用分支分析方法研究中华猕猴桃与美味猕猴桃的亲缘关系

本文根据形态特征和染色体资料,以毛花猕猴桃为外类群,用分支分析法研究美味猕猴桃与中华猕猴桃(含二倍体和四倍体)的亲缘关系,产生了三个步长相等的Wagner树。其中一树能较好地与现有地理分布和细胞学资料吻合。反映出中华猕猴桃二倍体衍生出四倍体类型,二者具有直接祖裔关系:美味猕猴桃与中华猕猴桃是已分支发展的两个分类群,但二者亲缘关系密切。可能属于同一物种复合体的两个近缘物种。     

Comparative electrophoretic profiles of esterases, and of glutamate, lactate and malate dehydrogenases, from Aeromonas hydrophila, A. caviae and A. sobria

Esterases, and glutamate, lactate and malate dehydrogenases of 64 Aeromonas hydrophila, A. caviae and A. sobria strains, were analysed by polyacrylamide agarose gel electrophoresis and by thin layer isoelectrofocusing. On the basis of the isoelectric points of malate dehydrogenase from the three species and the mobility of lactate dehydrogenase from A. sobria, 8 species specific zymotypes were defined: three for A. hydrophila strains, three for A. caviae strains and two for A. sobria strains. These zymotypes correlated with previously established DNA hybridization groups. The other electrophoretic data were found to be less useful for distinction between A. hydrophila and A. sobria strains, but supported differentiation into zymotypes for A. caviae strains. The two-dimensional electrophoretic profile established by plotting isoelectric point against electrophoretic mobility of the major esterase illustrated the degree of enzyme polymorphism among the strains of the three species. Variation in electrophoretic patterns within A. hydrophila and A. caviae might provide useful epidemiological markers.     

Role of disulfide bonds in the structure and activity of human insulin

Insulin contains two inter-chain disulfide bonds between the A and B chains (A7-B7 and A20-B19), and one intra-chain linkage in the A chain (A6-A11). To investigate the role of each disulfide bond in the structure, function and stability of the molecule, three des mutants of human insulin, each lacking one of the three disulfide bonds, were prepared by enzymatic conversion of refolded mini-proinsulins. Structural and biological studies of the three des mutants revealed that all three disulfide bonds are essential for the receptor binding activity of insulin, whereas the different disulfide bonds make different contributions to the overall structure of insulin. Deletion of the A20-B19 disulfide bond had the most substantial influence on the structure as indicated by loss of ordered secondary structure, increased susceptibility to proteolysis, and markedly reduced compactness. Deletion of the A6-A11 disulfide bond caused the least perturbation to the structure. In addition, different refolding efficiencies between the three des mutants suggest that the disulfide bonds are formed sequentially in the order A20-B19, A7-B7 and A6-A11 in the folding pathway of proinsulin.     

Cleavage of the capsid protein precursors of encephalomyocarditis virus in rabbit reticulocyte lysates

The cleavage pathway of the three capsid protein precursors of encephalomyocarditis virus, proteins A1, A, and B, was studied in rabbit reticulocyte lysates. Kinetic data suggested that the three proteins were cleaved through a sequential of A1 to A to B.     

Comparative study of the interaction mechanism of astilbin,isoastilbin, and neoastilbin with CYP3A4

The interactions of human CYP3A4 with three selected isomer flavonoids, such as astilbin, isoastilbin and neoastilbin, were clarified using spectral analysis, molecular docking, and molecular dynamics simulation. During binding with the three flavonoids, the intrinsic fluorescence of CYP3A4 was statically quenched in static mode with nonradiative energy conversion. The fluorescence and ultraviolet/visible (UV/vis) data revealed that the three flavonoids had a moderate and stronger binding affinity with CYP3A4 due to the order of the K_a1 and K_a2 values ranging from 10⁴ to 10⁵ L·mol⁻¹. In addition, astilbin had the highest affinity with CYP3A4, then isoastilbin and neoastilbin, at the three experimental temperatures. Multispectral analysis confirmed that binding of the three flavonoids resulted in clear changes in the secondary structure of CYP3A4. It was found from fluorescence, UV/vis and molecular docking analyses that these three flavonoids strongly bound to CYP3A4 by means of hydrogen bonds and van der Waals forces. The key amino acids around the binding site were also elucidated. Furthermore, the stabilities of the three CYP3A4 complexes were evaluated using molecular dynamics simulation.     

