摘要:

AbstractA sperm‐binding factor, which seems to have a primary role in binding sperm to the egg, was isolated from the egg surface ofHemicentrotus pulcherrimusand purified by monitoring the neutralization of the fertilization inhibition exerted by Fab fragments against crude sperm‐binding factor. An improved purification for this sperm‐binding factor is described in the present paper. The preparation of purified sperm‐binding factor revealed one major protein band with an apparent molecular weight of 61,000 after sodium dodecylsulfate‐polyacrylamide gel electrophoresis.A substance with the fertilization inhibitory effect on sperm, was isolated by diethylaminoethyl (DEAE)‐Sephadex column chromatography in the course of purification of the sperm‐binding factor and termed “sperm attack molecule.” One precipitin line was formed between the sperm attack molecule and anti‐crude sperm‐binding factor serum in a double‐immunodiffusion test. Fab fragments were prepared against partially purified sperm‐binding factor or sperm attack molecule, and the effect of these Fab fragments on eggs was investigated. Anti‐sperm‐binding factor Fab fragments inhibited the fertilizability of eggs, whereas anti‐sperm attack molecule fab fragments did not. However, anti‐sperm attack molecule Fab fragments impaired elevation of the vitelline layer. It is possible that the sperm attack molecule prevents polyspermy.Sperm attack molecule contains 3.7% neutral sugars. Its inhibitors effect

ISSN:0148-7280    

DOI:10.1002/mrd.1120180103

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

年代:1987

数据来源: WILEY

摘要:

AbstractIn a few mammals, the passage of maturing spermatozoa through the epididymis is characterized by development of persistent associations between one or more neighboring cells over the acrosomal region. The converse situation is described here in the loris,Nycticebus coucang, a prosimian primate. Loris spermatozoa released at spermiation enter the caput epididymidis as single cells and then become stacked in rouleaux of 2–8 spermatozoa there, the peri‐acrosomal plasmalemma of one being linked by a unique junctional complex to that of its neighbor. However, by the time the cauda is reached, all the spermatozoa have separated again to lie as single cells, which now display major aggregations of ordered material over the concave surface of the acrosome. The functional significance of these unusual sperm surface‐related phenomena in the loris epididymis is not

ISSN:0148-7280    

DOI:10.1002/mrd.1120180104

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

年代:1987

数据来源: WILEY

摘要:

AbstractIn this study, the chromosome constitution of both unfertilized oocytes and fertilized eggs isolated from the oviducts of LT/Sv strain mice were analyzed. Air‐dried chromosome preparations from unfertilized oocytes revealed that about one‐third of those examined were ovulated as primary oocytes. These were arrested at metaphase of the first meiotic division and exhibited the characteristic “tetrad” chromosome configuration. The remaining two‐thirds of the unfertilized oocytes were ovulated at metaphase of the second meiotic division. The fertilized eggs were isolated from the oviducts of LT/Sv females previously mated to (C57BL × CBA) F1 hybrid males. Analysis of the fertilized eggs at metaphase of their first cleavage mitosis revealed that about one‐third of the eggs examined were digynic triploids, whereas the remaining two‐thirds had the normal diploid chromsome constitution. In the triploids, the 40 female chromosomes present (mouse, n = 20) were derived from a single diploid pronucleus formed after the extrusion of a first polar body, and following the monospermic fertilization of primary oocytes. The female pronuclear‐derived chromosomes invariably exhibited “homologous pairing,” and these were associated at their centromeres. The ovulation, penetration, and subsequent fertilization of primary oocytes is an extremely unusual phenomenon in mammals and only appears to occur on a regular basis in LT/Sv mice. The premature “cytoplasmic maturation” of these oocytes is of interest, as they clearly have the same developmental capacity as secondary oocytes. The significance of these observations in relation to folliculogenesis and litter size in

ISSN:0148-7280    

DOI:10.1002/mrd.1120180105

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

年代:1987

数据来源: WILEY

摘要:

AbstractThe aim of this study has been the development of a noninvasive method of predicting the pregnancy potential of human oocytes and embryos intended for in vitro fertilization and embryo replacement. A multifactorial system which distinguishes, with a high degree of accuracy, between normal pregnancy, abnormal pregnancy, and non‐pregnancy‐producing embryos is reported. The variables included are (1) follicular fluid proteins alpha1‐antitrypsin, complement C3, immunoglobulin IgG2, and total protein, and total proteoglycan level separated by isoelectric focusing; (2) follicular volume; and (3) an embryo appearance rating. The study group consisted of (1) follicles which produced embryos of known performance after transfer (a) when the number of embryos transferred = the number of implantations and, (b) where one embryo transferred = no pregnancy; (2) follicles which produced oocytes which did not cleave after insemination; and (3) follicles from which no oocyte was aspirated. Canonical discriminant analysis of follicular fluid variables and follicular volume has been used to characterize the oocyte performance groups. Correct classification was achieved in 69% of normal pregnancy, 70% of abnormal pregnancy, 33% of no pregnancy, and 47% of no cleavage oocytes. An embryo appearance rating was included with the above variables for a separate discriminant analysis of only those oocytes which had formed embryos after insemination. Correct classification was achieved in 81% of normal‐pregnancy, 70% of abnormal‐pregnancy, and 70% of nopregnanc

