The spindle assembly checkpoint is made up of the evolutionarily conserved proteins Bub1, Bub3, Mad1, Mad2, and Mad3.
The restriction points within different cell cycle phases represent key checkpoints, where the critical decisions are made for the cells to divide.
At the first checkpoint we were made to wait, 'only 15 minutes' - which turned into an hour - for the local prince who was due down the road from the other direction.
To your left and right are lovely prospects of lakes shining in the sun, or bugs scurrying away from your hesitating hand as you gauge the distance to your next hold, or tantalizing glimpse of the checkpoint towards which you are making your way.
The checkpoints have now been made virtually impregnable; they consist of a series of three or four concrete barriers, five feet high and a yard thick, arranged in a slalom pattern; each barrier has two opening — a narrow one, to accommodate pedestrian traffic, and one that is just wide enough to permit the passage of conventional civilian and commercial vehicles.
Ideally, Amazon's checkpoint times should be made known to consumers to prevent any such errors.
In some cases, these sources say, acts of sabotage occurred within earshot of police checkpoints, yet no arrests were made.
Many efforts have been made to discover checkpoints and key transcription factors responsible for phase transitions in cell cycles [ 1, 19, 22- 29].
But in August 2006, when the arrests were made, security at passenger checkpoints focused mostly on detecting metals.
DNA damage is evaluated at the G2 cell-cycle checkpoint, and, if needed, any corrections can be made [40].
