摘要:

AbstractSuccess rates of superovulation in response to gonadotropic hormone treatment and in vitro fertilization (ie, mitotic cleavage following insemination) of mouse eggs from outbred CD‐1, hybrid CB6Fl, or hybrid B6CBAF1, mice were compared using either a mouse inseminationmedium, modified Krebs‐Ringer‐bicarbonate (m‐KRB), or a human insemination medium, Ham's F10 nutrient mixture. Inseminations were performed in either organ culture dishes or screw‐top, flat‐side tissue culture tubes. Mean superovulation rates (± SD) were 24.2 (5.1) for CD‐1, 33.0 (5.8) for CB6F1, and 16.3 (6.6) for B6CBAF1mice. For in vitro cleavage the best combination of mouse strain, insemination medium, and culture container was achieved using CB6F1, mice, m‐KRB medium, and culture tubes. However, Ham's medium used with either hybrid mouse strain was shown to be employable for fertilization of mouse eggs in vitro as a quality control assay and/or experimental model system for testing the human in vitro fertili

ISSN:0148-7280    

DOI:10.1002/mrd.1120070202

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

年代:1983

数据来源: WILEY

摘要:

AbstractA suboptimal sperm concentration was used to assess the capacity of catecholamines to stimulate the fertilization of cumulus free F1,(C57BL × CBA) mouse ova in vitro. At a concentration of 50 μM, (L) epinephrine significantly increased the proportion of ova fertilized at 2 × l05spermatozoa/ml. However, when (D, L) propranolol at an equimolar concentration was tested for inhibition of the (L) epinephrine effect, fertilization was inhibited in both the test and control dishes. At l0μM, propanolol by itself or in the presence of 50μM (L) epinephrine significantly increased the number of ova fertilized at 2 × l05sperm/ml. Norepinephrine (50 μM) and phentolamine (50 μM), either alone or together, were also slightly stimulatory. Some data are presented to suggest that propranolol may act in a nonadrenergic manner to precipitate the acrosome reaction and that the stimulatory effect is maximised when it is added to spermatozoa at the same time as ova addition. It was suggested that propranolol may act to trigger calcium influx by a nonspecific alteration in membrane function for example in (Ca + Mg) ATPase activity. It was concluded that spermatozoa at suboptimal densities are capable of achieving fertilization and that sperm concentration dependency in fertilization in vitro may be a reflection of the proportion of spermatozoa achieving capac

ISSN:0148-7280    

DOI:10.1002/mrd.1120070203

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

年代:1983

数据来源: WILEY

摘要:

AbstractWe have studied the relationship between acid release, cytoplasmic alkalinization, and the extent of chromosome condensation during parthenogenetic activation of sea urchin eggs. The relative rate of acid release inStrongylocentrotus purpuratuseggs was determined from pH measurements of egg suspensions. Acid release in inseminated eggs began after a lag of 0.4 min and the relative rate increased 108‐fold, declined, and release was essentially complete by 8‐min postinsemination. An average of 3.8 ± 0.23 × 10−12moles H+cell−was released as determined by backtitration with NaOH. Acid release characteristics of eggs parthenogenetically activated with either NH4C1, methylamine ethylamine, n‐propylamine, n‐butylamine, or benzylamine were qualitatively similar. There was no detectable lag peroid and the increase in relative rate of acid release was directly proportional to the carbon number of the amine used, eg, from 8.3‐fold methylamine to 470‐fold with benzylamine. The total equivalents of acid released ranged from 0.50–8.2 × 10−12moles H+·cell−in direct proportion to the concentration of amine used. The degree fo cytoplasmic alkalinization induced as a function of methylamine and benzylamine concentration was determined by pH measurements fo egg homogenates; egg cultures were also prepared for microscopic examination of chromosome condensation. None of the eggs had condensed chromosomes at 0.5‐mM methylamine whereas a cytoplasmic alkalinization of 0.6 pH units was observed. Increased methylamine levels up to 10mM resulted in chromiosome condensation in only 20% of the eggs. A similar result was found with benzylamine. We conclude that acid release and cytoplasmic alkalinization during chemical parthenogenesis are insufficient to mimic sperm induction of chromiosome condensation and suggest that an additional factor(s) is required for chromosome condensation by

ISSN:0148-7280    

DOI:10.1002/mrd.1120070204

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

年代:1983

数据来源: WILEY

摘要:

AbstractWhen the dry sperm of the sea urchin, Hemicentrotus pulcherrimus, were diluted 100 times in artificial sea water at 0°C and at 20°C, they became motile and the levels of ATP and creatine phosphate decreased rapidly. The level of ADP hardly changed, and the AMP level increased after the dilution. After the dilution, the respiratory rate at 2°C was almost one fifth that of 20°C. Both phospholipid and glycogen were used for the energy sources in sea urchin sperm. The level of phospholipid was 10‐fold higher than that of glycogen in the dry sperm. The phospholipid level decreased after dilution at 20°C, though the level hardly changed at 0°C, suggesting that phospholipid was hardly metabolized the lower temperature. The level of α ‐glycerophosphate increased at 20°C after the dilution but did not change at 0°C. The level of glycogen decreased after the dilution, regardless of the temperature. The glycolysis was also activated after the dilution. Of the intermediates of the tricarboxylic acid cycle, the citrate concentration increased at 0°C and the malate concentration also increased at 0°C and especially st

