What is the Difference Between Kinetochore and Nonkinetochore Microtubules?

The main difference between kinetochore and nonkinetochore microtubules lies in their function and attachment to chromosomes during cell division.

Kinetochore microtubules are connected to the kinetochores of chromosomes during mitosis. Kinetochores are disk-shaped protein structures assembled on the centromeric region of DNA, providing the major attachment point for spindle microtubules during mitotic or meiotic divisions. These microtubules are responsible for correctly segregating chromosomes into daughter cells.

Nonkinetochore microtubules are not attached to kinetochores. They interact with chromosome arms and other nonkinetochore microtubules from opposite poles. During anaphase, nonkinetochore microtubules from opposite poles overlap and push against each other, elongating the cell.

In summary, kinetochore microtubules directly interact and attach to kinetochores of chromosomes, ensuring the proper distribution of DNA to daughter cells. On the other hand, nonkinetochore microtubules are responsible for elongating the cell during anaphase and are not directly attached to kinetochores.

Comparative Table: Kinetochore vs Nonkinetochore Microtubules

Here is a table comparing the differences between kinetochore and nonkinetochore microtubules:

In summary, kinetochore microtubules directly interact and attach with kinetochores of chromosomes, ensuring the proper distribution of DNA to daughter cells during cell division. In contrast, nonkinetochore microtubules do not attach to kinetochores and work with kinetochore microtubules to align and separate chromosomes, playing a role in cell elongation.