bluuebunny/crossref_metadata_2025_split huggingface dataset:
Species specificity of hybridoma antibodies to surface antigens of guinea pig sperm
Authors: Primakoff Paul , Heaton M. Rebecca , Myles Diana G. 
Published: February 2005

AbstractThe species specificity of hybridoma antibodies to sperm surface antigens was studied. A collection of over 50 hybridoma antibodies that bind to the guinea pig sperm surface was tested for binding to mouse, rat, hamster, and human sperm by indirect immunofluorescence. None of the antibodies bind to mouse sperm. rat sperm, or human sperm. All but three of the antibodies also fail to bind to hamster sperm. AH‐30, AH‐31, and AH‐1032, the three antibodies that crossreact with hamster sperm, show a different topographical localization on hamster sperm from that seen on guinea pig sperm. The three antibodies do not precipitate a 125I surface‐labeled antigen from hamster sperm extracts. However, from guinea pig sperm extracts, all three antibodies precipitate 125I surface‐labeled polypeptides with molecular weights (Mr) of 62,000, 52,000, and 38,000. This result suggests that the crossreacting antibodies may be recognizing different antigens on hamster and guinea pig sperm.
Spermiogenesis and the ultrastructure of mature sperm in Eurygaster intergriceps
Authors: Danilova L. V. , Gaber E. S. , Shinyaeva L. I. 
Published: February 2005

AbstractAn electron‐microscope study of spermiogenesis and the ultrastructure of mature sperm was made on Eurygaster integriceps. During spermiogenesis, a manchette consisting of two large groups of microtubules and an unusual centriolar adjunct are formed. The latter looks like two half cylinders located almost at right angles to one another. Its wall consists of several dark layers divided by lighter areas. The centriole and its adjunct are not identified in the mature sperm. Bug spermatids have a large amount of amorphous pericentriolar matter, which assists in establishing an unusual nuclear pattern.The mature sperm is distinguished by a number of unique features. Its nucleus consists of three interconnected parts: the inner and outer cylinders and a part freely suspended along the middle piece. The intranuclear channel is blindly closed at the apical end and filled with dark amorphous matter that originates from the pericentriolar matter. The acrosome has an extracellular part resembling a diagonally striated rod, which is sometimes disengaged from its surface. The axoneme has 9+9(2) + 2 tubules. It is connected with the Nebenkern by dark arms.
Adenylate cyclase activity of membrane fractions isolated from sea urchin sperm
Authors: Mourelle Marisabel , Vargas Irma , Darszon Alberto 
Published: February 2005

AbstractThe adenylate cyclase activity of sperm membrane fragments isolated from Lytechinus pictus sperm according to Cross [20] has been studied. Two distinct fractions preferentially coming from the flagellar plasma membrane are obtained. Surface I125‐labeling experiments performed by Cross [20] indicate that these membranes are representative of the entire sperm plasma membrane. Both fractions are enriched in their adenylate cyclase activity: the specific activity of the top membranes is eightfold higher than in whole sperm, whereas that of the middle membranes is 15‐fold higher. The cyclase seems to be associated with the membranes. Lytechinus pictus egg jelly has no effect or slightly inhibits the adenylate cyclase activity of the isolated sperm plasma membrane fragments. Mg++ and Na+ stimulated their cyclase activity about sevenfold at 2.5 mM Mn++ and 3.2 mM ATP. At this ATP to Mn++ ratio, high concentrations of Ca++ have a small stimulatory effect.
Effects of cyclic AMP on the motility of mature and immature hamster epididymal spermatozoa studied by reactivation of the demembranated cells
Authors: Yeung C. H. 
Published: February 2005

AbstractHamster spermatozoa from the caput and cauda epididymides were demembranated with 0.04% Triton X‐100 and reactivated with 1 mM ATP. Motility parameters were analysed by video recording and stroboscopic photography. In the absence of added cAMP, reactivated cauda sperm showed percentage motility and forward swimming patterns similar to those of intact cells, but velocities were lower. When 2 or 20 μM cAMP was present, the velocities were increased but there was no effect on beat frequencies or percentage of forward progressing sperm. Cyclic AMP also markedly increased the percentage of cauda sperm which at first displayed nonprogressive “looping” movement. Addition of cAMP to the reactivation medium greatly improved the otherwise feeble and irregular motility of the demembranated caput sperm by increasing the percentage motility and beat frequencies of nonprogressive cells. It also induced forward motility with beat frequencies and velocities similar to cauda sperm reactivated in the absence of cAMP, but looping was never seen, indicating a change in the flagellar apparatus with maturation. The time required for the exhibition of the cAMP effects was reduced when caput sperm were reactivated in extracts of another previously maximally reactivated caput sperm preparation. The results suggest the production of some potent compound(s) by the axonemes for the manifestation of the cAMP effects.
Human sperm motility after migration into, and incubation in, synthetic media
Authors: Mortimer D. , Courtot A. M. , Giovangrandi Y. , Jeulin C. , David G. 
Published: February 2005

