pronucleus

Also found in: Dictionary, Thesaurus, Encyclopedia, Wikipedia.

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.

Farlex Partner Medical Dictionary © Farlex 2012

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.

Medical Dictionary for the Health Professions and Nursing © Farlex 2012

References in periodicals archive ?

Sperm pretreatment with dithiothreitol increases male pronucleus formation rates after intracytoplasmic sperm injection (ICSI) in swamp buffalo oocytes.

Male Pronuclear Formation and Embryo Development Following Intracytoplasmic Injection of Ovine Pretreated Sperm

Separation of a pronucleus by premature cytokinesis: a mechanism for immediate diploidization of tripronuclear oocytes?

Early Fertilization Abnormalities in the Human: An Exhausted Area of Research?

Formation of the male pronucleus and early embryonic development after sperm penetration was inhibited if oocytes which have no cumulus cells matured [20].

Supplementation of goat follicular fluid in TCM 199 based medium on in vitro matured oocyte

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).

THE FUTURE PROSPECTIVE OF GENOMIC BIOTECHNOLOGY IN ANIMAL BREEDING: THEIR POTENTIAL FOR LIVESTOCK PRODUCTION IN PAKISTAN

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).

Comet assay: a prognostic tool for DNA integrity assessment in infertile men opting for assisted reproduction

"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.

North research offers hope to infertile couples

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.

Chapter 14: Establishing pregnancy: from coitus to syngamy

The pronucleus is more or less located in a central position.

Effects of azadirachtin on mortality rate and reproductive system of the grasshopper Heteracris littoralis Ramb. (Orthoptera: Acrididae)

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.

First human pregnancy from nuclear transfer: lasted until 29 weeks' gestation

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.

Exposure assessment for endocrine disruptors: some considerations in the design of studies

Each set of DNA exists in a separate structure, called a pronucleus; therefore, both male and female pronuclei exist.

Applications of Transgenic and Knockout Mice in Alcohol Research

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.