Polar fibers are spindle fibers
that extend from the two poles of a dividing cell.
They connect to the centromere
region of chromosomes via kinetochore fibers
in order to manipulate and separate the chromosomes during cell division.
, polar fibers extend from the cell poles to align chromosomes at the metaphase plate. In anaphase
, polar fibers connected to chromosomes shorten thereby separating sister chromatids
and pulling them toward the spindle poles. Polar fibers not connected to chromosomes lengthen and elongate the cell.