Definition of micropyle in English:

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Pronunciation: /ˈmīkrəˌpīl/


1A small opening in the surface of an ovule, through which the pollen tube penetrates, often visible as a small pore in the ripe seed.
Example sentences
  • It remains to be studied exactly how the pollen tubes reach the micropyle of the ovules.
  • However, pollen tubes from control pollen showed normal morphology when growing towards the micropyle of an ovule in a HTS plant.
  • Within the ovary, pollen tubes also grew in the ECM to penetrate the micropyle and subsequently grew intercellularly within the nucellus up to the embryo sac.
1.1A small opening in the egg of a fish, insect, etc., through which spermatozoa can enter.
Example sentences
  • Coupling these screens with a visual assessment of seed formation has yielded mutants defective in FG development or in the ability of pollen tubes to release their sperm after entering the micropyle.
  • In a favorable situation, an opening called the micropyle appears and releases amoebocytes, which differentiate into cells of all the other types.
  • Each cupule is recurved, has a lip-like projection near the point of attachment, and contains several ovules arranged in a curved row with their micropyles facing the cupule opening.



Pronunciation: /ˌmīkrəˈpīlər/
Example sentences
  • Changes in peroxidase activities in the micropylar and the lateral endosperm half of tomato seeds were followed after the beginning of imbibition.
  • The activities of both enzymes increase in a similar temporal manner in the micropylar and lateral endosperm during and following germination.
  • They bear a single wing on one shoulder of the triangular seed body, opposite the tapered, micropylar end, which renders them bilaterally asymmetrical in the plane of compression.


Early 19th century: from micro- 'small' + Greek pulē 'gate'.

For editors and proofreaders

Syllabification: mi·cro·pyle

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