2005 National DNA Day Online Chatroom Transcript
This is just one question from an archive of the National DNA Day Moderated Chat held in April 2005. The NHGRI Director and many genomics experts from across NHGRI took questions from students, teachers and the general public on topics ranging from basic genomic research, to the genetic basis of disease, to ethical questions about genetic privacy.
| 5288 |
Why do mature red blood cells and the cells of the lense of the eye not have DNA?
| |
Belen Hurle, Ph.D.: Because they are highly specialized cells. Red blood start out with a nucleus, like other cells, but when they fill up with hemoglobin the nucleus is squished smaller and smaller until it disappears. With no nucleus, red blood cells are fragile and live only about 120 days. In your body, about 2 million red blood cells die per second! But your bone marrow produces new ones just as fast. The lens fibers are highly elongated, thin, flattened structures without nuclei and other organelles. They are filled with proteins - crystallins |
|
