Archegonium

Diagram of archegonium anatomy

An archegonium (pl: archegonia), from the ancient Greek ἀρχή ("beginning") and γόνος ("offspring"), is a multicellular structure or organ of the gametophyte phase of certain plants, producing and containing the ovum or female gamete. The archegonium has a long neck canal and a swollen base. Archegonia are typically located on the surface of the plant thallus, although in the hornworts they are embedded.

In the moss Physcomitrella patens, archegonia are not embedded but are located on top of the leafy gametophore (s. Figure). The Polycomb protein FIE is expressed in the unfertilised egg cell (right) as the blue colour after GUS staining reveals. Soon after fertilisation the FIE gene is inactivated (the blue colour is no longer visible, left) in the young embryo.^[1][2]

Gene expression pattern determined by histochemical GUS assays in Physcomitrella patens

They are also much-reduced and embedded in the megagametophytes of gymnosperms. The term is not used for angiosperms or the gnetophytes Gnetum and Welwitschia because the megagametophyte is reduced to just a few cells, one of which differentiates into the egg cell. The function of surrounding the gamete is assumed in large part by diploid cells of the megasporangium (nucellus) inside the ovule. Gymnosperms have their archegonium formed after pollination inside female pine cones (megastrobili).^[3]

The corresponding male organ is called the antheridium.

References

1. ^ Assaf Mosquna, Aviva Katz, Eva L. Decker, Stefan A. Rensing, Ralf Reski, Nir Ohad (2009): Regulation of stem cell maintenance by the Polycomb protein FIE has been conserved during land plant evolution. Development 136, 2433-2444. [1]
2. ^ The Polycomb gene FIE is expressed (blue) in unfertilised egg cells of the moss Physcomitrella patens (right) and expression ceases after fertilisation in the developing diploid sporophyte (left). In situ GUS staining of two female sex organs (archegonia) of a transgenic plant expressing a translational fusion of FIE-uidA under control of the native FIE promoter. [2]
3. ^ Brooklyn Botanic Garden[3]

This botany article is a stub. You can help Wikipedia by expanding it.v · Categories: Plant anatomy Cryptogams Gymnosperms Plant reproduction Botany stubs Wikimedia Foundation. 2010. Игры ⚽ Поможем сделать НИР Interphase Imperial Circle Look at other dictionaries: Archegonium — (unreif, reif, und befruchtet) von Marchantia polymorpha …   Deutsch Wikipedia Archegonium — Ar che*go ni*um, n. [NL., fr. Gr. ? the first of a race.] (Bot.) The pistillidium or female organ in the higher cryptogamic plants, corresponding to the pistil in flowering plants. [1913 Webster] …   The Collaborative International Dictionary of English archegonium — archegonium. См. архегоний. (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. Archegonĭum — (griech.), das weibliche Geschlechtsorgan der höhern Kryptogamen (s. d. und Moose) …   Meyers Großes Konversations-Lexikon Archegonium — Archegonium, mehrzelliges, von einer einschichtigen Wand aus sterilen Zellen umgebenes, meist flaschenförmiges f Gametangium der Moose und Farnpflanzen, in dem stets nur eine Eizelle gebildet wird. Am Grunde des A. befindet sich eine… …   Deutsch wörterbuch der biologie archegonium — [är΄kə gō′nē əm] n. pl. archegonia [är΄kə gō′nē ə] [ModL, dim. < Gr archegonos, the first of a race: see ARCH & GONIUM] the flask shaped female reproductive organ in mosses, ferns, and other related plants archegonial adj …   English World dictionary archegonium — archegonial, archegoniate /ahr ki goh nee it, ayt /, adj. /ahr ki goh nee euhm/, n., pl. archegonia / nee euh/. Bot. the female reproductive organ in ferns, mosses, etc. [1850 55; < NL, equiv. to archegon ( < Gk archégonos first of a race; see… …   Universalium Archegonium — Ar|che|go|ni|um 〈[ çə ] n.; s, ni|en; Bot.〉 weibl. Fortpflanzungsorgan bei Moosen u. Farnen [<grch. archegonos „uranfänglich, zuerst entstanden“] * * * Archegonium   [zu griechisch archégonos »Stammvater eines Geschlechts«, »Urheber«] das, s/ …   Universal-Lexikon archegonium — noun (plural archegonia) Etymology: New Latin, from Greek archegonos originator, from archein to begin + gonos procreation; akin to Greek gignesthai to be born more at arch , kin Date: 1854 the flask shaped female sex organ of bryophytes, lower… …   New Collegiate Dictionary archegonium — Female sex organ of liverworts, mosses, ferns and most gymnosperms …   Dictionary of molecular biology 18+ © Academic, 2000-2024 Contact us: Technical Support, Advertising Dictionaries export, created on PHP, Joomla, Drupal, WordPress, MODx. Mark and share Search through all dictionaries Translate… Search Internet Share the article and excerpts Direct link … Do a right-click on the link above and select “Copy Link”