AbstractTen frames/sec microcinematography (“film”), 1 second timed‐exposure photomicrography (“photo”), and laser Doppler velocimetry (LDV) were used to analyse the swimming patterns of human spermatozoa after migration (1 h at 37°C) into an overlying layer of either BWW or Menezo's B2 media. The upper layer of medium was carefully removed and further incubated at 37°C for either 4 h (B2) or 5 h (BWW) and the sperm motility analysed again. Five experiments were performed using semen from different donors. Film and photo analyses gave the relative incidence of nonprogressive and progressively motile spermatozoa plus, for the progressive spermatozoa, the velocities of progression (Vp) and amplitudes of lateral head displacement (Ah). LDV gave the percentage of motile spermatozoa and the modal instantaneous velocity (Vm). All postmigration sperm populations showed large significant increases in the percentage of motile spermatozoa, with good survival during incubation. The progressive postmigration spermatozoa generally moved with greater Vp and Ah than in the initial seminal plasma‐diluted material; Vm was also increased. There were further increases in both Vp and Ah during incubation, but no change in Vm was detected. While the majority of spermatozoa were progressive, some showed a highly active pattern of movement which resulted in no net forward progression. The possible homology between these spermatozoa and the “hyperactivated” motility of capacitated spermatozoa in other mammalian species is discussed. Apparent discrepancies between the three methods used for motility analysis were seen, the possible causes and significances of which are also discussed.
Human nonovulatory oocyte‐cumulus complexes: Ultrastructure, macromolecular synthesis, and developmental potential
Authors: Tesařík Jan , Kopečny Václav , Dvořák Milan , Pilka Ladislav , Kurilo Ljubov F. 
Published: February 2005

AbstractHuman nonovulatory oocyte‐cumulus complexes were obtained from large antral follicles 34 h after the injection of hCG. Their ultrastructure, RNA and protein synthesis, and the ability of oocyte maturation and subsequent fertilization in vitro were the subject of this study. The oocyte nucleus was situated in the cell periphery, possessing one or two dense nucleoli. Intranucleolar vacuoles were sometimes present. Mitochondria and smooth endoplasmic reticulum were the most abundant cytoplasmic structures. The number of cortical granules was rather low. Cumulus cells showed responsiveness to exogeneous hCG/endogeneous LH stimulation as morphologic signs of the oocyte‐cumulus uncoupling and of the early luteinization. Furthermore, the oocytes were capable of meiotic maturation in vitro, and following subsequent in vitro insemination the majority of them were penetrated by spermatozoa. However, polyspermy was detected in most cases, and cleavage was not achieved. A developmental defect of nonovulatory oocytes was suggested by an extremely low level of RNA synthesis while continuing active protein synthesis by nonovulatory oocytes was demonstrated. In contrast, the associated cumulus cells synthesized both RNA and protein, suggesting that the majority of granulosa cells of the nonovulatory follicles was probably unaltered. It is hypothesized that the development of nonovulatory follicles after induction of ovulation might reveal the developmental pattern which would lead, in some cases, to ovulation of nonviable human oocytes both in stimulated and natural cycles.
Births after a prolonged delay between oocyte recovery and fertilization in vitro
Authors: Fishel S. B. , Edwards R. G. , Purdy J. M. 
Published: February 2005

AbstractTwo normal, healthy children have been born after an oocyte was collected from each of two patients during their natural menstrual cycle, incubated for many hours and then fertilized in vitro. Details of the follicular phase prior to oocyte recovery, fertilization and embryonic development in vitro, and replacement of the embryos are described in detail. One embryo cleaved rapidly after its delayed fertilization, with blastomeres of uneven size and cellular fragments. The luteal phase seemed to be weak in both patients.
Effect of follicle cells on the maturation and developmental competence of ovine oocytes matured outside the follicle
Authors: Staigmiller R. B. , Moor R. M. 
Published: February 2005