Notes on the ecology of fishes of the genus Aphanius and Gambusia affinis in Southern Iraq

SUMMARY. The ecology of three commonly occurring cyprinodonts, Aphanius dispar (Ruppell), A. sophiae (Heckel) and A. mento (Heckel) was studied in the Lower Mesopotamian Plain of Iraq. These fishes are chiefly herbivorous, live in the same habitat and generally take the same food, although the dentition of the jaw and pharynx in A. dispar differs from that of A. mento and A. sophiae . The gut contents were mostly filamentous algae. In laboratory experiments all three species ate Gambusia embryos. A. dispar and A. sophiae ate mosquito larvae whereas A. mento did not. All three species were infected with a cestode parasite which prevented development of female ovaries. The behaviour of the three species was different. Both A. dispar and A. sophiae form schools, swimming and feeding together. In their natural habitat, males and females of A. dispar were in separate schools. A. mento did not form schools; the males of this species displayed aggressive behaviour. Some observations were also made on Gambusia affinis (Baird & Girard).     

Morphology and systematic significance of sclerolepidia in the weevils (Coleoptera: Curculionoidea)

The Russian sturgeon, Acipenser gueldenstaedtii, is closely related to three other sturgeon species (A persicus, A. naccarii and A baerii), with populations in the Caspian Sea containing a cryptic lineage with an A. baerii‐like mtDNA profile. Using morphological evidence (morphometrics, meristics) and additional genetic analysis (cytochrome b gene and control region sequencing), cryptic lineages within the Russian sturgeon and their relation to other closely related species of sturgeons are further examined. These data indicate that three genetic forms exist within what is presently known as A. gueldenstaedtii. These forms include the pure A. gueldenstaedtii and A. baerii‐like individuals plus a third rare genetic form whose mtDNA is similar to the mtDNA of the Adriatic sturgeon, A. naccarii. Morphological comparison of the three forms and the Yenisei River A baerii indicates that although the three forms of A. gueldenstaedtii are not different from one another, all three significantly differ from the Yenisei River A. baerii. Competing explanations, including translocation and centre of origin hypotheses are considered. The three geneticforms of A. gueldenstaedtii likely colonized different geographic areas during different geological periods, and subsequently evolved in these regions independently into the species currently recognized as A. gueldenstaedtii, A. naccarii and A. baerii.     

Simultaneous evaluation of mRNAs of dopamine β-hydroxylase,tyrosine hydroxylase and proenkephalin a from three human pheochromocytomas

Using the rabbit reticulocyte cell-free translation system, the relative proportions of in vitro translatable mRNAs of three proteins in three human pheochromocytomas: tyrosine hydroxylase (TH), dopamine β-hydroxylase (DBH) and proenkephalin A have been compared.TH expression appeared rather constant in the three tumors. In contrast, those of DBH and proenkephalin A were more variable. Though the actual level of each mRNA was not determined, the identical value of DBH/proenkephalin A mRNAs ratio in the three tumors could suggest a coordination in the expression of these two proteins.     

Effect of ferric citrate on amyloid‐beta peptides behavior

Amyloid beta (Aβ) aggregation and oxidative stress are two of the central events in Alzheimer's Disease (AD). Both these phenomena can be caused by the interaction of Aβ with metal ions. In the last years the interaction between Zn^II, Cu^II, and Aβ was much studied, but between iron and Aβ it is still little known. In this work we determine how three Aβ peptides, present in AD, interact with Fe^III‐citrate. The three Aβ peptides are: full length Aβ1‐42, an isoform truncated at Glutamic acid in position three, Aβ3‐42, and its pyroglutamated form AβpE3‐42. Conformation and morphology of the three peptides, aggregated with and without Fe^III‐citrate were studied. Besides, we have determined the strength of the interactions Aβ/Fe^III‐citrate studying the effect of ethylenediaminetetraacetic acid as chelator. Results reported here demonstrate that Fe^III‐citrate promotes the aggregation in all the three peptides. Moreover, Aspartic acid 1, Glutamic acid 3, and Tyrosine 10 have an important role in the coordination with iron, generating a more stable complex for Aβ1‐42 compared to that for the truncated peptides.     

