摘要:

AbstractWe have examined the formation of the egg attachment stalk in the lobstersHomarus americanusandH. gammarus. The formation of the stalk is similar in both species. Ovulated oocytes are surrounded by a single coat, envelope 1, composed of layers 1A and 1B. After passage through the gonopore and exposure to sea water, envelope 1 swells and becomes sticky. A second coat, envelope 2, forms between the oocyte and envelope 1 during a complex cortical reaction initiated after fertilization. Eggs pass over the ventral surface of spawning females to the region of the pleopods, where they stick by means of layer 1A to each other and to the ovigerous setae. Layers 1A and 1B are soft and pliable at this time. During egg attachment, the pleopods beat vigorously and cause envelope 1 to stretch and form attachment stalks. Beating probably also causes the attachment stalks to twist and wrap around the ovigerous setae. After the egg mass is secured to the ovigerous setae, envelope 1 of both the attachment stalk and egg coat condenses to form a tough material capable of securing the egg mass to the pleopods for intervals up to 16 months. After larvae hatch, portions of the egg coats and the attachment stalks are retained on the ovigerous setae until the female undergoes her next molt.

ISSN:0148-7280    

DOI:10.1002/mrd.1120180402

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

年代:1987

数据来源: WILEY

摘要:

AbstractUsing mice as subjects, we investigated the effects of indomethacin (ID) on follicle rupture and nuclear maturation, and studied the fertilizability of ova retained in the follicles as a result of ovulation inhibition by ID.Ten units each of PMSG and hCG were administered intraperitoneally to mice at 56‐hr intervals to induce superovulation. ID was administered 90 min after hCG injection. The ova recovered from the oviduct 17 hr after hCG injection numbered 32.2 ± 7.8, 16.9 ± 5.8, 5.6 ± 2.9, and 1.0 ± 1.3 for mice receiving 0, 0.5, 1.0, and 2.0 mg ID, respectively, demonstrating dose‐dependent inhibition of ovulation. Ten hours after hCG administration, the intrafollicular ova that had matured to metaphase second stage comprised 43% in both groups.The fertilization rate (73.7%, 56/76) for the follicle‐retained eggs in the 2 mg ID mice was similar to that for controls (72.9%, 62/85). Essentially the same results were seen with respect to efficacy of ovulation inhibition, rate of egg maturation, and fertilizability of the intrafollicular ova when ID was administered 30 min before hCG injection. These findings indicate that in the mouse, prostaglandins (PG), while required for follicle rupture, are not involved in the ovum maturation process, including fertilizability, under the experimental conditions

ISSN:0148-7280    

DOI:10.1002/mrd.1120180403

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

年代:1987

数据来源: WILEY

摘要:

AbstractMembrane components involved in adhesion properties of cultured Sertoli cells have been studied by a combination of immunological and biochemical methods. An antiserum prepared against Sertoli cells induced reversible rounding and detachment of the cells from the culture dishes. The cell surface morphology during detachment was studied by scanning electron microscopy and indirect immunofluorescence. A Triton soluble fraction of crude membrane preparations inhibited the antibody‐induced detachment. The antibodies recognized a restricted number of membrane glycoproteins [detectable as prominent bands on Sodium dodecylsulphate polyacrilamide gel electrophoresis (SDS‐PAGE), Mr170, 140, 80, and 48K] both in the Triton soluble fraction of crude membrane preparation and on intact Sertoli cells. The data suggest that the molecules involved in adhesion properties of cultured Sertoli cells are integral membrane glycoproteins exposing antigenic determinants at the cell surf

ISSN:0148-7280    

DOI:10.1002/mrd.1120180404

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

年代:1987

数据来源: WILEY

摘要:

