micropyle


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Related to micropyle: embryo sac, synergid, antipodal cells

mi·cro·pyle

(mī'krō-pīl),
1. Minute opening believed to exist in the investing membrane of certain oocytes as a point of entrance for the sperm.
2. Former name for micropore.
[micro- + G. pylē, gate]

micropyle

(mī′krə-pīl′)
n.
Zoology A pore in the membrane covering the ovum of some animals through which a spermatozoon can enter.

mi′cro·py′lar adj.

micropyle

a small canal in the integument surrounding the ovule of a flowering plant, through which the POLLEN TUBE usually enters the ovule on the way to the EMBRYO SAC. Water enters the seed via the micropyle prior to GERMINATION.

micropyle

an opening through which a spermatozoon enters certain ova.
References in periodicals archive ?
The duration of sperm motility was much lower than the average time of opening of the micropyle, 27 seconds, and in this way it can reduce the sperm penetration ability.
The eight nuclei are normally arranged with four at the micropyle end and four at the opposite end of the embryo sac.
Oocyte size was measured as the mean length of six mature oocytes (those with a visible micropyle on the chorion) using a microscale (BioQuip) with a 0.
In teleosts, the only common aspect is the absence of an acrosome, which has been related to the presence of a micropyle in the egg (Riehl, 1997).
Following germination, inhibition of pollen growth can occur at any time before entering the micropyle at the base of the ovary and the subsequent fertilization of the egg cell and central cell.
General egg sculpture disappears in the side where micropyle takes place (Fig.
Sperm enters the egg through the micropyle, a small opening in the chorion.
57) oblong, bearing conspicuous micropyle at narrow end, opposite end is papillose; seed coat thick, woody, comprising nearly 20--25% of the diameter of the seed; empty individuals are dark brown to black in color, some specimens are reddish in color due to the reflectance of white endosperm within the seed; examination of endosperm from seeds shows cells intact; embryo present (Fig.
5 Stieda bodies A prominent stieda body present; sub- and parastieda bodies absent Sporocyst residuum Prominent; made up of clumped globules Micropyle Absent Sporozoites Two per sporocyst 10-13 by 1.
Twenty-two percent of the variation in fertilizing sperm length was associated with historical events perhaps due to constraints imposed by the requirements for successful sperm storage by females, penetration of the micropyle, and subsequent karyogamy.
The presence of a micropyle and the mat of adhesive, chorionic filaments in ripe ova and their absence in ripening ova unequivocally demonstrate that ova classified as ripe are the most developed, pre-oviposited stage.