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P Gaddum-Rosse

Publications and source records attributed to P Gaddum-Rosse.

At least 19 recordsLinked to original sources
PubMed1987

Influence of the calcium ionophore A23187 on rat egg behavior and cortical F-actin.

Rat eggs treated with the calcium ionophore A23187 and subjected to long-term observation by phase microscopy were found to undergo many developmental changes that are normally associated with fertilization. These included cortical granule exocytosis and the abstriction of the second polar body. In addition, time-lapse video microscopy revealed that, unlike untreated eggs, whose surfaces remained relatively immotile, the ionophore-treated eggs underwent a lengthy period of surface undulatory activity. Since all of these events were remarkably similar in timing and morphology to those seen in fertilized eggs, we conclude that A23187 is capable of activating rat eggs. Using NBD-phallacidin, the distribution of F-actin in ionophore-activated eggs was determined. During most of the postactivation period the eggs possessed an uninterrupted, uniform band of polymerized actin encompassing the entire cortex of the egg. However, during a discrete 1.5-h period after the formation of the second polar body, an area adjacent to the region of polar body abstriction exhibited more intense staining than the rest of the cortex. Cytochalasin B treatment caused a dramatic reduction and/or rearrangement in cortical NBD-phallacidin staining in activated eggs as compared to activated controls not exposed to the drug. We observed that all the developmental changes described above could be produced in the absence of exogenous calcium, suggesting that the rat egg possesses internal stores of calcium sufficient to elicit an activational response. We conclude that the ionophore-induced release of free calcium ions into the cytosol stimulates many of the developmental changes that are normally seen during fertilization. These results indicate that calcium influx and cytoskeletal activity are correlated during the activation of this animal egg.

Actins↗
PubMed1986

The distribution of polymerized actin in the rat egg and its sensitivity to cytochalasin B during fertilization.

The distribution of polymerized actin in rat eggs fertilized in vitro was determined using NBD-phallacidin (NBD-ph). Unfertilized and fertilized eggs exhibited a 3-5-micron-thick band of fluorescence that encompassed the entire cortical cytoplasm. There was no dramatic increase in the staining of the cortex in association with any component of the fertilizing sperm during its incorporation into the egg. Unfertilized eggs and fertilized eggs obtained at intervals after sperm-egg fusion were treated with cytochalasin B (CB; 5 micrograms/ml) and subsequently stained with NBD-ph. Unfertilized eggs treated with CB exhibited a continuous ring of cortical staining identical to that seen in untreated eggs. Eggs treated with CB 15 min after sperm-egg fusion exhibited small gaps in the cortical staining pattern, whereas those exposed to CB 1 hr after fusion exhibited larger gaps and the staining pattern appeared punctate. This pattern could be seen throughout the remainder of the 7 hr period of sperm incorporation and for at least 13 hr thereafter. CB-treated fertilized eggs that were washed to remove the drug again exhibited uninterrupted cortical staining on treatment with NBD-ph. CB also induced the resorption of surface elevations that are normally seen on the eggs during sperm incorporation, but it did not affect the morphology of unfertilized eggs. The sensitivity to CB during fertilization coincides with the onset of a variety of egg shape changes that occur during the period of sperm incorporation (Battaglia and Gaddum-Rosse, Gamete Res., 10:107-118, 1984a).(ABSTRACT TRUNCATED AT 250 WORDS)

Actins↗
PubMed1985

Mammalian gamete interactions: what can be gained from observations on living eggs?

Studies on fertilization have involved a variety of investigational techniques from the simple to the very complex. Perhaps the most direct approach has been the observation and photographic recording of the interactions of living gametes in vitro. The purpose of this paper is to review the major contributions that have been made, by means of this technique, to our knowledge of mammalian fertilization, and to examine its advantages and limitations. Some of the events of mammalian fertilization that have been observed in living eggs and are reviewed herein include sperm penetration through the zona pellucida, contact of the fertilizing spermatozoon with the oocyte surface and the subsequent incorporation of the sperm head into the oocyte cytoplasm, the formation and disappearance of the incorporation cone, the gradual incorporation of the sperm flagellum, surface movements of the oocyte after activation, and the formation of the second polar body. One advantage of studying living eggs is the opportunity it affords to witness events as they actually occur and, under favorable circumstances, to observe the whole series of events in individual eggs. Only by this mechanism can certain features of the process be fully appreciated and accurate data obtained on the timing of events. With the addition of time-lapse photographic methods, some of the more subtle changes become more amenable to study. Among the limitations of the technique are its limited resolution and the necessity for examining the gametes outside their normal in vivo environment.

