When a cells assets get divided between daughter cells, Dr. Quansheng Du wants to make sure both offspring do well.
Hes dissecting the complex, continuous and amazing process that enables one cell to become two.
When all goes well, cell division, or mitosis, helps repopulate a damaged organ or replenish endogenous stem cells.
When it goes badly, it can result in cancer or developmental defects.
What we are trying to understand is how cells divide, says Dr. Du, cell biologist at the Medical College of Georgia, who recently received $2 million in grants from the National Institutes of Health and the American Cancer Society to pursue his studies.
He focuses on the mitotic spindle, a sort of demarcation line that helps a dividing cell divvy up its genetic information. Once a cell decides to divide, it duplicates its genetic material and the nuclear envelope containing the material dissolves. Microtubules, stick-like projections that look like spokes on a wheel, start moving, reorganizing into a spindle-shaped structure that attaches and aligns the genetic material at the center of the spindle. The cell, sensing the microtubule attachment, initiates a process that pulls the duplicated genetic material apart.
The outcome of normal cell division is typically two cells that look just like the original. In a culture dish and in humans, the process takes about an hour.
Not every cell can divide. Terminally differentiated cells, such as neurons and muscle cells, cant.
However, stem cells, known for their flexibility, divide well and at least three ways. They can divide genetic material evenly, forming two identical stem cells. They can undergo asymmetric cell division, birthing one identical stem cell as well as a new daughter cell that differentiates into another cell type, such as a skin cell or neuron. They can even make two uniquely differentiated cells, thus depleting the stem cell.
|Contact: Toni Baker|
Medical College of Georgia