bluuebunny/crossref_metadata_2025_split huggingface dataset:
The motility of rabbit spermatozoa recovered from the female reproductive tract
Authors: Cooper G. W. , Overstreet J. W. , Katz D. F. 
Published: February 2005

AbstractThe motility of rabbit spermatozoa recovered from the vagina, endocervix, uterus, and four regions of the oviduct was assessed visually by phase‐contrast microscopy at intervals from one minute to 16 hours after a single mating. The percentage of motile cells in each sample was dependent on the temperature of recovery, ie, 23° vs 37°C, but was not influenced by the temperature of observation. Spermatozoa in the lower isthmus of the oviduct were the most temperature sensitive population to recovery at 23°C. When all manipulations and observations were performed at 37°C, the percentage of spermatozoa with progressive motility varied according to the region sampled and interval after mating. Populations from the vagina, uterus and upper regions of the oviduct usually had a high proportion of progressively motile cells with vigorous flagellar activity. Fewer spermatozoa showed progressive movement on recovery from the endocervix and lower 2 cm of the tubal isthmus and their flagellar activity was generally depressed. The decrease in flagellar beat frequency noted in the latter regions may be a major factor limiting sperm ascent in the female tract. A unique pattern of “activated” motility was seen exclusively in populations taken from the oviducts at 6 to 16 hours after mating. This motility pattern, consisting of alternating episodes of linear progressive and vigorous nonprogressive movement, may be analogous to the activated motility described for capacitated rodent spermatozoa.
Growth rate of oocytes in laboratory‐maintained Xenopus laevis
Authors: Keem Kirsten , Smith L. Dennis , Wallace Robin A. , Wolf Dennis 
Published: February 2005

AbstractWhen female Xenopus laevis are injected with [3H]‐vitellogenin or [14C] N‐acetyl glucosamine, most of the labeled material becomes associated three days later with oocytes having a diameter of 0.9–1.1 mm; smaller and larger oocytes are less labeled. With time, the pattern of labeling shifts to larger oocytes, indicating that those oocytes initially labeled continue to grow. We have measured such shifts as a function of time to provide estimates for oocyte growth rates from the end of stage III (diameter = 0.6 mm) to stage VI (diameter = 1.2 mm). The total time required for oocytes to progress through this size increase is 16–24 weeks in unstimulated females and 9–12 weeks in human chorionic gonadotropin (hCG)‐stimulated females. The fastest rate of growth occurs from mid‐stage IV (approximately 0.8 mm diameter) until midstage V (1.2 mm diameter), which corresponds to the period of most pronounced vitellogenin uptake. The relative proportion of oocytes within this size range is also reduced, as predicted under steady‐stage conditions. Evidence is also presented which indicates that the steady‐state level of full‐grown oocytes is maintained by a combination of replenishment and atresia. These results provide the first description of the kinetics of oocyte growth in X laevis females maintained under normal laboratory conditions and should be useful for any considerations of macromolecular events occurring during oogenesis.
High prolactin level and double spermatozoa
Authors: Baccetti B. , Fraioli F. , Paolucci D. , Selmi G. , Spera G. , Renieri T. 
Published: February 2005

AbstractIn a man with a pituitary prolactin‐secreting adenoma almost only double spermatozoa were produced. These cells were almost completely enveloped in a unique membrane, a common bilocular acrosome capped two paired nuclei, and all the other organelles were double. After 120 days of treatment with 2‐brom‐α‐ergocryptine the prolactin level was corrected, and only normal, single spermatozoa were produced. The authors suggest that a high prolactin level inhibits cell division.
The structural organization of sperm chromatin
Authors: Young R. J. , Sweeney K. 
Published: February 2005

