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51.
Walter A. Heidmann Annegret Büthe Martin Beyerbach Reinhard Löhmer und Harald A. Rüssel-Sinn 《Journal of Ornithology》1989,130(3):311-320
Zusammenfassung Rückstände chlorierter Kohlenwasserstoffe in Eiern und Lebern von im Binnenland Niedersachsens brütenden Vogelarten — Feldsperling, Mehlschwalbe, Weißstorch, Graureiher, Saatkrähe, Stockente und andere Arten — werden angegeben und deren Abhängigkeit von Brutort, Nahrung und Zugverhalten diskutiert.
Chlorinated hydrocarbons of some bird species breeding in the inland of Lower Saxony (FRG)
Summary Residues of chlorinated hydrocarbons in eggs and livers of some bird species — Tree Sparrow, House Martin, White Stork, Heron, Rook, Mallard, and further species — are presented. The dependence on place of breeding, food web, and migration is discussed.相似文献
52.
Abstract 3-Chlorobiphenyl-degrading bacteria were obtained from the mating between Pseudomonas putida strain BN10 and Pseudomonas sp. strain B13. Strains such as BN210 resulted from the transfer of the genes coding the enzyme sequence for the degradation of chlorocatechols from B13 into BN10, whereas B13 derivatives such as B131 have acquired the biphenyl degradation sequence from BN10. During growth of the hybrid strains on 3-chlorobiphenyl 90% chloride was released. Activities of phenylcatechol 2,3-dioxygenase, benzoate dioxygenase, catechol 1,2-dioxygenase, chloromuconate cyloisomerase and 4-carboxymethyl-enebut-2-en-4-olide hydrolase were found in 3-chlorobiphenyl-grown cells. The hybrid strains were found to convert some congeners of the Aroclor 1221 mixture such as mono- and dichloro-substituted biphenyls. 相似文献
53.
A procedure for the regeneration of Vitis rootstocks plantlets by organogenesis from foliar tissues is described. Leaves from mature plants grown in growth chambers or from plantlets grown in tubes were wounded with a scalpel and cultured on a modified Murashige and Skoog liquid medium containing different concentrations of benzyl-aminopurine. The presence of benzyl-aminopurine is required for shoot formation. The age of the source explant, the composition of the culture medium and the culture temperature are important parameters of the regeneration process.Abbreviations BA
6-benzyl-aminopurine
- MS
Murashige and Skoog medium
- MM
modified Murashige and Skoog medium 相似文献
54.
The enzyme acetyl-CoA: 17-O-deacetylvindoline 17-O-acetyltransferase which terminates vindoline biosynthesis has been isolated from Catharanthus roseus leaves, further characterized and purified to homogeneity by three step column chromatography and subsequent preparative isoelectric focusing. Kinetic properties concerning the enzyme reaction are discussed. Five multiple forms of the acetyl-transferase could be observed, each consisting of two subunits. This enzyme is now the best characterized of the enzymes involved in vindoline biosynthesis.Abbreviations DTE
dithiothreitol
- EDTA
ethylenediamine-tetraacetic acid
- HEPES
N-(2-hydroxyethyl)-piperazine-N-2-ethanesulfonic acid
- IEF
isoelectric focusing
- KPi
potassium phosphate
- Mr
rel.molecular mass
- PEG
polyethylene glycol
- SDS-PAGE
sodium dodecylsulfate polyacrylamide gel electrophoresis
- Tris
2-amino-2-(hydroxymethyl)-1,3-propandiol 相似文献
55.
Pollination Ecology of Pedicularis punctata Decne. (Scrophulariaceae) in the Kashmir Himalaya 总被引:2,自引:0,他引:2
Abstract The pollination ecology of Pedicularis punctata was studied in the Pir Panjal Range of the Kashmir Himalaya in the summer of 1989. Its nectarless, rostrate, long-tubed flower was found to be pollinated exclusively by Bombus foragers vibrating pollen while the stigma contacted pollen in the pollinator's cervical crevice. Workers of Bombus tunicatus and B. flavothoracicus comprised 95% of its pollinators. Pollen-foraging fidelity of its pollinators was greatest where diversity of Bombus -pollinated plant species in three plant communities was least. Foragers on other plants carried virtually no Pedicularis pollen. P. punctata is a mid-season blooming species similar in its pollination syndrome to comparable species in other geographic regions. The enigmatic function of its long, nectarless corolla tube, even more exaggerated in other Asiatic species, requires further investigation. 相似文献
56.
