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  • 1980-1984  (5)
  • spermatozoa  (3)
  • Adenosine-3′:5′-cyclic monophosphate  (1)
  • Meliponinae  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Identification and quantitation of adenosine-3′:5′-cyclic monophosphate in plants using gas chromatography-mass spectrometry and high-performance liquid chromatography (1981)
    Springer
    Planta 152 (1981), S. 195-201 
    Details
    ISSN: 1432-2048
    Keywords: Adenosine-3′:5′-cyclic monophosphate ; Nicotiana (cAMP) ; Zea (cAMP) ; Phaseolus (cAMP)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Direct evidence has been obtained for the presence of adenosine-3′:5′-cyclic monophosphate (cAMP) in tobacco (Nicotiana tabacum L.) callus tissue cultures, bean (Phaseolus vulgaris L.) seedlings and immature kernels of sweet corn (Zea mays L.) through the use of a highly specific and sensitive gas chromatography-mass spectrometric assay. Levels of endogenous cAMP ranged from 70 to 126 pmol/g fresh weight. Corresponding levels of cAMP determined for the same samples using radioimmunoassay were consistently three to four times higher. Contrary to previous reports for citrus plants, measurable levels of cAMP could not be detected in young lemon leaves within the limits of detection of the mass-spectrometric assay method. In the case of tobacco callus tissue, the coumarin glucoside, scopolin, which was present in large amounts and showed similar chromatographic behaviour to cAMP, interferred strongly with the mass-spectrometric measurements of cAMP in inadequately purified extracts. The use of high-performance liquid chromatography, in addition to standard chromatographic purification methods, produced highly purified plant extracts for quantitation of cAMP and also provided a method for the separation of cAMP from its 2′:3′-isomer.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00385144
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    Nerol: An alarm substance of the stingless bee,Trigona fulviventris (Hymenoptera: Apidae) (1982)
    Springer
    Journal of chemical ecology 8 (1982), S. 1167-1181 
    Details
    ISSN: 1573-1561
    Keywords: Alarm substance ; nest defense ; nerol ; mandibular gland ; Hymenoptera ; Apidae ; Meliponinae ; stingless bees ; Trigona fulviventris ; Apiomerus pictipes ; Hemiptera ; Reduviidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Bees of the genusTrigona and subgenusTrigona possess volatile materials in their mandibular glands, used as alarm substances and as marking pheromones. Heads of workers ofTrigona fulviventris were analyzed by gas chromatography-mass spectrometry. The two major volatile components were nerol (∼ 50%), and octyl caproate (∼ 20%). Relative to other substances tested at a Costa Rican nest, treatments containing 20 μg of nerol attractedT. fulviventris, depressed numbers of bees leaving the nest by about 50%, and elicited wing vibration and biting. The responses were similar to those obtained with the contents of one worker head. Attraction and biting were also seen in response to captures of colony members by assassin bugs (Apiomerus pictipes) outside a nest entrance; one bee responded in about 15% of the captures. This alarm behavior, although weak, is of interest since it was thought thatT. fulviventris was unusual for its subgenus in its lack of nest defense behaviors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00990750
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    The movement characteristics of rabbit spermatozoa before and after activation (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 275-282 
    Details
    ISSN: 0148-7280
    Keywords: spermatozoa ; activation ; oviduct ; sperm movements ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Spermatozoa were flushed with mineral oil from the lower isthmus of the rabbit oviduct at four hours postcoitus (pc) and 11 hours pc. Videotapes were made of sperm behavior in the native isthmic fluid and after dilution of the fluid with culture medium. The tapes showed that, initially, spermatozoa in the native isthmic fluid were virtually immotile, but immediately resumed movement on contact with the culture medium. Isthmic sperm motility then evolved over a five- to 10-minute interval into the characteristic biphasic pattern of activated movement. Cine films of isthmic spermatozoa taken with a high-speed camera were analyzed to determine flagellar beat frequency, maximum flagellar curvature, and swimming velocity. Progressiveness ratios and hydrodynamic power outputs were then calculated for individual spermatozoa. Two phases of activated sperm movement, a whiplash phase and a progressive phase, were identified and characterized. The power output of activated spermatozoa increased twentyfold in comparison with the preactivated state. The power output of activated spermatozoa did not differ between the two phases of activated movement.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040403
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    Paper (German National Licenses)
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  • 4
    Electronic Resource
    Electronic Resource
    Morphological and ultrastructural characterization of mammalian spermatozoa processed for flow cytometric DNA analyses (1984)
    New York, NY : Wiley-Blackwell
    Gamete Research 10 (1984), S. 339-351 
    Details
    ISSN: 0148-7280
    Keywords: spermatozoa ; flow cytometry ; DNA staining ; nuclear morphology ; ultrastructure ; mammals ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The morphological and ultrastructural changes that occur during preparation of porcine, bovine, and murine spermatozoa for flow cytometric quantification of the relative DNA content of the X- and Y-chromosome-bearing sperm populations were examined. Ejaculated spermatozoa from the boar and bull were washed using a series of dimethyl sulfoxide (DMSO) solutions prior to fixation, whereas the epididymal mouse spermatozoa were washed only in phosphate-buffered saline (PBS). Spermatozoa from all three species were then fixed in ethanol and processed for fluorochrome staining by a treatment regimen consisting of sulfhydryl reduction and proteolysis. The processed sperm nuclei were stained for DNA with the fluorochrome, 4′-6-diamidino-2-phenylindole (DAPI) before quantification by flow cytometry. Scanning and transmission electron micrographs of sperm heads taken at various steps of the preparation and staining procedures show 1) that the rigorous washing procedure disrupted the plasma and outer acrosomal membranes, 2) that ethanol fixation resulted in removal of the outer membranes and disintegration of the nuclear envelope, and 3) that thiol and proteolysis treatment removed the remaining cellular organelles including the tail and rapidly induced partial decondensation of the tightly packed chromatin. Sequential micrographs showed that the nuclear matrix of all three species increased in thickness about twofold during the preparation and staining. Consequently, the harsh procedures currently used for quantitative staining of DNA for high-resolution flow cytometric analyses destroy most cellular organelles and thereby prevent simultaneous characterization of DNA content and other sperm cell constituents.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120100402
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    Paper (German National Licenses)
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  • 5
    Electronic Resource
    Electronic Resource
    The crater defect in boar spermatozoa: A correlative study with transmission electron microscopy, scanning electron microscopy, and light microscopy (1980)
    New York, NY : Wiley-Blackwell
    Gamete Research 3 (1980), S. 259-266 
    Details
    ISSN: 0148-7280
    Keywords: spermatozoa ; boar ; crater defect ; electron microscopy ; nucleus ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Nuclear vacuoles resembling the “crater defect” described in bull spermatozoa were observed in 14 boars. Both the incidence of the defect and semen quality were monitored with phase contrast microscopy over a three-month period. The percentages of cratered spermatozoa varied widely both among boars and in ejaculates from the same boar taken on different days. The presence of cratered spermatozoa at a level of 5% or more appeared to be associated with low semen quality. The defect was studied with scanning and transmission electron microscopy and was found to consist of nuclear invaginations, about 0.5 μm in diameter, containing some scanty amorphous electron-dense material. In boars showing a high incidence of spermatozoa with crater defects, abnormalities of the acrosome and perforatorium were common.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120030308
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    Paper (German National Licenses)
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