Editing Archegonium (section)

==Bryophytes==
In [[bryophytes]] and other [[cryptogam]]s, [[sperm]] reach the archegonium by swimming in water films, whereas in [[Pinophyta]] and [[angiosperms]], the [[pollen]] are delivered by wind or animal vectors and the sperm are delivered by means of a [[pollen tube]].{{cn|date=December 2023}}

[[File:DEV035048A.jpg|thumb|Gene expression pattern determined by histochemical GUS assays in ''[[Physcomitrella patens]]'']]
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 unfertilized [[egg cell]] (right) as the blue colour after [[GUS reporter system|GUS staining]] reveals. Soon after [[fertilisation]], the [[FIE gene]] is inactivated (the blue colour is no longer visible, left) in the young embryo.<ref>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. [http://dev.biologists.org/cgi/content/short/136/14/2433]</ref><ref>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.
{{cite web
 |url=http://dev.biologists.org/content/vol136/issue14/cover.shtml
 |title=Development -- About the Cover (July 2009, 136, (14))
 |access-date=2009-07-03
 |url-status=dead
 |archive-url=https://web.archive.org/web/20090626214348/http://dev.biologists.org/content/vol136/issue14/cover.shtml
 |archive-date=2009-06-26
}}</ref>