AbstractThis study was undertaken to analyze the changes of elemental concentrations around/on the plasma membrane of the head, midpiece, and principal piece regions of individual rat spermatozoa during maturation in the male genital tract by X‐ray microprobe analysis. Around/on the plasma membrane of the three different subcellular regions, concentrations of sodium, potassium, chlorine, and calcium decreased gradually during sperm passage through the male genital tract. Phosphorous showed almost constant concentrations. In contrast, magnesium concentration increased significantly through the process of maturation, and the concentration in the vas deferens was about three times higher than that in the testis. The Na‐to‐K ratios on the midpiece also increased gradually during matur

ISSN:0148-7280    

DOI:10.1002/mrd.1120180405

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

年代:1987

数据来源: WILEY

摘要:

AbstractThe structure, relative density, and distribution of anionic sites on the surface of epididymal and ejaculated spermatozoa were studied using polycationic ferritin (CF), colloidal iron hydroxide (CIH), various enzymatic treatments, methylation, and de‐acetylation. Macro‐molecules containing sugar residues, probably sialic acid, are part of the sperm membrane and show a characteristic distribution and density that is dependent of the sperm region and of its origin. Unlike the spermatozoa of other eutheria examined, the exposure of the stallion spermatozoa to neuraminidase treatment did not produce significant changes in the density of the negative charge of the sperm surface. The ability of purified neuraminidase to act only after saponification suggests that sialic acid may be present in the acetylated form. When CIH was used it is seen that the density of the negative charge is rather uniform within a particular segment of the spermatozoa and abruptly changes at the junction of morphologically distinct segments (Between the acrosomal and post acrosomal region of the sperm head and between the post acrosomal region and middle piece of the flagellum). The acrosome presented more negative groups dissociated at pH 1.8 than the postacrosomal region. A greater concentration of anionic sites over the flagellum was also observed when CIH and CF were used. This assymetry probably represents different domains that may be related to specific functions.The cytochemical observations and the cellular electrophoretic mobility measurements did not show striking differences on the negative charge of sperm obtained from different regions of epididymis and ejaculates in contrast to previous results in other species. The spermatozoa collected from caput epididymidis bind CIH but not all population present equal response. In corpus and cauda region of epididymis the population displaying the capacity to bind CIH or CF significantly over the head and tail surface was the majority.This study corroborates that the distribution and density of terminal oligosaccharide residues on the sperm plasma membrane has species specific characteristics. The surface charge of the spermatozoa obtained either during the breeding or nonbreeding season, determined by measurements of cellular electrophoretic mobility and by the binding pattern of CIH and CF, does not show significant differen

ISSN:0148-7280    

DOI:10.1002/mrd.1120180406

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

年代:1987

数据来源: WILEY

摘要:

AbstractThe occurrence of second polar body (PB2) retention in in‐vitro fertilized hamster eggs is reported. Of 2,872 eggs examined, 6.9% (199 eggs) failed to extrude PB2. Eggs that failed to extrude PB2 were more likely to be polyspermic than eggs with PB2 (63% and 14.6%, respectively), and the number of fusing sperm per egg was higher in the abnormal eggs. These data indicate that eggs which fail to extrude PB2 have an impaired block to polyspermy. The level of PB2 retention varied between females and ranged from all eggs extruding PB2 to 20% of the eggs failing to extrude PB2 (41% and 4% of the females, respectively). There was no correlation within a female between the percentage of eggs that failed to extrude PB2 and the level of polyspermy in the sister eggs with PB2. Therefore, regardless of the condition of their sister eggs, eggs that fail to extrude PB2 have an impaired block to polyspermy and eggs that extrude PB2 have a normal bloc

ISSN:0148-7280    

DOI:10.1002/mrd.1120180407

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

年代:1987

数据来源: WILEY

摘要:

AbstractThe ultrastructural localization of B‐1,3‐glucanase in three species of sea urchin eggs was determined using a monospecific antibody in an electronmicroscopic immunogold procedure. In all three species,Lytechinus variegatus, Strongylocentrotus purpuratus, andArbacia punctulata, B‐1,3‐glucanase was localized specifically to the cortical granules. No other organelle within the egg contained significant label. During the fertilization reaction, B‐1,3‐glucanase was released from cortical granules into the perivitelline space and became associated with the hyaline layer. No significant label was found in association with the fertilizati

