(n.) Fullness of sperm, or seed; the passage of more than one spermatozoon into the vitellus in the impregnation of the ovum.
Example Sentences:
(1) The relation of these layers to the movements of the spermatozoon, to the activation of the egg, to the block to polyspermy, and to each other are discussed.
(2) The incidence of polyspermy, which did not exceed 5% in Series I and reached 58% in Series II, was dependent on the genotype of both gametes.
(3) Microscopic examinations of eggs stained with aceto-orcein or the DNA fluorochrome bisbenzimide and direct observations on isolated sperm aster complexes show that halothane induces polyspermy (multiple sperm entry) when present at fertilization.
(4) The purine inhibits the detachment of the vitelline layer from the sea-urchin egg plasma membrane after fertilization and this effect leads to polyspermy.
(5) The eggs of the surf clam Spisula solidissima have a built-in mechanism that prevents polyspermy: the eggs show a 70 percent decrease in sperm receptivity 5 seconds after fertilization, and become completely resistant to sperm by 15 seconds.
(6) When inseminated with sperm of the newt, Cynops pyrrhogaster, mature Bufo oocytes exhibited polyspermy accompanied by a gradual hyperpolarization and a slowly developing positive plateau, without the fast spike that occurs in self-species fertilization.
(7) The zona pellucida block to polyspermy is very effective since only one sperm penetrated the zona pellucida in 72.8% of the 876 fertilized eggs examined.
(8) The fertilizing capacity of sperm was evaluated after 0, 24, and 30 h of incubation by adding oocytes to the culture and determining the incidences of fertilization and polyspermy.
(9) Thus, universal roles of zona hardening in the block to polyspermy and in oviductal interaction with embryos have been discounted.
(10) The change in distribution of labelled macromolecules on the zona surface may be a prerequisite for successful sperm-zona binding and the specific association of labelled glycoconjugates in the region of the egg plasma membrane may be involved in the preparation of the egg surface for sperm-egg interactions involving cortical granule exocytosis and the block to polyspermy.
(11) Correction of polyspermy through pronucleus extraction in the absence of membrane relaxants was applied to 25 polyspermic human zygotes.
(12) The present study was undertaken to determine what type(s) of block(s) to polyspermy exist in Chaetopterus.
(13) As a step toward defining in molecular terms the sperm-triggered block to polyspermy reaction established by the egg at fertilization, vitelline (VE) and fertilization (FE) envelopes were isolated from eggs of the Sounth African clawed toad Xenopus laevis and some of their physicochemical properties determined.
(14) In A. callosa, fertilization in low Na+ SW causes a 60% decline in enzyme release and a similar increase in the number of sperm remaining on the VC at 4 min as well as a great increase in polyspermy.
(15) It is proposed that the hyperpolarization of the egg membrane in response to fertilization constitutes a long-lasting electrical block to polyspermy in crab eggs.
(16) The consequences of interactions between porcine sperm, eggs, and oviduct cells before and during fertilization in vitro (IVF) has been examined with particular reference to the block to polyspermy.
(17) This block to polyspermy is inactivated by GlcNAc (2mM) or 150 mM-Na+ (choline substituted) SW.
(18) Zona cutting was associated with a low loss of oocytes (less than 1%), no increase in polyspermy and normal development in vitro and in vivo after fertilization.
(19) Comparisons with data from animals, and measures aimed at preventing polyspermy are suggested.
(20) Polyspermy increased significantly with 10 mM GR in oocyte incubation medium.
Sperm
Definition:
(n.) The male fecundating fluid; semen. See Semen.
(n.) Spermaceti.
Example Sentences:
(1) A study revealed that the percentage of active sperm in semen 30 seconds after ejaculation was 10.3% when a nonoxynol 9 latex condom was used as opposed to 55.9% in a nonspermicidal condom.
(2) Here we report that sperm from psr males fertilizes eggs, but that the paternal chromosomes are subsequently condensed into a chromatin mass before the first mitotic division of the egg and do not participate in further divisions.
(3) Sperm specimens were obtained from 13 men participating in our in vitro fertilization program.
(4) Whether hen's egg yolk can be used as a sperm motility stimulant in the treatment of such conditions as asthenospermia and oligospermia is subjected for further study.
(5) Sperm were examined at 4.5 h, 8 to 9 h, and 24 to 25 h of incubation (37 degrees C, 5% CO2, and 95% air).
(6) Since the advance and return of sperm inside the tubes could facilitate the interaction of sperm with secretions participating in its maturation, the persistent infertility after vasectomy could be related to the contractile alteration that follows the excessive tubal distention.
(7) Peaks in the sperm index were preceded by 6 days with peaks in the serum testosterone concentration.
(8) Those without sperm, or with cloudy fluid, will require vasoepididymostomy under general or epidural anesthesia, which takes 4-6 hr.
(9) A sperm whale myoglobin gene containing multiple unique restriction sites has been constructed in pUC 18 by sequential assembly of chemically synthesized oligonucleotide fragments.
(10) Major limitations of the conventional sperm penetration assay are the inability to assess several aspects of sperm function (zona binding and penetration) and the absence of human ovulatory products known to influence fertilization.
(11) Couples applying to in vitro fertilization were admitted into this project when the sperm concentration was greater than 20 million per mL and motility greater than 30 per cent.
(12) To develop a new immunobead binding test (IBT) procedure that will detect sperm antibody in cervical mucus (CM), especially in very small samples of mucus.
(13) This procedure can quickly provide acrosome-reacted bull sperm for use with various in vitro fertilization procedures and for assessment of male fertility.
(14) Males were then sacrificed and organ weights, testicular spermatid counts, and cauda epididymal sperm count and sperm morphology were obtained.
(15) The freezing procedure increased sperm motility in approximately 30% of samples from both animals.
(16) The time of sperm penetration in the mouse eggs, however, was delayed for one-half to one hour when ejaculated sperm were used.
(17) The epididymis appeared distended but without any visible sperms.
(18) Liposomes of PC10 rapidly destroyed sperm motility while PC12 acrosome-reacted sperm remained motile for several h. Liposomes of PC with greater than or equal to 14-carbon fatty acyl chains had no effect on the AR or motility of sperm.
(19) Additionally, the data demonstrate that hamster sperm can remain viable for several hours after becoming immotile, and that many of the immotile sperm are capable of being reactivated.
(20) Heterogeneity in thiol content of sperm within individual samples was also observed.