摘要:

AbstractThe use of a self‐contained unit‐gravity cell separation apparatus for separation of populations of mouse testicular cells is described. The apparatus, a Celsep™, maximizes the unit area over which sedimentation occurs, reduces the amount of separation medium employed, and is quite reproducible. Cells thus isolated have been good sources for isolation of DNA, and notably, high molecular weigh

ISSN:0148-7280    

DOI:10.1002/mrd.1120120102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractImmature (germinal vesicle stage)Rana pipiensoocytes typically remain arrested in prophase I of meiosis even after extended periods of in‐vitro culture, if not stimulated with hormones. We have, however, sporadically observed “spontaneous” occurrences of oocyte maturation in vitro without the addition of hormones. This study documents some of our observations on this phenomenon and presents experimental results concerning the effects and possible involvement of estrogen and follicle wall components in regulating spontaneous oocyte maturation. Estrogen was found to inhibit spontaneous oocyte maturation (GVBD) in a dose‐dependent fashion. Follicles in which spontaneous maturation was inhibited by estrogen retained their responsiveness (GVBD) to both frog pituitary homogenate (FPH) and progesterone stimulation. Inhibitory effects of estrogen on spontaneous maturation, however, were not reversed following incubation of washed follicles in plain culture medium without added hormones. Possible involvement of progesterone synthesis in spontaneous oocyte maturation was ascertained by simultaneously monitoring endogenous progesterone synthesis and the occurrence of spontaneous GVBD over the course of the maturation process. In spontaneous maturing follicle there was a gradual increase in basal levels of progesterone synthesis that preceded GVBD. Significantly, addition of estrogen abolished both the spontaneous progesterone production and spontaneous oocyte maturation. When FPH was added to follicles exhibiting spontaneous oocyte maturation, progesterone production was augmented and the time course of oocyte maturation was greatly accelerated. Involvement of ovarian components in the maturation process was investigated by selective removal of various follicle layers by microdissection. Removal of follicle epithelium and theca layer (defolliculation) markedly decreased spontaneous and FPH‐induced maturation, whereas removal of the entire follicle wall (denudation) completely blocked it. Our results suggest that both spontaneous and FPH‐induced maturation involve an estrogen sensitive process in the follicle wall. Thus, somatic follicle cells appear to serve as a common mediator for both types of maturation, which are linked by some intrafollicular mechanism involving steroidogenesis. Hence, estrogen may play an important role as an endogenous intrafollicular regulator of oocyte meiotic

ISSN:0148-7280    

DOI:10.1002/mrd.1120120103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractIn these experiments the mean number of sperm bound to the zonae pellucidae of immature human oocytes and to the vitelli of zona‐free hamster oocytes were counted after centrifuging the oocytes through a discontinuous dextran gradient into a fixative. Sperm suspensions (107sperm/ml) were preincubated in BWW medium containing 35 mg/ml of human serum albumin for 0 to 20 hr and coincubated with oocytes for 4 hr.The kinetics of sperm binding and sperm penetration were clearly different for the two types of oocytes in this system. Sperm binding to the zona pellucida appeared to be associated with zona penetration; when the zona was penetrated, many sperm were tightly bound and vice versa. A similar association between human sperm binding to the zonafree hamster oocyte and hamster oocyte penetration was not so apparent. Transmission electron microscopy revealed that all sperm which were “bound” to the hamster vitellus were acrosome reacted. On the surface of the human zona pellucida acrosome intact and acrosome reacted sperm were observed.These results suggest that tight binding of spermatozoa to the zona pellucida may be an important preliminary step in human fertilization. If this is true the activity of the sperm's “receptor for zona” may not be detected by the assay with zona‐free hams

ISSN:0148-7280    

DOI:10.1002/mrd.1120120104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractThe appearance of the nuclear abnormality “crater defect” is described in spermatozoa from the domestic horse (Equadae). Under scanning electron microscopy, the defect appears as a severe depression at any area of the sperm nucleus or as a blister or swelling at some point on the sperm nucleus. Ultrastructurally, the crater appears as a nuclear vacuole containing amorphous material similar to that described in bull and boar sperm. The craters ranged in size from 0.5 to 2 μm in diameter. Within ejaculates of stallions having this defect, the percentages of sperm with crater defects varied widely over time, being as high as 60% and as low as

ISSN:0148-7280    

DOI:10.1002/mrd.1120120105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractThe functional capacity for sperm interaction with the human zona pellucida and zona‐free hamster oocyte was tested after human spermatozoa were capacitated by passage through a column of human cervical mucus. The results were compared with those obtained when spermatozoa from an aliquot of the same semen sample were capacitated by the standard laboratory methods involving sequential washing by dilution and centrifugation of the semen. Washed‐capacitated sperm suspensions were more successful than mucus‐capacitated sperm in attaching to the zona‐free hamster oocyte and in fusing with its oolemma. However, the ability of mucus‐capacitated sperm to penetrate the human zona pellucida was equal to washed capacitated sperm. These experiments demonstrate an approach that may be useful in comparative studies of human sperm capacitation in vivo and

