DNA-binding complex. As a consequence, E2F7 and E2F8 repress E2F target genes, such as E2F1, and reducing the level of each subunit results in an increase in E2F1 expression and activity. Importantly, depletion of either E2F7 or E2F8 prevents the cell-cycle effects that occur in response to DNA damage. Thus, E2F7 and E2F8 act upstream of E2F1, and influence the ability of cells to undergo a DNA-damage response. E2F7 and E2F8, therefore, underpin the DNA-damage response.