AbstractThe structure of rabbit, fowl, and Xenopus laevis sperm chromatin was explored by study of the reaction of their decondensed nuclei with DNase 1 and micrococcal nuclease. Those of rabbit and fowl were readily digested by DNase 1, and the polyacrylamide gel electrophoresis profiles of DNAs extracted from the digests were similar, each being polydisperse with a single discrete band of DNA smaller than 72 base pairs. There were differences, however, between the sperm chromatins in the course of their digestion by micrococcal nuclease. A limit digest at about 45% acid solubility was obtained with Xenopus sperm chromatin, while 90% of fowl sperm DNA was rendered acidsoluble by the enzyme. The gel profiles of the limit digests were polydisperse, but only those of rabbit and fowl sperm chromatins possessed a discrete band of DNA smaller than 72 base pairs. Bleomycin did not react with DNA of rabbit, fowl, or Xenopus spermatozoa. Since bleomycin reacts with somatic cell chromatin, and the course of DNase 1 or micrococcal nuclease digestion of sperm chromatin was different from that found for somatic cell chromatin, it would appear that sperm chromatin does not have the repeating nucleosometype structure of somatic cell chromatin. The nuclease digestion studies further suggest that the organization of rabbit and fowl sperm chromatins is similar, and is different from that of Xenopus sperm chromatin. The dependence of the structure of sperm chromatin on the composition of its basic proteins, and a possible structure for a protamine‐type sperm chromatin, are discussed.
Fertilizability of cryopreserved zona‐free hamster ova
Authors: Fleming Alan D. , Yanagimachi Ryuzo , Yanagimachi Hiroko 
Published: February 2005

AbstractMature unfertilized ova from superovulated hamsters were freed from all investments and frozen at −50°C. They were cooled at about 1°C/min to 0°C then at 0.8° to 0.6°C/min to −50°C. At 0°C, dimethyl sulfoxide was added to a final concentration of 1.25 M. The ova were stored at −50°C for up to four months. Thawing was performed at 2–4°C/min and followed by several washes with insemination medium. Approximately 90% of the ova were normal in appearance after thawing. The frozen and thawed ova with normal appearance could be penetrated by hamster or human spermatozoa at a rate comparable to unfrozen controls. The ability of hamster ova to tolerate storage at a relatively convenient temperature (−50°C) for long periods (tested for up to four months) makes possible their shipment at low cost to institutions lacking this resource. There they can be used for basic biological studies of sperm–egg interaction or in the clinical assessment of human sperm quality.
Fragmentation of condensed chromatin in nuclei of a plant sperm, pteridium aquilinum (L.) Kuhn
Authors: Wakeford R. J. , Bell P. R. 
Published: February 2005

AbstractNuclei of pteridium sperm have been dispersed by turbulence in natural or slightly alkaline buffer after stripping off the cytoplasm with nonionic detergent. The nuclei tended to break up into fragments arranged in a linear order. These fragments fluoresced brightly with acridine orange as did intact nuclei. Grounds are given for identifying the smaller fragments with chromosomes. It is proposed that the sperm nucleus of British Pteridium, possibly an autotetrapolid, consists of a sequence of paired homologues.
Genetic influences on mouse sperm capacitation in vivo and in vitro
Authors: Hoppe P. C. 
Published: February 2005

AbstractIntial in vivo studies were performed to observe the proportion of eggs fertillized at specific intervals after natural mating and ovulation in our research mouse colony. Proestrous females of the C57BL/10Wt, SJL/Wt inbred strains and the F1 hybrid cross (B10 × SJL or reciprocals) were paired in the after‐noon with males of their respective strain and examined for vaginal plugs at the midpoint of the dark period (2400 hours). Oviducts were periodically collected from mated females, and ovulation was first observed at 4, 5.2, and 3 hours after 2400 hours in the B10, SJL, and F1 hyrid, respectively. The clutch of eggs from each ovulating female, was placed in culture, and cleavage oviduct lavage verifying female mating was placed in culture, and cleavage was used as the criterion for fertilizaition. Fifty percent of the eggs were fertilized 2.2, 5.0, and 2.5 hours after ovulation in B10, SJL, and F1 hybrid females, respectively. Because twice the legth of time was required to fertilize a similar proportion of eggs from the SJL strain as the F1 hybrid, these two strains were used for determining their rate of fertilization under more fully controlled conditions in vitro. Forty‐nine percent of F1 hybrid eggs were fertilized after 4 hours incubation with SJL epididymal sperm, whereas 53% fo SJL and 56% of F1 hybrid eggs were fertilized after only 2 hours incubation with F1 hybrid epididymal sperm. Thus, using sperm from these two mouse strains, the amount of time required to fertilize approximately 50% of the eggs within a clutch both in vivo and vitro was very similar. These observations demonstrte teh validity of using this in vitro system for fertilization studies and confirm that the temporal events in sperm capacitation and egg penetration are dependent on the genotype of the sperm. Similarities in fertilization rates at specific times after ovulation or insemination in vitro imply that the initiationof sperm capacitation in vivo occurs near the time of ovulation and several hours after mating. We tentatively suggest that follicular fluid may be required for completion of mouse sperm capacitaiton in vivo.
Decondensation of sperm nuclei of australian marsupials: Effects of air drying and of calcium and magnesium
Authors: Cummins J. M. 
Published: February 2005

