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  • 1
    ISSN: 0022-5320
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    American Journal of Anatomy 149 (1977), S. 423-430 
    ISSN: 0002-9106
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: After inducing the acrosomal reaction in guinea pig spermatozoa in vitro, the sperm were tested for proteolytic activity by applying them to membranes of fixed gelatin. One to 5% of them showed slight evidence of proteolytic activity, while the rest were completely negative. Sperm that had retained their acrosomes throughout the incubation period displayed intense proteolytic activity. These results suggest that proteinases may be lost from spermatozoa as a result of the acrosomal reaction.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 0002-9106
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The acrosomes of mammalian spermatozoa contain a proteolytic enzyme which may be of importance for fertilization. The release and activity of the enzyme can be visualized directly when the spermatozoa are applied to fixed gelatin membranes. The purpose of this study was to determine the pattern of enzyme release from the spermatozoa of a variety of mammalian species. Thin, transparent membranes of pure gelatin were prepared on microscope slides and fixed in glutaraldehyde. Spermatozoa were applied to the membranes and their proteolytic behavior observed under dark-medium phase objectives at 37°C. In all the species examined (rabbit, bull, hamster, rat, guinea pig and man) extensive depolymerization of the gelatin substrate occurred around the sperm heads. With the exception of human spermatozoa, the onset of proteolysis was clearly identified with the posterior half of the acrosome. In the case of human spermatozoa, no such distinction could be made. It is suggested that the proteolytic enzyme of most mammalian spermatozoa is located in the posterior segment of the acrosome.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 0002-9106
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Direct observations of ciliary activity on the mucosal surface of mammalian oviducts have rarely been reported. Yet such studies might help to determine the relative value of ciliary action in gamete transport through the ducts. The purpose of this study was to examine the direction and rapidity of ciliary currents in the oviducts of two mammalian species, the rabbit and the pig. Fresh oviducts were slit open longitudinally and submerged in Hanks' balanced salt solution at 37°C. The movements of particulate matter, such as stained lycopodium spores and 15 μ microspherents, placed on the mucosal surface, were observed and recorded on film. In both species ciliary currents in the ampulla swept the particles toward the ampullar-isthmic junction. In the isthmus of the pig oviduct the particulate matter was transported in the reverse direction, toward the ovary. The pro-ovarian current could be demonstrated throughout the isthmus, beginning a few millimeters above the uterotubal junction. In the rabbit a similar current was detected, but it was not as extensive as in the pig. In the upper isthmus of the rabbit oviduct, particulate matter and rabbit eggs in the “mucin coat” merely rotated or “tumbled” on the surface with little movement in either direction. This is the first report of pro-ovarian ciliary currents for any mammal, and we believe these to be important for sperm transport through the isthmus. The action of cilia during egg transport is discussed.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 0002-9106
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The direction of ciliary beat has been examined in vitro in human and pig-tailed macaque (M. nemestrina) oviducts. Ducts removed under anesthesia were slit open longitudinally while submerged in Hanks solution at 37° C, and particulate matter was applied to the mucosal surface. Contrary to previous observations in pig and rabbit oviducts, transport of particles was consistently in a downward direction, toward the proximal (uterine) end, in the two species examined in this study.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 0002-9106
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Many of the cilia in the oviducts of rhesus monkeys are formed in the follicular phase of the menstrual cycle, and lost in the subsequent luteal phase (Brenner, 1969a). This striking phenomenon has rarely been observed in other species, and its occurrence in human oviducts is a point of dispute. This study was designed to determine whether cyclic shedding and renewal of oviductal cilia occur in a primate species other than the rhesus monkey and to reveal the surface characteristics of the oviductal mucosa in a subhuman primate. Oviducts were removed from Macaca nemestrina females at three specific times during the menstrual cycle and examined by scanning electron microscopy. The fimbriae appeared to be extensively ciliated at midcycle but only sparsely ciliated in the early follicular and late luteal phases. Early in the cycle, large numbers of cells were seen in the process of ciliogenesis, but in the late luteal phase there were signs of ciliary degeneration and shedding. The ampullar epithelium showed similar though less dramatic changes, and the isthmus little change. Long-term ovariectomy caused almost complete deciliation of the fimbrial and ampullar epithelium, but treatment of ovariectomized animals with estrogen for only a few days restored the epithelium to normal. Despite the high degree of variability in the mucosa, it was clear that the oviducts of M. nemestrina, like those of the rhesus monkey, undergo cyclic ciliogenesis and deciliation. The surface features of the oviductal lining in M. nemestrina are described here for the first time.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Gamete Research 10 (1984), S. 107-118 
    ISSN: 0148-7280
    Keywords: Rat ; fertilization ; in vivo ; in vitro ; topography ; egg ; actin ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The surface topography of the rat egg was examined during fertilization in vitro and in vivo. Using phase optics, 348 in vitro fertilized and 50 in vivo fertilized eggs were continuously monitored throughout the 7-hour period of sperm incorporation. A myriad of different surface configurations were seen, with each egg exhibiting one or more of the following changes. A small number of eggs (4-6%) formed surface elevations over the sperm head after its detachment from the flagellum, 15-30 min after sperm-egg fusion; 1 to 1.5 hr after fusion, 40-50% of the eggs produced the so-called incorporation cone, a prominent surface elevation over the decondensing sperm nucleus. The vast majority of eggs (74-82%) formed surface elevations over the proximal tip of the flagellum 2-3 hr after sperm-egg fusion. These had no association with the decondensing sperm nucleus. A few eggs (11-12%) exhibited multiple protrusions that were distributed randomly about the egg surface, whereas 14-20% did not manifest any surface elevations and remained spherical throughout the sperm incorporation period. Regardless of the type of surface change, all of the eggs resumed a spherical shape by the time sperm incorporation was complete. These observations are in contrast to the conclusions by previous authors that formation of the so-called incorporation cone over the decondensing sperm nucleus is a ubiquitous event.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Gamete Research 6 (1982), S. 215-223 
    ISSN: 0148-7280
    Keywords: spermatozoon ; egg ; fertilization ; in vitro ; incorporation ; cincmatography ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Cumulus-free mouse eggs were placed on microscope slides and inseminated with capacitated mouse spermatozoa. Fertilization could then be observed through the phase contrast microscope and recorded by time-lapse cinematography. Following the penetration of the fertilizing spermatozoon through the zona pellucida and the fusion of the sperm head with the vitelline membrane, the entire sperm tail gradually entered the vitellus. The time required for tail incorporation into the vitellus as measured in 49 eggs varied from 3 h 3 min to 5 h 49 min, with a mean time of 4 h 23 min. When tail incorporation began, the greater part of the flagellum was still outside the zona pellucida; occasionally it slipped into the perivitelline space, but generally it remained outside the zona and shortened by degrees as incorporation proceeded. The motility of the fertilizing spermatozoon declined abruptly very soon after fusion of the sperm head with the vitellus and remained at a very low level during the 3-6 h required for tail incorporation. Sperm motility, therefore, does not appear to be the main determinant in tail incorporation and the primary mechanism responsible for it remains unclear. As the sperm tail slowly entered the vitellus, the second meiotic division was completed with concomitant extrusion of the second polar body. Key stages in second polar body formation were correlated with events in tail incorporation. Differences between fertilization in vitro and in vivo are discussed.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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