oogonium


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oogonium

 [o″o-go´ne-um]
[Gr.], a primordial oocyte during fetal development; near the time of birth it becomes a primary oocyte.

o·o·go·ni·um

, pl.

o·o·go·ni·a

(ō'ō-gō'nē-ŭm, -ă),
1. Primordial germ cells; proliferate by mitotic division. All oogonia develop into primary oocytes before birth occurs; no oogonia are present after birth.
2. In fungi, the female gametangium bearing one or more oospores.
[G. ōon, egg, + gonē, generation]

oogonium

(ō′ə-gō′nē-əm)
n. pl. oogo·nia (-nē-ə) or oogo·niums
1. Any of the cells that give rise through mitosis to the oocytes and are found in the ovaries of vertebrates.
2. A female reproductive structure in certain thallophytes and in oomycetes, usually a rounded cell or sac containing one or more oospheres.

o′o·go′ni·al (-nē-əl) adj.

o·o·go·ni·um

, pl. oogonia (ō'ŏ-gō'nē-ŭm, -nē-ă)
1. Primordial germ cells; proliferate by mitotic division.
2. In fungi, the female gametangium bearing one or more oospores.
[G. ōon, egg, + gonē, generation]

oogonium

  1. an early DIPLOID (1) stage in GAMETOGENESIS of female animals giving rise to the OOCYTES.
  2. (in algae and fungi) the female sex organ containing the OOSPHERES.
References in periodicals archive ?
As for the germinal cells, positive PR existed in the cytoplasm during the early ovary development stages (stages I-III), including oogonium and endogenous vitellogenic oocytes, whereas positive PR stained in the nucleus of oocyte cells during stage III to stage V.
This research was prepared for the study on mechanism of bovine oogonium's proliferation and differentiation.
It was also beneficial for regulation environment simulation for oocyte gene expression in vivo and study regulation of c-FLIP(L) on differentiation and proliferation of oogonium at the gene level.
Three main stages of development were observed: (1) undeveloped (ovary transparent, oocyte oogonium), (2) developing (ovary cream, oocyte early, middle, or late nucleolus) and (3) early ripe or ripe (ovary yellow or dark yellow, yolk granule or premature).
A single-celled oogonium (not a multicellular archegonium, as found in embryophytes) surrounds the single egg cell; however, the nonmotile female gamete, and oogamous reproduction, are similar to embryophytes.
Analysis on the basis of cell size and morphology revealed five stages of female germ cell: the oogonium and four stages of oocyte.
Each oogonium had a large nucleus with chromatin, several mitochondria and the endoplasmic reticulum in the cytoplasm (Fig.