Pronucleus

The nucleus of a sperm or an egg prior to fertilization. Sperm and egg cells carry half the number of chromosomes of other nonreproductive cells. When the pronucleus of a sperm fuses with the pronucleus of an egg, their chromosomes combine and become part of a single nucleus in the resulting embryo, containing a full set of chromosomes. See also chromosome, nucleus, transgenic

The nucleus of a sperm or egg prior to fertilization. See also: nucleus, transgenic

Either of the two haploid gamete nuclei just prior to their fusion in the fertilized ovum.