Oogonium


Oogonium
Oogonium
Gray's subject #3 38
MeSH Oogonia

"Oogonium" (plural oogonia) may refer to either a primordial oocyte in a female fetus or the female gametangium of certain thallophytes.

Contents

in the fetus

Oogonia are formed in large numbers by mitosis early in fetal development from primordial germ cells. In humans they start to develop between weeks 4 and 8 and are present in the fetus between weeks 5 and 30. Once the primordial germ cells have arrived in the ovary, they develop into oogonia. Oogonia migrate from the yolk sac to the genital ridge (site of the future ovaries) located on the posterior abdominal wall. Oogonia develop by mitosis. However, some of them become primary oocytes, which begin meiosis which is halted in prophase I. When they have entered Prophase I of meiosis they become primary oocytes; it is important to note that this process is complete before birth, in contrast to spermatogenesis. Primary oocytes are present from week 10 until menopause at ~53 years in human females.

in thallophytes

In phycology and mycology, oogonium refers to a female gametangium if the union of the male (motile or non-motile) and the female gamete takes place within this structure.[1][2] Oogonia are usually rounded cells or sacs containing one or more oospheres. The male (antheridium) usually produces many cells with flagella except in the Rhodophyta which have no flagella.[3]

References

  1. ^ Stegenga, H. Bolton, J.J. and Anderson, R.J. 1997. Seaweeds of the South African West Coast. Bolus Herbarium, University of Cape Tow. ISBN 0 7992 1793 X
  2. ^ Smyth, G.M. 1955. Cryptogamic Botany. vol. 1. McGraw-Hill Book Company
  3. ^ Fritsch, F.E. 1965. The Structure and Reproduction of the Algae. Vol. 1 Cambridge University Press

External links


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • oogonium — OOGÓNIUM s.n. Oogon. [pron. o o go ni um. / < germ. Oogonium, cf. it. oogonio]. Trimis de LauraGellner, 13.09.2007. Sursa: DN …   Dicționar Român

  • Oogonium — O [ o]*go ni*um, n.; pl. L. {O[ o]gonia}, E. {O[ o]goniums}. [NL., fr. Gr. w, o n an egg + ? offspring.] (Bot.) A special cell in certain cryptogamous plants containing o[ o]spheres, as in the rockweeds ({Fucus}), and the orders {Vaucherie[ae]}… …   The Collaborative International Dictionary of English

  • oogonium — oogonium. См. оогоний. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • Oŏgonĭum — (v. griech. ōŏn, »Ei«), das weibliche, die zur Empfängnis bereite Eizelle enthaltende Organ mancher Algen u. Pilze, das nach empfangener Befruchtung die Ei oder Oosporen erzeugt (s. Algen u. Pilze) …   Meyers Großes Konversations-Lexikon

  • Oogonium — Oŏgonĭum (grch.), das weibliche Fortpflanzungsorgan vieler Algen und Pilze, aus welchem nach Befruchtung die Oosporen hervorgehen …   Kleines Konversations-Lexikon

  • Oogonium — Oogonium, 1) Pflanzen: meist einzelliges Gametangium bei Algen und Pilzen mit ⇒ Oogamie, in dem eine oder mehrere Eizellen gebildet werden; 2) Tiere: Urkeimzelle im Eierstock der Metazoen, aus der bei der ⇒ Oogenese das Ei entsteht …   Deutsch wörterbuch der biologie

  • oogonium — [ō΄ōgō′nē əm , ō΄əgō′nē əm] n. pl. oogonia [ō΄ō gō′nēə, ō΄ə gō′nēə] or oogoniums [ModL < OO + GONIUM] 1. the female reproductive organ in certain algae and fungi, consisting of a large cell in which the eggs (oospheres) are developed 2.… …   English World dictionary

  • Oogonium — Antheridium (rot) und Oogon (rechts daneben) der Armleuchteralge Chara contraria Als Oogon oder Oogonium wird bei einigen Algen und Pilzen die unbewegliche Eizelle (die Oosphäre) mit ihrer Umhüllung bezeichnet. (Oogonium; vom Griechischen oon …   Deutsch Wikipedia

  • oogonium — Female sexual structure in certain algae and fungi, containing one or more gametes. After fertilization the oogonium contains the oospore …   Dictionary of molecular biology

  • Oogonium — A female ancestral germ cell that divides several times to give rise to an oocyte that, in turn, develops into an ovum (an egg). The second o in oogonium is pronounced separately from the first: o·o·gon·i·um. The word was created from the prefix… …   Medical dictionary


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.