animal pole


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an·i·mal pole

the point in a telolecithal oocyte (egg) opposite the yolk, where most of the protoplasm is concentrated and where the nucleus is located; from this region, the polar bodies are extruded during maturation.
Synonym(s): germinal pole

animal pole

n. Embryology
The portion of an egg that is opposite the vegetal pole, that contains the nucleus and most of the cytoplasm, and from which polar bodies are extruded during maturation.

animal pole

Etymology: L, anima
the active, formative part of an ovum. It contains the nucleus and the bulk of the cytoplasm and is the site where the polar bodies form. In mammals, the animal pole is also the site where the inner cell mass develops and gives rise to germ layers. Also called germinal pole. Compare vegetal pole.

an·i·mal pole

(an'i-măl pōl)
The point in a telolecithal egg opposite the yolk, it is the site of the nucleus and most of the protoplasm; from this region, polar bodies are extruded during maturation.
Synonym(s): germinal pole.
Animal poleclick for a larger image
Fig. 36 Animal pole . The animal pole in a generalized ovum.

animal pole

the point on the surface of an animal ovum nearest to the nucleus and normally at the opposite side of the egg from the aggregation of yolk droplets at the VEGETAL POLE.
References in periodicals archive ?
The inhibition of pronuclear movements by dibromo-BAPTA is consistent with the explanation that the buffer disrupts the organization of microtubules near the animal pole.
The suggestion that the medaka egg has two independent microtubule networks is consistent with the situation in X, laevis, in which two independent networks of microtubules are present during the first cell cycle: one is near the animal pole and is associated with the pronuclei, while the other is the parallel array of microtubules near the vegetal pole (Elinson and Rowning, 1988; Houliston and Elinson, 1991; Elinson and Palacek, 1993; Sardet et al.
The movements of droplets within the irradiated regions were very similar to those in control (not treated with demecolcine) eggs; that, is roughly along meridian lines and away from the animal pole [ILLUSTRATION FOR FIGURE 3 OMITTED].
Droplets of mineral oil were injected into five eggs, which were oriented with their animal pole uppermost.
We injected vegetable oil into 11 eggs and oriented them with their animal pole uppermost.
In other words, endogenous droplets, moving toward the vegetal pole, passed by the droplets of injected fluid, which were either stationary or moving toward the animal pole.
The inhibition suggests that the formation of the blastodisc in the medaka egg is the result of the streaming of ooplasm to the animal pole and that microfilaments are involved in this streaming.
2+] present at the animal pole throughout the period of segregation (Fluck et al.
Specifically, in demecolcine-treated eggs oriented with their animal pole uppermost, oil droplets collected at the animal pole even as ooplasm was also streaming in that direction.
Moreover, the failure of injected droplets of several other fluids - fluorinated aliphatic compounds, silicone fluid, mineral oil, and vegetable oil - consistently to move away from the animal pole and toward the vegetal pole during segregation is inconsistent with the hypothesis.