Animals↗
PubMed1984

In vitro fertilization in the rat: observations on living eggs.

The purpose of this study was to observe and record some of the key events during in vitro fertilization in the rat. Freshly ovulated eggs were incubated with epididymal spermatozoa at 37 degrees C and removed 4.5 to 7.5 hours later for microscopic examination. The head of the fertilizing spermatozoon penetrated the zona pellucida with its long axis perpendicular to the zona: this orientation was maintained during subsequent incorporation into the vitellus. Sperm motility was drastically reduced soon after sperm-egg fusion. Simultaneously, the flagellum, most of which was still outside the zona, assumed a characteristic curved posture. Time-lapse cinematography demonstrated that the vitellus frequently underwent surface movements during the tail incorporation process, suggesting that its cortex was undergoing significant changes. This study presents the first long-term observations on the fertilization of living rat eggs in vitro.

Animals↗
PubMed1983

Secretory cells of the oviduct of the pig-tailed monkey, Macaca nemestrina, during the menstrual cycle and after estrogen treatment.

The secretory cells of the oviductal epithelium in the pig-tailed monkey, Macaca nemestrina, have been studied by light and electron microscopy. Changes during the menstrual cycle and after ovariectomy, with and without subsequent estrogen treatment, have been documented. During the early follicular phase the epithelium is recovering from deciliation and secretory cell atrophy that occur in the late luteal phase. A few fimbrial and a moderate number of ampullar and isthmic cells contain a few electron-dense, homogeneous secretory granules in their apical cytoplasm. During the late preovulatory and early post-ovulatory periods, secretory cell structure varies considerably. Fimbrial cells typically display apical protrusions that contain no or a few small, mainly homogeneous, secretory granules. The cytoplasm is crowded with elements of the Golgi complex, with granular endoplasmic reticulum profiles often intimately associated with mitochondria, and with variable numbers of polysomes and glycogen granules. In ampullar and isthmic cells secretory granules are more abundant than in fimbrial cells, and electron-lucent vacuoles appear. The granules are of two types: 1) those having an electron-dense, homogeneous matrix, and 2) those possessing lamellar structures within moderately dense matrices. The lamellae of the second type course in parallel arrays separated by a distance of approximately 15.5 nm and exhibit a periodicity of approximately 11.3 nm. Possible transitional stages between the lamellar granules and the vacuoles containing lamellar fragments are observed. Secretion occurs by exocytosis. During the late luteal phase no fimbrial cells have secretory granules. In the ampulla many of the cells have poor development of the organelles involved in secretory activity and have few or no secretory granules. In others, a moderate number of secretory granules are present; in one animal, exocytosis is observed. In the untreated ovariectomized animal no secretory granules occur, and the organelle content is much less than in the cycling and the estrogen-treated monkeys. In ovariectomized, estradiol-treated monkeys, some areas of all three oviductal segments are well stimulated whereas others display little or no secretory activity.

Animals↗
PubMed1982

Laser light-scattering study of the effect of washing on sperm motility.

The effect of washing on human sperm motility was measured by means of dynamic laser light-scattering spectroscopy. Semen samples from 24 fertile donors were diluted with Biggers, Whitten and Whittingham (BWW) medium and subsequently centrifuged at one of the following forces: 235 x g, 325 x g, 400 x g, 470 x g, 500 x g, 600 x g, and 800 x g. The duration of centrifugation was 8 minutes for the first wash, 6 minutes for the second wash, and 3 minutes for the third wash. Sperm motility was evaluated in terms of the root mean square swimming speed of the spermatozoa and the mean migration rate of washed spermatozoa in estrous bovine cervical mucus (BCM). It was found that sperm motility and viability were improved when semen samples were washed at 235 x g, even after three washes. However, washing at forces of 600 x g or more reduced sperm motility and also their ability to penetrate cervical mucus in vitro. Repeated washing at forces between 300 x g and 500 x g had little deleterious effect on sperm motility.

