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.
References in periodicals archive ?
The micropylar collar was prominent and continuous and presented a conspicuous micropylar disc (diameter: 20.4 [micro]m, thickness: 7.96 [micro]m; Figure 1C) at its centre; and the micropyle (diameter: 2.4 [micro]m) was observed in the centre of this disc (Figure 1D).
[16.] Yanagimachi R (1957) Some properties of the sperm-activating factor in the micropyle area of the herring egg.
The integument reached the top of the nucellus and formed a micropyle through continuous cell division.
(B) Scanning electron microscopy photograph of an Atala egg showing highly sculptured chorion ultrastructure and micropyle. Bar measures 200 pm.
This hypothesis is supported by BEAMENT (1948, 1952), who reported the role of the micropyle in transporting insecticides to the interior of the egg, since the chorion is an impermeable structure for toxic substances.
The importance of the duration of sperm motility is in the time required by the sperm to penetrate the oocyte micropyle and for fertilization to occur.
In form, the seed is oval and much closer towards the micropyle [40].
On its way, the pollen tube penetrates the stigmatic surface, is then guided through the stigma and style and placenta, grows onto the funiculus, and finally enters the micropyle of the ovule for double fertilization (Figures 1 and 3A).
Butterfly eggs These eggs can be things of beauty, with ribbing and fluting pointing the eye toward a little opening called the micropyle. Through the micropyle, sperm enter and fertilize a typically oval or round egg as it is being deposited on a leaf.
Morphological information did not extend to the micropyle, ridge pattern or filaments on the ova or eggs.
With this strategy, spermatozoa are stored in the micropyle of eggs within the ovary after gamete transfer to the female and eggs are not fertilized until immersed in seawater.
Through division of the cells in the micropylar end of the nucellus, a cell proliferation is developed that extends beyond the micropyle (Figure 6A).