Requirements for Exits

In these experiments, chromosome decondensation and nuclear envelope assembly (late mitotic events) coincided with decreases in the cyclin B level and MPF activity. To determine whether degradation of cyclin B is required for exit from mitosis, researchers added a mutant mRNA encoding a nondegradable cyclin B to a mixture of RNase-treated Xenopus egg extract and sperm nuclei. As shown in Figure 2 l-9d, MPF activity Increased in parallel with the level of the mutant cyclin B, triggering condensation of the sperm chromatin and nuclear envelope disassembly (early mitotic events). However, the mutant cyclin B produced in this reaction never was degraded. As a consequence, MPF activity remained elevated, and the late mitotic events of chromosome decondensation and nuclear envelope formation were both blocked. This experiment demonstrates that the fall in MPF activity and exit from mitosis depend on degradation of cyclin B. 

Shaulian, E., Schreiber, M., Piu, F., Beeche, M., Wagner, E.F., and Karin, M., The mammalian UV response c-Jun induction is required for exit from p53-imposed growth arrest. Cell, 103, 897-907,2000. 

Xu, L., Ajimura, M., Padmore, R., Klein, C., and Kleckner, N. (1995). NDT80, a meiosis-specific gene required for exit from pachytene in Saccharomyces cerevisiae. Mol. Cell. Biol. 15,6572-6581. 

Submerged pump can be provided but separate U-seal piping is required for exit liquor to prevent gases coming out from the tank. 

There are specific design and construction requirements for exits and exit routes that include the following ... 

The primary defense in the event of an incident in a hazardous occupancy is to leave the building. Accordingly, the codes provide stringent requirements for exits and exitways. (See UBC 1001.2 for Definitions). Some of the requirements are outlined below and are further illustrated in Fig. 3. 

There are many speeial requirements for exit corridors in an H occupancy (See Fig. 3) ... 

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