oocyte


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oocyte

 [o´o-sīt]
an immature ovum; it is derived from an oogonium, and is called a primary oocyte prior to completion of the first maturation division, and a secondary oocyte between the first and second maturation division.

o·o·cyte

(ō'ō-sīt),
Female gamete or sex cell. When fertilized by a sperm, an oocyte is capable of developing into a new individual of the same species; during matuation, the oocyte, like the sperm, undergoes a halving of its chromosomal complement so that, at its union with the male gamete, the species number of chromosome (46 in humans) is maintained; yolk contained in the oocytes of different animal species varies greatly in amount and distribution, which influences the pattern of the cleavage divisions.
See also: egg, ovum.
Synonym(s): ovocyte
[G. ōon, egg, + kytos, a hollow (cell)]

oocyte

(ō′ə-sīt′)
n.
A diploid cell from which an egg or ovum develops by meiosis. A primary oocyte divides to produce a polar body and a secondary oocyte, which divides again to produce the ovum and another polar body.

oocyte

Egg Histology The female reproductive or germ cell. Cf Sperm.

o·o·cyte

(ō'ŏ-sīt)
The female sex cell. When fertilized by a sperm, a gamete or zygote is capable of developing into a new individual of the same species; during maturation, the oocyte, like the sperm, undergoes a halving of its chromosomal complement so that, at its union with the male gamete, the species number of chromosomes (46 in humans) is maintained; yolk contained in the oocyte (ova in nonhuman species) varies greatly in amount and distribution, which influences the pattern of the cleavage divisions. In nonhuman females, the term is ovum.
[G. ōon, egg, + kytos, a hollow (cell)]

oocyte

A cell in the OVARY that undergoes MEIOSIS to produce an OVUM. In meiosis the 46 chromosomes are reduced to half the normal number (HAPLOID), so that the full complement can be restored by a haploid contribution from the sperm. Primary oocytes develop in the ovaries of the fetus but only a fraction of these will ever give rise to OVULATION. Secondary oocytes divide to form the mature OVUM but the second maturation division occurs only after the ovum has been fertilized by a sperm.

oocyte

an early stage in GAMETO GENESIS of female animals, ‘primary’ oocytes being DIPLOID (1) and ‘secondary’ oocytes HAPLOID (1) having undergone the first meiotic division. Human females are born with the primary oocytes already formed, which may increase the risk of NONDISJUNCTION of chromosomes. See also DOWN'S SYNDROME.

o·o·cyte

(ō'ŏ-sīt)
Female gamete or sex cell.
[G. ōon, egg, + kytos, a hollow (cell)]
References in periodicals archive ?
In the present study, the effect of cryoprotectants at different stages of oocyte development (pool from the initial to vitelogenic; or mature stage) was studied.
When we have surplus oocytes, we propose them to a woman candidate for IVF who wanted to use her own oocytes but who turned out to be a poor responder.
In contrast to men who produce new sperm cells throughout their life women are born with a finite number of oocytes. When this pool is depleted menopause starts.
Oocyte of MII stage oocyte: To obtain MII oocytes, adult female mice ovaries were superovulated by IP injection of 10 IU PMSG followed with another injection of 10 IU human chorionic gonadotrophin (hCG, Sereno, Switzerland) 48 h later.
Table-II: Correlation of oocytes with ovarian reserve parameters.
Oocyte maturation: gamete-somatic cells interactions, meiotic resumption, cytoskeletal dynamics and cytoplasmic reorganization.
santolla, the particular organization of the oocytes, according to the morphological characteristics to the interior of the maturation lobes, suggests a synchronous oocyte maturation, which progresses as the oocytes move away from the center of the ovary.
MII oocyte was considered mature, while embryo quality grading was based on the standards described in literature.15 The high-quality embryo was defined as at least 6 cells generated from cleavage on day 3, with generally uniform size and morphology and <20% cell debris.16 Embryo implantation rate was defined as the number of intrauterine gestational sac divided by the number of transferred embryos.
In cattle, reproductive life duration is much shorter, hence oocyte number present in ovary and number of ovulations also comparatively lower than human beings.
They were hollow collapsed structures with a hypertrophied granulosa in the space previously occupied by the oocyte (Fig.
Accumulation of oocytes and/or embryos by vitrification: a new strategy for managing poor responder patients undergoing pre implantation diagnosis.