Cell cycle checkpoints are surveillance mechanisms that safeguard genome integrity. While the extrinsic pathways that halt the cell cycle in response to DNA damages have been well documented, the intrinsic pathways that ensure orderly progression of cell cycle events are not well understood. We demonstrate that Drosophila MEK and ERK constitute an essential intrinsic checkpoint pathway that res...

Deregulated expression of the c-myc proto-oncogene can lead to apoptosis under certain physiological conditions. By introducing a conditionally active Myc allele into primary embryo fibroblasts null for p53, and into fibroblasts without endogenous p53 expression but ectopically expressing a temperature-sensitive p53 allele, we show that expression of wild-type p53 is required for susceptibility...

p19ARF has been implicated as a key regulator of p53 stability and activation. While numerous stresses activate the p53 growth arrest pathway, those requiring p19ARF remain to be elucidated. We used p19ARF knockout mouse embryo fibroblasts to show that DNA damage and microtubule disruption require p19ARF to induce p53 responses, whereas ribonucleotide depletion and inhibition of RNA synthesis b...

a 67-year-old male suffering from depressive symptomatology was admitted to the inpatient clinic at firat university school of medicine; and his psychiatric evaluation revealed major depressive episode according to dsm-iv. he developed chest discomfort, chest pain and shortness of breath of acute onset accompanying pulseless ventricular tachycardia (vt) leading to cardiac arrest following sertr...

The endosperm is a terminal seed tissue that is destined to support embryo development. In most angiosperms, the endosperm develops initially as a syncytium to facilitate rapid seed growth. The transition from the syncytial to the cellularized state occurs at a defined time point during seed development. Manipulating the timing of endosperm cellularization through interploidy crosses negatively...

CUL4-RING ubiquitin E3 ligases (CRL4s) were recently shown to exert their specificity through the binding of various substrate receptors, which bind the CUL4 interactor DNA damaged binding protein1 (DDB1) through a WDxR motif. In a segregation-based mutagenesis screen, we identified a WDxR motif-containing protein (WDR55) required for male and female gametogenesis and seed development. We demon...

Abstract Study question Screen the key gene groups that determine development of blastocyst. Explore effect ovol1/2 on early embryonic development. Summary answer We founded there were insufficient activation Major ZGA genes in AE group,and focused candidate ovol1/2. What is known already At present, clinical success rate assisted reproductive technology (ART) less than 50%. A large number embr...

The p53 tumor suppressor gene responds to cellular stress by activating either cell cycle arrest or apoptosis. A growing number of target genes involved in each of these pathways have been identified. However, the mechanism by which the apoptosis versus arrest decision is made remains to be elucidated. Perp is a proapoptotic target gene of p53 expressed to high levels in apoptotic cells compare...

some otolaryngologists administer topical phenylephrine for bleeding control in adenoidectomy surgery. absorption of this drug from surgical site can lead to increase in blood pressure due to vasoconstriction and then bradycardia related to baroreceptore reflex.  our case was an intraoperative arrest of a 9-yrs-old girl related to administration of topical phenylephrine during adenoidectomy how...