AbstractSpermatozoa of six species of Australian marsupials have been studied. The nucleus is highly unstable when compared with those of eutherian mammals. When thin films of spermatozoa in buffered saline are air‐dried on glass slides, the nucleus disintegrates and flattens, leaving the acrosome, midpiece, and tail intact. This spreading of the nucleus can be inhibited by seminal plasma proteins and by bovine serum albumin, but is potentiated by detergents. The nucleus also decondenses spontaneously in the presence of high concentrations (>0.25M) of calcium and magnesium salts, leaving the head membranes, acrosome, midpiece, and tail intact. This is inhibited by EDTA. In some species, certain areas of the nucleus appear more resistant t o Ca++/Mg++ treatment, and the initial stages of decondensation are uneven. Ultrastructurally the Ca++/Mg++ dispersed chromatin shows a moderately fine, branching, fibrillar structure, interspersed with dense granules. Treatment with disulphide bond cleaving agents together with detergents results in rapid and complete dispersal of the chromatin and acrosome, and slow digestion of midpiece and tail structures. Treatment with HCl, NaCl, KCl, EDTA, detergents, and sucrose has no effect on nuclear integrity, but treatment with NaOH (0.9–1.0M) results in complete digestion of the whole sperm. These findings are discussed in the light of evolutionary differences between marsupial and eutherian mammals in terms of sperm structure and composition.
An automated procedure to measure DNA synthesis in preimplantation mouse embryos
Authors: Cozad Karen M. , Verbanac Kathryn M. , Goldbard Simon B. , Warner Carol M. 
Published: February 2005

AbstractThis paper describes a sensitive, reproducible, and automated procedure to measure DNA synthesis in preimplantation mouse embryos. Conditions for the DNA synthesis assay have been optimized as follows: (1) 4 μCi/ml3H‐thymidine (sp. act. 20 Ci/immole); (2) a labeling period from 2 to 7 hours; (3) a 3‐hour preincubation period for blastocysts and from 0 to 7 hours preincubation for 8‐cell embryos; and (4) from 1 to 64 embryos per assay. The amount of DNA synthesis per embryo was found to be directly proportional to the number of cells (nuclei) per embryo. The described assay should be useful for future studies on the effect of synthetic and natural compounds on the development of preimplantation mouse embryos, as measured by perturbations in embryonic DNA synthetic activity.
Temperature dependence of capacitation in bat sperm monitored by zona‐free hamster ova
Authors: Lambert Hovey 
Published: February 2005

AbstractThe temperature dependence of capacitation in bat sperm (Myotis lucifugus lucifugus) was studied by monitoring fertilizations rates of zona‐free hamster ova at different temperatures. Spermatozoa were cultured in BWW medium at temperatures 4°C, 24°C, 32°C, 42°C, and 55°C from 0–24 hr. Activation of sperm could be determined visually due to the change in movement seen through light microscopy. Activation was later confirmed by higher rates of fertilization. Preincubation of the bat sperm was found to have a direct effect on the success of penetration of the zona‐free hamster ova. Holding bat spermatozoa at low temperature for long intervals allowed them to remain motile but unable to fertilize. Sperm are not irreversibly damaged, however, and activation, when the temperature is increased to 32°C, is faster than when sperm are intitially put at 32°C, resulting in good fertilization rates.
Inhibition of starfish oocyte maturation by some inhibitors of proteolytic enzymes
Authors: Kishimoto Takeo , Clark Theodore G. , Kondo Hisayo K. , Shirai Hiroko , Kanatani Haruo 
Published: February 2005

AbstractStarfish oocyte maturation is triggered by a natural hormone, 1‐methyladenine (1‐MeAde), produced in the follicle cells, or artificially by dithiothreitol (DTT). These substances act on the oocyte surface to produce a cytoplasmic maturation‐promoting factor (MPF), which induces germinal vesicle breakdown (GVBD) and subsequent processes of meiotic maturation. Further, MPF is amplified in immature oocytes that have received the injection of MPF. In this paper the effect of leupeptin and antipain, protease inhibitors of microbial origin, on starfish oocyte maturation was investigated. The protease inhibitors were found to inhibit 1‐MeAde‐induced maturation when they were applied externally or injected into oocytes. DTT‐induced maturation was also inhibited by injection of leupeptin. However, leupeptin did not inhibit the maturation‐inducing action of MPF or MPF amplification. These results show that the protease inhibitors suppress the production of MPF by 1‐MeAde or DTT, suggesting that some endogenous protease(s) acts in the production of MPF.
Fertilization of cumulus‐free, zona‐intact mouse ova in vitro at high and low sperm concentrations
Authors: Stanger J. D. , Quinn P. 
Published: February 2005

