pronucleus


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Related to pronucleus: Female pronucleus

pronucleus

 [pro-noo´kle-us]
the haploid nucleus of a germ cell.
female pronucleus the haploid nucleus of the fully mature oocyte, which loses its nuclear envelope and liberates its chromosomes to meet the synapsis with those from the male pronucleus.
male pronucleus the nuclear material of the head of a spermatozoon, after it has penetrated the oocyte and acquired a pronuclear membrane.

pro·nu·cle·us

, pl.

pro·nu·cle·i

(prō-nū'klē-ŭs, -klē-ī),
1. One of a pair of nuclei undergoing fusion in karyogamy.
2. In embryology, the nuclear material of the head of the sperm (male pronucleus) or of the oocyte (female pronucleus), after the oocyte has been penetrated by the sperm; each pronucleus normally carries a haploid set of chromosomes, so that the merging of the pronuclei in fertilization reestablishes diploidy.

pronucleus

(prō-no͞o′klē-əs, -nyo͞o′-)
n. pl. pronu·clei (-klē-ī′)
The haploid nucleus of a sperm or egg before fusion of the nuclei in fertilization.

pro·nu′cle·ar adj.

pro·nu·cle·us

, pl. pronuclei (prō-nū'klē-ŭs, -ī)
1. One of a pair of nuclei undergoing fusion in karyogamy.
2. embryology The nuclear material of the head of the sperm (male pronucleus) or of the oocyte (female pronucleus), after the oocyte has been penetrated by the sperm; each pronucleus normally carries a haploid set of chromosomes, so that the merging of the pronuclei in fertilization reestablishes the diploidy.
References in periodicals archive ?
Sperm pretreatment with dithiothreitol increases male pronucleus formation rates after intracytoplasmic sperm injection (ICSI) in swamp buffalo oocytes.
Separation of a pronucleus by premature cytokinesis: a mechanism for immediate diploidization of tripronuclear oocytes?
Formation of the male pronucleus and early embryonic development after sperm penetration was inhibited if oocytes which have no cumulus cells matured [20].
Pronuclear microinjection: The microinjection into pronucleous is the most common method known in microinjection of exogenous DNA into the pronucleus of a newly fertilized egg (zygote).
Of single stranded (S5) and ds DNA breaks, in the sperms the latter have greater mutagenic potential, because of the absence of an error free copy as a template for DNA repair in the G1 phase male pronucleus. The indices of DNA damage increase with decreasing sperm counts (27).
"First, they need to test if a normal male pronucleus with appropriate chromosome numbers and without mutations can form when introduced into an animal egg; and there has to be evidence that these sperm-like cells are properly reprogrammed with male-specific imprints, without which they cannot function properly in early embryos." Professor Robin Lovell Badge, from the Medical Research Council Institute of Medical Research, said the work was a follow-up to animal research in which laboratory-made mouse sperm was used to produce offspring.
These include 1) the cortical reaction, 2) completion of meiosis 2 with extrusion of the second polar body, and 3) formation of pronucleus and syngamy.
SAN ANTONIO -- An experimental infertility therapy involving the transfer of a patient's pronucleus into a donated enucleated oocyte produced the world's first reported human pregnancy from nuclear transfer in China, Dr.
For example, genes contributed to the embryo via the sperm are required for placental formation: When an egg has a pronucleus from another female injected into it, no placenta develops; in contrast, an egg that has its pronucleus replaced such that all genes are paternal does not develop into a normal embryo, but the placenta develops.
Each set of DNA exists in a separate structure, called a pronucleus; therefore, both male and female pronuclei exist.
After confirming that the ovum has reached the stage where it can allow fertilization, he removes the donor's sperm cells, which by then are in a pronucleus state.