G0 phase


G0 phase

The G0 phase (G sub 0) is a period in the cell cycle where cells exist in a quiescent state. G0 is sometimes referred to as a "post-mitotic" state since cells in G0 are in a non-dividing phase outside of the cell cycle. Cells enter the G0 phase from a cell cycle checkpoint in the G1 phase, such as the restriction point (animal cells) or the start point (yeast). This usually occurs in response to a lack of growth factors or nutrients. During the G0 phase, the cell cycle machinery is dismantled and cyclins and cyclin-dependent kinases disappear. Cells then remain in the G0 phase until there is a reason for them to divide. Some cell types in mature organisms, such as parenchymal cells of the liver and kidney, enter the G0 phase semi-permanently and can only be induced to begin dividing again under very specific circumstances; other types, such as epithelial cells, continue to divide throughout an organism's life.

Although many cells in the G0 phase may die along with the organism, this does not mean that cells that enter the G0 phase are destined to die; this is often simply a consequence of the cell lacking any stimulation to re-enter in the cell cycle.

However, the term "post-mitotic" is sometimes used to refer not only to quiescent cells but also to senescent cells. Cellular senescence is a state that occurs in response to DNA damage or degradation that would make a cell's progeny nonviable; it is often a biochemical alternative to the self-destruction of such a damaged cell by apoptosis.

ee also

* Cell Cycle


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Phase contrast microscopy — Phase contrast image of a cheek epithelial cell Phase contrast microscopy is an optical microscopy illumination technique of great importance to biologists in which small (invisible to the human eye) phase shifts in the light passing through a… …   Wikipedia

  • phase — [ faz ] n. f. • 1661 astron.; h. 1544 fig.; répandu XIXe; gr. phasis « lever d une étoile » 1 ♦ Astron. Chacun des aspects que présentent la Lune et les planètes à un observateur terrestre, selon leur éclairement par le Soleil. ⇒ apparence. Les… …   Encyclopédie Universelle

  • Phase (waves) — Phase in waves is the fraction of a wave cycle which has elapsed relative to an arbitrary point.[1] Contents 1 Formula 2 Phase shift 3 Phase difference …   Wikipedia

  • PHASE (TRANSITIONS DE) — Les premières transitions de phase observées ont été des changements d’état tels que la fusion de la glace ou la vaporisation de l’eau. Lors d’un changement d’état, le système, au sens de la thermodynamique, se présente comme la réunion de deux… …   Encyclopédie Universelle

  • Phase Boundary Catalysis — (PBC) in chemistry is a type of heterogeneous catalytic system which facilitates the chemical reaction of a particular chemical component in immiscible phase react on a catalytic active site located at phase boundary. The chemical component is… …   Wikipedia

  • Phase shift keying — Traduction terminée Phase shift keying → …   Wikipédia en Français

  • Phase-shift mask — Phase shift masks are photomasks that take advantage of the interference generated by phase differences to improve image resolution in photolithography. There exist alternating [cite web|url = http://www.freepatentsonline.com/6977127.html | title …   Wikipedia

  • Phase (matiere) — Phase (matière) Pour les articles homonymes, voir Phase. En sciences physiques, une phase est un milieu dans lequel les paramètres varient de manière continue ; cela inclut notamment la composition chimique et la densité. De fait, un corps… …   Wikipédia en Français

  • Phase (matière) — Pour les articles homonymes, voir Phase. En sciences physiques, une phase est un milieu dans lequel les paramètres varient de manière continue ; cela inclut notamment la composition chimique et la densité. De fait, un corps pur dans un état… …   Wikipédia en Français

  • Phase qualificative de la coupe du monde de football 2006 — Éliminatoires de la coupe du monde 2006 Sport Football Organisateur(s) FIFA Édition 17e Date printemps 2004 …   Wikipédia en Français

  • Phase thermodynamique — Phase (matière) Pour les articles homonymes, voir Phase. En sciences physiques, une phase est un milieu dans lequel les paramètres varient de manière continue ; cela inclut notamment la composition chimique et la densité. De fait, un corps… …   Wikipédia en Français


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.