\Linda and her life-long friend Pat
Long, long ago
I blogged that it seemed as though biomedical research was a babushka doll;
every time you solved a problem another emerged. Well, it still seems that way; the deeper we
probe into how our system works, the more mystifying it appears. If you don’t believe me, read this:
You already
know that our DNA comes in distinct linear segments called chromosomes, and
that when a cell divides these chromosomes are duplicated and divvied up
evenly. You also know that our cells
have elaborate means of selecting which genes are activated at the correct time
and place; we call these controls epigenetic markers. You may not have known that one of these
epigenetic controls involves tightly wrapping the linear chromosomes around
little knots of things called histones, thus preventing the messenger RNA strips
from translating selected genes into proteins.
Well, now it
appears that a cell’s entire DNA is not contained in chromosomes; there exist
numerous small circles of “extra chromosomal” DNA swimming around in the
nuclear cytoplasm. Moreover, when a cell
splits these little circles don’t necessarily divide evenly. These little circles come in many sizes, and
are numerous. What they do is not at all clear, but you can
bet your MAGA cap that they’re doing something; probably several things in
fact, and some of them important.
Inevitably, much research is underway.
Babushka dolls.
Full employment for molecular biologists until the end of time.
