No waiting for anaphase [1d. First place]

Abstract

This HeLa cell, which is expressing both a kinetochore marker (EGFP-CENP-B) and a centrosome marker (Venus-centrin), has been depleted of the spindle assembly checkpoint protein Mad2. In the absence of Mad2, the cell rapidly progresses from early prometaphase through anaphase and cytokinesis. The spindle assembly checkpoint functions to generate a WAIT signal until all sister kinetochore pairs become properly attached to the mitotic spindle. Loss of checkpoint function leads to anaphase initiation before kinetochores are completely aligned at the spindle equator. Despite the rapid nature of these divisions, the majority of the kinetochores appear to separate properly in Mad2-depleted cells. However, at least a few lagging chromosomes are frequently observed in these cells, demonstrating the importance of checkpoint function. Note that the frame width is approximately 30 micronsComponente Curricular::Educação Superior::Ciências Biológicas::Biologia Gera