Progress on Deciphering Genetics
Of Mice Comes Surprisingly Fast
By SCOTT HENSLEY
Staff Reporter of THE WALL STREET JOURNAL
Scientists are making unexpectedly rapid progress in deciphering the genetic
code of mice, the single most important mammal for research, and it looks like
the results will give an immediate boost to biomedical investigators.
Word of advances in understanding the mouse genome comes after the
historic mapping of the human genetic code was published.
An unexpected bonus for researchers is that the genetic variation among three
inbred mouse strains studied by Celera Genomics Group is about one-third
lower than the rate of differences between individual humans, the company
said Thursday. This small rate of variation, said J. Craig Venter, president and
chief scientific officer for Celera, should make it easier to find important clues
to biology and disease in humans.
One-letter variations in the As, Ts, Cs and Gs that are the alphabet of DNA
help account for a host of biological differences, including susceptibility to
disease and traits such as eye color. By studying these variations, scientists
can uncover secrets about illness and possible cures.
In humans these single-letter variations, sometimes called single nucleotide
polymorphisms, or SNPs, occur about once every 1,200 to 1,500 letters.
The DNA of inbred laboratory mice doesn't vary much from mouse to mouse.
Indeed, Celera found that the rate of single-letter variations is only about one
in 2,000 letters.
Since the mice are so similar, and the variations so few, it may be easier than
previously thought for researchers to identify particular genes associated with
characteristics of interest in mice.
"There are clear-cut biological differences associated with these strains of
mice," Dr. Venter said. "Now we can attempt to link the changes in the
genetic code to differences in physiology, response to drugs and susceptibility
to diseases."
Earlier this week Celera said it had completed the first rough map of a mouse
genome drawn from DNA from three different strains of mice that are
commonly used in laboratory experiments. Celera said the mouse-genome
data will only be available through subscriptions. Therefore, Dr. Venter said, it
is unlikely that the company would publish its analysis in a scientific journal,
though it may publish the findings some other way.
This Sunday, Dr. Venter is expected to describe some of the first findings
about the mouse genome at a meeting of the American Association for the
Advancement of Science in San Francisco.
Mouse genes offer a short cut to understanding human genetics. "Mouse
experiments are many times faster and cost less than 1% of human
experiments," said Ken Paigen, director of the Jackson Laboratory, of Bar
Harbor, Maine.
Separately, the Mouse Sequencing Consortium, comprising three drug
companies and multiple public research centers, said Thursday that it was
halfway to its goal of producing a rough draft of the mouse genome in six
months. Since its founding in October, the consortium has sequenced enough
mouse DNA to cover two-thirds of its genome. By April, the group expects
to have between 93% and 95% of the genome sequenced, although it won't
be assembled into an ordered map at that time. |