Three N-terminal domains of beta-1,3-glucanase A1 are involved in binding to insoluble beta-1,3-glucan.

Limited proteolysis of beta-1,3-glucanase A1 by three different proteases, trypsin, chymotrypsin, and papain, gave three major active fragments. The sizes of the three major fragments generated by each protease treatment were identical to those of beta-1,3-glucanase A2, A3, and A4 detected in both the culture supernatant of Bacillus circulans WL-12 and the periplasmic space of Escherichia coli carrying a cloned glcA gene. These results indicate a four-domain structure for the enzyme. At the N terminus of the glucanase, duplicated segments of approximately 100 amino acids were observed. N-terminal amino acid sequence analysis revealed that the active fragments with sizes corresponding to those of A2 and A3 lack the first segment (domain) and both duplicated segments (domains), respectively. The fragment corresponding to A4 lacks both duplicated segments and the following ca. 120-amino-acid region. By losing the first, second, and third (corresponding to the segment of 120 amino acids) domains, beta-1,3-glucanase progressively lost the ability to bind to pachyman, beta-1,3-glucan. An active fragment which did not have the three N-terminal domains did not show significant binding to pachyman. Thus, all three N-terminal domains contribute to binding to beta-1,3-glucan, and the presence of three domains confers the highest binding activity on the glucanase. The loss of these binding domains remarkably decreased pachyman-hydrolyzing activity, indicating that the binding activity is essential for the efficient hydrolysis of insoluble beta-1,3-glucan.     

Secondary structure and membrane topology of dengue virus NS4A protein in micelles

Dengue virus (DENV) non-structural (NS) 4A is a membrane protein essential for viral replication. The N-terminal region of NS4A contains several helices interacting with the cell membrane and the C-terminal region consists of three potential transmembrane regions. The secondary structure of the intact NS4A is not known as the previous structural studies were carried out on its fragments. In this study, we purified the full-length NS4A of DENV serotype 4 into dodecylphosphocholine (DPC) micelles. Solution NMR studies reveal that NS4A contains six helices in DPC micelles. The N-terminal three helices are amphipathic and interact with the membrane. The C-terminal three helices are embedded in micelles. Our results suggest that NS4A contains three transmembrane helices. Our studies provide for the first time structural information of the intact NS4A of DENV and will be useful for further understanding its role in viral replication.     

Isolation and Characterization of Actinomyces propionicus

Three cultures of Actinomyces have been identified as Actinomyces propionicus. Two of these strains are recent isolates, one, 427, from a case of cervico-facial actinomycosis, and one, 439, from a case of lacrimal canaliculitis. The third strain, 346, was described by F. Lentze as A. israelii serological type II. These three strains were compared with the type strain of A. propionicus ATTC 14157 and with known strains of five other Actinomyces species. Morphologically and biochemically the three new cultures of A. propionicus were identical with the type strain but closely resembled A. israelii. In serological tests making use of fluorescent antibody, all four A. propionicus strains gave negative results with antisera for A. israelii, A. bovis, A. naeslundii, and A. eriksonii, but gave positive results with antisera for A. propionicus 14157 and strain 346. The A. propionicus antisera did not stain other Actinomyces species. A. propionicus contains diaminopimelic acid (DAP) in its cell wall and produces propionic acid from glucose. All three new isolates were shown to contain DAP and to produce propionic acid. By use of the presence of DAP in the cell wall and serological tests as the differential criteria, the three cultures described in the report were specifically identified as A. propionicus.     

