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 ?
Influence of oocyte recovery method, in vitro fertilization method and serum source on embryonic development of in vitro matured bovine oocytes.
In vitro maturation, fertilization and embryo culture of oocytes obtained from vitrified auto-transplanted Mouse ovary.
The first visible sing of atresia in vitellogenic oocytes (stage 5 atretic oocytes), was the thickening of the zona radiata.
Correlation of oocytes with ovarian reserve parameters: A moderate negative correlation of age and FSH levels were observed with quality of oocytes, number of oocyte inseminated, number of oocyte fertilized and number of follicle restored.
Each test was repeated three times, and 30 oocytes were analyzed per group in each replicate.
The chromatin nucleolus, early chromatin perinucleolus and late chromatin perinucleolus oocytes were observed in the previtellogenic stage, (Figs.
Number of retrieved oocytes (n)###19.03+-9.75**###13.85+-8.56###12.07+-6.94###10.28+-9.31###0.006
On day 17 the endometrium had reached a thickness of 8 mm and 3 MII oocytes from a matched donor were fertilized; two embryos (both 4 cell stage, grade I) were transferred on day 19.
In non-damaged oocytes, p63 exists in an inactive form.
Oocytes of GV stage: Adult female mice ovaries were superovulated by intraperitoneal injection (IP) of 10 IU pregnant mare serum gonadotrophin (PMSG, Folligon; Intervet, Australia).