摘要:

AbstractThe spermatozoon ofHemirhamphodon pogonognalhusshows modifications that are frequent though not obligate in internally fertilizing sperm, notably elongation of the nucleus and extension of the mitochondria of the midpiece as an elongate sheath around the proximal region of the axoneme. These similarities to poecilid and jenynsid sperm are considered homoplasic. As in the mature sperm of all but one investigated teleost, an acrosome is absent. The elongate, blade‐shaped, electron‐dense nucleus has a mean length of 3.2 μm; its basal implantation fossa, less than one‐tenth of the length of the nucleus, houses the anterior half of the distal and only centriole (of triplet construction with satellite rays), a centriolar plug, and a mass connecting the centriole to the wall of the fossa. A unilateral putative centriole adjunct is present. The anterior region of the axoneme is surrounded by a mitochondrial sleeve, and internal to this, separated by a cisterna, by a submitochondrial sleeve. The mitochondrial sleeve unites posteriorly with the submitochondrial sleeve. Between the submitochondrial sleeve and the axoneme is a space, the cytoplasmic canal, that is open to the exterior posteriorly. The discrete, cristate mitochondria, in their sleeve, are unique in investigated atherinomorph sperm in being bilateral, grouped on only two opposing sides of the axoneme, with an arc‐shaped ‘intermitochondrial link’ between. The 9 + 2 flagellum is unique for the Animalia in having 23 radial subplasmalemmal rods, repeated longitudinally (periodicity 0.025 pm) in a quasicrystalline array. Internal fertilization is deduced to have arisen in the Exocoetoidei independently of that in the Cyprin

ISSN:0148-7280    

DOI:10.1002/mrd.1120240302

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

年代:1989

数据来源: WILEY

摘要:

AbstractOptimal conditions of electrofusion for blastomeres of two‐cell bovine embryos to produce tetraploid embryos were investigated. The high fusion rate (73–95%), viability, and develop mental capacity were obtained under a field strength of 1.0 kV/cm with direct current pulses of 10 or 25 μsec duration applied twice. Cytological study showed that 78.6% (11/14 embryos) of embryos exposed to electrofusion had tetraploid chromosome sets and the others were diploid or hexaploid. The tetraploid embryos had the capability to develop up to morulae stage in v

ISSN:0148-7280    

DOI:10.1002/mrd.1120240303

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

年代:1989

数据来源: WILEY

摘要:

AbstractCumulus‐intact and ‐denuded unfertilized oocytes from two mouse strains were exposed to 1.5 m ethanol (EtOH) or two cryoproteclant solutions, 1.5 M propanediol (PROH) or 1.5 M dimethylsulfoxide (DMSO), for 4.5 min at 27°C, and the proportion of activating or degenerating oocytes studied. Exposure to DMSO did not significantly increase activation above that of oocytes not exposed to DMSO. Treatment of oocytes in PROH resulted in the activation of up to 87% of viable oocytes. This was significantly higher (P<01) than in control oocytes and comparable to the rate of activation after treatment with EtOH (59–96% activation). In solutions at 1°C, 47% of control oocytes were activated, which was not significantly different from the rate of activation in EtOH (36%) or PROH (50%) at 1°C. Following treatment with PROH, up to 87% of oocytes degenerated within a period of 6 h in vitro. The age of the oocytes (h post hCG) and the time of cumulus removal with the enzyme hyaluronidase, relative to the time of exposure to the chemicals, influenced the level of degeneration in most groups. Significantly fewer oocytes degenerated when cumulus cells were removed before treatment (0–31%) than when the cumulus was left intact throughout the treatment and 6 h culture period (10–87%). Exposure to PROH at 1°C reduced oocyte degeneration to 5%. We conclude that PROH causes significantly greater losses of oocytes as a result of parthenogenetic activation and degeneration than of exp

ISSN:0148-7280    

DOI:10.1002/mrd.1120240304

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

年代:1989

数据来源: WILEY

摘要:

AbstractImmunogold procedures for actin detection were used in combination with experimental cryptorchidism in the rabbit as a modei to shed more light on the function of subacrosomal actin during spermiogenesis. In the normal testis, actin was localized in the perinuclcar substance (PNS) from round spermatid onward but it was not detected in late spermatids. Actin labeling in each type of spermatid was essentially unmodified after 24 hr of cryptorchidism. However, among relevant immediate and delayed effects, discontinuous acrosomes overlying a continuous PNS with normal actin labeling were noted. Nuclear invaginations were seen in combination with subacrosomal dilatations: at this site actin labeling was found only in the PNS closely apposed to the nuclear envelope. In subacrosomal areas lacking PNS, actin labeling also was lacking. These results suggest that the subacrosomal actin (F‐actin) is a component of the PNS that is tightly bound to the nuclear envelope rather than the overlying inner acrosomal membrane. Therefore, a function for the subacrosomal actin either in anchoring the acrosome to the nucleus or in capping the inner acrosomal membrane appears unlikely. The data rather suggest a capping function for the nuclear membrane during spermiogenesi

