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
  • 1
    Electronic Resource
    Electronic Resource
    Bovine oviductal fluid components and their potential role in sperm cholesterol efflux (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 25 (1990), S. 195-204 
    Details
    ISSN: 1040-452X
    Keywords: Capacitation ; Acrosome reaction ; High-density lipoproteins ; Progesterone ; Estrous cycle ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Bovine oviductal fluid (OF) was collected and analyzed throughout the estrous cycle, and the capacity of the protein and lipoprotein components to support cholesterol efflux from bovine sperm was evaluated. Blood was collected and assayed for progesterone (P4) to monitor the estrous cycle. Protein and lipoprotein separation was achieved by density gradient centrifugation. Two major bands were identified. The first (1.056 〈 ∂20 〈 1.140 g/ml) corresponded to bovine and rabbit plasma high-density lipoprotein (HDL) based on distribution in the density gradient and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The second band (1.235 〈 ∂20〈1.243 g/ml) consisted predominantly of oviductal fluid albumin (OFA). Oviductal fluid protein concentration increased as serum P4 decreased around the time of estrus. Mean OF protein concentration was 21.3 mg/ml when serum P4 was lower than 0.5 ng/ml and 6.9 mg/ml when serum P4 was greater than 0.5 ng/ml. An inverse log relationship was found between HDL protein concentration and serum P4. Unesterified cholesterol (UC), cholesteryl ester, and phospholipid (PL) content of HDL for HDL protein concentrations of 3-56.1 μg/ml were 1.35-46.2 μg/ml, 1.91-44.48 μg/ml, and 1.69-59.8 μg/ml, respectively. Phosphatidylcholine and -ethanolamine were the major PLs present in the HDL fraction and their molar ratio (4:1 mol/mol) was relatively constant through the estrous cycle. The OFA fraction of the same samples accounted for more than 90% of total protein and for most of the variation in OF protein. To determine the ability of OF components to serve as sperm cholesterol acceptors, OF samples were incubated 1:1 (v/v) with and without 4 × 108 bovine sperm in 1.0 ml of modified Tyrode's solution and OF for 2 hr at 39°C. After incubation, HDL and OFA fractions were isolated and analyzed for changes in protein and lipid content. After OF, samples were incubated with sperm, an increase in UC was found in the HDL fractions. UC in HDL increased by 12.1 ± 1.0 μg/ml (X ± SE) when serum P4 was ≤0.5 ng/ml. For samples corresponding to higher serum P4, the increase in UC was 3.60 ± 0.89 μg/ml. Values for UC in HDL were corrected for the contribution of UC from OFA of OF samples. Cholesterol efflux from sperm has been implicated in the process of sperm capacitation. These results indicate that HDL from OF is elevated during the follicular phase of the estrous cycle and can serve as an acceptor for bovine sperm cholesterol.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080250213
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Increasing carbon dioxide from five percent to ten percent improves rabbit blastocyst development from cultured zygotes (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 33 (1992), S. 276-280 
    Details
    ISSN: 1040-452X
    Keywords: Expanding blastocysts ; Culture ; CO2 ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: One-cell rabbit zygotes were cultured at 39°C in basal synthetic medium II (BSM-II) with 5%, 10%, or 15% CO2 and humidified air to determine the effect of CO2 concentration on development in vitro. After 4 days in culture, 37% of the embryos grown in 10% or 15% CO2 had reached the hatching blastocyst stage, but only 10% of the embryos were hatching when cultured under 5% CO2 (P = 0.01). Over all blastocysts, cell numbers were 207, 246, and 205 for the 5%, 10%, and 15% CO2 treatments, respectiveiy. In a second experiment to determine if there was a beneficial effect, particularly at the blastocyst stage, of a higher concentration of CO2, embryos were cultured 4 days in either 5% or 10% CO2 or for 2 days in 5% CO2 followed by 2 days in 10% CO2. The numbers of blastomeres per embryo and embryo diameter were greater (P 〉 0.05) in embryos cultured continuously in 10% CO2 or in 10% CO2 only during days 3 and 4 of culture than in embryos cultured continuously in 5% CO2. In a third experiment, one-cell rabbit zygotes were cultured with 5% or 10% CO2 in a defined, protein-free medium consisting of 1:1 RPMI 1640 and Dulbecco's modified Eagle's medium. The proportion of embryos hatching and cell counts were significantly greater (P 〉 0.01) when cultured in the presence of 10% CO2. These data indicate that a 10% CO2 atmosphere exerts a beneficial effect on the development of zygotes into expanding and hatching rabbit blastocysts in vitro. © 1992 Wiley-Liss, Inc.