Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • fertilization  (2)
Collection
Publisher
Years
  • 1
    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
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    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
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...