ISSN:0148-7280    

DOI:10.1002/mrd.1120240305

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

年代:1989

数据来源: WILEY

摘要:

AbstractThe noradrenergic agonists norepinephrine and isoproterenol elicit greater stimulatory swim ming responses in sea urchin spermatozoa than epinephrine. The β‐blocker atenolol induces an even greater motile rate, while the α‐blocker phentolamine has only a moderate effect, it also causes a minimal reduction in the sperm cells' response to atenolpol. Caffeine increases the motility but to a lesser degree than 8‐Br‐cAMP. In drug interaction assays, both caffeine and 8‐Br‐cAMP depress the adrenergic effects. Agents that affect access of calcium to the flagellar apparatus (verapamil and trifluoperazine) depress the motility below the level of the controls when incubated separately with the sperm suspensions and counteract the stimulation due to atenolol. Adrenergic modulation of sperm motility thus appears to be both a calcium‐dependent and a cyclic nucleotide‐

ISSN:0148-7280    

DOI:10.1002/mrd.1120240306

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

年代:1989

数据来源: WILEY

摘要:

AbstractThe acrosome reaction induced by the mouse egg's zona pcllucida in mouse sperm has been shown to proceed in two stages as characterized empirically by sequential changes in patterns of chlorletracycline fluorescence on the sperm plasma membrane surfaces. The chlortctracy‐cline fluorescence pattern characteristic of fully intact sperm is designatedB:in sperm bound to structurally intact zonae that induce the acrosome reaction, the B pattern changes first to an intermediate patternSand then to a terminal patternARcharacteristic of the completed acrosome reaction. In the same study, it was shown, using a 9‐amino acridine fluorescent pH probe, that completion of the first stage was characterized by increase in H+permeability such that the H+gradient between sperm head and medium was dissipated. In this study, we show that the fluorescent pH probe 9‐N‐dodecylamino acridine and the intracellular Ca2+fluores cent probe fura‐2 are both localized to the anterior part of the sperm head encompassing the acrosomal compartment in intact sperm, and the fluorescence associated with each probe is lost as the first stage of the acrosome reaction is completed. Loss of the pH probe fluorescence, patternN, corresponds to onset of H+permeability, and loss of fura‐2 fluorescence, pattern F, corresponds to onset of Ca2+permeability. Localization of intracellular fura‐2 fluorescence to the acrosomal compartment required extracellular Mn2+to quench surface‐bound fura‐2 AM, the tetra‐acetoxymethyl ester of fura‐2 used to load the cells. Loss of acrosomal fura‐2 fluorescence is due to quenching by tracer Mn2+accompanying Ca2+. Onset of membrane permeability to both H+and Ca2+, asseenby loss of patterns N and F, occurred in synchrony in populations of sperm bound to isolated, structurally intact zonae, with an overall time coursfe of 210 min postbinding. The loss of pattern N in individual sperm cells bound to zonae was rapid, with a half time of 2.1 min. Concomitant with this rapid loss of pattern N was a shift in the amplitude of flagellar motion from large to small. The lag times to pattern N loss in 50 individual cells ranged from 30 to 140 min. The variable lag times determine the population kinetics; the rate of the endpoinl reaction seen in the individual cells is rapid and constant.Dissipation of the H+gradient with immediate loss of pattern N was readily achieved by addition of nigericin with no change in the time course of the onset of Ca2+permeability of the membranes enclcsing the acrasome. Onset of Ca2+permeability was always accompanied by onset of H+permeability, but the alkalinization caused by H+permeability induced by nigericin had no effect on Ca2+permeability in intact sperm. This indicates that the permeabilization of the membranes marking the endpoint reaction of the B‐to‐S transition is most likely due to pore formation induced by punctate fusion of the plasma and outer acrasomal membranes, as would be expected

ISSN:0148-7280    

DOI:10.1002/mrd.1120240307

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

年代:1989

数据来源: WILEY

摘要:

