Found 2 items, similar to pronucleus.
English → English (WordNet) Definition: pronucleus pronucleus n : the nucleus of the ovum or sperm after fertilization but before they fuse to form the nucleus of the zygote [also: pronuclei (pl)]
English → English (gcide) Definition: Pronucleus Pronucleus \Pro*nu"cle*us\, n.; pl. Pronuclei (-[imac]). [NL. See Pro-, and Nucleus.] (Biol.) One of the two bodies or nuclei (called male and female pronuclei) which unite to form the first segmentation nucleus of an impregnated ovum. [1913 Webster] Note: In the maturing of the ovum preparatory to impregnation, a part of the germinal vesicle (see Polar body, under Polar) becomes converted into a number of small vesicles, which aggregate themselves into a single clear nucleus. which travels towards the center of the egg and is called the female pronucleus. In impregnation, the spermatozo["o]n which enters the egg soon loses its tail, while the head forms a nucleus, called the male pronucleus, which gradually travels towards the female pronucleus and eventually fuses with it, forming the first segmentation nucleus. [1913 Webster]