Cell Separation↗
PubMed1981

Some observations on sperm transport through the uterotubal junction of the rat.

Entry of spermatozoa into the oviducts of mammals is restricted by the uterotubal junctions. The extent to which these junctions act as selective valves, or filters, for sperm transport has not been determined. A new technique has been developed that permits the direct visualization of sperm transport through the uterotubal junction of the rat in vitro. After mating or artificial insemination, the female tract is removed to a special "observation dish" containing oxygenated Earle's solution maintained at 37 degrees C. The oviducts are severed 1.0 - 1.5 mm above the uterotubal junctions. Under appropriate magnification and with oblique transillumination, spermatozoa may be observed emerging from the cut ends. It was noted that only motile spermatozoa emerged and that they usually appeared individually, with an interval of several minutes between each. Their egress was not directly related to contractions of the uterine cornu. Neither immotile spermatozoa nor a dye solution were observed to pass through the uterotubal junction. It is concluded that sperm motility is important, and probably essential, for sperm entry into the oviducts in the rat. Scanning electron microscopy revealed that the rat uterotubal junction forms a small mound or papilla projecting into the uterine cavity. No ciliated cells were observed in this region.

Animals↗
PubMed1981

Sperm penetration into cervical mucus in vitro. III. Effect of freezing on estrous bovine cervical mucus.

The influence of the storages period on estrous bovine cervical mucus after it was stored in the freezing compartment of the laboratory refrigerator was evaluated by an in vitro sperm penetration test with human spermatozoa, laser light-scattering, and a spinnbarkeit test. Data obtained from the sperm penetration test were analyzed by a mathematical model that correlates the sperm motility with the sperm transport rate and the penetrability of the mucus. The tests showed that estrous bovine cervical mucus can be stored for up to 4 weeks at -12 degrees C without a change in its physical properties. The results of this study strengthen the suggestion that bovine mucus could be employed as a substitute for human cervical mucus.

Animals↗
PubMed1980

Cyclic variations in the oviuductal ciliated cells during the menstrual cycle and after estrogen treatment in the pig-tailed monkey, Macaca nemestrina.

The epithelium of the oviduct of the pig-tailed monkey, Macaca nemestrina was studied 1) to determine whether quantitative changes in the number of ciliated, deciliated, reciliating and nonciliated cells occur during the menstrual cycle and under certain experimental conditions and 2) to describe the ultrastructure of the ciliated and ciliogenic cells. The mean percentage of ciliated cells decreased from 48.2 in the fimbriae and 48.3 in the ampullae in the postovulatory stage to 7.7 and 18.8, respectively in the late luteal phase; these changes are significant as determined by Duncan's multiple range test. In the early follicular phase 3.9% of the cells in the fimbriae and 11.2% in the ampullae are ciliated, and the number of ciliogenic (deciliated and reciliating) cells is the highest of any time in the cycle in both the fimbrial (6.3%) and ampullar (8.4%) epithelium. In contrast, although the percentage of ciliated cells in the isthmus varies from 44.4 in the preovulatory phase to 34.3 in the early follicular phase, the differences between the various times in the cycle are not significant. However, in the late luteal phase, the values for the fimbriae and ampullae are significantly different from that of the isthmi. Ciliated cells constitute less than 1% of both the fimbrial and ampullar epithelium 2 3/4 years after ovariectomy, but 16.7 in the isthmic tissue. In ovariectomized monkeys treated for 7 or 12 days with estradiol benzoate reciliation occurs, but to a significantly lesser extent in the fimbriae and ampullae than in the pre- or postovulatory animals; the degree of reciliation in the isthmus is not different from the values noted during the cycle. The ultrastructure of ciliated, deciliated and reciliating cells is described. Of much interest is the finding of cytoplasmic protrusions containing variable numbers of ciliary axonemal complexes. It is postulated that such internalization of ciliary micotubules may represent one way in which deciliation may be accomplished.

Animals↗
PubMed1980

Sperm penetration into cervical mucus in vitro. II. Human spermatozoa in bovine mucus.