AbstractThe effect of varying the sperm concentration between 2 × 105 sperm/ml and 8 × 106 sperm/ml on fertilization of cumulus‐free, zona‐intact F1 (CBA × C57BL) mouse ova by QS and F1 (CBA × C57BL) mouse spermatozoa was studied. The spermatozoa from both strains of mice exhibited optimal fertilization rates at 2 × 106 sperm/ml. However, at sperm concentrations greater than 4 × 106 sperm/ml and less than 1 × 106 sperm/ml, fertilization rates were significantly reduced. F1 spermatozoa were more susceptible to dilution than QS spermatozoa. A significant interaction between strain and sperm concentration indicated that the two strains produced different fertilization rates at different sperm densities.Extracts of epididymal fluid, medium from capacitated spermatozoa, or ampulla fluid did not improve the fertilization rate at 2 × 105 sperm/ml, but retaining the cumulus oophorus did. The decrease in fertilization rate at 8 × 106 sperm/ml can in part be attributed to a nondialysable inhibitor from the neat sperm preparation that appeared to be of epididymal origin.
Evidence for acrosin‐like enzyme in sperm extract and its involvement in fertilization of the ascidian, halocynthia roretzi
Authors: Sawada Hitoshi , Yokosawa Hideyoshi , Ishii Shin‐Ichi , Hoshi Motonori 
Published: February 2005

AbstractThe presence of a protease has been demonstrated in sperm of the solitary ascidian, Halocynthia roretzi, by using t‐butyloxycarbonyl‐L‐Val‐L‐Pro‐L‐Arg‐4‐methylcoumaryl‐7‐amide (Boc‐Val‐Pro‐Arg‐MCA) and other arginyl or lysyl MCA derivatives as substrates. Several properties of the enzyme were investigated in a crude extract. The activity had a pH optimum near 8.0 and was enhanced by the addition of CaCl2. The Km value of 87μM was determined for Boc‐Val‐Pro‐Arg‐MCA under the optimal conditions. An apparent molecular weight was estimated to be 35,000 by gel filtration. The enzyme was inhibited with diisopropyl fluorophosphate, leupeptin, antipain, p‐aminobenzamidine, Val‐Pro‐Arg‐CH2Cl, and soybean trypsin inhibitor, but scarcely inhibited with chymostatin, elastatinal, p‐chloromercuribenzoic acid, tosyl‐Lys‐CH2Cl, and tosyl‐Phe‐CH2Cl. Boc‐Val‐Pro‐Arg‐MCA, the most susceptible of the substrates examined, showed the most effective inhibition against fertilization of ascidian eggs.Thus, this enzyme in ascidian sperm extract has features closely similar to mammalian acrosin [EC 3.4.21.10], and we conclude that the enzyme is involved in fertilization as one of the lysins.
Ultrastructure of the biflagellate spermatozoon of tomopteris helgolandica greef, 1879 (annelida, polychaeta)
Authors: Franzén Åke 
Published: February 2005

AbstractThe spermatozoon of the polychaete Tomopteris helgolandica is of an aberrant type with two flagella, each measuring about 40μm. The nucleus is roughly conical and weakly bent. At the anterior end it is rounded and covered only by the nuclear and plasma membranes. Membraneous, electron‐dense structures are applied laterally to the nucleus. These structures may have a helical arrangement. The middle piece contains about ten mitochondria, two centrioles, and two centriolar satellite complexes. The centriolar regions are connected with the posterior part of the nucleus. The axonemes of the two tail flagella lack the usual central complex with central tubules, radial spokes, or related structures. No arms seem to be present on the A tubules of the doublets. In the middle piece the tail flagella are surrounded by invaginations of the plasma membrane forming flagellar canals. The sperm has a bilateral symmetry whereas the primitive sperm has a radial symmetry. The occurrence of two tail flagella in this spermatozoon has no phylogenetical connection with biflagellate spermatozoa in other animal groups. A series of mutations has resulted in the development of two flagella emerging from the two centrioles, the lack of a central complex in the axoneme, and the lack of a typical acrosome. In the Polychaeta, sperm structure is generally more related to function that to phylogenetics. During swimming the spermatozoon of Tomopteris rotates around its longitudinal axis.
Ultrastructure of cortical granule release and zona interaction in monospermic and polyspermic human ova fertilized in vitro
Authors: Sathananthan A. H. , Trounson A. O. 
Published: February 2005