ISSN:0148-7280    

DOI:10.1002/mrd.1120120106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractChromatin within swollen or lysed isolated sperm nuclei of the sea urchin,Strongylocentrotus purpuratus, was examined by electron microscopy. Spread preparations of lysed sperm nuclei demonstrated dense aggregates of nondispersed material and beaded filaments radiating from these aggregates. These beaded fibers are similar in size and appearance to the “beads‐on‐a‐string” seen as characteristic of chromatin spreads from numerous interphase nuclei. The beads are nucleosomes that have an average diameter of 130 Å. The interconnecting string is 40 Å indiameter and corresponds to the spacer DNA. In thin sections of swollen nuclei the sperm chromatin appears to be composed of 400 Å superbeads that are closely apposed to form 400 Å fibers. As the chromatin disperses, the superbeads are seen to be attached to one another by chromatin fibers of 110 Å diameter. In thin sections, the 400 Å superbeads appear to disperse directly into the 110 Å fibers with no intervening structures. This work demonstrates that the heterochromatin in Strongylocentrotus purpuratus sperm nuclei is composed of nucleosomes that form 100 Å filaments that are compacted into 400 Å superbeads. The superbeads coalesce to give the morphological appearan

ISSN:0148-7280    

DOI:10.1002/mrd.1120120107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractGuinea pig spermatozoa were collected from the caudae epididymides in various isotonic solutions and the intracellular sodium and potassium content was determined by atomic absorption spectroscopy. The sperm intracellular Na and K content was found to be influenced by large variations in the extracellular concentrations of these ions. Treatment of spermatozoa suspended in a saline‐based solution with the monovalent ionophores monensin or nigericin caused an approximate 2‐fold increase in the intracellular Na content and a 3–6 fold decrease in the intracellular K content. Incubation of the spermatozoa in a K+‐free minimal culture medium (MCM‐PL) at a pH of 7.6 or 8.3 for 2 hr caused an approximate 2‐fold increase in the sperm intracellular Na content and a 5‐fold decrease in the intracellular K content. The motile spermatozoa incubated for 2 hr at pH 7.6 showed less than 5% acrosome reactions, compared with 30–40% acrosome reactions after incubation at pH 8.3, in response to the addition of 5 mM Ca2+. Changes in the sperm intracellular elemental composition during culture in vitro, which may lead to an acrosome reaction

ISSN:0148-7280    

DOI:10.1002/mrd.1120120108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractRat caproyl esterase (E.C.3.1.1.1), extracted from testis with Tween 80, was purified by cation exchange and lectin affinity chromatography. The 104‐fold purified enzyme had an activity of 840 μmol/hr per mg protein.The purified esterase did not contain any hyaluronidase or N‐acetyl‐glucosaminidase activity. Electrophoresis on sodium dodecyl sulfate polyacrylamide gels revealed a single band of approximately 60,000 molecular weight. The esterase had an isoelectric point of 5.1. Inhibition experiments showed high sensitivity of the enzyme to sulfhydryl agents and complete inactivation by sodium aurothiomalate.The purified caproyl esterase was shown to digest the cumulus matrix from mou

ISSN:0148-7280    

DOI:10.1002/mrd.1120120109

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractThe ultrastructure of human cervical mucus was studied by scanning electron microscopy. In fertile women, naturally occurring midcycle cervical mucus showed an arrangement of parallel fibers oriented along the main axis of the mucus sample. Sperm migration through a column of cervical mucus in vitro was also studied. It was found that sperm present among the longitudinal fibers were oriented parallel to the them and to the main axis of the mucus sample.

ISSN:0148-7280    

DOI:10.1002/mrd.1120120110

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractBoar sperm plasma membrane proteins (PMPs) with affinity for the zona pellucida were partially purified from columns of dextran sulfate using a linear salt gradient and a buffered detergent that retained their ability to block directly the binding of uncapacitated and capacitated sperm to isolated porcine oocytes. PMPs that bound most strongly to dextran sulfate (fraction IV) were also most effective in blocking sperm binding to porcine oocytes. These tightly bound proteins also bound to isolated zonae to a greater extent than other fractions. Monovalent antibodies to fraction IV PMPs completely blocked sperm binding to isolated eggs. Fraction IV PMPs lost the ability to inhibit directly the binding to eggs when treated with chaotropic agents and trypsin; the fraction also displayed a tendency to aggregate in the absence of high salt. This property and the affinity of proteins in this fraction for sulfated polysaccharides indicate that specific hydrophilic interactions may play a significant role in sperm‐zona attachment

ISSN:0148-7280    

DOI:10.1002/mrd.1120120111

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY