ISSN:0148-7280    

DOI:10.1002/mrd.1120040102

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

年代:1981

数据来源: WILEY

摘要:

AbstractOf eggs ovulated in LT/Sv mice, 10–20% undergo spontaneous parthenogenetic activation, and 40–50% of the parthenotes develop to blastocysts when cultured in simple defined medium from the one‐cell stage. Similar percentages of oocytes isolated from Graafian follicles undergo parthenogenetic activation after spontaneous maturation in simple defined medium, but embryonic development proceeds no further than the two‐cell stage. The simple defined medium that supported preimplantation development of ovulated eggs and spontaneous maturation of extrafollicular oocytes contained no serum, free amino acids, or vitamins. The present experiments were conducted to determine what conditions during spontaneous maturation of extrafollicular oocytes could promote the ability of oocytes to develop to blastocysts after parthenogenetic activation and mimic the environment of preovulatory follicles.Cumulus‐enclosed oocytes that were matured in simple medium supplemented with fetal bovine serum (FBS) developed to blastocysts after spontaneous parthenogenetic activation. Furthermore, minimum essential medium (MEM), a complex medium containing free amino acids and vitamins, could substitute completely for FBS for maturing oocytes from (C57BL/6J × LT/Sv)F1mice, and to a lesser extent for maturing LT/Sv oocytes. Therefore, even though germinal vesicle breakdown in mouse oocytes and preimplantation development of mouse eggs can occur in the absence of an exogenous supply of free amino acids and vitamins, a complete, or normal, mouse oocyte maturation cannot. These results also demonstrated that gonadotropins are not necessary during oocyte meiotic maturation for parthenogenetically activated eggs to develop through the preimplantation stages.Luteinizing hormone or 17β‐estradiol in MEM during oocyte maturation had no effect on the subsequent development of parthenotes. In contrast, follicle stimulating hormone (FSH) and progesterone in the maturation medium decreased the number of ova that subsequently cleaved, and FSH decreased the number of cleaved eggs that developed t

ISSN:0148-7280    

DOI:10.1002/mrd.1120040103

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

年代:1981

数据来源: WILEY

摘要:

AbstractA major inhibitor of acrosin in rhesus monkey and rabbit oviduct fluid, isolated by isoelectrofocusing in sucrose gradients, displayed a broad peak in the acidic region of the column and was demonstrated to contain secretory IgA specific for acrosin. Its identity was established by immunodiffusion, by the removal of acrosin inhibition with antisera to IgA (α‐chain), and by its correct molecular weight during ultracentrifugation. Purified human serum IgA also inhibited rabbit, rhesus monkey, and human acrosins, but neither purified human IgG nor IgM had any inhibitory effect on these acrosins. Neither oviduct fluid secretory IgA nor purified human serum IgA inhibited the activity of bovine pancreatic trypsin. The high specificity of secretory IgA for acrosin and its presence in every rabbit and rhesus monkey oviduct fluid specimen examined suggests a possible regulatory role for this antibody in reproducti

ISSN:0148-7280    

DOI:10.1002/mrd.1120040104

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

年代:1981

数据来源: WILEY

摘要:

AbstractIn order to derive information about possible mechanisms by which the sperm head is converted into the male pronucleus during fertilization in the rabbit, unfertilized egg homogenate was assayed for two enzyme activities. Protamine was extracted from rabbit sperm, purified, and labelled with [14C] in an in vitro reaction and used as a probe to assay for a protein kinase which could transfer [32P]PO4from [γ‐32P]ATP onto the substrate. A kinase with a pH optimum of approximately 8.0 to 8.5 is described. Assays for the enzyme glutathione reductase were performed using homogenates from eggs or embryos at three early stages of development. Results suggest that oocytes can oxidize 2.58 × 10−6μmol NADPH per minute per oocyte, unfertilized eggs 5.16 × 10−7μmol NADPH per minute per ovum, and 20‐ to 24‐hour postcoitus fertilized eggs 2.30 × 10−6μmol NADPH per minute per ovum. The relevance of these observations to male pronuclear form

ISSN:0148-7280    

DOI:10.1002/mrd.1120040105

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

年代:1981

数据来源: WILEY

摘要:

AbstractA culture medium and culture conditions are described that enable generative cell division and sperm formation to occur in a large proportion (greater than 70%) of the pollen tubes of Tradescantia paludosa within six to eight hours of culture of pollen. The nature of the nitrogen source, speed of shaking, and ratio of pollen to medium are important parameters in determining the extent of sperm formation. Addition of the plant hormones indole acetic acid, gibberellic acid, and kinetin to the growth medium does not influence generative cell division.