Summary Flowering cultivars of Hibiscus rosa-sinensis L. were either cross-pollinated or self-pollinated. Fruit set was observed on 52% of the cross-fertilized flowers, while only 4.6% of the self-fertilized flowers were not abscised. Once during fruit and seed growth, the subtending leaf was exposed to 14CO2, and translocation of labelled photoassimilate was recorded by macro- and microautoradiography. Phloem transport into the raphe occurred in both fruits with fertilized and fruits with non-fertilized ovules. Since empty ovules showed some sink strength, it is assumed that growth of vegetative seed-tissue signalizes the retardation of completion of the abscission process. During fruit growth a considerable amount of starch is deposited in the distal layer of the abscission zone. Part of this starch is consumed during growth of cross-fertilized fruits. 相似文献
57.
The role of beta-hydroxyaspartate and adjacent carboxylate residues in the first EGF domain of human factor IX. 总被引:21,自引:7,他引:14
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D J Rees I M Jones P A Handford S J Walter M P Esnouf K J Smith G G Brownlee 《The EMBO journal》1988,7(7):2053-2061
beta-Hydroxyaspartic acid is a post-translationally modified amino acid found in a number of plasma proteins in a domain homologous to epidermal growth factor. Its presence can be correlated with a high affinity Ca2+ binding site, with a dissociation constant of 10-100 microM. We describe a system for the expression of human coagulation factor IX in dog kidney cells in tissue culture, in which the post-translational modifications and the biochemical activity are indistinguishable from factor IX synthesized in vivo. This system has been used to express eight different point mutations of human factor IX in the first epidermal growth factor domain in order to study the role of beta-hydroxyaspartate at residue 64, and the adjacent carboxylate residues at positions 47, 49 and 78. We conclude that this domain is essential for factor IX function and suggest that Ca2+ binds to carboxylate ions in this domain and stabilizes a conformation necessary for the interaction of factor IXa with factor X, factor VIII and phospholipid in the next step of the clotting cascade. 相似文献
58.
59.
A long-term suspension culture ofBrachycome dichromosomatica (2n = 4) was induced from a cotyledon-derived callus. Subcultures were obtained every week up to three years. The bulk of the cultures displayed a stable diploid karyotype, while one cell line evolved with 2n = 5 chromosomes in the 86th reinoculation. No further chromosomal change occurred also in that cell line. It is assumed that the fifth chromosome is the expression of a trisomy 2.The chromatin ultrastructure was of the species-specific chromomeric type in the wild-type line, while the trisomic line displayed more condensed chromatin, what probably indicates a rather inactive state of the extra-chromosome.Brachycome dichromosomatica is suggested to represent an ideal species to follow-up karyotype stability and/or variation in cell culture.As a former student W. N. dedicates this paper in gratitude and admiration to Prof. DrElisabeth Tschermak-Woess on the occasion of her 70th birthday. Prof.Woess with her scientific work has stimulated in an unique manner the study of nuclear structures in plants, of endopolyploidy and polytene chromosomes, and has thus established the basis for the rapidly increasing research in these fields. 相似文献
60.
Summary Two -glucosidase genes, designatedbglA andbglB, were isolated from a gene bank ofClostridium
thermocellum DSM 1237. The coding sequences forbglA andbglB were located on non-homologous DNA fragments of 3.2– and 3.4-kb, respectively. Both genes direct inEscherichia
coli the synthesis of cytoplasmic -glucosidases, which differ with respect to substrate specificity and temperature profile. The properties of thebglA-encoded -glucosidase A closely resemble that of a -glucosidase previously isolated fromC.
thermocellum cultures. 相似文献