Metaphase

During metaphase, sister chromatids align at the metaphase plate (equatorial plate), midway between the poles.  Formation of the mitotic spindle is completed.

During metaphase, sister chromatids align at the metaphase plate (equatorial plate), midway between the poles.  Formation of the mitotic spindle is completed.

The centromere is a highly condensed region of DNA which forms the junction point for the two sister chromatids.  A protein complex located on the centromere, the kinetochore, provides the attachment point for microtubules of the spindle apparatus.

Microtubules of the spindle apparatus extend from the centrioles of the centrosome.  One set attaches to the kinetochore of the chromatids (kinetochore microtubules); one set overlaps with opposing microtubules at the midline; and a third set extends away from the spindle (astral microtubles).

Microtubules of the spindle apparatus extend from the centrioles of the centrosome.  One set attaches to the kinetochore of the chromatids (kinetochore microtubules); one set overlaps with opposing microtubules at the midline; and a third set extends away from the spindle (astral microtubles).