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

/pro·nu·cle·us/ (-noo´kle-us)
1. the precursor of a nucleus.
2. the haploid nucleus occurring after meiosis in a germ cell.

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.

pronucleus

[-no̅o̅′klē·əs] pl. pronuclei
Etymology: Gk, pro + L, nucleus, nut kernel
the nucleus of an ovum or a spermatozoon after fertilization but before fusion of the chromosomes to form the nucleus of the zygote. Each pronucleus contains the haploid number of chromosomes, is larger than the normal nucleus, and is diffuse in appearance. The pronucleus of the ovum is formed only after it has completed its second meiotic division and the second polar body has formed, which occur after the spermatozoon has penetrated. It then loses its nuclear envelope, releasing the chromosomes so that synapsis with the chromosomes of the male pronucleus, which is contained in the head of the spermatozoon, can occur. Also called germinal nucleus, germ nucleus. See also oogenesis, spermatogenesis.

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.

pronucleus

pl. pronuclei; the haploid nucleus of a sex cell.

female pronucleus
the haploid nucleus of the fully mature ovum 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 ovum and acquired a pronuclear membrane.
References in periodicals archive ?
To anticipate, maternal and paternal pronuclei have distinct roles: the maternal pronucleus has a special relationship to the body of the embryo proper, and the paternal pronucleus has a special relationship to the embryo's chorion.
Inositol, which is known to play an important role in the in vitro maturation of oocyte, is involved in phospholipid synthesis for new cell membranes (Hawthorne, 1982; Vance, 1986), pronucleus formation during in vitro fertilization (Kane and Bavister, 1988), and it acts as the phosphatidylinositol second messenger (Kane and Bavister, 1988).
At 12 h after IVF, oocytes were fixed in 2% formaldehyde for 40 min to examine sperm penetration, polyspermic oocytes and pronucleus formations.
To make transgenic mice, the most widely used technique is the microinjection of transgene-containing vectors into the embryonic pronucleus.
Once the transgenic vector is constructed, it is injected into the pronucleus, usually male's because of its larger size, using a micromanipulator.
Currently, the most popular way to generate transgenic mice is to inject a constructed vector into the pronucleus of an embryo using a micromanipulator.
Direct microinjection of recombinant DNA into a pronucleus of a zygote (Gordon et al.
Since such procedure does not require zygote with visible pronuclei, it may be a practical alternative to the pronuclear microinjection in the pig because the pronucleus injection in this species is often difficult due to the opaque ooplasm.
Although transgenic pigs become important tools in biomedical research in the field of xenotransplantation and human genetic disease model, conventional pronucleus microinjection has not been to be the choice of procedure sufficient to produce transgenic pigs needed (Nottle et al.
2003) demonstrated approximately 50% of ICSI embryos were transgenic, which was a few times higher than transgenic efficiency generally obtained from pronucleus microinjection.