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  • 1
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 2 (1982), S. 93-101 
    ISSN: 0886-1544
    Keywords: cell motility ; singlet microtubules ; dynein ; coccid insect ; aflagellate spermatozoa ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In this report we demonstrate that in the coccid insects Pseudococcus, Phenacoccus, and Planococcus the whole spermatozoon is made up by a nuclear central core surrounded by two complete and one incomplete turns of concentric microtubule palisades. Microtubules of the outer row are linked by a system of short projections 6 nm long; those of the inner row are linked to each other by similar arms; a second system of 6 nm arms links the tubules of each inner row to those of the respective outer row. All these systems of arms are longitudinally spaced every ∼ 12 nm. The motility of this spermatozoon is due to waves progressing from the posterior extremity to the anterior one. By SDS polyacrylamide gel electrophoresis a group of high molecular weight polypeptides is detected, one of which migrates in coincidence with the A dynein band from sea urchin sperm. Our data suggest that occurrence in coccid spermatozoon of a motility due to singlet tubules-dynein interaction.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Gamete Research 10 (1984), S. 373-396 
    ISSN: 0148-7280
    Keywords: fish spermatozoa ; comparative spermatology ; Cyprinidae ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The spermatozoa of seven fishes belonging to Cyprinid family are examined. They have no acrosome, like all Teleost fishes, a spheroidal or slightly elliptic nucleus, always eccentrically placed on the tail, two variously oriented centrioles, and a postnuclear cytoplasmic region of various size that contains some mitochondria (2 to 10) and surrounds a periaxonemal postnuclear canal. The tail is of moderate length (from 36 to 60 μm) and contains a “9 + 2” axoneme: both dynein arms are present. Comparative examination of the spermatozoa in the seven species shows that significant differences occur among them, even when they belong to the same genus. These concern the tail length; the position of the centrioles, the proximal with respect to the central one and with respect to the nucleus; the number of mitochondria, which is in relationship to the depth of the postnuclear canal. In the uniform general pattern of the ultrastructure of the Cyprinid spermatozoa, each species is characterized by a particular organization of the sperm organelles; in this respect, the two species examined by us, Leuciscus cephalus and souffia, are more closely related, even if easily recognizable one from the other. From a phylogenetic point of view, the comparative spermatology of the Cyprinid fishes suggests that the mitochondrial number is a good character, which enables us to order them in a phylogenetic arrangement.
    Additional Material: 40 Ill.
    Type of Medium: Electronic Resource
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