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1Latest Papers from Table of Contents or Articles in PressM. Rolland ; P. T. Edlefsen ; B. B. Larsen ; S. Tovanabutra ; E. Sanders-Buell ; T. Hertz ; A. C. deCamp ; C. Carrico ; S. Menis ; C. A. Magaret ; H. Ahmed ; M. Juraska ; L. Chen ; P. Konopa ; S. Nariya ; J. N. Stoddard ; K. Wong ; H. Zhao ; W. Deng ; B. S. Maust ; M. Bose ; S. Howell ; A. Bates ; M. Lazzaro ; A. O'Sullivan ; E. Lei ; A. Bradfield ; G. Ibitamuno ; V. Assawadarachai ; R. J. O'Connell ; M. S. deSouza ; S. Nitayaphan ; S. Rerks-Ngarm ; M. L. Robb ; J. S. McLellan ; I. Georgiev ; P. D. Kwong ; J. M. Carlson ; N. L. Michael ; W. R. Schief ; P. B. Gilbert ; J. I. Mullins ; J. H. Kim
Nature Publishing Group (NPG)
Published 2012Staff ViewPublication Date: 2012-09-11Publisher: Nature Publishing Group (NPG)Print ISSN: 0028-0836Electronic ISSN: 1476-4687Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsKeywords: AIDS Vaccines/adverse effects/*immunology ; Genetic Predisposition to Disease ; HIV Antibodies/immunology ; HIV Infections/immunology/*prevention & control/*virology ; HIV-1/*genetics/*immunology ; Humans ; Molecular Sequence Data ; Phylogeny ; Randomized Controlled Trials as Topic ; Sequence Analysis, DNA ; env Gene Products, Human Immunodeficiency Virus/*genetics/*immunologyPublished by: -
2Articles: DFG German National LicensesStaff View
ISSN: 0378-1119Keywords: Recombinant DNA ; footprinting ; rat liverSource: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: BiologyType of Medium: Electronic ResourceURL: -
3Articles: DFG German National LicensesStaff View
ISSN: 1615-6102Keywords: Endomembrane system ; Lilium regale ; Nucleus ; Placental cell ; Transfer cell ; Transmitting tissueSource: Springer Online Journal Archives 1860-2000Topics: BiologyNotes: Summary Placental cells line the ovarian transmitting tract inLilium regale and produce exudates for secretion. Sections through the highly lobed nuclei of these cells reveal the presence of membrane profiles which form vesicles with varying dimensions in cross section. Computer reconstruction of the nucleus reveals that the vesicle profiles form a complex reticulum of tubular cisternae, which spans the whole nucleus, enclosing a maze of continuous lumen space. Connections between the vesicles and the inner nuclear envelope are visible at various points along the nuclear envelope. This complex network of tubules which constitutes the reticulum arises from the inner nuclear membrane. The nuclear reticulum dramatically increases the inner-envelope surface area, comprising 82% of the total membrane perimeter of inner nuclear envelope and nuclear reticulum. The inner nuclear envelope invaginates into the nucleus forming the nuclear reticulum and the outer nuclear envelope evaginates into the endoplasmic reticulum (ER), indicating that there is a continuity between the lumens of the nuclear reticulum and the ER. The nuclear reticulum is labelled with zinc iodide-osmium tetroxide, a staining pattern identical to that seen in the ER. Positive reaction to the zinc iodide-osmium tetroxide indicates that the nuclear reticulum is a site for Ca2+ deposition. The nuclear reticulum forms an extension of the endomembrane system which reaches deep into the nucleoplasm. The lumenal continuity of this system means that there is a channel for communication from the cytoplasm into the nucleoplasm, and that this channel sequesters calcium.Type of Medium: Electronic ResourceURL: -
4Articles: DFG German National LicensesStaff View
ISSN: 1615-6102Keywords: Conifer ; Microtubule ; Microfilament ; Myosin ; Picea abies ; Pollen tubeSource: Springer Online Journal Archives 1860-2000Topics: BiologyNotes: Summary InPicea abies (Norway spruce), microtubules and actin microfllaments both form a dense matrix throughout the tube mainly parallel to the direction of elongation. In these conifer pollen tubes the organization of this matrix is different from that in angiosperms. This study tests our hypothesis that differences in cytoskeletal organization are responsible for differences in tube growth and physiology. Pollen grains were germinated in media containing cytoskeletal disrupters and analyzed for germination, tube length, tube branching, and tip swelling. Disruption of microtubules significantly inhibits tube elongation and induces tube branching and tip swelling. Tip swelling is probably caused by disruption of the microtubules in the tip that are perpendicular to the direction of elongation. Confocal microscopy indicates that colchicine and propyzamide cause fragmentation of microtubules throughout the tube. Oryzalin and amiprophosmethyl cause a complete loss of microtubules from the tip back toward the tube midpoint but leave microtubules intact from the midpoint back to the grain. Disruption of microfilaments by cytochalasins B and D and inhibition of myosin by N-ethylmaleimide or 2,3-butanedione monoxime stops tube growth and inhibits germination. Microfilament disruption induces short branches in tubes, probably originating from defective microfilament organization behind the tip. In addition, confocal microscopy coupled with microinjection of fluorescein-labeled phalloidin into actively growing pollen tubes indicates that microfllament bundles extend into the plastid-free zone at the tip but are specifically excluded from the growing tip. We conclude that microtubules and microfilaments coordinate to drive tip extension in conifer pollen tubes in a model that differs from angiosperms.Type of Medium: Electronic ResourceURL: -
5Articles: DFG German National LicensesStaff View
