Preimplantation mouse blastocysts were dissected into inner cell mass (ICM) and trophoblast cells. These fragments were transferred to pseudo-pregnant mice which were left intact or ovariectomized. The latter group received progesterone to permit blastocysts and the dissected fragments to enter into quiescence, prior to injection of oestradiol to induce implantation. Trophoblastic vesicles, wit...

Yeast that naturally exhaust their glucose source can enter a quiescent state that is characterized by reduced cell size, and high cell density, stress tolerance and longevity. The transition to quiescence involves highly asymmetric cell divisions, dramatic reprogramming of transcription and global changes in chromatin structure and chromosome topology. Cells enter quiescence from G1 and we fin...

Most cells in adult mammals are non-dividing: differentiated cells exit the cell cycle permanently, but stem cells exist in a state of reversible arrest called quiescence. In damaged skeletal muscle, quiescent satellite stem cells re-enter the cell cycle, proliferate and subsequently execute divergent programs to regenerate both post-mitotic myofibers and quiescent stem cells. The molecular bas...

Cellular quiescence is a reversible non-dividing state. Subsets of adult mammalian stem cells, namely neural stem cells, spend the majority of their time in quiescence. The ability of stem cells to adopt the quiescent state appears to be crucial for long-term maintenance of the stem cell compartment. Tumour cells can also become quiescent and this renders them resistance to most chemotherapeuti...

Cellular quiescence, defined as reversible growth/proliferation arrest, is thought to represent a homogenous state induced by diverse anti-mitogenic signals. We used transcriptional profiling to characterize human diploid fibroblasts that exited the cell cycle after exposure to three independent signals--mitogen withdrawal, contact inhibition, and loss of adhesion. We show here that each signal...

a multi-step process that involves abrogation of several barriers to uncontrolled proliferation [1]. These barriers include checkpoints that, by activating inhibitory pathways, block cell division either reversibly (quiescence) or irreversibly (senescence, apoptosis). Typically, confluence and the absence of mitogens or nutrients induce quiescence, while cell ageing, inappropriate signaling or ...

Wediscuss serendipitousROSATobservations of the Be transient A0538-66, which contains the fastest known accreting X-ray pulsar (69 ms). We show that this transient is detected several times during quiescence at a level of about 1034−35 erg s−1. Considering this low luminosity it is more likely that X-rays are produced by matter falling onto the neutron star magnetosphere, rather than onto the s...

Evidence suggests the transcription factor GATA-2 is a critical regulator of murine hematopoietic stem cells. Here, we explore the relation between GATA-2 and cell proliferation and show that inducing GATA-2 increases quiescence (G(0) residency) of murine and human hematopoietic cells. In human cord blood, quiescent fractions (CD34(+)CD38(-)Hoechst(lo)Pyronin Y(lo)) express more GATA-2 than cyc...

Sleep is evolutionarily conserved and required for organism homeostasis and survival. Despite this importance, the molecular and cellular mechanisms underlying sleep are not well understood. Caenorhabditis elegans exhibits sleep-like behavioral quiescence and thus provides a valuable, simple model system for the study of cellular and molecular regulators of this process. In C. elegans, epiderma...