摘要:

AbstractBetter than 75% fertilization of C57BL/6 mouse eggs with C57BL/6 sperm is obtained in vitro in a modified Kreb's‐Ringer‐bicarbonate medium containing 8 mM HEPES. No fertilization of obtained when Ca2+is omitted from this medium. The drug verapamil, which interferes with Ca2+channels and blocks the acrosome reaction [Schackmann et al, 1978] and fertilization in the sea urchin, also blocks fertilization of mouse eggs in vitro when included in complete medium at a concentration of 80 μg/ml. Tetraethylammonium, which inhibits delayed axonal potassium currents and prevents the acrosome reaction in sea urchin sperm, also completely inhibits fertilization of mouse eggs in vitro at a concentration of 5 mM. Tetramethylammonium, which does not inhibit potassium movements at the same concentration reduces fertilization by about 50%. The data are consistent with the hypothesis that ion movements are necessary for activation of the sperm and/or egg in mouse fertiliza

ISSN:0148-7280    

DOI:10.1002/mrd.1120030102

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

年代:1980

数据来源: WILEY

摘要:

AbstractGenetic variation in spermatozoa was used to examine mechanisms important for fertilization in the mouse. A significantly greater proportion of cauda epididymal sperm from C57BL/6 (inbred) males were motile than from random‐bred (CFW) males. Random‐bred sperm, however, were able to fertilize a significantly greater percentage of eggs in vitro than were inbred sperm. When sperm of these two genotypes were used for insemination in vivo, and the penetrated eggs cultured through the first cleavage, the levels of cleavage were similar, suggesting that neither levels of sperm motility nor sperm penetration in vitro accurately reflect the ability of the same sperm populations to penetrate eggs in v

ISSN:0148-7280    

DOI:10.1002/mrd.1120030103

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

年代:1980

数据来源: WILEY

摘要:

AbstractThe hypothesis that motility of avian sperm is regulated by acetylcholine was examined by treating rooster (Gallus domesticus) sperm with choline analogs and paraoxon, an inhibitor of colonesterases. Acetylcholine chloride (AChCl) was most effective, acetylthiocholine iodide and butyrylthiocholine iodide were less effective, and choline chloride was ineffective in stimulating sperm motility. Histochemical localization of cholinesterase activity with the electron microscope showed enzyme activity to be associated with membranes of the head and within fibrillar components of the tail. Increasing concentrations of paraoxon decreased cholinesterase activity and increased sperm motility. The data provide evidence that the motility of avian sperm, like that of mammal and sea urchins, may be regulated in part by a system with similarities to the cholinergic neurotransmitter system.

ISSN:0148-7280    

DOI:10.1002/mrd.1120030104

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

年代:1980

数据来源: WILEY

摘要:

AbstractThe architecture and transformation of the vitelline envelope of the developing oocyte into the chorion of the mature egg of Fundulus heteroclitus have been examined by scanning and transmission electron microscopy. The mature vitelline envelope is structurally complex and consists of about nine strata. The envelope is penetrated by pore canals that contain microvilli arising from the oocyte and macrovilli from follicle cells. During the envelope's transformation into the chorion, the pore canals are lost and the envelope becomes more fibrous and compact and its stratified nature less apparent. The micropyle, of pore, through which the sperm gains access to the enclosed egg is located at the bottom of a small funnel‐shaped depression in the envelope. Internally, the micropyle opens on the apex of a cone‐like elevation of the chorion. During the development of the envelope, structured chorionic fibrils, the components of which are presumed to be synthesized by the follicle cells, become attached to its surface. These chorionic fibrils are though to aid in the attachment of the egg to the substratum and perhaps to help prevent water loss during low tides when the egg may be expo

ISSN:0148-7280    

DOI:10.1002/mrd.1120030105

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

年代:1980

数据来源: WILEY

摘要:

AbstractA reproducible and effective method for fertilization eggs of Xenopus laevis was developed based of systematic manipulation of environmental factors. The effects of varying concentrations of individual components of a fertilization medium were tested by measuring jelly swelling, sperm motility, and sperm longevity. Results were used to develop an improved medium for fertilization, consisting of 41.25 mM NaCl, 1.25 mM KCl, 0.25 mM CaCl2, 0.0625 mM MgCl2, 0.5 mM Na2HPO4, 2.5 mM HEPES, 1.9 mM NaOH, final pH(2°) 7.8

ISSN:0148-7280    

DOI:10.1002/mrd.1120030106

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

年代:1980

数据来源: WILEY

摘要:

AbstractOvaries from pubertal mice were dissected into fragments containing 1–4 antral follicles, which were cultured on the surface of a chemistry defined medium. After 17–20 hrs oocytes were released from the cultured follicles and their meiotic status recorded. In the presence or absence of exogenous gonadotropins oocytes in these cultures behaved meiotically as expected if they had been studied in the intact animal. Media containing 100 μM of progesterone for the duration of the culture period caused atresia of the oocytes, and although the addition of gonadotropins reduced this necrosis they did not induce the resumption of meiosis. The meiotic stimulating effect of gonadotropins was also inhibited if progesterone was present in the culture media for the first 3 hours only. Estradiol (100 μM) similarly inhibited the meiotic inducing action of gonadotropins when left in the medium for the duration of culture, but had no effect when administrated for a shorter period. The results from this model system, would indicate that the meiotic‐initiating action of gonadotropins can be modulated by exposure to progesterone and es

ISSN:0148-7280    

DOI:10.1002/mrd.1120030107

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

年代:1980

数据来源: WILEY

ISSN:0148-7280    

DOI:10.1002/mrd.1120030108

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

年代:1980

数据来源: WILEY

ISSN:0148-7280    

DOI:10.1002/mrd.1120030101

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

年代:1980

数据来源: WILEY