ISSN:0148-7280    

DOI:10.1002/mrd.1120180106

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

年代:1987

数据来源: WILEY

摘要:

AbstractThe ability of morphologically abnormal mouse sperm to bind to the zona pellucida of the egg was examined with techniques of fertilization in vitro. After incubation with sperm, cumulus‐free ova were scored by either phase microscopy or scanning electron microscopy for the number and type of sperm bound. The percentages of abnormal sperm bound to zonae were compared to the percentages of abnormal sperm in the inseminating suspension. In general, all abnormal classes (except broadly spatulate sperm) bound to zonae at a frequency significantly lower than their representation in the inseminating suspension. However, when the percentage of abnormal sperm was quite high, no significant difference existed between frequencies of abnormal sperm bound and in the inseminating solution. The percentage of abnormal sperm bound did not increase significantly over time. Scanning electron microscopy studies demonstrated that the association of abnormal sperm with the zona pellucida varied according to sperm morphology. Normal and some abnormal sperm bound at an angle perpendicular to the zona, while more grossly abnormal sperm bound to ova tangentiall

ISSN:0148-7280    

DOI:10.1002/mrd.1120180107

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

年代:1987

数据来源: WILEY

摘要:

AbstractThe centrifugation of oocytes from the domestic species is a necessary prerequisite to allow visualization of nuclei for the introduction of foreign DNA. This improvement in visibility which has allowed the production of transgenic animals is accompanied by a clear stratification of the organelles. In immature oocytes from the sheep, pig, and cow, four distinct zones are formed. These comprise, lipid, membrane‐bound vesicles, organelle‐free cytoplasm, and mitochondria. In mature ovine oocytes, a fifth zone of smooth endoplasmic reticulum (SER) beneath that of the vesicles is formed. This SER is produced at discrete locations within the untreated cell. The potential for removal of these fractions has implications for relating patterns of protein synthesis with particular structural components.In intact oocytes, the cortical granules are located in a peripheral position beneath the plasma membrane. However, even after subjection to high centrifugal force (65,000g for 60 min), they maintain their original location. However, treatment with the cytoskeletal inhibitors, nocodozole and cytochalasin, results in rapid exocytosis after centrifugation. It is concluded that the maintenance of the spatial relationships of this organelle is mediated through the peripheral cytoskele

ISSN:0148-7280    

DOI:10.1002/mrd.1120180108

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

年代:1987

数据来源: WILEY

摘要:

AbstractThe acquisition of cytogenetic data from mammalian oocytes has required considerable time and expense, since only a relatively small number of oocytes could be processed from three to four animals daily. The availability of a procedure that would facilitate fixation and preparation of air‐dried slides from 25–30 superovulated mice within a 3‐h period would enhance development of germ cell cytogenetic data by reducing technician time and animal maintenance expense. We present such a procedure for mouse metaphase II oocytes. Mice were superovulated and the oocytes collected were fixed en masse prior to making air‐dried slides. Chromosomes were subsequently C‐banded to enhance objective cytogenetic analysis. The reliability of the procedure was determined by harvesting 44,814 oocytes from 1,875 mice over a 9‐month period and calculating the proportion of cells cytogenetically analyzed to those not analyzed. Cytogenetic analysis of oocytes is an assay for chemicals (and other agents) capable of inducing numerical and structural chromosomal

ISSN:0148-7280    

DOI:10.1002/mrd.1120180109

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

年代:1987

数据来源: WILEY

摘要:

AbstractCyclic AMP has been implicated as a regulator of capacitation, but the control of its metabolism in sperm remains obscure. A recent study of mouse sperm has shown capacitation‐related changes in the activities of both adenylate cyclase, which increased during incubation, and cyclic nucleotide phosphodiesterase, which decreased. The present study was conducted to extend these observations by measuring phosphodiesterase activity in sperm incubated in media with modified calcium and/or glucose content, conditions known to modulate fertilizing ability. Phosphodiesterase activity of sequential sperm samples, taken first when sperm are essentially uncapacitated and then when they are either partially or completely capacitated, decreased with time under all conditions, and in each case the greater fall in activity was seen in the medium that would support the greater change in fertilizing ability of the sperm population. Sperm washed by centrifugation to remove epididymal fluid also displayed a reduction in phosphodiesterase activity with time. The medium surrounding the sperm contained about half of the total phosphodiesterase activity, as well as 5′‐nucleotidase and adenosine deaminase. The crude enzyme preparation showed complex kinetic behavior when assayed over a range of cAMP concentrations, but the reduction in activity with time was seen at all substrate levels. The observed changes in phosphodiesterase activity, together with the increased adenylate cyclase activity seen under these sperm incubation conditions, would increase cAMP availability with time, thus providing further evidence for a fundamental role for cAMP in controlling the events of capacit

ISSN:0148-7280    

DOI:10.1002/mrd.1120180110

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

年代:1987

数据来源: WILEY

ISSN:0148-7280    

DOI:10.1002/mrd.1120180102

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

年代:1987

数据来源: WILEY