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080330307
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Surface alterations of the bovine oocyte and its investments during and after maturation and fertilization in vitro (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 38 (1994), S. 421-430 
    Details
    ISSN: 1040-452X
    Keywords: Cumulus ; Oocyte ; Zona pellucida ; SEM ; Ultrastructure ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Surface characteristics of the bovine oocyte and its investments before, during, and after maturation, and fertilization in vitro were evaluated by scanning electron microscopy (SEM). Oocyte diameters were also measured during SEM analysis of the oocyte. The cumulus cells manifested a compact structure with minimal intercellular spaces among them in the immature oocytes. These became fully expanded with increased intercellular spaces after maturation in vitro, but contracted again after fertilization. The zona pellucida (ZP) showed a fibrous, open mesh-like structure in the maturing and matured oocytes. The size and number of meshes on the ZP decreased dramatically after fertilization. The vitelline surface of immature oocytes was characterized by distribution of tongue-shaped protrusions (TSPs) varying in density. After 10 and 22 hr of maturation incubation, oocyte surface microvilli (MV) increased to become the predominant surface structure, and TSPs decreased substantially. The vitelline surface of fertilized oocytes (at 6 and 20 hr) was similar to that of the matured oocytes, but unfertilized oocytes had less dense MV than did fertilized oocytes (at 20 hr). The diameter of the oocytes decreased from 99 to 80 μm during maturation and increased to 106 μm after insemination (P 〈 0.05). Membrane maturation was characterized by surface changes from a TSP-predominant pattern to a MV-predominant pattern. Thus, the bovine oocyte maturation process was found to involve the expansion of cumulus cells and the maturation of the ZP, which changes dramatically upon fertilization. Also, volumetric changes occurred in ooplasm processed for SEM following oocyte maturation and insemination. © 1994 Wiley-Liss, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080380410
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Nuclear transfer in cattle: Effect of nuclear donor cells, cytoplast age, co-culture, and embryo transfer (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 35 (1993), S. 29-36 
    Details
    ISSN: 1040-452X
    Keywords: Cloning ; Nuclear transplantation ; Oocyte ; Blastomere ; Cattle ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: There are many factors affecting the efficiency of nuclear transfer technology. Some are evaluated here using our novel approach by enucleating oocytes at 20-22 hr after in vitro maturation (IVM), culturing the enucleated oocytes (cytoplasts) for 8-10 hr or 18-20 hr to gain activation competence and then conducting nuclear transfer. In the first experiment, we demonstrated that cumulus cell (CC) monolayer can support some cloned embryos to develop into morulae or blastocysts. Co-culture with CC and bovine oviduct epithelial cell (BOEC) monolayers resulted in no differences (P 0.05) in supporting the development of cloned embryos (Experiment 2). When in vitro matured oocytes were enucleated at 22 hr after IVM followed by nuclear transfer 18-20 hr later, cleavage and morula or blastocyst development of the cloned embryos were similar to those resulting from the enucleated oocytes which had been matured in vivo (Experiment 3). Frozen embryos as nuclear donor cells worked equally well as fresh embryos for cloning in embryo development which was superior to IVF embryos (Experiment 4). However, fresh embryos resulted in a higher proportion (P 〈 0.05) of blastomere recovery than did frozen or IVF ambryos. Finally, embryo transfer of cloned embryos from our procedure produced a viable calf, demonstrating the commercial value of this novel approach of the technology. © 1993 Wiley-Liss, Inc.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080350106