ISSN:0148-7280    

DOI:10.1002/mrd.1120040106

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

年代:1981

数据来源: WILEY

摘要:

AbstractMouse zonae pellucidae contain receptors for sperm throughout their structure since spermatozoa will bind to both the inner and outer surfaces of isolated zona fragments. Antibodies raised against mechanically isolated mouse zonae pellucidae were only capable of suppressing sperm binding to the outer zona surface in association with the formation of a precipitate in this region.These results indicate that such antisera are not capable of interacting directly with the sperm receptors on the zona pellucida but rely upon the less efficient mechanism of steric hindrance to prevent sperm from gaining access to the sperm binding sites.

ISSN:0148-7280    

DOI:10.1002/mrd.1120040107

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

年代:1981

数据来源: WILEY

摘要:

AbstractMaturation of Xenopus laevis oocytes can be induced by mianserine, a tricyclic antidepressant. K+‐free medium facilitates this maturation process. Mianserine must be kept in contact with the oocytes during the whole process of maturation for maximal efficiency. It is inactive after injection into the oocytes. Mianserine induces the formation of maturation‐promoting factor (MPF) in the treated oocytes. Mianserine‐induced maturation is strongly inhibited by theophylline, even in K+‐free medium. Progesterone displays synergistic effects with mianserine for the induction of maturation. Likewise, oestradiol shows cooperative maturing effects with progesterone as well as with mianserine. It is suggested that mianserine exerts its primary effects on oocyte maturation by inhibiting a membrane adenylate

ISSN:0148-7280    

DOI:10.1002/mrd.1120040108

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

年代:1981

数据来源: WILEY

摘要:

AbstractTaurine and hypotaurine were examined for their efficacy in replacing sperm motility factor (SMF), prepared from bovine adrenal cortex, for in vitro fertilization in the golden hamster. Combinations of these amino acids at concentrations of 0.001, 0.01, 0.1, and 1 mM together with 16 μM isoproterenol (a catecholamine β‐agonist) were added to the sperm incubations. After three hours of sperm preincubation, oviductal eggs were added to the sperm suspensions and examined for penetration and stage of fertilization after three or five hours of culture. At 0.001 mM, neither taurine or hypotaurine was capable of maintaining motility of hamster sperm for four to 4½ hours or of inducing fertilization. With all other concentrations, both amino acids were found to maintain motility of sperm as well as SMF. Hypotaurine stimulated motility to a greater extent than taurine and both required isoproterenol for the greatest motility. A low proportion of cumulus‐free ova were fertilized when sperm were preincubated with either amino acid alone over the range of 0.01 to 1 mM; however, over 80% fertilization was consistently obtained when isoproterenol was also present during sperm incubation. Proportions of ova fertilized with taurine or hypotaurine present during sperm preincubation were comparable to those achieved with SMF. The possibility that taurine or hypotaurine is the sperm motility factor is discussed.After three hours of sperm/egg incubation, a lag in the early events of fertilization was observed in experimental groups treated with one of the amino acids (0.01 mM) alone compared with groups treated with isoproterenol present. However, if sperm/egg incubation was extended from three to five hours, no increase in number of eggs penetrated was found. Therefore, the delay observed at three hours was considered a function of fewer numbers of capacitated sperm present in the absence of isoproterenol rather than of the need for an extended capacitatio

ISSN:0148-7280    

DOI:10.1002/mrd.1120040109

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

年代:1981

数据来源: WILEY

摘要:

AbstractThe star‐like spermatozoon of Astacus astacus consists of a spheroidal central body around which various prolongations of same, denominated spines, are arranged. In the interior of the gamete the following parts may be distinguished: (1) The acrosomic region, formed by a complex vesicle, or thick‐walled, helmetshaped body, whose opening is orientated towards the nuclear region. In the interior of the vesicle different structures can be appreciated. (2) The nuclear region, which is formed by a large cupuliform nucleus limited by a double membrane. In the nucleoplasm numerous bundles of microtubules, mixed with noncondensated chromatin fibers, are found. (3) The laminar region, present in other Decapoda, is practically nonexistent. Within the spines of these spermatozoa, only microtubules can be observed. The morphology of this crayfish is similar to that presented by Brachiura, another group of Reptan

ISSN:0148-7280    

DOI:10.1002/mrd.1120040110

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

年代:1981

数据来源: WILEY

ISSN:0148-7280    

DOI:10.1002/mrd.1120040101

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

年代:1981

数据来源: WILEY