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1.
Didier Merle 《Geobios》2005,38(4):505
Jsowerbya, nov. gen. (Gastropoda: Muricidae) includes three species from the Eocene of the Paris and Hampshire basins. It increases the number of extinct muricid genera, which curiously represent a very small fraction of the described genera. The species of Jsowerbya, often mistaken for the muricopsine genus Muricopsis, possess a unique combination of characters shared with the subfamilies Ocenebrinae and Ergalataxinae. A cladistic analysis, based on structural homologies of the spiral sculpture, however, suggests that Jsowerbya is closely related to the Ocenebrinae. Thus, Jsowerbya is here regarded as one the most basal Ocenebrinae. 相似文献
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Didier Arseguel Armand Lattes Michel Baboul ne 《Biocatalysis and Biotransformation》1990,3(3):217-225
Horseradish peroxidase was chemically conjugated on its carbohydrate moieties with short aliphatic chains (C8 and C16). An analytical method using FT.IR spectroscopy was developed to analyze this alteration in enzyme structure. This method is non-destructive, and can be applied directly to samples of the reaction mixture. More general applications of this technique are described and discussed. 相似文献
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Didier Rognan 《Journal of Physiology》2006,99(2-3):232-244
The concomitant development of in silico screening technologies and of three-dimensional information on therapeutically relevant macromolecular targets makes it possible to navigate in the structural proteome and to identify targets fulfilling user-defined queries. This review illustrates some in-house recent advances in the development of target libraries and how they can be browsed to unravel chemogenomic information. 相似文献
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Making use of a newly designed mobilizable suicide vector, the genetic determinants encoding Shigella sonnei lipopolysaccharide (LPS) were stably integrated into the chromosome of the live attenuated Vibrio cholerae vaccine strain CVD103-HgR. Expression studies showed that the production of complete S. sonnei O-polysaccharide (O-PS)-bearing LPS was limited in bivalent recombinant strains that were also proficient in the synthesis of the host-encoded Inaba O-PS. Conversely, high amounts of LPS carrying S. sonnei O-PS are produced in monovalent Inaba-deficient derivatives, even in those strains which do not co-express the compatible R1 LPS core. Thus, the non-enterobacterial V. cholerae LPS core efficiently acts as a receptor for covalent binding of S. sonnei O-PS provided that competition with the host O-PS is avoided. Expression of the R1 core interferes with cell division in recombinant V. cholerae without affecting other physiological properties of vaccine strain CVD103-HgR. Both monovalent and bivalent strains stimulated high serum-antibody titres specific for their respective O-serotype(s) when administered to rabbits. The potential of V. cholerae as an expression carrier for heterologous O-serotypes is discussed. 相似文献
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Didier Gascuel 《Helgoland Marine Research》1986,40(3):321-326
The study of the migration dynamics of glass eels(Anguilla anguilla) in a small estuary of the French Atlantic coast shows a two-stage sequence: (1) From November to March, the glass eels migrate upstream by using the tidal currents. The estuarine hydrology leads to a natural trapping of migrants in a typical area where the current speed slows down. The location of this zone depends on hydraulic conditions. The greater the tide is the farther upstream this area will be. This phenomenon leads to an increasing catchability of elvers. (2) From April onwards, when the water temperature reaches 10–12 °C, the glass eels swim actively upstream in the estuary. Then, fish concentrate just below the first dam. This behaviour shift shows the beginning of the colonization process of the whole riverine system. 相似文献
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E Didier P Didier N Fargeix J Guillot J P Thiery 《The International journal of developmental biology》1990,34(4):421-431
The expression of end-chain sugar residues and of oligosaccharidic sequences has been investigated in chick germ cells at critical stages during the migration, proliferation and sexual differentiation of these cells. Fluorescent lectins and indirect immunofluorescence studies using the NC-1/HNK-1 monoclonal antibody indicate a remarkable control of glycosylation during germ cell embryonal life. Besides a retained expression of glucose/mannose residues, it was found that alpha- and beta-galactose residues, N-acetyllactosamine and N-N' diacetylchitobiose sequences as well as the sulfated trisaccharidic NC-1 epitope were detectable in a stage-specific pattern. Present at a very high density in the cytoplasm and on the surface of the early germ cells at premigrative and migratory stages, the staining for these carbohydrate sequences gradually disappeared when the germ cells settled and proliferated in the developing gonadal primordia. The disaccharide Gal beta 1----3 Gal NAc was exclusively detected in migrating PGCs. In sexualized gonads, acetyllactosamine and/or diacetylchitobiose were similarly reexpressed in both oogonia and spermatogonia. Spermatogonia displayed beta-galactose residues and a high immunoreactivity with the NC1 Mab, indicating modulations in PGC glycosylations related to the acquisition of sexual phenotypes. In addition NC-1 was found to be expressed in the somatic component of the undifferentiated gonad and in the testis interstitial gland. 相似文献
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Identification and expression of water stress- and abscisic acid-regulated genes in a drought-tolerant sunflower genotype 总被引:17,自引:0,他引:17
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Spatial structure of mitochondria and ER denotes changes in cell physiology of cultured tobacco protoplasts 总被引:7,自引:3,他引:4
Didier Stickens Jean-Pierre Verbelen 《The Plant journal : for cell and molecular biology》1996,9(1):85-92
The structure of mitochondria and of the endoplasmic reticulum (ER) in mesophyll protoplasts and regenerated cells was studied in vivo using the dye DiOC6 (3) (3,3'-dihexyloxacarbocyanine iodide) and confocal laser scanning microscopy (CLSM). The relation to the cell's physiology was investigated using a hormone-based model system for elongation and division. The structure of the mitochondria and of their population depends on the status of the cell. In freshly isolated protoplasts small spherical mitochondria are clustered around the nucleus and the chloroplasts. During the first 4 days of culture they are transformed into long vermiform organelles which distribute evenly throughout the cytoplasm. In a medium containing only auxins, cells then enter a period of expansion. Their mitochondria retain the same structure but increase in quantity. In a medium with auxins and cytokinins cells start dividing. Their mitochondria typically become numerous and very small, and are distributed throughout the cytoplasm. Both types of organization were observed during weeks of ongoing expansion or division. The ER is always present as a network close to the cell membrane. In freshly isolated protoplasts a considerable part of the ER is clustered around the chloroplasts, the remaining part of the network has a reduced complexity and is partly broken. During subsequent protoplast culture the network grows into a complex web with fine meshes incorporating lots of plate-like structures. This is the case in elongating cells as well as in dividing cells. Finally, the ER looks similar to the structure found in epidermal cells of the intact plant. 相似文献