Pronucleus

Pronucleus
The process of fertilization in the ovum of a mouse.

A pronucleus (plural: pronuclei) is the nucleus of a sperm or an egg cell during the process of fertilization, after the sperm enters the ovum, but before they fuse. Sperm and egg cells are haploid, meaning they carry half the number of chromosomes. When the pronucleus of a sperm fuses with the pronucleus of an egg, their chromosomes combine and become part of a single diploid nucleus in the resulting embryo, containing a full set of chromosomes.

The appearance of two pronuclei is the first sign of successful fertilization as observed during in vitro fertilisation, and is usually observed 18 hours after insemination or ICSI. The zygote is then termed a two-pronuclear zygote (2PN). Two-pronuclear zygotes transitioning through 1PN or 3PN states tend to develop into poorer-quality embryos than ones who remain 2PN throughout development,[1] and may be significant in embryo selection in IVF.

References

  1. ^ Reichman DE, Jackson KV, Racowsky C (May 2009). "Incidence and development of zygotes exhibiting abnormal pronuclear disposition after identification of two pronuclei at the fertilization check". Fertil. Steril. 94 (3): 965–970. doi:10.1016/j.fertnstert.2009.04.018. PMID 19476942. 

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Look at other dictionaries:

  • pronucléus — [ pronykleys ] n. m. • 1875; de pro et nucléus ♦ Biol. Noyau haploïde d un œuf fécondé. Pronucléus mâle, femelle. ● pronucléus nom masculin Noyau du spermatozoïde (pronucléus mâle) ou de l ovule (pronucléus femelle). pronucléus [pʀonykleys] n. m …   Encyclopédie Universelle

  • Pronucleus — Pro*nu cle*us, n.; pl. {Pronuclei} ( [imac]). [NL. See {Pro }, and {Nucleus}.] (Biol.) One of the two bodies or nuclei (called male and female pronuclei) which unite to form the first segmentation nucleus of an impregnated ovum. [1913 Webster]… …   The Collaborative International Dictionary of English

  • pronucleus — pronucleus. См. пронуклеус. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • Pronuclĕus — Pronuclĕus, Spermakern, s. Befruchtung …   Meyers Großes Konversations-Lexikon

  • pronucleus — [prō no͞o′klē əs, prōnyo͞o′klē əs] n. pl. pronuclei [prō no͞o′klēī΄, prōnyo͞o′klēī΄] [ModL: see PRO 1 & NUCLEUS] Zool. the haploid nucleus of either the spermatozoon or the ovum which unite in fertilization to form the fused double (or diploid)… …   English World dictionary

  • Pronucleus — A cell nucleus with a haploid set of chromosomes (23 chromosomes in humans) resulting from meiosis (germ cell division). The male pronucleus is the sperm nucleus after it has entered the ovum at fertilization but before fusion with the female… …   Medical dictionary

  • pronucleus — Haploid nucleus resulting from meiosis. In animals the female pronucleus is the nucleus of the ovum before fusion with the male pronucleus. The male pronucleus is the sperm nucleus after it has entered the ovum at fertilization but before fusion… …   Dictionary of molecular biology

  • Pronucleus femininus — patelės probranduolis statusas T sritis gyvūnų raida, augimas, ontogenezė, embriologija atitikmenys: lot. Pronucleus femininus ryšiai: platesnis terminas – apvaisintas kiaušinis …   Veterinarinės anatomijos, histologijos ir embriologijos terminai

  • Pronucleus masculinus — patino probranduolis statusas T sritis gyvūnų raida, augimas, ontogenezė, embriologija atitikmenys: lot. Pronucleus masculinus ryšiai: platesnis terminas – apvaisintas kiaušinis …   Veterinarinės anatomijos, histologijos ir embriologijos terminai

  • Pronucleus femininus — moteriškas probranduolis statusas T sritis embriologija atitikmenys: lot. Pronucleus femininus ryšiai: platesnis terminas – apvaisintas kiaušinėlis …   Medicininės histologijos ir embriologijos vardynas

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