大亚湾红树林研究Ⅱ,澳头港部分红树植物的生态生理

对大亚湾澳头港的３种红树植物的光合速率、呼吸速率和蒸腾速率进行测定,结果表明：桐花树、白骨壤和木榄的光合速率日进程呈双峰曲线,日平均光合速率的大小为桐花树＞木榄＞白骨壤,而日均呼吸速率的大小为桐花树＞白骨壤＞木榄,呼吸速率的变化幅度小于光合速率,提示白骨壤的生产力最低,可能与其所处的生境含盐量更高有关。蒸腾速率日进程呈单峰曲线,且泌盐植物桐花树和白骨壤的日均值很接近,都高于拒盐种木榄,表明蒸腾速率与它们的泌盐或拒盐生理特性密切相关。总体上,这些红树植物具有较高的光合速率、较低的呼吸速率和蒸腾速率,有利于生长在盐渍淹水的特殊海滩环境。     

DNA-dependent adenosinetriphosphatase A is the eukaryotic analogue of the bacteriophage T4 gene 44 protein: immunological identity of DNA replication-associated ATPases.

We report the construction of three stable murine hybridomas that secrete monoclonal antibodies which recognize calf thymus DNA-dependent adenosinetriphosphatase A. All three of the antibodies react specifically with calf thymus ATPase A and the gene 44 protein from the bacteriophage T4 DNA-dependent ATPase. Each of the three anti-ATPase A antibodies appears to recognize a different epitope and none of the antibodies inhibit DNA-dependent ATP hydrolysis by ATPase A. Furthermore, one of the antibodies has been shown to react with two different preparations of HeLa cell DNA-dependent ATPases and a yeast DNA-dependent ATPase, all of which have been implicated in the enzymology of DNA replication. These findings provide strong evidence for the role of ATPase A in DNA replication. These observations lead us to conclude that, apart from the nucleotide binding sites, there are at least three epitopes common to both the bacteriophage and eukaryotic DNA-dependent ATPases that we have examined and that the different preparations of the eukaryotic ATPases contain the same DNA-dependent ATPase.     

Distribution of Anisakis larvae, identified by genetic markers, and their use for stock characterization of demersal and pelagic fish from European waters: an update

In the present paper, recent results obtained on the use of different distributions observed in larval species of Anisakis, genetically identified by means of allozyme markers, for stock characterization of demersal (Merluccius merluccius), small (Trachurus trachurus) and large pelagic (Xiphias gladius) finfish species in European waters, are reviewed and discussed. Several species of Anisakis were identified in the three fish hosts: A. simplex (s.s.), A. physeteris, A. typica, A. ziphidarum, A. pegreffii, A. brevispiculata and A. paggiae. Canonical discriminant analysis performed on all the samples of the three fish species collected in areas comprising their geographical range, according to the different species of Anisakis identified, showed distinct fish populations in European waters. In all the three fish hosts, the pattern of distribution of Anisakis larvae allowed discrimination of Mediterranean stocks from Atlantic stocks. In the case of swordfish, the possible existence of a southern Atlantic stock separated from a northern one is also suggested. Congruence and discordance with the population genetic data inferred from allozyme markers on the same samples of the three fish species are also discussed.     

Delineation of immunologically and biochemically distinct HLA-A2 antigens

Cytotoxic T cell (CTL) recognition of influenza virus in conjunction with HLA-A2 was examined in a population study. Virus-infected target cells from three unrelated A2-positive donors were not lysed by virus-immune CTL from any donor matched only for A2. The A2 antigens of these three donors were indistinguishable from the A2 antigens of other A2-positive donors as assessed by extensive serologic analyses; however, isoelectric focusing (IEF) of A2 molecules from these three donors demonstrated that their A2 heavy polypeptide chains are structurally distinct from those of "normal" A2-positive donors. To date 11% of all A2-positive donors tested exhibited a "variant" A2-associated CTL restriction antigen, and IEF of A2 heavy chains from all "variant" A2-positive cells revealed structural differences in each of these polypeptides. These results suggest there may be considerably greater polymorphism of HLA-A gene products than has been revealed by current serologic techniques.     