AbstractThe hypothesis that follicle cells play a central role in endowing the oocyte with developmental competence during maturation has been tested in coculture studies. Oocytes and follicle cells in various combinations were cultured for 24 h with gonadotrophins and estrogen in a nonstatic culture system. Developmental competence was assessed by transfer of oocytes to inseminated receipient ewes followed by embryonic examination 12 days later or at parturition.Denuded and corona‐enclosed oocytes resume meiosis in culture but remain immature and developmentally incompetent. By contrast, oocytes supported by the cumulus and underlying granulosa (cumulus‐oocyte complexes) undergo full maturation and normal subsequent embryonic development (42.6% to embryos). Addition of supplementary follicle cells during culture (5 × 106 cells/ml medium) is without beneficial effect on denuded oocytes. However, supplementary cells confer competence on corona‐enclosed oocytes (37% to embryos).A dual cellular requirement for full maturation involving both cell numbers and some direct cell‐oocyte contact is highlighted by our experiments. The results demonstrate further that the nonstatic system provides a simple but reliable method of producing large numbers of fully matured oocytes for both research and clinical purposes.
Cytological analysis of nuclear migration and dissolution during steroid‐induced meiotic maturation in vitro of follicle‐enclosed oocytes of the goldfish (Carassius auratus)
Authors: Lessman Charles A. , Kavumpurath Soosamma 
Published: February 2005

AbstractThe effect of progestogens on nuclear or germinal vesicle dissolution (GVD) was tested in goldfish (Carassius auratus) follicle‐enclosed oocytes in vitro. The results indicated the following hierarchy of GVD activity: 17α20β dihydroxy progesterone (DHP) > 17α hydroxy progesterone (HP) > progesterone (P). Further studies with DHP indicated that nuclear migration (GVM) preceded GVD, and that no significant GV size changes (ie, diameter in animal‐vegetal pole axis) occurred during GVM. The in situ GV visualization technique used (ie, acetic acid yolk clearing with concurrent nuclear precipitation) was verified using standard paraffin sectioning procedures. The two techniques yielded highly correlated results and indicated that GVM is initiated between 12–18 hr, after DHP addition at 15°C. The goldfish oocyte in vitro system as described here is a useful model for the study of hormonally induced GVM and GVD.
Ultrastructural aspects of in vivo fertilization in the cow
Authors: Crozet Nicole 
Published: February 2005

AbstractIn vivo fertilization of cow eggs has been studied by electron microscopy. Eggs were recovered from intracervically inseminated heifers 30 to 42 hr after the onset of oestrus. The corona cells remained attached to 4 out of the 15 eggs studied, but no sign of sperm phagocytosis was noted.Spermatozoa close to the zona pellucida, but not in contact with it, were not acrosome reacted. In contrast, all sperm penetrating the zona pellucida had completed the acrosome reaction. Vesiculated products of the reaction were present at the zona surface of every penetrated egg, indicating that in this species, the acrosome reaction occurs at the surface of the zona pellucida.During sperm passage through the zona pellucida, the equatorial segment overlaid by its plasma membrane remained intact.Soon after penetration into the ooplasm, the sperm nucleus decondensed; at the same time, the female chromosomes resulting from the second meiotic division aggregated in a few masses of condensed chromatin. A nuclear envelope started to form around the condensed female chromatin, while it was not yet present around the decondensing male nucleus.After swelling, the two pronuclei presented similar ultrastructural morphology; they contained small, compact, agranular nucleoli with a large fibrillar center and unevenly distributed chromatin. The pronuclear envelope contained pores and presented characteristic blebbing. The endoplasmic reticulum was closely apposed to the nuclear envelope and large Golgi structures were proximal to the pronuclei.
Chloral hydrate effects on oogenesis in Marsilea vestita Hook. et Grev
Authors: Kermarrec Odette , Tourte Yves 
Published: February 2005

