a song | Going
genome may be the latest genetic breakthrough, but the one Biology Assistant
Prof. Julie Anderson is studying may also hold a few of life's secrets.
By David Van Meter
human genetic code, or genome sequence, is not exactly light reading.
A, T, C and G are repeated in varying order enough times to fill 200 phone
books. But for Julie Anderson, it's a runaway best seller.
biologist in her third year at TCU after four years of post-doctoral work
at the University of Colorado Health Sciences Center, Anderson has long
been interested in how cells divide and die -- or more specifically, the
genes that regulate the cellular life cycle. To know how those genes work,
Anderson believes, is to figure out how the worst injuries can be reversed,
and the cruelest diseases stopped.
cells divide a lot, like skin cells," explained Anderson from her
fifth-floor Winton-Scott lab. "Certain cells in adults don't divide
at all, like nerve cells. In the case of spinal cord injuries, damaged
nerve cells don't regenerate, and that leads to permanent paralysis.
we learn about the life cycle of these cells, the closer we are to one
day reversing this paralysis. "In Alzheimer's disease, we know that
certain cells in the brain die. Finding out how the life of those cells
is regulated and why they are dying is very important in treating that
Yet, to learn
why cellular life cycles go awry, Anderson is looking not at the bloated
human DNA code, but instead at the double helix sequence of a much simpler
life form called Saccharomyces cerevisiae. Or yeast.
first sequenced its genome in 1996, which has since been followed by the
fruit fly and a worm called a nematode. In yeast, approximately 38 percent
of its proteins are similar to human proteins.
my junior and senior classes, I always try to get across the point to
students that genes are responsible for making proteins, and proteins
are the workers in our cells," Anderson said.
Anderson and graduate student Sylvia Zuber are studying a gene that "codes"
a protein that ensures every cell's chromosomes are equally divided as
the cell prepares to split into two new ones.
normal form of the gene (called BUB by scientists, or budding uninhibited
in the presence of benomyl) will sense the problem and prevent the cell
from dividing," she explains, "but in a cell with a defective
gene, the cell doesn't realize its chromosome count is off and it splits,
producing cells with too many or two few chromosomes. A hallmark of many
tumor cells is that they have a weird number of chromosomes."
believes that what she learns from yeast can be applied to humans -- which
makes the value of the human genome sequence all the more valuable.
sequence of the human genome is a high resolution map that gives us a
better handle on where problems or mutations are in our genes," Anderson
said. "What we can do now -- and this is where computers are extremely
valuable -- is take those sequences and compare them with the sequences
of other organisms. The thought is that those parts of the genome that
are highly conserved throughout evolution all the way from the yeast to
the human must have a very important function in how life processes work.
really is the frontier of medicine. We're not going to have cures for
cancer in two years, but the human genome sequence does allow researchers
to move past the laborious sequencing step right into the functional aspect
of figuring out how our genes work."