AbstractPrevious studies from this center have indicated that the cynomolgus macaque (Macaca fascicularis) may serve as a model for human sperm interaction with the cervix and uterus. In some macaque species, transcervical aspiration of the uterine contents carries a significant risk of disturbing the cervical milieu due to the serpentine nature of the cervix. The only alternatives have been surgical procedures such as laparotomy or laparoscopy. In this paper, we report our experience with a new technique for ultrasound‐guided sampling of spermatozoa in the macaque uterus. Twenty adult female cynomolgus macaques were monitored for menses (first day of menses = day l), and one mating per cycle was allowed on day 10, 11, or 12. In one group of ten animals, cervical mucus was sampled at 3 or 18 hr postcoitus (pc) and ultrasound‐guided uterine aspiration was performed at 24 hours pc. In a second group of ten monkeys, uterine aspiration was at six hr pc and sperm numbers and motility were counted in the uterine fluid. Uterine fluid was obtained from fourteen of twenty monkeys. Pregnancy occurred in ten of the twenty experimental cycles. Ultrasound‐guided uterine aspiration appears to be a reliable method for the evaluation of sperm transport in female macaques. The correlations between uterine sperm recovery and cervical mucus sperm populations arc discussed. The high conception rate in treatment cycles indicates that this procedure can be performed without apparent risk to preg

ISSN:0148-7280    

DOI:10.1002/mrd.1120240308

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

年代:1989

数据来源: WILEY

摘要:

AbstractPostcoital (pc) cervical mucus was collected in 73 menstrual cycles of cynomolgus monkeys and in 43 cycles of rhesus monkeys at 2,6,10,30 hr pc. Videomicrography was used to analyze sperm numbers and movement in the mucus. Both cynomolgus and rhesus monkeys had comparable populations of motile sperm in the mucus at 2 hr pc. However, by 6 hr pc, cervical mucus from cynomolgus monkeys contained twice as many total sperm and motile sperm as mucus from rhesus monkeys (P<.05). Mean swimming speeds of the free‐swimming cervical sperm were similar for the two species at this time. No motile sperm were recovered in mucus from rhesus monkeys at 30 hr pc. In cynomolgus monkeys, however, 14 of the 26 animals examined at 30 hr pc had motile sperm in their mucus. These sperm exhibited lower percent molility, percent free‐swimming sperm, and swimming speed than those sperm observed at 6 hr pc. Uterine sperm were collected by transcervical or transuterine aspiration from cynomolgus monkeys. In the transcervical technique, sperm were successfully obtained in four of nine animals examined at 6 hr and in four of five animals at 30 hr pc. The percentage of motile sperm in the uterine fluid was high, 82% ± 4%, and the swimming speeds (86 ± 2μm/sec) were higher than those observed in cervical mucus. Approximately 5–10% of the uterine sperm exhibited swimming motions similar to the hyperactivated motility seen in most mammals. These findings indicate that the sperm cervical mucus interaction in vivo in cynomolgus monkeys has more similarities to the human situation than does the interaction in rhesus

ISSN:0148-7280    

DOI:10.1002/mrd.1120240309

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

年代:1989

数据来源: WILEY

摘要:

AbstractThe time course and conditions necessary for oocyte maturation and subsequent fertilization in vitro were studied in the domestic cat. Darkly pigmented oocytes surrounded by cumulus cells and a tight corona radiata were collected from ovaries removed at ovariohysterectomy. After culture in Eagle's minimum essential medium, oocytes were evaluated for nuclear maturation by analyzing chromosomal spreads. Oocytes achieved metaphase II after intervals of 40–48 hr of in vitro incubation. The incidence of maturation was enhanced (P<0.05) when oocytes were recovered from inactive (54%) or follicular (56%) stage donors compared to those recovered from luteal phase (29%) or pregnant (35%) cats. The proportion of oocytes successfully maturing in vitro in medium containing no hormone supplementation (37%) was less (P0.05) by either maintenance/transport temperature (4°C vs. 22°C) or delaying recovery of oocytes from antral follicles (2–8 hr vs. 24–32 hr). Approximately 36% of the in vitro matured oocytes cocultured with spermatozoa demonstrated evidence of fertilization; however, there appeared to be a critical development period for maximizing the incidence of fertilization. These results demonstrate that domestic cat antral oocytes are capable of maturing in vitro, and maturation is influenced by the reproductive status of the donor and the presence of gonadotropins in the culture medium. These oocytes are capable of forming embryos and developing to at least the 16‐cell sta

ISSN:0148-7280    

DOI:10.1002/mrd.1120240310

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

年代:1989

数据来源: WILEY

ISSN:0148-7280    

DOI:10.1002/mrd.1120240311

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

年代:1989

数据来源: WILEY