Oocyte

An Oocyte is a cell in an ovary that may undergo meiotic division to form an ovum. Oocytes are produced in the ovaries during female sexual development. The process of forming an oocyte is called oogenesis.

Structure

Oocytes are surrounded by granulosa cells and contained within a follicle. Each oocyte is contained within a follicle, which supports the developing oocyte and secretes hormones necessary for its development.

Development

Oocytes begin their development in the fetus. They are arrested in prophase of meiosis I and remain in this state until puberty. At puberty, hormonal changes cause the resumption of meiosis. The oocyte completes meiosis I to form the secondary oocyte and the first polar body. The secondary oocyte then begins meiosis II but is arrested in metaphase and will only complete meiosis II if fertilization occurs.

Function

The primary function of the oocyte is to contribute half of the genetic material necessary for the development of a new organism. The oocyte also provides the cytoplasm, mitochondria, and other cellular components necessary for early embryonic development.

Clinical significance

Abnormalities in oocyte development can lead to a variety of reproductive disorders, including infertility, polycystic ovary syndrome, and premature ovarian failure. Oocytes can also be harvested for use in in vitro fertilization procedures.

See also

• Oogenesis
• Ovarian follicle
• Meiosis
• Fertilization

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  Oocyte
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  Oocyte Poles
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  Oocyte Determinants