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

/oo·cyte/ (-sīt) the immature female reproductive cell prior to fertilization; derived from an oogonium. It is a primary o. prior to completion of the first maturation division, and a secondary o. in the period between the first and second maturation divisions .

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

[ō′əsīt]
Etymology: Gk, oon + kytos, cell
a primordial or incompletely developed ovum.

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)]

oocyte

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.
References in periodicals archive ?
During the early stages of meiosis, the primary oocyte becomes surrounded by a single layer of follicular cells.
During this phase, follicular diameter increases from 20 to 400 [micro]m due largely to growth of the primary oocyte.
One fish sampled from the control river water exposure group was identified as intersex and contained a small number of primary oocytes in the perinucleolar stage.
The intersex condition included clusters of primary oocytes nested in an otherwise normal testicular tissue and, in the more severe condition, contained secondary oocytes (Figure 6E).
Primary oocyte An intermediate cell type in oogenesis arising from an oogonium and remaining in the first meiotic prophase until ovulation.
Primordial follicle The most primitive follicle consisting of the primary oocyte surrounded by a single layer of follicular cells with a thin basement membrane.
5h, arrow); RVPOs (187-200 [micro]m), and smaller new vitellogenic primary oocytes (NVPOs) (<100 [micro]m), the latter resulting from recent oogonial mitosis (Fig.
In addition in experiment groups the reduction in the number of primary oocytes has been noticed and it was observed that the development of oocytes were stopped.
membranacea ovarian, coelomic, and recently spawned oocytes indicates that sperm fuse with primary oocytes during or shortly after ovulation.
At ovulation, usually only 1 primary oocyte divides to produce a secondary oocyte.

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