Human spermatozoa pentrate estrous bovine cervical mucus readily in vitro and maintain good motility and viability for a number of hours. They show pronounced unidirectional motion in mucus that has been aligned linearly. Data from tube preparations indicate that human spermatozoa from a given ejaculate travel more rapidly in estrous bovine mucus than in human midcyle mucus. They are prevented from penetrating luteal phase bovine mucus. The results are discussed in relation to a model of the molecular structure of cervical mucus, derived from laser light-scattering spectroscopy. In addition, it is suggested that bovine cervical mucus could be developed as a possible substitute for human cervical mucus in cases of infertility due to deficient endogenous mucus.

Animals↗
PubMed1980

Sperm penetration into cervical mucus in vitro. I. Comparative studies.

Comparative studies have been carried out on the behavior of human and bovine spermatozoa toward homologous cervical mucus in vitro. In both cases the degree of sperm penetration and the pattern of sperm motility were influenced in a characteristic fashion by prior manipulation of the mucus: the most rapid and extensive penetration, and pronounced unidirectional motion, were seen in mucus that had been aligned linearly. By contrast, spermatozoa from rabbits, guinea pigs, rats, and mice were largely prevented from entering either midcycle human or estrous bovine cervical mucus, regardless of its physical arrangement. The observations on sperm motility patterns and the degree of penetration are discussed in relation to a model of the molecular arrangement of cervical mucus, derived in our laboratory from laser light-scattering spectroscopy.

Animals↗
PubMed1977

Proteolytic activity of guinea pig spermatozoa after induction of the acrosomal reaction in vitro.

After inducing the acrosomal reaction in guinea pig spermatozoa in vitro, the sperm were tested for proteolytic activity by applying them to membranes of fixed gelatin. One to 5% of them showed slight evidence of proteolytic activity, while the rest were completely negative. Sperm that had retained their acrosomes throughout the incubation period displayed intense proteolytic activity. These results suggest that proteinases may be lost from spermatozoa as a result of the acrosomal reaction.

Acrosome↗
PubMed1977

Molecular arrangement of cervical mucus: a reevaluation based on laser light-scattering spectroscopy.

Evidence obtained from laser light-scattering spectroscopy suggests that the molecular arrangement of cow estrous cervical mucus is an ensemble of entangled random-coiled macromolecules rather than a cross-linked macromolecular network, the model heretofore widely accepted. This new model can account for the following phenomena: (1) The viscoelastic properties of the estrous mucus and human mid-cycle cervical mucus are the result of the way in which the glycoproteins are entangled. Variations of these properties during the reproductive cycle may simply be due to changes in the water content of the cervical mucus. (2) Penetration of spermatozoa in mucus may be entirely mechanical without involving any kind of enzymatic lysis of cross-links (this is supported by changes in the pattern of spermatozoa flagellation during sperm penetration of cervical mucus as shown in motion picture films). (3) The orientation of spermatozoa in the cervical muscus need not be due to the presence of 'channels' between micelles but simply to an artifact, the stretching or flow of the mucus, which orients the entangled macromolecules and thus facilitates the penetration of spermatozoa in an axis parallel to them.

Animals↗
PubMed1975

Studies on the mucosa of postmenopausal oviducts: surface appearance, ciliary activity, and the effect of estrogen treatment.

The epithelial lining of the human oviduct is known to be responsive to the fluctuating hormonal levels of the normal menstrual cycle, but its response to the changes in hormonal climate at the time of the menopause is not clearly defined. In this study the oviducts of nine postmenopausal patients were obtained at the time of abdominal hysterectomy, and the lining epithelium was studied by scanning electron microscopy. The activity of cilia on the fresh tissue was assessed by their ability to transport particulate matter applied to the epithelial surface. The fimbriae of oviducts from women who had received little or no estrogen treatment before surgery showed a significant deciliation of the epithelium, compared with specimens from premenopausal patients, and even showed some sloughing of cells from the surface. The secretory cells appeared inactive. However, the specimens from patients who had been treated with estrogen for periods of 1 year or more showed a remarkable maintenance of the epithelium, with the proportion of ciliated cells remaining almost as high as in premenopausal oviducts, even as late as 25 years after the menopause. The ampullar and isthmic portions showed less obvious changes. Cilia in oviducts from the former group (short-term or no treatment) were incapable of transporting 15-mum microspheres or lycopodium spores applied to the epithelial surface, whereas the oviductal cilia obtained from patients under long-term estrogen therapy showed efficient transport of particulate matter. The results are discussed in relation to earlier conflicting reports on the postmenopausal oviduct.

Adult↗