Unusual sialilation of three different rare genetic variants of serum DBP: Gc 1A17, Gc 1A16, and Gc 1A11

Summary The proteins of three anodal Gc1 variants, Gc 1A16, 1A11, and 1A17, are characterized by the most acidic isoelectric points observed so far among the different Gc mutants. Stepwise removal of N-acetylneuraminic acid (NANA) by treatment with neuraminidase was performed to estimate the degree of sialilation of these Gc variants. The results indicate that both proteins, the anodal and the cathodal component of these Gc 1 mutants, carry sialic acid residues. This observation is remarkable in so far as usually only the anodal component of the Gc 1 protein contains NANA and only a single residue. From the experiments carried out it can be deduced that Gc 1A16 has two NANA residues in the anodal and one NANA residue in the cathodal component. Gc 1A16 was found in four members of three generations in a Danish family; the variant segregated as a Mendelian trait. More difficult to interprete are the results obtained with the variants Gc 1A11 and Gc 1A17. Gc 1A11 probably has three NANA residues in the anodal and two NANA residues in the cathodal component. Gc 1A11 has been observed in two mother-child pairs and is presumably also a simple genetic trait. Gc 1A17 has also several NANA residues in both Gc proteins; it is suggested that the anodal component has either three or four NANA residues and the cathodal component either two or three NANA residues. Family information on this variant is not yet available.     

葱属植物棱叶薤的形态性状与核型特征

对新疆不同地理位置分布的葱属植物棱叶薤的形态性状以及核型特征进行了研究,结果表明:鳞茎、株型、叶形等43个形态性状在3个棱叶薤居群之间不存在差异,而株芽、叶色、叶长、单株叶片数、小花数目、花序高度、花葶长度等19个性状在3个棱叶薤居群之间存在显著或极显著差异。采集自乌鲁木齐红旗水库居群的棱叶薤的核型公式是2n=2x=16=12m+4sm;塔城阿西尔乡巴尔鲁克山居群的棱叶薤的核型公式是2n=3x=24=18m+3sm+3st;裕民巴旦杏保护区居群的棱叶薤的核型公式是2n=4x=32=28m(4SAT)﹢4sm。棱叶薤居群内形态性状和倍性稳定,居群间存在形态性状分化,同时还存在二倍体、三倍体、四倍体的倍性分化。居群间染色体结构组成和相对长度组成也存在差异。核型类型均为2A型。     

Purification and characterization of the cytotoxic Cerebratulus A toxins

Mucus secreted from the skin of a marine worm, Cerebratulus lacteus, contains a family of polypeptide cytotoxins (A toxins) in addition to the previously reported polypeptide neurotoxins (B toxins). The A toxins were purified by Sephadex G-50 chromatography and then CM-cellulose gradient chromatography at pH 7.5 and pH 3.5. The three most abundant A toxins (designated according to their order of CM-cellulose elution) were homogeneous by gel electrophoreses, amino acid composition, and by NH2-terminal and COOH-terminal partial sequence analyses. Each of the three A toxins consists of a single basic polypeptide chain of 93 to 99 residues, cross-linked by three or four disulfide bonds, lacking reducing sugar and cysteinyl residues. The three A toxins rapidly lysed human red cells and Ehrlich ascites tumor cells at 1 to 10 microgram/ml concentrations. On a molar basis toxin A-III is about 4 times more active than melittin (bee venom lysin) and over 10 times more active than cardiotoxin (elapid snake lysin) upon human red cells. Purified A toxins lacked phospholipase A activity. The cytoxins as well as the neurotoxins were concentrated within the body wall integument.     

A taxonomic review of the genus Astrocharis Koehler (Echinodermata: Ophiuroidea: Asteroschematidae), with a description of a new species

A revision of the genus Astrocharis Koehler (Echinodermata: Ophiuroidea: Asteroschematidae) is based on 41 specimens, including three syntypes of Astrocharis virgo Koehler, one syntype of Astrocharis ijimai Matsumoto and the holotype of Astrocharis gracilis Mortensen. Astrocharis gracilis is a junior subjective synonym of A. ijimai. A. virgo and A. ijimai are redescribed. A new species, Astrocharis monospinosa is described from southwestern Japan. A tabular key to the three species of the genus Astrocharis is provided.