ISSN:0148-7280    

DOI:10.1002/mrd.1120070205

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

年代:1983

数据来源: WILEY

摘要:

AbstractCapacitation of guinea pig spermatozoa in vitro was inhibited by the disulfide‐reducing agent dithiothreitol (DTT). Even a brief treatment with DTT inhibited capacitation unless an oxidizing agent (glutathione disulfide) was present in the posttreatment medium. Precapacitated spermatozoa were unable to undergo the acrosome reaction in the presence of DTT, indicating that this reagent also blocks the acrosome reaction. Acrosome‐reacted spermatozoa were incapable of attaching to and penetrating the zona pellucida in the presence of DTT. Even when acrosome‐reacted spermatozoa were directly brought to the surface of zona‐free eggs, they were unable to bind to and fuse with the egg plasma membrane so long as DTT was present in the medium. These observations suggest that the tertiary and quaternary structures of sperm surface proteins regulated by their thioldisulfide status are of critical importance in the physiology and function of spermatozoa preliminary to and in the process of fertil

ISSN:0148-7280    

DOI:10.1002/mrd.1120070206

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

年代:1983

数据来源: WILEY

摘要:

AbstractThe concept of Byskov which hypothesizes a glycoprotein inducer of meiosis for the mammalian fetal ovary has been tested by examining the incorporation of the specific precursor3H‐fucose into the rete ovarii of day 14 mouse ovaries. Semiquantitation of grains in autoradiographs has documented a concentration over the rete ovarii which exceeded that over the oogonia, ovarian fibroblasts, or surface epithelia. These data support the concept that the cytoplasm of mouse rete ovarii is capable of synthesizing a glycoprotein that may be the meiosis‐inducing substa

ISSN:0148-7280    

DOI:10.1002/mrd.1120070207

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

年代:1983

数据来源: WILEY

摘要:

AbstractStudies on the survival of mouse embryos revealed that fewer offspring were produced when blastocysts, rather than morulae, were transferred to foster mothers. Approximately 8–10 h after fertilization F1 hybrid eggs (C57BL/6J × LT/Sv) were collected and cultured to morulae (day 4) or blastocysts (day 5 ) before transfer into uteri of day 3 foster mothers. A few recipients were killed on day 8 of gestation and deciduae were examined histologically. Embryos developing from transferred morulae were found to lie deep within the deciduae and were surrounded by numerous, large blood islands. Conversely, embryos developing from transferred blastocysts implanted more distally to the maternal blood vessels with only a few blood islands surrounding the embryos. These observations, suggesting abnormal implantation with insufficient embyro nourishment, were confirmed when uteri of foster mothers were examined on day 19 of gestation. Although the proportion of implantations from transferred morulae or blastocysts was similar (42 % and 47%, respectively), significantly more of the implantations were resorbed after transfer of blastocysts (78%) as compared with morulae (15%). These results demonstrate that transfer of day 5 cultured blastocysts into uteri of foster mothers increases embryonic mortality as a consequence of improper implantati

ISSN:0148-7280    

DOI:10.1002/mrd.1120070208

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

年代:1983

数据来源: WILEY

摘要:

AbstractAdenylate cyclase activities were studied in porcine sperm in the presence and absence of Mn++before and after incubation in vivo and in vitro. Incubation of sperm in vivo for 30 min increased the Mg++‐stimulated adenylate cyclase activity from 35.1 pmoles cyclic AMP formed per mg protein per 10 min to 50.4 pmoles. The activity stimulated by Mg++and Mn++increased from 392 to 729 pmoles after 30 min of in vivo incubation. Activity after incubation in vivo for 120 min was not different from activity after 30 min. In vitro incubation of porcine sperm in Ca++‐free Ringer‐fructose resulted in no change, but incubation in oviductal and uterine flushings obtained from gilts soon after ovulation increased Mg++‐stimulated activity by 24% and Mg++−+ Mn++‐stimulated activity by 49%. In vitro incubations in preovulatory flushings plus follicular fluid or in bovine serum albumin also increased adenylate cycla

ISSN:0148-7280    

DOI:10.1002/mrd.1120070209

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

年代:1983

数据来源: WILEY

ISSN:0148-7280    

DOI:10.1002/mrd.1120070210

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

年代:1983

数据来源: WILEY

ISSN:0148-7280    

DOI:10.1002/mrd.1120070212

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

年代:1983

数据来源: WILEY