oogenesis


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oogenesis

 [o″o-jen´ĕ-sis]
the development of mature ova from oogonia. adj., adj oogenet´ic.

o·o·gen·e·sis

(ō'ō-jen'ĕ-sis),
Process of formation and development of the oocyte.
Synonym(s): ovigenesis, ovogenesis
[G. ōon, egg, + genesis, origin]

oogenesis

/oo·gen·e·sis/ (o″o-jen´ĕ-sis) the process of formation of female gametes (oocytes).oogenet´ic
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Oogenesis, depicting only six of the 46 double-stranded chromosomes (oogonium, primary oocyte), three of the 23 double-stranded chromosomes (secondary oocyte, first polar body), and three of the 23 single-stranded chromosomes (second polar body, spermatozoon, and female and male pronuclei) in human oogenesis, and showing random assortment of homologous chromosome pairs. Crossing over, which may occur in meiosis I, has been omitted. Progression through meiosis II is only completed if fertilization occurs; the spermatozoon and male pronucleus are depicted out of scale for clarity.

oogenesis

(ō′ə-jĕn′ĭ-sĭs)
n.
The formation, development, and maturation of an ovum.

o′o·ge·net′ic (-jə-nĕt′ĭk) adj.

oogenesis

[ō′əjen′əsis]
Etymology: Gk, oon + genesis, origin
the formation of the female gametes, or ova. The female infant is born with the entire number of primary oocytes that will function throughout reproductive life. Only a fraction of these survive until puberty, and only a small percentage will be ovulated. Follicles containing the primary oocytes are found in varying stages of development in the ovary of the sexually mature woman. Egg and sperm formation differ considerably in the number and size of gametes resulting from gametogenesis, the total number of gametes produced in a lifetime, and the time sequence for the initiation of the meiotic divisions and the completion of the cycle. Also called ovogenesis. Compare spermatogenesis. See also gametogenesis, meiosis, menstrual cycle, ovulation. oogenetic, adj.
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Oogenesis

oogenesis

Embryology The process of ♀ gamete formation

o·o·gen·e·sis

(ō'ŏ-jen'ĕ-sis)
Process of formation and development of the oocyte.
Synonym(s): ovigenesis.
[G. ōon, egg, + genesis, origin]
Enlarge picture
OOGENESIS

oogenesis

(o?o-jen'e-sis) [? + genesis, generation, birth]
The developmental process by which the mature human ovum (the female reproductive cell) is formed. Formation begins during the first 3 months of female embryonic life with the development of ovarian follicles. Each follicle contains one oogonium which, through the process of mitosis, becomes a primary oocyte containing 46 chromosomes. The oocyte then undergoes the first meiotic reduction division, resulting in formation of a secondary oocyte and a polar body, each containing 22 autosomes (half the number of chromosomes that are found in nongerm cells) and one X heterosome. Further division is arrested in prophase until the female reaches puberty. The second meiotic division begins at ovulation and reaches metaphase where, once again, division is arrested until the ovum is fertilized. The second meiotic division is completed at fertilization, ending with formation of the mature haploid ovum and one polar body. Synonym: ovigenesis
See: illustration; meiosisoogenetic (-je-net'ik), adjective

oogenesis

The production of egg cells (ova) in the ovaries and their preparation for release and fertilization. Oogenesis starts in the fetal ovary with the formation of OOGONIA. These divide by MEIOSIS to form OOCYTES.

oogenesis

or

ovogenesis

the process of GAMETE production in female DIPLOID (2) animals. see GAMETO GENESIS.

oogenesis

the development of mature ova from oogonia. See also avian oogenesis.
References in periodicals archive ?
Archegonial development, fern, oogenesis, phylogeny, Plagiogyria euphlehia
On the other hand, this development differs from that of Photinus ignitus (Fall) (Coleoptera: Lampyridae) females that store substances produced by accessory glands of the reproductive tract of males and digests them into amino acids for oocytes up to two days after mating (ROONEY; LEWIS, 1999), which demonstrates the importance of mating for the oogenesis of this insect.
Immune physiologyand oogenesis in fetal and adulthumans, ovarian infertility, and totipotencyofadultovarian stem cells.
Vitellogenin is a protein produced in female fish in response to estradiol production during normal cycles of oogenesis.
The bunched (bun) gene in Drosophila is required for several developmental events such as follicle cell patterning during oogenesis and peripheral nerve system formation during embryo genesis.
The dynamics of oogenesis and the annual ovarian cycle of Stichopus californicus (Echinodermata: Holothuroidea).
It mandates that genomes, before they unite, must undergo oogenesis and spermatogenesis.
Oogenesis and sexual maturation in Merelrix lusoria (Roding 1798) (Bivalvia: Veneridae) in western Korea.
Oogenesis is a nutrition-limited process, and nutrition is obtained during both the larval and adult stage.
The steroid hormone estrogen is essential in reproduction and plays important roles in sexual maturation and differentiation, including oogenesis, vitellogenesis, and testicular development.
Although the applicability of these in vitro findings to the in vivo setting is uncertain, aromatase is required for the transformation of androgen to estradiol, and estrogen receptor P mediates estrogen effects in granulosa cells, actions that are essential for follicular growth and maturation, oogenesis, ovulation, and normal luteal functions in vivo (Ryan 1982).