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Bovine oviductal epithelial cells (boec) and oviducts: I. For embryo culture. Ii. Using sem for studying interactions with spermatozoa (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 31 (1995), S. 519-530 
    Details
    ISSN: 1059-910X
    Keywords: Oviduct cell ; Embryo culture ; Spermatozoa ; SEM ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The oviduct (uterine tube) plays a major role in reproduction. It is a dynamic organ which selectively permits a few sperm to undergo capacitation and reach the oocyte which has continued to undergo maturation following ovulation. Then following fertilization the embryo undergoes cleavage before arriving in the uterus. Extensive information has become available from in vitro studies on oocytes as well as spermatozoal interactions with oviductal cells. Bovine oviduct epithelial cell (BOEC) monolayers with simple media provide an environment in which zygotes can be cultured to blastocysts in 6 days with cell numbers essentially equivalent to blastocysts grown totally in the donor animal. These yield normal pregnancy rates upon transfer. The simple protein-free media currently under test hold promise for elucidating specific requirements of the preimplantation embryo and these defined conditions facilitate many related studies on in vitro fertilization and genetic engineering of embryos.The second part of this paper is an extensive study on the interaction of fresh and frozen-thawed bull spermatozoa with BOEC and segments of intact oviducts as viewed by SEM. Both types of oviductal cells were incubated at 39°C for 0, 3, 6, and 9 hours, using material obtained from periovulatory cows. Sperm attached immediately to both types of epithelium and reached a peak at 3 hours. They were found primarily in the furrows of the intact oviducts. Secretory droplets appeared rapidly on the anterior portion of the sperm head and acrosomal changes were evident in 3 hours, similar to those reported in vivo. Changes were more rapid with frozen-thawed sperm. © 1995 Wiley-Liss, Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070310608
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Cholesterol efflux from bovine sperm. I. Induction of the acrosome reaction with lysophosphatidylcholine after reducing sperm cholesterol (1988)
    New York, NY : Wiley-Blackwell
    Gamete Research 20 (1988), S. 145-157 
    Details
    ISSN: 0148-7280
    Keywords: acrosome reaction ; bovine ; lysophosphatidylcholine ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Methods were developed to quantitatively reduce the cholesterol (Chol)/phospholipid (PL) ratio of bovine sperm and to determine the effectiveness of this treatment in capacitating sperm. Washed sperm (2 × 108) were incubated in 1.0 ml of modified Tyrode's solution (TS) containing unilamellar liposomes of phosphatidylcholine (PC), phosphatidylethanolamine (PE), and [14C]-Chol (35:35:30 molar ratio, 300 nmol total PL). [3H]-triolein was included as a nonexchangable marker. After 90 min at 39°C, a 13% net exchange of [14C]-Chol from liposomes to sperm was observed (n = 4), and sperm motility was 80%. Sperm were then washed and 50 × 106 sperm were incubated as before with PC/PE liposomes containing no Chol. After 90 min, sperm were separated from liposomes by centrifugation. Measurement of [14C]-Chol in the liposomes (supernatant) and parallel gas chromatographic analysis of extracted, saponified liposomes (n = 4) indicated that 30% of sperm Chol was removed by this procedure. Chol efflux decreased percent motile sperm by less than 10% but reduced sperm velocity by more than 50%. Sperm incubated with no liposomes (control), with liposomes containing Chol ( + Chol), and with