ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Articles  (8)
  • Cytokinesis  (4)
  • Life and Medical Sciences  (4)
  • 1
    Electronic Resource
    Electronic Resource
    Nuclear cytoplasmic domains, microtubules and organelles in microsporocytes of the slipper orchid Cypripedium californicum A. Gray dividing by simultaneous cytokinesis (1996)
    Springer
    Sexual plant reproduction 9 (1996), S. 145-152 
    Details
    ISSN: 1432-2145
    Keywords: Cytokinesis ; Microtubules ; Microsporogenesis ; Orchids ; Phragmoplast ; Pollen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Microsporocytes of the slipper orchidCypripedium californicum A. Gray divide simultaneously after second meiosis. The organization and apportionment of the cytoplasm throughout meiosis are functions of nuclear-based radial microtubule systems (RMSs) that define domains of cytoplasm - a single sporocyte domain before meiosis, dyad domains within the undivided cytoplasm after first meiosis, and four spore domains after second meiosis. Organelles migrate to the interface of dyad domains in the undivided cytoplasm after first meiotic division, and second meiotic division takes place simultaneously on both sides of the equatorial organelle band. Microtubules emanating from the telophase II nuclei interact to form columnar arrrays that interconnect all four nuclei, non-sister as well as sister. Cell plates are initiated in these columns of microtubules and expand centrifugally along the interface of opposing RMSs, coalescing in the center of the sporocyte and joining with the original sporocyte wall at the periphery to form the tetrad of microspores. Organelles are distributed into the spore domains in conjunction with RMSs. These data, demonstrating that cytokinesis in microsporogenesis can occur in the absence of both components of the typical cytokinetic apparatus (the preprophase band of microtubules which predicts the division site and the phragmoplast which controls cell-plate deposition), suggest that plant nuclei have an inherent ability to establish a domain of cytoplasm via radial microtubule systems and to regulate wall deposition independently of the more complex cytokinetic apparatus of vegetative cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02221394
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Minispindles and cytoplasmic domains in microsporogenesis of orchids (1989)
    Springer
    Protoplasma 148 (1989), S. 26-32 
    Details
    ISSN: 1615-6102
    Keywords: Cytokinesis ; Cytoplasmic domains ; Meiosis ; Microtubules ; Minispindles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Changes in the microtubular cytoskeleton during meiosis and cytokinesis in hybrid moth orchids were studied by indirect immunofluorescence. Lagging chromosomes not incorporated into telophase nuclei after first meiotic division behave as small extra nuclei. Events in the microtubular cycle associated with these micronuclei are similar to and synchronous with those of the principal nuclei. During second meiotic division the micronuclei trigger formation of minispindles which are variously oriented with respect to the two principal spindles. After meiosis, radial systems of microtubules measure cytoplasmic domains around each nucleus in the coenocyte. Cleavage planes are established in regions where opposing radial arrays interact and the cytoplasm cleaved around micronuclei is proportionately smaller than that around the four principal nuclei. These observations clearly demonstrate that nuclei in plant cells are of fundamental importance in microtubule organization and provide strong evidence in support of our recently advanced hypothesis that division planes in simultaneous cytokinesis following meiosis are determined by establishment of cytoplasmic domains via radial systems of nuclear-based microtubules rather than by division sites established before nuclear division.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01403988
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Pollen development in orchids (1991)
    Springer
    Protoplasma 165 (1991), S. 155-166 
    Details
    ISSN: 1615-6102
    Keywords: Cytokinesis ; F-actin ; Microsporogenesis ; Microtubules ; Orchids ; Phragmoplast
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Cytokinesis in microsporocytes of moth orchids is unusual in that it occurs simultaneously after meiosis, the cytoplasm does not infurrow in the division planes, and cell plates are deposited in association with centrifugal expansion of phragmoplasts. Microtubules radiating from the nuclear envelopes appear to be of fundamental importance in establishment of division planes. Primary interzonal spindles develop between sister nuclei and interaction of radial microtubules triggers development of secondary interzonal spindles between non-sister nuclei. From three to six or more phragmoplasts, depending upon the arrangement of nuclei in the coenocyte, develop from these postmeiotic arrays. The phragmoplasts consist of co-aligned microtubules and F-actin organized into bundles that are broad proximal to the mid-plane and taper distally. Ultrastructure of the phragmoplast/cell plate reveals that abundant ER is associated with vesicle aggregation and coalescence. Cell plates are deposited in association with phragmoplasts as they expand centrifugally to join the parental wall and/or fuse with one another in the interior of the cell.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01322286
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Division polarity, development and configuration of microtubule arrays in bryophyte meiosis (1987)
    Springer
    Protoplasma 138 (1987), S. 1-10 
    Details
    ISSN: 1615-6102
