Jump to content

Talk:Oocyte activation

Page contents not supported in other languages.
From Wikipedia, the free encyclopedia

added content

[edit]

The following content was added in this dif. This appears to be important to include, but needs to be worked over for sourcing. The content is probably workable but it is written like a literature review, not a like an encyclopedia article. Will work on this; others are invited to as well. There are also claims about human health here that we need to be sure are sourced per WP:MEDRS.

Since its discovery in 2002, phospholipase C zeta (PLCζ) has been assumed to be the sperm factor responsible for triggering Ca2+ oscillations in the oocyte during its activation. [1] PLC-δ4 knockout (KO) mice exhibit male infertility, and studies have shown that sperm from these animals fails to induce oocyte activation and to cause calcium oscillations. [2]

Studies using recombinant PLC-ζ protein showed that this proteins by itself is capable to induce calcium oscillation and activation of the oocyte in mice. [3] One of the animal models used to investigate the roles of PLC-ζ was a transgenic mouse that shows broad ectopic PLC-ζ expression. In these animals, PLC-ζ was ectopically expressed in their oocytes and although they initially appear healthy, their oocytes exhibit autonomous Ca2+ oscillation, second polar body extrusion, pronucleus formation, parthenogenetic development and some mice also developed benign ovarian teratomas. [4]

PLC-ζ is present in both human and mice sperm, and it is assumed to have the same role in egg activation in both species. PLC-ζ was undetectable in sperm from patients who failed intracytoplasmic sperm injection (ICSI) and this same sperm were unable to induce Ca2+ oscillations in mouse oocytes. Otherwise when the sperm was injected with mouse PLC-ζ mRNA these patients restored the capacity of activate oocytes. [5]

References

  1. ^ Christopher M. Saunders, Mark G. Larman, John Parrington, Llewellyn J. Cox, Jillian Royse, Lynda M. Blayney, Karl Swann, F. Anthony Lai. PLCζ: a sperm-specific trigger of Ca2+ oscillations in eggs and embryo development. Development 129: 3533–3544, 2002.
  2. ^ Fukami K, Nakao K, Inoue T, Kataoka Y, Kurokawa M, Fissore RA, Nakamura K, Katsuki M, Mikoshiba K, Yoshida N, Takenawa T. Requirement of phospholipase Cdelta4 for the zona pellucida-induced acrosome reaction. Science 292: 920–923, 2001.
  3. ^ ]Kouchi Z, Fukami K, Shikano T, Oda S, Nakamura Y, Takenawa T, Miyazaki S. Recombinant phospholipase Czeta has high Ca2+ sensitivity and induces Ca2+ oscillations in mouse eggs. J Biol Chem 279: 10408–10412, 2004.
  4. ^ Yoshida N, Amanai M, Fukui T, Kajikawa E, Brahmajosyula M, Iwahori A, Nakano Y, Shoji S, Diebold J, Hessel H, Huss R, Perry AC. Broad, ectopic expression of the sperm protein PLCZ1 induces parthenogenesis and ovarian tumours in mice. Development 134: 3941–3952, 2007.
  5. ^ Yoon SY, Jellerette T, Salicioni AM, Lee HC, Yoo MS, Coward K, Parrington J, Grow D, Cibelli JB, Visconti PE, Mager J, Fissore RA. Human sperm devoid of PLC, zeta 1 fail to induce Ca2+ release and are unable to initiate the first step of embryo development. J Clin Invest 118: 3671–3681, 2008.

-- Jytdog (talk) 06:51, 8 December 2016 (UTC)[reply]

How long time

[edit]

How long time does the process take for a human egg? — Preceding unsigned comment added by 183.89.196.156 (talk) 23:08, 26 January 2017 (UTC)[reply]