Chol-free liposomes ( - Chol) were washed and resuspended in TS with 0.2% BSA and 30 μg lysophosphatidylcholine (LPC)/mg bovine serum albumin (BSA). Percent sperm undergoing the acrosome reaction (AR) upon incubation with LPC-BSA was used as a measure of sperm capacitation. After 60 min of exposure to LPC-BSA at 39°C, the mean (± SE) percent motile sperm for control, +Chol, and  - Chol treatments was 57.0 ± 4.9, 60.0 ± 4.7, and 57.0 ± 6.8, respectively. Corresponding values for percent AR were 14.0 ± 3.4, 20.3 ± 4.4, and 39.7 ± 1.2. These results suggest that loss of Chol from bovine sperm may be an early step in sperm capacitation in this species.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120200205
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Cholesterol efflux from bovine sperm: II. Effect of reducing sperm cholesterol on penetration of zona-free hamster and in vitro matured bovine ova (1988)
    New York, NY : Wiley-Blackwell
    Gamete Research 20 (1988), S. 413-420 
    Details
    ISSN: 0148-7280
    Keywords: sperm ; capacitation ; acrosome reaction ; cholesterol ; bovine ; ovum ; lysophosphatidylcholine ; in vitro ; fertilization ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Several reports have indicated that sperm capacitation includes loss of membrane cholesterol (Chol) with a concomitant decrease in the Chol-to-phospholipid (PL) ratio. Methods were developed for quantifiable removal of bovine sperm Chol, which predisposed sperm to induction of the acrosome reaction upon addition of lysophosphatidylcholine (LPC). The objective of this study was to evaluate the effect of Chol removal from bovine sperm on penetration of zona-free hamster and intact bovine ova in vitro. Washed ejaculated bovine sperm were incubated (2 h, 39°C) in a modified Tyrode's solution (TALP) containing (1) Chol-free liposomes ( - Chol, 50 × 106 sperm and 600 nmol phospholipid/ml); (2) liposomes containing 30 mol% Chol (+ Chol, 2 × 108 sperm and 300 nmol total lipid/ml); or (3) no liposomes (Control). We have previously shown that net Chol efflux from sperm is 31% of the total sperm Chol with  - Chol liposomes and less than 1% with control media. Sperm were then washed twice and challenged with LPC bound to bovine serum albumin (BSA) using celite as a carrier. Treated sperm (25 × 106) were incubated immediately with either zona-free hamster ova (HO) or in vitro matured bovine ova (BO) in 50-μl droplets of TALP under medical fluid in an atmosphere of 5% CO2 in air (3 h, 39°C). Ova were fixed in ethanol:acetic acid, stained with 1% orcein, and examined. Percent penetration (%P) of HO (X ± SEM) for 30 and 40 μg of LPC/mg BSA was 59.4 ± 5.3 and 82.9 ± 5.4; 38.5 ± 5.6 and 52.3 ± 4.7; and 16.0 ± 4.6; and 23.2 ± 5.6 for  - Chol, Control, and + Chol treatments, respectively (n = 3). %P of BO (X ± SEM) for 30, 35, and 40 μg of LPC/mg BSA was 43.3 ± 5.4, 70.7 ± 7.5, and 81.5 ± 5.1 for  - Chol and 16.4 ± 6.9, 36.2 ± 6.9, and 44.2 ± 8.6 for Control treatments, respectively (n = 3). In a second set of experiments %P of BO (X ± SEM) was 63.6 ± 6.8, 31.8 ± 4.9, and 10.5 ± 3.4 for  - Chol, Control, and +Chol treatments, respectively, when 40 μg LPC/mg BSA was added (n = 2). %P and the number of sperm per fertilized ovum were consistently higher for the  - Chol treatment for both HO and BO (P 〈 .01). These results demonstrate that Chol removal from bovine sperm facilitates penetration of ova in vitro suggesting a potential role in bovine sperm capacitation.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120200403
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    facet.materialart.
    Unknown
    Bovine oviductal epithelial cells (boec) and oviducts: I. For embryo culture. Ii. Using sem for studying interactions with spermatozoa (1995)
    Wiley
    Details
    Publication Date: 1995-08-15
    Print ISSN: 1059-910X
    Electronic ISSN: 1097-0029
    Topics: Natural Sciences in General
    Published by Wiley
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 9
    facet.materialart.
    Unknown
    Livestock Cloning (1999)
    American Association for the Advancement of Science
    Details
    Publication Date: 1999-01-22
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...