(
2005-12-09)
Kapoor, Tarun M.; Lampson, Michael A.; Hergert, Polla; Cameron, Lisa; Cimini, Daniela; Salmon, Edward D.; McEwen, Bruce F.; Khodjakov, Alexey
The stable propagation of genetic material during cell division depends on the congression
of chromosomes to the spindle equator before the cell initiates anaphase. It is generally assumed
that congression requires that chromosomes are connected to the opposite poles of the bipolar
spindle (i.e., “bi-oriented”). We found that chromosomes can congress before becoming bioriented.
By combining the use of reversible chemical inhibitors, live-cell light microscopy and
correlative electron microscopy, we found that mono-oriented chromosomes could glide towards
the spindle equator alongside kinetochore fibers attached to other already bi-oriented
chromosomes. This congression mechanism depended on the kinetochore-associated plus enddirected
microtubule motor CENP-E (kinesin-7).
