Micropyle

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micropyle

[′mī·krə‚pīl]
(botany)
A minute opening in the integument at the tip of an ovule through which the pollen tube commonly enters; persists in the seed as an opening or a scar between the hilum and point of radicle.

Micropyle

 

(1) An opening in the membrane of the eggs of insects, arachnids, some mollusks, fishes, and a number of other animals, through which the spermatozoon penetrates. (2) An opening in the apex of the ovule in higher seed plants, through which the pollen tube penetrates during pollination. The micropyle is formed because the integuments surrounding the ovule are unattached.


Micropyle

 

the canal in the integument or integuments of a plant through which the ovule is penetrated in gymnosperms by pollen grains and in angiosperms by pollen tubes. The external opening of the micropyle may be observed on the surface of a mature seed in the form of a dark dot.

References in periodicals archive ?
The non-adhesive micropyle region contains the major sperm-activating molecule, sperm motility initiating factor (SMIF), and this glycoprotein induces sperm motility and functions to maintain sperm in the micropyle region, thus enhancing chances for fertilization (Yanagimachi et al.
Egg architecture of Naucoridae (Heteroptera): internal and external structure of the chorion and micropyle Proc Entomol Soc Wash 101(1):1-25.
two ovules, their micropyles directed towards the cone axis, borne on the adaxial surface of an ovuliferous scale itself in the axil of a bract, to make a compound structure in accordance with Florin's model.
the micropyle of the exposed ovule, which ancestrally has produced a drop of secreted water.
The fine structure of the micropyles of the eggs of Myxine glutinosa and Eptatretus burgeri (Cyclostomata).
Although the mechanism or mechanisms by which motility was inhibited were not investigated, three possibilities seem plausible: (1) The ability of SMIF to elicit motility could be affected; since the presence of SMIF in the micropyle area is essential for sperm motility (Yanagimachi et al.
Some properties of the sperm activating factor in the micropyle area of the herring egg.