    Keywords: Meiosis ; Microtubules ; Cytokinesis ; Immunofluorescence ; Bryophytes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary First and second division spindles and the three cell plates of moss meiosis are oriented in accordance with polarity established during meiotic prophase. Plastids are located at the second division poles and cytoplasmic infurrowing marks the planes along which the cytoplasm will cleave into four spores. Anaphase I spindles that terminate in two focal points of microtubules straddling opposite cleavage furrows reflect the unusual tetrahedral origin of the functionally bipolar spindle. The organelles (except for the plastids which remain in the four cytoplasmic lobes) are polarized in the first division equatorial region at the time of phragmoplast microtubule assembly and remain in a distinct band after microtubule disassembly. Prophasic spindles appear to be directly transformed into metaphase II spindles in the predetermined axes between mutually perpendicular pairs of plastids. Cell plates form by vesicle coalescence in the equatorial regions of the two sets of second division phragmoplasts at approximately the same time as a cell plate belatedly forms in the organelle band. The cytoplasmic markers (plastid migration, cytoplasmic lobing and infurrowing) that predict poles and cleavage planes in free cells lacking a preprophase band strongly strengthens the concept that division sites are capable of preserving preprogrammed signals that can be triggered later in the process of cell division.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01281179
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Acetylcholine and cholinesterase in the insect central nervous systemThe authors wish to thank Prof. Kenneth D. Roeder of Tufts College for his invaluable technical advice and helpful criticism. (1941)
    Philadelphia : Wiley-Blackwell
    Journal of Cellular and Comparative Physiology 18 (1941), S. 401-403 
    Details
    ISSN: 0095-9898
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1030180312
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Pattern and process of wall formation in developing endosperm (1995)
    New York, NY : Wiley-Blackwell
    BioEssays 17 (1995), S. 803-812 
    Details
    ISSN: 0265-9247
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Endosperm is emerging as a system for investigating the genetic control of wall placement and deposition in plant development. Development of endosperm progresses in distinct stages from a wall-less syncytial stage to a cellular stage that is entirely typical of plant meristems where the division plane is predicted by a preprophase band of microtubules (PPB) and cytokinesis is completed by formation of a cell plate in association with a phragmoplast. Four developmentally different types of walls, each associated with a different microtubule system, are sequentially produced: (1) free growing walls deposited in the absence of mitosis and phragmoplasts; (2) walls guided by cytoplasmic phragmoplasts formed adventitiously in the absence of mitosis; (3) walls formed by interzonal phragmoplasts in a cell cycle that lacks PPBs; and (4) wall deposition driven by interzonal phragmoplasts in a cycle that includes PPBs. We are using methods of differential screening to isolate cDNA clones corresponding in temporal and spatial pattern to the types of wall development, and are studying mutants for clues to the genetic controls of wall development.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bies.950170910
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Determination of the physical structure of biological materials at biosensor interfaces by techniques of increasing magnification from microscopic to molecular scale (1991)
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 18 (1991), S. 212-222 
    Details
    ISSN: 0741-0581
    Keywords: Scanning tunneling microscopy ; Langmuir-Blodgett films ; Covalent deposition ; Lipids ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: Chemical selectivity of biosensors is derived from biological materials interfaced to the surface of transducing devices. Molecular recognition events lead to macroscopic function suitable for analytical measurements. The structure-function relationships of biochemical species at interfaces must be established to characterize and optimize biosensor operation. The techniques of ellipsometry, fluorescence microscopy, electron microscopy, and scanning tunneling microscopy are used to investigate the structure of monolayers and multilayers of proteins and lipids at interfaces that are prepared by Langmuir-Blodgett techniques and by self-assembly from bulk solution. The relative merits and limitations of the measurement techniques in the determination of aspects of interfacial structure are considered.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1060180303
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Practical Aspects of Lattice Imaging of Cellulose (1987)
    New York, NY : Wiley-Blackwell
    Journal of Electron Microscopy Technique 6 (1987), S. 349-356 
    Details
    ISSN: 0741-0581
    Keywords: Lattice imaging ; Low dose technique ; Cellulose ; Crystallite size ; Digital image processing ; Formvar micronet ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The lattice imaging technique for cellulose, a typical electronbeam-sensitive material, was developed by using a conventional 120 kV electron microscope. Routine procedures for specimen preparation and high resolution, low dose electron microscopy are described in detail. A new, simple method was introduced for the preparation of a Formvar micronet to support the thin carbon film. The lattice imaging technique was successfully applied to algal celluloses as well as bacterial cellulose, which is composed of much smaller crystallites than the former. Digital image processing was found to be effective in enhancing the lattice images. The bacterial cellulose ribbon contained crystallites 10-25-nm wide, which is much greater than the basic unit of cellulose fibril extruded from the cell surface. This shows that unit fibrils can fasciate with each other, merging into a single crystallite.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1060060405
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...