AbstractChloral hydrate [3.5 × 10−2 M] applied to archegonium of Marsilea vestila during oogenesis modifies the asymmetry of the gametic mitoses and the nuclear migrations. Multinucleate female gametes are obtained whose polarity is disturbed. At the ultrastructural level, the distribution of the organelles is changed profoundly. The ‘fertilization cone’ disappears, and there is increased vacuolation associated with myelin figures in the cytoplasm and the appearance of filament bundles. The nuclei also contain vacuoles and myelin figures.
Spontaneous oocyte maturation in Rana pipiens: Estrogen and follicle wall involvement
Authors: Lin Yu‐Wai Peter , Schuetz Allen W. 
Published: February 2005

AbstractImmature (germinal vesicle stage) Rana pipiens oocytes 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 maturation.
The kinetics of human sperm binding to the human zona pellucida and zona‐free hamster oocyte in vitro
Authors: Singer Sherry L. , Lambert Hovey , Overstreet James W. , Hanson Frederick W. , Yanagimachi Ryuzo 
Published: February 2005

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 (107 sperm/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 hamster oocytes.
Caproyl esterase from rat testis: Purification and action on cumulus cells
Authors: Waibel R. , Granet R. , Ficsor G. , Ginsberg L. 
Published: February 2005

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 mouse ova.
Further characterization of boar sperm plasma membrane proteins with affinity for the porcine zona pellucida
Authors: Peterson R. N. , Henry L. , Hunt W. , Saxena N. , Russell L. D. 
Published: February 2005

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 attachments.
“Spontaneous” hardening of the zona pellucida of mouse oocytes during in vitro culture. II. The effect of follicular fluid and glycosaminoglycans
Authors: De Felici M. , Salustri A. , Siracusa G. 
Published: February 2005

AbstractWe have previously reported that when isolated mouse oocytes are cultured in vitro their zonae pellucidae (ZP) become increasingly resistant to solubilization by chymotrypsin (“spontaneous” ZP hardening).In the present paper we report that follicular fluid contains factors that totally prevent such hardening. Furthermore, medium conditioned by granulosa cells partially prevents hardening.The protection against ZP hardening offered by follicular fluid may be ascribed, at least in part, to its content in sulfated glycosaminoglycans heparin and chondroitinsulfate B which, when added to the culture medium at physiological concentrations, show a marked antihardening effect.
Altered sex ratio of live young after transfer of fast‐ and slow‐developing mouse embryos
Authors: Tsunoda Y. , Tokunaga T. , Sugie T. 
Published: February 2005

AbstractWe cultured eight‐cell mouse embryos to blastocyst stage, divided them into three groups according to the time of blastocoel formation, and transferred them separately into recipients. The proportion of live young from the fast‐developing embryos was slightly high (49%) but not significantly different from those of other embryos (38% and 39%). However, the sex ratio of live young from the fast‐ and slow‐developing embryos was significantly shifted toward the male (71%) and to the female (80%), respectively.
The human pronuclear ovum: Fine strcture of monospermic and polyspermic fertilization in vitro
Authors: Sathananthan A. H. , Trounson A. O. 
Published: February 2005

AbstractThe fine structure of pronuclear ova (monospermy and polyspermy) and one‐cell embryos has been investigated in our IVF programme. Sixteen oocytes were collected at laparoscopy after appropriate hormonal stimulation and were matured and fertilized in vitro by methods that have given rise to normal pregnancies.Pronuclear ova showing monospermic fertilization had two vesicular pronuclei surrounded by aggregations of cellular organelles. The male pronucleus was closely associated with a sperm axoneme, while the female pronucleus was dismantling its envelope and condensing its chromatin ahead of its counterpart in late pronuclear ova. Each pronucleus had dispersed chromatin, dense compact nucleoli, and intranuclear annulate lamellae. Smooth endoplasmic reticulum, annulate lamellae, Golgi complexes, and mitochondria formed a conspicuous part of the perinuclear ooplasm. The one‐cell embryos were either in syngamy or in the process of undergoing first cleavage. Positive evidence of cortical granule release and second polar bodies were detected in the perivitelline space. A block to polyspermy seemed to operate at the level of the inner zona.Dispermic and polyspermic ova had 3–16 pronuclei resembling those of monospermic ova and had sperm tails in the ooplasm. Sperm were also seen penetrating the inner zona and were occasionally found in the perivitelline space. Incomplete cortical granule release and early signs of cytoplasmic fragmentation were noted in polyspermic ova.Both normal and abnormal features of these ova are reported and compared with pronuclear structure in vivo and in vitro.