(n.) A more or less spherical and transparent mass of granular protoplasm, which by a process of multiplication and growth develops into a mass of cells, constituting a new individual like the parent; an egg, spore, germ, or germ cell. See Illust. of Mycropyle.
(n.) One of the series of egg-shaped ornaments into which the ovolo is often carved.
Example Sentences:
(1) A specimen of a very early ovum, 4 to 6 days old, shown in the luminal form of imbedding before any hemorrhage has taken place, confirms that the luminal form of imbedding does occur.
(2) The results indicate that the sperm swelling test and the zona-free hamster ovum penetration assay are evaluating different functional qualities of sperm that are apparently not associated with each other.
(3) This study documents a molecular change in the murine ovum related to its exposure to oviductal fluid.
(4) The OCI-related membrane appeared a cause of OCI interference with fimbrial ovum capture by preventing the contact between the fimbrial cilia and the cumulus oophorus.
(5) Also, for determination of the fertilizing capacity of the semen, a zona-free hamster ovum penetration test was done in 49 men, while 14 men were studied by determination of the fertilization of human oocytes in vitro.
(6) The antiprogesterone RU 486 was utilized to evaluate the possible role of progesterone in ovum maturation, ovulation, fertilization, and embryo cleavage.
(7) It is suggested that the beta inhibitory activity of the uterus and the alpha excitatory activity of the rest of the oviduct are involved in the regulation of ovum transport.
(8) Among antigens possible unique to the reproductive process, sperm antigens, antigens of seminal plasma and of the ovum, antigens of placental hormones and of placenta specific proteins appear suitable targets of the production of fertility regulating vaccines.
(9) The preovulatory surge of gonadotropins activates a cascade of proteolytic enzymes resulting in the rupture of the follicular wall and the release of a fertilizable ovum during ovulation.
(10) The development of vaginal ultrasound transducers has facilitated ovum pick-up (OPU) by providing higher precision and less trauma than are found with laparoscopy and other ultrasound-assisted techniques.
(11) In Johnson v. Calvert, a surrogate mother in California failed to gain custody of the child she bore after gestating an embryo from the ovum and sperm of the couple who hired her.
(12) Risk factors that may theoretically alter ovum quality or the hormonal environment include ovulation induction, fertilization in vitro, delayed ovulation, and transperitoneal ovum migration.
(13) Thus, spermatozoa deposited in the vicinity of the USHG immediately following oviposition (to simulate a release of spermatozoa from this region) can be transported to the infundibulum and effectively fertilize the next ovum ovulated.
(14) However, they do not as yet permit a judgment as to the degree that ovum pickup through a fistula was impaired.
(15) We evaluated the differences between this group and those patients presenting either with a blighted ovum or beyond the first trimester, as well as the outcome of those patients with spotting early in gestation.
(16) It is too soon to learn whether this method will be reversible, but use of silastic should prevent adhesions while providing another mechanical barrier between ovum and sperm.
(17) Indomethacin was effective in preventing follicular rupture and ovum extrusion when administered simultaneously with gonadotropin.
(18) A 33% clinical pregnancy rate per ovum pick-up was achieved with the Buserelin-hMG treatment.
(19) The pregnancy rates were higher than a matched IVF series in the male factor and female ASAB groups and reached statistical significance for the ovum donation group.
(20) Lamellar structures, therefore, are considered to be storage material chiefly used in the second half of the cleavage for developmental processes in the rat ovum.
Pronucleus
Definition:
(n.) One of the two bodies or nuclei (called male and female pronuclei) which unite to form the first segmentation nucleus of an impregnated ovum.
Example Sentences:
(1) In the triploids, the 40 female chromosomes present (mouse, n = 20) were derived from a single diploid pronucleus formed after the extrusion of a first polar body, and following the monospermic fertilization of primary oocytes.
(2) Both nucleate and anucleate fragments lose the capability of transforming sperm nucleus into fully formed pronucleus sometime between 3 and 5 h after activation.
(3) A series of transgenic mice was produced by microinjection of a segment of DNA, containing 460 base pairs of the phosphoenolpyruvate (P-enolpyruvate) carboxykinase promoter-regulatory region ligated to the bovine growth hormone structural gene, into the male pronucleus of fertilized mouse eggs.
(4) Retrievals in which one or more oocytes exhibited one pronucleus were compared with retrievals in which no one-pronuclear oocytes (control) were observed.
(5) Strengthening of lethal and cytogenetic effects was only observed in case when embryos were placed in the caffeine solution, prior to onset of the first DNA replication in the male pronucleus.
(6) During the course of the formation of the male pronucleus, the subacrosomal rod and tail become detached from the head and disintegrate.
(7) Following transvaginal sonographic oocyte retrieval in vitro fertilization is performed and the fertilized (pronucleus-stage) or embryos are transferred into the tube by laparoscopy.
(8) When the drug is removed 3 h after insemination, the meiotic spindle(s) is reconstructed, the second polar body(ies) is extruded, and a female pronucleus (or micronuclei) forms.
(9) Evaluation of data concerning DNA amounts, heterochromatin contents, distribution of breaks, repair capacities in two-break sites and oxygen concentrations in mature spermatozoa revealed no contradiction to the hypothesis that the greater sensitivity of Phryne cincta is mainly due to a high degree of spiralization of the paternal pronucleus chromosomes.
(10) This conditioned medium was alone able to affect sperm penetration and male pronucleus formation in cumulus oocytes, but it did not exert any influence on denuded oocytes.
(11) Sperm centrioles were also closely associated with the male pronucleus (16-20 hr after insemination) in pronuclear stage embryos.
(12) Microtubules of unknown origin are associated with the sperm pronucleus during its migration.
(13) Correction of polyspermy through pronucleus extraction in the absence of membrane relaxants was applied to 25 polyspermic human zygotes.
(14) On the other hand, in the fully mature oocytes, which were activated by sperm penetration, the sperm nucleus was transformed into the male pronucleus.
(15) From the nine eggs used in this experiment one egg developed a pronucleus and one egg developed to a four-cell stage.
(16) Mature sperm have neither detectable centrosomes nor detectable kinetochores, and shortly after sperm incorporation kinetochores become detectable in the decondensing male pronucleus.
(17) In frogs and mammals, the oocytes are arrested at the second metaphase of meiosis whereas in echinoderms they are blocked later, at the pronucleus stage.
(18) This centrosome is attached to the centrosomal fossa, a bowl-shaped depression of the nuclear envelope of the male pronucleus.
(19) One per cent displayed a single pronucleus, and haploid chromosome complements were found in the corresponding cleaved embryos which were considered to be parthenotes.
(20) Studying the haploid portion of the male pronucleus using the hamster test reflects the process of meiosis.