ISSN: 1615-6102Keywords: Actin ; Confocal microscopy ; Cytoskeleton ; Gymnosperm ; Microfilaments ; Picea abies ; Pollen tubesSource: Springer Online Journal Archives 1860-2000Topics: BiologyNotes: Summary Actin microfilaments form a dense network within pollen tubes of the gymnosperm Norway spruce (Picea abies). Microfilaments emanate from within the pollen grain and form long, branching arrays passing through the aperture and down the length of the pollen tube to the tip. Pollen tubes are densely packed with large amyloplasts, which are surrounded by branching microfilament bundles. The vegetative nucleus is suspended within the elongating pollen tube within a complex array of microfilaments oriented both parallel to and perpendicular with the growing axis. Microfilament bundles branch out along the nuclear surface, and some filaments terminate on or emanate from the surface. Microfilaments in the pollen tube tip form a 6 μm thick, dense, uniform layer beneath the plasma membrane. This layer ensheathes an actin depleted core which contains cytoplasm and organelles, including small amyloplasts, and extends back 36 μm from the tip. Behind the core region, the distinct actin layer is absent as microfilaments are present throughout the pollen tube. Organelle zonation is not always maintained in these conifer pollen tubes. Large amyloplasts will fill the pollen tube up to the growing tip, while the distinct layer of microfilaments and cytoplasm beneath the plasma membrane is maintained. The distinctive microfilament arrangement in the pollen tube tips of this conifer is similar to that seen in tip growth in fungi, ferns and mosses, but has not been reported previously in seed plants.Type of Medium: Electronic ResourceURL: -
6Articles: DFG German National LicensesStaff View
ISSN: 1615-6102Keywords: Cicer arietinum ; Confocal microscopy ; Lucifer yellow CH ; Plasmodesmata ; Trichomes ; VacuolesSource: Springer Online Journal Archives 1860-2000Topics: BiologyNotes: Summary A vacuolar continuum exists from base to tip in the secretory trichomes of chickpea (Cicer arietinum). This continuum is seen in living trichomes which have been labeled with Lucifer yellow CH and examined with confocal microscopy. It encompasses the large vacuole of the lower stalk cell, the vacuoles and tubules of the central stalk cell, the thin tubules of the upper stalk cell, and the tubules and vacuoles of the secretory head cells. The vacuolar-tubular system is structurally distinct within each cell, forming a gradient of large vacuoles in the lower stalk cell, thick tubules in the central stalk cell, and thin anastamozing tubules in the upper stalk cell. This membrane system appears to be continuous between trichome cells, as thin tubules emanate from plasmodesmata between stalk cells and between the upper stalk and lower head cell. In the upper stalk cell, the thin tubules of this continuum are streaming up and down the long axis of the cell at 0.67 μm/s. The larger vacuolar-tubular system in the central and lower stalk cells is also slowly moving, with apparent peristalsis occurring in the central cell. The vacuolar-tubular system of the secretory head cells is completely labeled with Lucifer yellow when the dye has only partly diffused up the long walls of the trichome, indicating that the streaming tubular system delivers solute through the stalk cells to the secretory head cells faster than diffusion through the trichome walls. In the lower head cells, tubules emanate from the plasmodesmata connecting to the upper stalk cell, and these tubules are continuous with the head cell vacuoles. In addition, another layer of thin tubules forms along the edges of the secretory head cells, at the site of exocytotic secretion. We propose that the continuous vacuolar-tubular system in these trichomes functions to rapidly deliver solute from the base of the trichome to the secretory head cells. This system provides a pathway for the transport of secretory material.Type of Medium: Electronic ResourceURL: -
7Articles: DFG German National LicensesStaff View
ISSN: 1615-6102Keywords: Microtubules ; Placental cells ; Transfer cells transmitting tissue ; Lilium longiflorumSource: Springer Online Journal Archives 1860-2000Topics: BiologyNotes: Summary Placental cells in the ovarian transmitting tissue ofLilium spp. are organized as transfer cells with inbuddings facing the ovarian locule. A detailed analysis of microtubule (MT) organization during development of these polarized cells is reported here. Formation of wall projections occurs at the apical part of the cell starting on the day of anthesis, and a fully mature secretion zone is found four days after anthesis. MTs are organized into distinct cortical and central arrays. The cortical array undergoes a unique transition at anthesis. MTs in the basal half of the cell remain in longitudinal bundles while in the apical half of the cell their longitudinal orientation is replaced by a transverse alignment. One day after anthesis, these transverse bundles become a meshwork of short, randomly organized MTs, while MTs in the basal half of the cell retain their longitudinal alignment. The realignment of MTs in the apical half of the cell coincides with the deposition of the secondary cell wall. The central array is composed of short, randomly arranged strands of MTs in the cytoplasm between the nucleus and the apical and basal periclinal walls of the cell. This array first appears as solitary strands in the apical part of the cell one day before anthesis. The central array extends during development and is eventually seen in the basal half of the cell. We propose that MTs in the cortical region near the apical wall act as templates for the deposition of cellulose microfibrils in the secondary cell wall. MTs in the central array in these transfer cells may be involved in the trafficking of vesicles and/or positioning of organelles near the secretion zone.Type of Medium: Electronic ResourceURL: