pronucleus

IPA: proʊnˈukɫiʌs

Either of the two haploid nuclei (of a sperm and ovum) that fuse during fertilization

Examples of "pronucleus" in Sentences

The nucleus of the mature ovum is termed the female pronucleus.
Now the centrosome, which is beside the male pronucleus, shows signs of activity.
In the process a pronucleus is formed which then combines with the female pronucleus.
In this way the centrosome approaches the female pronucleus, and thus finally the two nucleii are brought into close proximity.
Close to it lies its centrosomes (Fig. 35, _ce_), and there is thus formed what is known as the _male pronucleus_ (Fig. 35-40, _mn_).
-- Completion of the process of extrusion of the chromatic material; _fn_ shows the two chromosomes retained in the egg forming the female pronucleus.
The chromatin material, in both the male and female pronucleus, soon breaks up into a network in which it is no longer possible to see that each contains two chromosomes (Fig. 41).
It becomes surrounded by prominent rays to form an aster (Fig. 41, _ce_), and then it begins to move toward the female pronucleus, apparently dragging the male pronucleus after it.
The tail by which it has been moving is cast off, and the head containing the chromosomes and the centrosome enters the egg, forming what is called the male pronucleus (Figs. 35-38, _mn_).
If, however, it takes place before, the male pronucleus simply remains dormant in the egg while the polar cells are being protruded, and not until after that process is concluded does it begin again to show signs of activity which result in the cell union.