AbstractCortical granule release and interaction with the zona pellucida are reported in monospermic and polyspermic fertilized ova and early human embryos cultured in vitro.Twenty‐seven preovulatory oocytes from women with tubal or idiopathic infertility were recovered by laparoscopy, after induction of follicular maturation with clomid and human chorionic gonadotropin. These were then inseminated with husband's or donor sperm, cultured for 3–72 hr, routinely fixed in glutaraldehyde/osmium and examined ultrastructurally.Evidence of cortical granule release was observed in all ova and embryos investigated and their contents were identified either at the egg surface or in the perivitelline space or interacting with the inner zona, apparently reinforcing its structure. The latter is very likely the morphological expression of the zona reaction.Delayed release was seen in certain regions of normally fertilized ova and particularly in polyspermic ova, where massive “explosions” of granules occurred. This was attributed to delayed cortical maturation. The mechanics of release were similar in both monospermic and polyspermic ova. Spontaneous dehiscence was also described in one injured unfertilized oocyte.The significance of the cortical and zona reactions as an effective block to polyspermy at the level of the inner zona, which becomes more impenetrable to supplementary sperm, is discussed.
Evidence against a (2)n synchronous increase of spermatogonia to produce spermatocytes in drosophila hydei
Authors: Hanna Peter J. , Liebrich Winfrid , Hess Oswald 
Published: February 2005

AbstractThe numbers of primary spermatocytes within cysts as well as numbers of postmeiotic spermatids in bundles in Drosophila hydei were determined. Within the contents of a single testis the cysts of primary spermatocytes are found to contain 5–11 germ cells. Furthermore, the number of spermatocytes per cyst is age‐dependent, in that pupae have a mean of 8.1 cells whereas fertile adult males have a mean of 7.1 cells. Counts of spermatids in section of testes add further support to the view that the primary spermatocytes, from which the spermatids originated, were not formed in a strict geometric progression.
Metabolism of lipid and carbohydrate in sea urchin spermatozoa
Authors: Mita Masatoshi , Yasumasu Ikuo 
Published: February 2005

AbstractWhen the dry sperm of the sea urchin, Hemicentrotus pulcherrimus, were diluted 100 times in artificial sea water at 0°C and at 20°C, they became motile and the levels of ATP and creatine phosphate decreased rapidly. The level of ADP hardly changed, and the AMP level increased after the dilution. After the dilution, the respiratory rate at 2°C was almost one fifth that of 20°C. Both phospholipid and glycogen were used for the energy sources in sea urchin sperm. The level of phospholipid was 10‐fold higher than that of glycogen in the dry sperm. The phospholipid level decreased after dilution at 20°C, though the level hardly changed at 0°C, suggesting that phospholipid was hardly metabolized the lower temperature. The level of α ‐glycerophosphate increased at 20°C after the dilution but did not change at 0°C. The level of glycogen decreased after the dilution, regardless of the temperature. The glycolysis was also activated after the dilution. Of the intermediates of the tricarboxylic acid cycle, the citrate concentration increased at 0°C and the malate concentration also increased at 0°C and especially strongly at 20°C.
Changes in cAMP‐dependent protein kinase activity in the 10,000g sediment of sea urchin embryos during early development
Authors: Fujino Yukio , Yasumasu Ikuo 
Published: February 2005

AbstractcAMP‐dependent protein kinase was found in the sediment obtained by centrifuging a homogenate of sea urchin embryos at 10,000g for 20 min, and was solubilized with 1% Triton X‐100. This enzyme was eluted at 0.16 M NaCl in a linear concentration gradient on a DEAE‐cellulose column, at which cAMP‐dependent protein kinase found in the supernatant was also eluted. The enzyme activity was enhanced about 1.5‐fold in the presence of 1 μM cAMP, and increased somewhat by adding cGMP or cIMP. The activation by cAMP of protein kinase in the sedimentable fraction was lower than in the supernatant fraction. The properties of the enzyme found in the 10,000g sediment and in the supernatant differ somewhat. The activity of the cAMP‐dependent protein kinase in the 10,000g sediment was high in the embryos at the blastula, the swimming blastula, and the mesenchyme blastula stages. On the other hand, the activity was undetectable in unfertilized eggs and in embryos at the morula, the gastrula, and the pluteus stages.