Essay on Mitosis: Mitosis and Mitotic Cell Division

Submitted By as08281998
Words: 501
Pages: 3

Title of Article: A mitosis mystery solved: How chromosomes align perfectly in a dividing cell
Author:
Source of the Article: Whitehead Institute for Biomedical Research
Date of the Article: February 12, 2012

20 Significant Ideas
1. The process of mitotic cell division has been studied intensely for more than 50 years.
2. Using fluorescence microscopy, today's scientists can see the tug-of-war cells undergo as they move through mitosis.
3. Thread-like proteins, called microtubules, extend from one of two spindle poles on either side of the cell and attempt to latch onto the duplicated chromosomes.
4. The process of mitosis is extremely precise.
5. As the spindle swings to the left, dynein appears on the right, but when the spindle swing to the right, dynein vanishes and reappears on the left side.
6. When it comes to manipulating DNA, cells verge on being obsessive and with good reason. Gaining or losing a chromosome during cell division can lead to cell death, developmental disorders, or cancer.
7. Then the microtubules tear the duplicated chromosomes in half, so that ultimately one copy of each chromosome ends up in each of the new daughter cells.
8. As the chromosomes swing back and forth, the area cleared of LGN changes in response.
9. Kiyomitsu says the axis that the spindle poles travel along is crucial to cells.
10. These are very strong regulatory paradigms that are setting down these cell division axes.
11. Instead of moving along an astral microtubule, the stationary dynein acts as a winch to pull on the spindle pole, and the microtubules and chromosomes attached to it, toward the cell cortex.
12. Kiyomitsu's work suggests a key role for Ran in directing spindle orientation.
13. "The spindle orientation is critical for maintaining the balance between stem cells and mature cells during development," he notes.
14. People have been looking at these proteins and players in mitosis for decades.
15. And careful cell biology allowed him to see that this was occurring.
16. People have been looking at this for a long time, but…