During fertilization, 23 chromosomes from the egg come together with 23 chromosomes from the sperm to form the complete set of 46 chromosomes in the embryo. These 23 chromosomes are carried in structures called pronuclei (singular: pronucleus) which are visible under the microscope after about 16-18 hours after the egg is inseminated. This is how embryologists determine fertilization occurred. 2PN indicates normal fertilization, while abnormal fertilization can be 0PN, 1PN, or 3PN.
Synonyms:
pronucleus, pronuclei, 1 PN, 2 PN, 3 PN, 0 PN, 1PN, 2PN, 3PN, 0PN, 4PN, 4 PN, PN, PNs