ISSN:0148-7280    

DOI:10.1002/mrd.1120180408

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

年代:1987

数据来源: WILEY

摘要:

AbstractThree different monoclonal rat antibodies, Acr1, Acr2, and Acr3, have been established against boar proacrosin. They are shown by enzyme‐linked immunosorbent and immunoblot assays to react with boar proacrosin and several different acrosin molecules derived therefrom during activation. The epitopes detected by the three antibodies are different from each other, one being highly sensitive to reduction and periodate treatment. The antibodies crossreact with various proacrosin and acrosin molecules derived from human sperm extract; they also show indirect immunofluorescent staining of the acrosomal region of ejaculated sperm from normal men but fail to react with round‐headed spermato

ISSN:0148-7280    

DOI:10.1002/mrd.1120180409

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

年代:1987

数据来源: WILEY

摘要:

AbstractExtracellular Ca2+is required for capacitation and fertilization in the mouse, but very little is known about the ability of other divalent cations to substitute for Ca2+. In this study, Sr2+, Ba2+, and Mg2+were evaluated for their ability to support capacitation, the acrosome reaction, hyperactivated motility, and fertilization. Ba2+proved to be ineffective, but Mg2+‐containing medium was able to support capacitation to a greater extent than unsupplemented Ca2+‐deficient media; despite this, Ca2+was required for fertilization. In contrast, Sr2+proved capable of substituting for Ca2+in all events. Furthermore, Sr2+‐induced responses were indistinguishable from the corresponding Ca2+‐induced ones: Sperm capacitated at the same rate and underwent the acrosome reaction to the same extent. However, demonstration of sperm:egg fusion in Sr2+required the use of zona‐free eggs. This was due not to the inability of the sperm to penetrate the zona but to the very rapid activation and cortical granule release by eggs in response to Sr2+. When zona‐intact eggs were used, the block to polyspermy had been mounted by the time sperm had penetrated the zona. A 15 min exposure to Sr2+was sufficient to block sperm fusion, but a longer exposure was required to ensure the resumption of meiosis in eggs; such a response was surprising in that the eggs were freshly ovulated and not susceptible to activation by many different treatments. Thus Sr2+can profoundly affect both gametes in the mouse: It substitutes completely for Ca2+in sperm responses and rapidly activates eggs, possibly by displacing Ca2+from intracellular stores into the cytoplasm, where the Ca2+can then trigger the various events of

ISSN:0148-7280    

DOI:10.1002/mrd.1120180410

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

年代:1987

数据来源: WILEY

摘要:

AbstractPooled semen judged to be normal in all parameters was divided into a number of aliquots which were either 1) kept untreated; 2) mixed with glycerol (10% v/v); 3) washed by centrifugation and resuspended to the original volume with buffer; or 4) washed and resuspended in buffer with glycerol (10% v/v). The progressive motility, viability, ultrastructure, and acrosomal enzyme activity (8 different hydrolases) were studied before and after cryotreatment.The described washing procedure effectively removed seminal plasma, and did not alter sperm motility, sperm viability, sperm ultrastructure, or the acrosomal enzymes studied. Glycerol (10%, v/v) had a deleterious effect on most parameters evaluated before cryotreatment. Cryotreatment severely altered the motility and viability of the spermatozoa and their acrosomal morphology but did not cause significant decreases in most of the acrosomal hydrolases measured. However, acrosin/proacrosin levels decreased by 50–80% and were correlated to the acrosomal damage. A simple assay for the measurement of acrosin/proacrosin enzyme levels in whole sperm is presented which could be used as a monitor for acrosomal integrity. No significant differences were seen between the samples cryotreated in the absence or presence of seminal plasm

ISSN:0148-7280    

DOI:10.1002/mrd.1120180411

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

年代:1987

数据来源: WILEY